syzbot

map[DenialOfService:true Explanation:**Bug Analysis:**

The bug is a memory leak of a `vsock` child socket. It occurs due to an
unhandled error path when `accept()` is called on a listening socket that has a
pending error (`sk_err`).

Here is the sequence of events triggered by the reproducer:
1. An unprivileged user creates a `vsock` socket (`r[0]`), binds it, and
attempts to `connect()` to an invalid port on the local CID
(`VMADDR_CID_LOCAL`).
2. The connection attempt fails (receives a RST), which sets `sk->sk_err =
ECONNREFUSED` on `r[0]`.
3. The user then calls `listen()` on `r[0]`. The `listen()` syscall successfully
transitions the socket to the `TCP_LISTEN` state but **does not clear the
`sk_err` field**.
4. The user creates a second socket (`r[1]`) and connects it to the listening
socket `r[0]`.
5. The listening socket receives the connection request, creates a child socket,
inserts it into the global connected table (incrementing its refcount), and
enqueues it into the accept queue (incrementing its refcount again).
6. The user calls `accept4()` on `r[0]`. `vsock_accept()` dequeues the child
socket from the accept queue. However, it checks `listener->sk_err` and finds it
set to `ECONNREFUSED`.
7. Because of this error, `vsock_accept()` rejects the connection: it sets
`vconnected->rejected = true`, drops the accept queue's reference to the child
socket, and returns the error without grafting the child socket to a new file
descriptor.

Since the child socket was never grafted to a file descriptor, it will never be
closed by user space. Furthermore, because it was removed from the accept queue,
it will not be cleaned up when the listening socket is eventually closed. The
child socket remains in the connected table indefinitely with a refcount of 1,
resulting in a memory leak of the socket structure and its associated transport
data (e.g., `virtio_vsock_sock`).

**Security Impact:**

* **Exploitable:** No. This is a pure memory leak. It does not lead to memory
corruption, use-after-free, or privilege escalation.
* **Denial Of Service:** Yes. An attacker can repeatedly trigger this leak to
consume kernel memory, eventually leading to an Out-Of-Memory (OOM) condition
and system crash.
* **Accessible From Unprivileged Processes:** Yes. Creating `AF_VSOCK` sockets
and calling `bind`, `connect`, `listen`, and `accept` does not require any
special capabilities.
* **Accessible From User Namespaces:** Yes.
* **VM Guest / Host Trigger:** Yes. The bug can be triggered locally on any
system that supports `AF_VSOCK` (including VM guests and hosts). The reproducer
uses the `VMADDR_CID_LOCAL` (loopback) transport, meaning it doesn't even
require a configured external vsock device to be triggered. Exploitable:false FilesystemTrigger:false NetworkTrigger:false PeripheralTrigger:false RemoteTrigger:false Unprivileged:true UserNamespace:true VMGuestTrigger:true VMHostTrigger:true]

map[SimplifiedCRepro:// autogenerated by syzkaller (https://github.com/google/syzkaller)

#define _GNU_SOURCE 

#include <endian.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mount.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <unistd.h>

uint64_t r[2] = {0xffffffffffffffff, 0xffffffffffffffff};

int main(void)
{
		syscall(__NR_mmap, /*addr=*/0x1ffffffff000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/0x32ul, /*fd=*/(intptr_t)-1, /*offset=*/0ul);
	syscall(__NR_mmap, /*addr=*/0x200000000000ul, /*len=*/0x1000000ul, /*prot=PROT_WRITE|PROT_READ|PROT_EXEC*/7ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/0x32ul, /*fd=*/(intptr_t)-1, /*offset=*/0ul);
	syscall(__NR_mmap, /*addr=*/0x200001000000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/0x32ul, /*fd=*/(intptr_t)-1, /*offset=*/0ul);
	const char* reason;
	(void)reason;
				intptr_t res = 0;
	if (write(1, "executing program\n", sizeof("executing program\n") - 1)) {}
//  socket$vsock_stream arguments: [
//    domain: const = 0x28 (8 bytes)
//    type: const = 0x1 (8 bytes)
//    proto: const = 0x0 (4 bytes)
//  ]
//  returns sock_vsock_stream
	res = syscall(__NR_socket, /*domain=*/0x28ul, /*type=*/1ul, /*proto=*/0);
	if (res != -1)
		r[0] = res;
//  bind$vsock_stream arguments: [
//    fd: sock_vsock_stream (resource)
//    addr: ptr[in, sockaddr_vm] {
//      sockaddr_vm {
//        svm_family: const = 0x28 (2 bytes)
//        svm_reserved1: const = 0x0 (2 bytes)
//        svm_port: vmaddr_port = 0x0 (4 bytes)
//        svm_cid: union vmaddr_cid {
//          any: const = 0xffffffff (4 bytes)
//        }
//        svm_zero: const = 0x0 (4 bytes)
//      }
//    }
//    addrlen: len = 0x10 (8 bytes)
//  ]
*(uint16_t*)0x200000000440 = 0x28;
*(uint16_t*)0x200000000442 = 0;
*(uint32_t*)0x200000000444 = 0;
*(uint32_t*)0x200000000448 = -1;
*(uint32_t*)0x20000000044c = 0;
	syscall(__NR_bind, /*fd=*/r[0], /*addr=*/0x200000000440ul, /*addrlen=*/0x10ul);
//  connect$vsock_stream arguments: [
//    fd: sock_vsock_stream (resource)
//    addr: ptr[in, sockaddr_vm] {
//      sockaddr_vm {
//        svm_family: const = 0x28 (2 bytes)
//        svm_reserved1: const = 0x0 (2 bytes)
//        svm_port: vmaddr_port = 0xffffffff (4 bytes)
//        svm_cid: union vmaddr_cid {
//          local: const = 0x1 (4 bytes)
//        }
//        svm_zero: const = 0x0 (4 bytes)
//      }
//    }
//    addrlen: len = 0x10 (8 bytes)
//  ]
*(uint16_t*)0x2000000001c0 = 0x28;
*(uint16_t*)0x2000000001c2 = 0;
*(uint32_t*)0x2000000001c4 = -1;
*(uint32_t*)0x2000000001c8 = 1;
*(uint32_t*)0x2000000001cc = 0;
	syscall(__NR_connect, /*fd=*/r[0], /*addr=*/0x2000000001c0ul, /*addrlen=*/0x10ul);
//  listen arguments: [
//    fd: sock (resource)
//    backlog: int32 = 0x5 (4 bytes)
//  ]
	syscall(__NR_listen, /*fd=*/r[0], /*backlog=*/5);
//  socket$vsock_stream arguments: [
//    domain: const = 0x28 (8 bytes)
//    type: const = 0x1 (8 bytes)
//    proto: const = 0x0 (4 bytes)
//  ]
//  returns sock_vsock_stream
	res = syscall(__NR_socket, /*domain=*/0x28ul, /*type=*/1ul, /*proto=*/0);
	if (res != -1)
		r[1] = res;
//  connect$vsock_stream arguments: [
//    fd: sock_vsock_stream (resource)
//    addr: ptr[in, sockaddr_vm] {
//      sockaddr_vm {
//        svm_family: const = 0x28 (2 bytes)
//        svm_reserved1: const = 0x0 (2 bytes)
//        svm_port: vmaddr_port = 0x0 (4 bytes)
//        svm_cid: union vmaddr_cid {
//          local: const = 0x1 (4 bytes)
//        }
//        svm_zero: const = 0x0 (4 bytes)
//      }
//    }
//    addrlen: len = 0x10 (8 bytes)
//  ]
*(uint16_t*)0x200000000100 = 0x28;
*(uint16_t*)0x200000000102 = 0;
*(uint32_t*)0x200000000104 = 0;
*(uint32_t*)0x200000000108 = 1;
*(uint32_t*)0x20000000010c = 0;
	syscall(__NR_connect, /*fd=*/r[1], /*addr=*/0x200000000100ul, /*addrlen=*/0x10ul);
//  accept4$unix arguments: [
//    fd: sock_unix (resource)
//    peer: nil
//    peerlen: nil
//    flags: accept_flags = 0x0 (8 bytes)
//  ]
//  returns sock_unix
	syscall(__NR_accept4, /*fd=*/r[0], /*peer=*/0ul, /*peerlen=*/0ul, /*flags=*/0ul);
	return 0;
}
]

map[KernelSrc:/app/workdir/cache/src/1244da8713a7b9651347df1a6951d3bcf4225f5a]

map[KernelObj:/app/workdir/cache/build/fad529b5d4f1ca7a41f9d1ee865e2023eecbb93f]

map[Index:codesearch-index]

gemini-3.1-pro-preview

map[DenialOfService:true Exploitable:false FilesystemTrigger:false NetworkTrigger:false PeripheralTrigger:false RemoteTrigger:false Unprivileged:true UserNamespace:true VMGuestTrigger:true VMHostTrigger:true]

You are an experienced Linux kernel security engineer. Your task is to analyze given kernel bug report
and determine its security impact based on the following dimensions.

Use the provided tools to examine the source code, check for capability checks (e.g., capable(), ns_capable()),
and understand the nature of the bug. Analyze the given kernel build and configuration.
You can check the kernel config by grepping ".config" file; you can check kernel cmdline by greeping
".config" file for "CONFIG_CMDLINE=". Assume sysctl parameters have default values.
But analyze for the corresponding production build w/o debugging tools enabled (like KASAN, KMSAN, UBSAN).

Don't make assumptions; verify them with source code access. Try different strategies when analyzing the bug:
 - think of ways in which the vulnerable code is unreachable
 - or the other way around: try to come up with different ideas of how an unprivileged user can reach the bug
If still unsure err on the side of the bug being non-exploitable/not-accessible.
In the final reply, provide a reasoning for your assessment.

Analysis dimensions:

* Exploitable:
Determine if the bug can result in memory corruption or elevated privileges.
Memory safety issues are almost always exploitable (KASAN or UBSAN reports for use-after-free, out-of-bounds;
refcounting issues, corrupted lists, etc). When kernel is crashing on a completly wild pointer access
(e.g. user-space address, or non-canonical address, but not on NULL or address corresponding to KASAN shadow
for NULL address), including both data accesses and control tranfers, that's also usually implies possibility
of exploitation. Such reports usually say "unable to handle kernel paging request".
Uses of uninitialized values detected by KMSAN may be exploitable b/c attacker frequently can affect uninit
values with spraying techniques. However, for these exploitabability depends on how exactly the uninit value
is used in the code, and what it affects.

Think of what happens after the bug is triggered. Some bugs cause kernel panic and halt execution,
they are harder to exploit. For example, BUG reports halts the kernel. However, WARNING reports don't halt
execution in production builds. Debug bug detection tools (like KASAN, KMSAN, KCSAN, UBSAN) are also not enabled
in production builds, so attacker can freely exploit these bugs w/o being detected by these tools.
If you see an integer overflow, think how the overflowed value used later (if it's used as allocation size,
or an array index). If you see an out-of-bounds read, think if it's followed by an out-of-bounds write as well.
Some KCSAN data-races may be exploitable by skilled attackers as well. Think what data structures got corrupted
as the result of data races and how. However, note that kernel has lots of "benign" data races that don't lead
to any runtime misbehavior at all.

* Denial Of Service:
Determine if the bug can result in denial-of-service. Most bugs can, since they cause system crash,
hangs, deadlocks, or resource leaks. This is mostly applicable to WARNING bugs that won't cause system crash
in production. For these think what will be consequences of the violation of the kernel assumptions flagged
by the WARNING. In some cases the unexpected condition is also properly handled by the normal control flow
(e.g. with "if (WARN_ON(...))"), these won't cause denial-of-service. If the condition is not handled,
then it may or may not cause denial-of-service.

* Accessible From Unprivileged Processes:
Determine if the bug can be reached from a typical (non-root) user process that does NOT have any special capabilities
(like CAP_SYS_ADMIN, CAP_NET_ADMIN, CAP_NET_RAW, CAP_PERFMON) or access to device nodes restricted to root.
Assume that unprivileged_bpf_disabled=1, that is eBPF loading is not accessible. However, cBPF (classical BPF)
is still accessible to non-root processes.
Assume that user namespaces are not accessible, that is, the process cannot get the mentioned capabilities even
within a new user namespace (checked by ns_capable() function in the kernel sources).

* Accessible From User Namespaces:
Determine if the bug can be reached within a user-namespace where the process has all capabilities
(including CAP_SYS_ADMIN, CAP_NET_ADMIN, CAP_NET_RAW, CAP_PERFMON). Such capabilities are checked with ns_capable()
function in the kernel sources.

* VM Guest Trigger:
Determine if the bug can be triggered from the context of a typical KVM guest (e.g., set up by a QEMU VMM).
Consider accesses to standard Linux host paravirtualized features (virtio-blk, virtio-net, etc.),
and handling of VM exits in the KVM code.

* VM Host Trigger in The Confidetial Computing Context:
Determine if the bug can be triggered in a confidential computing guest kernel from the context of a KVM host.
Consider access to standard Linux guest paravirtualized features (virtio-blk, virtio-net, etc.).

* Ethernet Network Trigger:
Determine if the bug can be triggered by processing ingress network Ethernet traffic, either directly (network stack)
or via drivers exposed to network data.

* Other Remote Trigger:
Determine if the bug can be triggered by processing remote traffic other than Ethernet (Wifi, Bluetooth, NFC, etc).

* Peripheral Trigger:
Determine if the bug can be triggered via an untrusted peripheral device that can be physically plugged
into a system, such as a USB device or a niche hardware driver handling external hardware inputs.
This is particularly important for mobile and desktop environments where users can plug in unknown devices.

* Malicious Filesystem Trigger:
Determine if the bug can be triggered by the kernel mounting and parsing a malicious filesystem image.
This is highly critical for Desktop and Mobile environments where external media or downloaded images
might be auto-mounted.

Prefer calling several tools at the same time to save round-trips.


Use set-results tool to provide results of the analysis.
It must be called exactly once before the final reply.
Ignore results of this tool.

The kernel bug report is:

2026/03/09 23:37:29 executed programs: 5
BUG: memory leak
unreferenced object 0xffff888128bb6d00 (size 1272):
  comm "kworker/0:1", pid 10, jiffies 4294944453
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    28 00 0b 40 00 00 00 00 00 00 00 00 00 00 00 00  (..@............
  backtrace (crc 31367ed9):
    kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
    slab_post_alloc_hook mm/slub.c:4547 [inline]
    slab_alloc_node mm/slub.c:4869 [inline]
    kmem_cache_alloc_noprof+0x372/0x480 mm/slub.c:4876
    sk_prot_alloc+0x3e/0x1b0 net/core/sock.c:2239
    sk_alloc+0x36/0x460 net/core/sock.c:2301
    __vsock_create.constprop.0+0x38/0x2f0 net/vmw_vsock/af_vsock.c:893
    virtio_transport_recv_listen net/vmw_vsock/virtio_transport_common.c:1557 [inline]
    virtio_transport_recv_pkt+0x855/0xfc0 net/vmw_vsock/virtio_transport_common.c:1685
    vsock_loopback_work+0x104/0x140 net/vmw_vsock/vsock_loopback.c:142
    process_one_work+0x26c/0x5d0 kernel/workqueue.c:3275
    process_scheduled_works kernel/workqueue.c:3358 [inline]
    worker_thread+0x243/0x490 kernel/workqueue.c:3439
    kthread+0x14e/0x1a0 kernel/kthread.c:436
    ret_from_fork+0x23c/0x4b0 arch/x86/kernel/process.c:158
    ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

BUG: memory leak
unreferenced object 0xffff8881141e93a0 (size 32):
  comm "kworker/0:1", pid 10, jiffies 4294944453
  hex dump (first 32 bytes):
    f8 6e 0a 00 81 88 ff ff 00 00 00 00 00 00 00 00  .n..............
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace (crc e7f5c8b3):
    kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
    slab_post_alloc_hook mm/slub.c:4547 [inline]
    slab_alloc_node mm/slub.c:4869 [inline]
    __do_kmalloc_node mm/slub.c:5262 [inline]
    __kmalloc_noprof+0x3bd/0x560 mm/slub.c:5275
    kmalloc_noprof include/linux/slab.h:954 [inline]
    kzalloc_noprof include/linux/slab.h:1188 [inline]
    lsm_blob_alloc+0x4d/0x80 security/security.c:192
    lsm_sock_alloc security/security.c:4375 [inline]
    security_sk_alloc+0x2d/0x290 security/security.c:4391
    sk_prot_alloc+0x8f/0x1b0 net/core/sock.c:2248
    sk_alloc+0x36/0x460 net/core/sock.c:2301
    __vsock_create.constprop.0+0x38/0x2f0 net/vmw_vsock/af_vsock.c:893
    virtio_transport_recv_listen net/vmw_vsock/virtio_transport_common.c:1557 [inline]
    virtio_transport_recv_pkt+0x855/0xfc0 net/vmw_vsock/virtio_transport_common.c:1685
    vsock_loopback_work+0x104/0x140 net/vmw_vsock/vsock_loopback.c:142
    process_one_work+0x26c/0x5d0 kernel/workqueue.c:3275
    process_scheduled_works kernel/workqueue.c:3358 [inline]
    worker_thread+0x243/0x490 kernel/workqueue.c:3439
    kthread+0x14e/0x1a0 kernel/kthread.c:436
    ret_from_fork+0x23c/0x4b0 arch/x86/kernel/process.c:158
    ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

BUG: memory leak
unreferenced object 0xffff888128bfa8a0 (size 96):
  comm "kworker/0:1", pid 10, jiffies 4294944453
  hex dump (first 32 bytes):
    00 6d bb 28 81 88 ff ff 00 00 00 00 00 00 00 00  .m.(............
    00 00 00 00 00 00 00 00 00 00 04 00 00 00 00 00  ................
  backtrace (crc 1fd60988):
    kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
    slab_post_alloc_hook mm/slub.c:4547 [inline]
    slab_alloc_node mm/slub.c:4869 [inline]
    __kmalloc_cache_noprof+0x377/0x480 mm/slub.c:5378
    kmalloc_noprof include/linux/slab.h:950 [inline]
    kzalloc_noprof include/linux/slab.h:1188 [inline]
    virtio_transport_do_socket_init+0x2b/0xf0 net/vmw_vsock/virtio_transport_common.c:923
    vsock_assign_transport+0x309/0x3a0 net/vmw_vsock/af_vsock.c:642
    virtio_transport_recv_listen net/vmw_vsock/virtio_transport_common.c:1575 [inline]
    virtio_transport_recv_pkt+0x8bc/0xfc0 net/vmw_vsock/virtio_transport_common.c:1685
    vsock_loopback_work+0x104/0x140 net/vmw_vsock/vsock_loopback.c:142
    process_one_work+0x26c/0x5d0 kernel/workqueue.c:3275
    process_scheduled_works kernel/workqueue.c:3358 [inline]
    worker_thread+0x243/0x490 kernel/workqueue.c:3439
    kthread+0x14e/0x1a0 kernel/kthread.c:436
    ret_from_fork+0x23c/0x4b0 arch/x86/kernel/process.c:158
    ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

BUG: memory leak
unreferenced object 0xffff888129e1e800 (size 1272):
  comm "kworker/1:3", pid 5832, jiffies 4294944454
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    28 00 0b 40 00 00 00 00 00 00 00 00 00 00 00 00  (..@............
  backtrace (crc 4bfb7c57):
    kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
    slab_post_alloc_hook mm/slub.c:4547 [inline]
    slab_alloc_node mm/slub.c:4869 [inline]
    kmem_cache_alloc_noprof+0x372/0x480 mm/slub.c:4876
    sk_prot_alloc+0x3e/0x1b0 net/core/sock.c:2239
    sk_alloc+0x36/0x460 net/core/sock.c:2301
    __vsock_create.constprop.0+0x38/0x2f0 net/vmw_vsock/af_vsock.c:893
    virtio_transport_recv_listen net/vmw_vsock/virtio_transport_common.c:1557 [inline]
    virtio_transport_recv_pkt+0x855/0xfc0 net/vmw_vsock/virtio_transport_common.c:1685
    vsock_loopback_work+0x104/0x140 net/vmw_vsock/vsock_loopback.c:142
    process_one_work+0x26c/0x5d0 kernel/workqueue.c:3275
    process_scheduled_works kernel/workqueue.c:3358 [inline]
    worker_thread+0x243/0x490 kernel/workqueue.c:3439
    kthread+0x14e/0x1a0 kernel/kthread.c:436
    ret_from_fork+0x23c/0x4b0 arch/x86/kernel/process.c:158
    ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

BUG: memory leak
unreferenced object 0xffff888114372e80 (size 32):
  comm "kworker/1:3", pid 5832, jiffies 4294944454
  hex dump (first 32 bytes):
    f8 6e 0a 00 81 88 ff ff 00 00 00 00 00 00 00 00  .n..............
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace (crc e7f5c8b3):
    kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
    slab_post_alloc_hook mm/slub.c:4547 [inline]
    slab_alloc_node mm/slub.c:4869 [inline]
    __do_kmalloc_node mm/slub.c:5262 [inline]
    __kmalloc_noprof+0x3bd/0x560 mm/slub.c:5275
    kmalloc_noprof include/linux/slab.h:954 [inline]
    kzalloc_noprof include/linux/slab.h:1188 [inline]
    lsm_blob_alloc+0x4d/0x80 security/security.c:192
    lsm_sock_alloc security/security.c:4375 [inline]
    security_sk_alloc+0x2d/0x290 security/security.c:4391
    sk_prot_alloc+0x8f/0x1b0 net/core/sock.c:2248
    sk_alloc+0x36/0x460 net/core/sock.c:2301
    __vsock_create.constprop.0+0x38/0x2f0 net/vmw_vsock/af_vsock.c:893
    virtio_transport_recv_listen net/vmw_vsock/virtio_transport_common.c:1557 [inline]
    virtio_transport_recv_pkt+0x855/0xfc0 net/vmw_vsock/virtio_transport_common.c:1685
    vsock_loopback_work+0x104/0x140 net/vmw_vsock/vsock_loopback.c:142
    process_one_work+0x26c/0x5d0 kernel/workqueue.c:3275
    process_scheduled_works kernel/workqueue.c:3358 [inline]
    worker_thread+0x243/0x490 kernel/workqueue.c:3439
    kthread+0x14e/0x1a0 kernel/kthread.c:436
    ret_from_fork+0x23c/0x4b0 arch/x86/kernel/process.c:158
    ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

BUG: memory leak
unreferenced object 0xffff8881054d0ea0 (size 96):
  comm "kworker/1:3", pid 5832, jiffies 4294944454
  hex dump (first 32 bytes):
    00 e8 e1 29 81 88 ff ff 00 00 00 00 00 00 00 00  ...)............
    00 00 00 00 00 00 00 00 00 00 04 00 00 00 00 00  ................
  backtrace (crc 72501265):
    kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
    slab_post_alloc_hook mm/slub.c:4547 [inline]
    slab_alloc_node mm/slub.c:4869 [inline]
    __kmalloc_cache_noprof+0x377/0x480 mm/slub.c:5378
    kmalloc_noprof include/linux/slab.h:950 [inline]
    kzalloc_noprof include/linux/slab.h:1188 [inline]
    virtio_transport_do_socket_init+0x2b/0xf0 net/vmw_vsock/virtio_transport_common.c:923
    vsock_assign_transport+0x309/0x3a0 net/vmw_vsock/af_vsock.c:642
    virtio_transport_recv_listen net/vmw_vsock/virtio_transport_common.c:1575 [inline]
    virtio_transport_recv_pkt+0x8bc/0xfc0 net/vmw_vsock/virtio_transport_common.c:1685
    vsock_loopback_work+0x104/0x140 net/vmw_vsock/vsock_loopback.c:142
    process_one_work+0x26c/0x5d0 kernel/workqueue.c:3275
    process_scheduled_works kernel/workqueue.c:3358 [inline]
    worker_thread+0x243/0x490 kernel/workqueue.c:3439
    kthread+0x14e/0x1a0 kernel/kthread.c:436
    ret_from_fork+0x23c/0x4b0 arch/x86/kernel/process.c:158
    ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

connection error: failed to recv *flatrpc.ExecutorMessageRawT: EOF




It is reproducible with the followint program.
Keep in mind that it may lack the precise threading, sandboxing, and some arguments of a working reproducer.
But it should give an idea of the involved syscalls.

// autogenerated by syzkaller (https://github.com/google/syzkaller)

#define _GNU_SOURCE 

#include <endian.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mount.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <unistd.h>

uint64_t r[2] = {0xffffffffffffffff, 0xffffffffffffffff};

int main(void)
{
		syscall(__NR_mmap, /*addr=*/0x1ffffffff000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/0x32ul, /*fd=*/(intptr_t)-1, /*offset=*/0ul);
	syscall(__NR_mmap, /*addr=*/0x200000000000ul, /*len=*/0x1000000ul, /*prot=PROT_WRITE|PROT_READ|PROT_EXEC*/7ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/0x32ul, /*fd=*/(intptr_t)-1, /*offset=*/0ul);
	syscall(__NR_mmap, /*addr=*/0x200001000000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/0x32ul, /*fd=*/(intptr_t)-1, /*offset=*/0ul);
	const char* reason;
	(void)reason;
				intptr_t res = 0;
	if (write(1, "executing program\n", sizeof("executing program\n") - 1)) {}
//  socket$vsock_stream arguments: [
//    domain: const = 0x28 (8 bytes)
//    type: const = 0x1 (8 bytes)
//    proto: const = 0x0 (4 bytes)
//  ]
//  returns sock_vsock_stream
	res = syscall(__NR_socket, /*domain=*/0x28ul, /*type=*/1ul, /*proto=*/0);
	if (res != -1)
		r[0] = res;
//  bind$vsock_stream arguments: [
//    fd: sock_vsock_stream (resource)
//    addr: ptr[in, sockaddr_vm] {
//      sockaddr_vm {
//        svm_family: const = 0x28 (2 bytes)
//        svm_reserved1: const = 0x0 (2 bytes)
//        svm_port: vmaddr_port = 0x0 (4 bytes)
//        svm_cid: union vmaddr_cid {
//          any: const = 0xffffffff (4 bytes)
//        }
//        svm_zero: const = 0x0 (4 bytes)
//      }
//    }
//    addrlen: len = 0x10 (8 bytes)
//  ]
*(uint16_t*)0x200000000440 = 0x28;
*(uint16_t*)0x200000000442 = 0;
*(uint32_t*)0x200000000444 = 0;
*(uint32_t*)0x200000000448 = -1;
*(uint32_t*)0x20000000044c = 0;
	syscall(__NR_bind, /*fd=*/r[0], /*addr=*/0x200000000440ul, /*addrlen=*/0x10ul);
//  connect$vsock_stream arguments: [
//    fd: sock_vsock_stream (resource)
//    addr: ptr[in, sockaddr_vm] {
//      sockaddr_vm {
//        svm_family: const = 0x28 (2 bytes)
//        svm_reserved1: const = 0x0 (2 bytes)
//        svm_port: vmaddr_port = 0xffffffff (4 bytes)
//        svm_cid: union vmaddr_cid {
//          local: const = 0x1 (4 bytes)
//        }
//        svm_zero: const = 0x0 (4 bytes)
//      }
//    }
//    addrlen: len = 0x10 (8 bytes)
//  ]
*(uint16_t*)0x2000000001c0 = 0x28;
*(uint16_t*)0x2000000001c2 = 0;
*(uint32_t*)0x2000000001c4 = -1;
*(uint32_t*)0x2000000001c8 = 1;
*(uint32_t*)0x2000000001cc = 0;
	syscall(__NR_connect, /*fd=*/r[0], /*addr=*/0x2000000001c0ul, /*addrlen=*/0x10ul);
//  listen arguments: [
//    fd: sock (resource)
//    backlog: int32 = 0x5 (4 bytes)
//  ]
	syscall(__NR_listen, /*fd=*/r[0], /*backlog=*/5);
//  socket$vsock_stream arguments: [
//    domain: const = 0x28 (8 bytes)
//    type: const = 0x1 (8 bytes)
//    proto: const = 0x0 (4 bytes)
//  ]
//  returns sock_vsock_stream
	res = syscall(__NR_socket, /*domain=*/0x28ul, /*type=*/1ul, /*proto=*/0);
	if (res != -1)
		r[1] = res;
//  connect$vsock_stream arguments: [
//    fd: sock_vsock_stream (resource)
//    addr: ptr[in, sockaddr_vm] {
//      sockaddr_vm {
//        svm_family: const = 0x28 (2 bytes)
//        svm_reserved1: const = 0x0 (2 bytes)
//        svm_port: vmaddr_port = 0x0 (4 bytes)
//        svm_cid: union vmaddr_cid {
//          local: const = 0x1 (4 bytes)
//        }
//        svm_zero: const = 0x0 (4 bytes)
//      }
//    }
//    addrlen: len = 0x10 (8 bytes)
//  ]
*(uint16_t*)0x200000000100 = 0x28;
*(uint16_t*)0x200000000102 = 0;
*(uint32_t*)0x200000000104 = 0;
*(uint32_t*)0x200000000108 = 1;
*(uint32_t*)0x20000000010c = 0;
	syscall(__NR_connect, /*fd=*/r[1], /*addr=*/0x200000000100ul, /*addrlen=*/0x10ul);
//  accept4$unix arguments: [
//    fd: sock_unix (resource)
//    peer: nil
//    peerlen: nil
//    flags: accept_flags = 0x0 (8 bytes)
//  ]
//  returns sock_unix
	syscall(__NR_accept4, /*fd=*/r[0], /*peer=*/0ul, /*peerlen=*/0ul, /*flags=*/0ul);
	return 0;
}

**Bug Analysis:**

The bug is a memory leak of a `vsock` child socket. It occurs due to an unhandled error path when `accept()` is called on a listening socket that has a pending error (`sk_err`).

Here is the sequence of events triggered by the reproducer:
1. An unprivileged user creates a `vsock` socket (`r[0]`), binds it, and attempts to `connect()` to an invalid port on the local CID (`VMADDR_CID_LOCAL`).
2. The connection attempt fails (receives a RST), which sets `sk->sk_err = ECONNREFUSED` on `r[0]`.
3. The user then calls `listen()` on `r[0]`. The `listen()` syscall successfully transitions the socket to the `TCP_LISTEN` state but **does not clear the `sk_err` field**.
4. The user creates a second socket (`r[1]`) and connects it to the listening socket `r[0]`.
5. The listening socket receives the connection request, creates a child socket, inserts it into the global connected table (incrementing its refcount), and enqueues it into the accept queue (incrementing its refcount again).
6. The user calls `accept4()` on `r[0]`. `vsock_accept()` dequeues the child socket from the accept queue. However, it checks `listener->sk_err` and finds it set to `ECONNREFUSED`.
7. Because of this error, `vsock_accept()` rejects the connection: it sets `vconnected->rejected = true`, drops the accept queue's reference to the child socket, and returns the error without grafting the child socket to a new file descriptor.

Since the child socket was never grafted to a file descriptor, it will never be closed by user space. Furthermore, because it was removed from the accept queue, it will not be cleaned up when the listening socket is eventually closed. The child socket remains in the connected table indefinitely with a refcount of 1, resulting in a memory leak of the socket structure and its associated transport data (e.g., `virtio_vsock_sock`).

**Security Impact:**

* **Exploitable:** No. This is a pure memory leak. It does not lead to memory corruption, use-after-free, or privilege escalation.
* **Denial Of Service:** Yes. An attacker can repeatedly trigger this leak to consume kernel memory, eventually leading to an Out-Of-Memory (OOM) condition and system crash.
* **Accessible From Unprivileged Processes:** Yes. Creating `AF_VSOCK` sockets and calling `bind`, `connect`, `listen`, and `accept` does not require any special capabilities.
* **Accessible From User Namespaces:** Yes.
* **VM Guest / Host Trigger:** Yes. The bug can be triggered locally on any system that supports `AF_VSOCK` (including VM guests and hosts). The reproducer uses the `VMADDR_CID_LOCAL` (loopback) transport, meaning it doesn't even require a configured external vsock device to be triggered.

gemini-3.1-pro-preview

							input: 10870
							output: 53
							thoughts: 424
						

**Memory Leak Debugging: A Kernel Dive**

Alright, let's break this down. We've got a reported memory leak within the kernel, specifically targeting allocations of `sk_prot_alloc`, `lsm_blob_alloc`, and potentially the call in `virtio_transport_do_socket_init`. The backtrace is giving us the critical clues: the trail leads us through `kmem_cache_alloc_noprof` which, as we know, is our slub allocator, then *directly* to `sk_prot_alloc`. Further, we can see calls in `sk_alloc`, and then specific calls around our vsock implementations.

The stack strongly suggests something's amiss in the vsock connection lifecycle, particularly when dealing with socket creation, binding, connecting, listening, and accepting, with the common thread being allocation within the `net/vmw_vsock` subsystem.

The reproducer provides a useful sequence: Create a vsock socket, bind it with `VMADDR_CID_ANY` and port 0, connect to `VMADDR_CID_LOCAL` on port `0xffffffff`, listen, create another socket, connect to `VMADDR_CID_LOCAL` and port 0, and then accept on the first socket. This seems like a race condition between sockets, likely causing the memory issue.

Given the backtrace, I'm going to start my analysis with `virtio_transport_recv_listen`. This seems like the most likely point of failure as it's the first kernel call in our backtrace. I'll need to understand how connections are handled, and how the allocators are behaving in this call path and then from there attempt to reproduce the scenario.

map[ContextFile:net/vmw_vsock/virtio_transport_common.c IncludeLines:true Name:virtio_transport_recv_listen]

map[SourceCode:1528:	/* Handle server socket */
1529:	static int
1530:	virtio_transport_recv_listen(struct sock *sk, struct sk_buff *skb,
1531:				     struct virtio_transport *t)
1532:	{
1533:		struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
1534:		struct vsock_sock *vsk = vsock_sk(sk);
1535:		struct vsock_sock *vchild;
1536:		struct sock *child;
1537:		int ret;
1538:	
1539:		if (le16_to_cpu(hdr->op) != VIRTIO_VSOCK_OP_REQUEST) {
1540:			virtio_transport_reset_no_sock(t, skb, sock_net(sk));
1541:			return -EINVAL;
1542:		}
1543:	
1544:		if (sk_acceptq_is_full(sk)) {
1545:			virtio_transport_reset_no_sock(t, skb, sock_net(sk));
1546:			return -ENOMEM;
1547:		}
1548:	
1549:		/* __vsock_release() might have already flushed accept_queue.
1550:		 * Subsequent enqueues would lead to a memory leak.
1551:		 */
1552:		if (sk->sk_shutdown == SHUTDOWN_MASK) {
1553:			virtio_transport_reset_no_sock(t, skb, sock_net(sk));
1554:			return -ESHUTDOWN;
1555:		}
1556:	
1557:		child = vsock_create_connected(sk);
1558:		if (!child) {
1559:			virtio_transport_reset_no_sock(t, skb, sock_net(sk));
1560:			return -ENOMEM;
1561:		}
1562:	
1563:		sk_acceptq_added(sk);
1564:	
1565:		lock_sock_nested(child, SINGLE_DEPTH_NESTING);
1566:	
1567:		child->sk_state = TCP_ESTABLISHED;
1568:	
1569:		vchild = vsock_sk(child);
1570:		vsock_addr_init(&vchild->local_addr, le64_to_cpu(hdr->dst_cid),
1571:				le32_to_cpu(hdr->dst_port));
1572:		vsock_addr_init(&vchild->remote_addr, le64_to_cpu(hdr->src_cid),
1573:				le32_to_cpu(hdr->src_port));
1574:	
1575:		ret = vsock_assign_transport(vchild, vsk);
1576:		/* Transport assigned (looking at remote_addr) must be the same
1577:		 * where we received the request.
1578:		 */
1579:		if (ret || vchild->transport != &t->transport) {
1580:			release_sock(child);
1581:			virtio_transport_reset_no_sock(t, skb, sock_net(sk));
1582:			sock_put(child);
1583:			return ret;
1584:		}
1585:	
1586:		if (virtio_transport_space_update(child, skb))
1587:			child->sk_write_space(child);
1588:	
1589:		vsock_insert_connected(vchild);
1590:		vsock_enqueue_accept(sk, child);
1591:		virtio_transport_send_response(vchild, skb);
1592:	
1593:		release_sock(child);
1594:	
1595:		sk->sk_data_ready(sk);
1596:		return 0;
1597:	}
 SourceFile:net/vmw_vsock/virtio_transport_common.c]

gemini-3.1-pro-preview

							input: 12851
							output: 49
							thoughts: 190
						

**Debugging a Vsock Leak**

Okay, so I'm tracking down this memory leak, and it looks like it's originating in `virtio_transport_recv_listen`. It's pretty clear from the code that it's calling `vsock_create_connected(sk)` to get a child socket, and then assigning the transport with `vsock_assign_transport(vchild, vsk)`. If that assignment fails, or something's wrong with the transport itself, the code block in question is executed:

```c
		if (ret || vchild->transport != &t->transport) {
			release_sock(child);
			virtio_transport_reset_no_sock(t, skb, sock_net(sk));
			sock_put(child);
			return ret;
		}
```

Now, hold on. `vsock_create_connected` is supposed to return a socket with a reference count of 1, right? And if we hit that `sock_put(child)`, shouldn't that be enough to free the socket? That should decrement the refcount to zero, releasing the memory. Something seems off here. Let me double-check the `vsock_create_connected` function to be sure. There might be a subtle nuance I'm missing, or maybe the refcounting isn't behaving as expected. Need to look closer.

map[ContextFile:net/vmw_vsock/af_vsock.c IncludeLines:true Name:vsock_create_connected]

map[SourceCode:1023:	struct sock *vsock_create_connected(struct sock *parent)
1024:	{
1025:		return __vsock_create(sock_net(parent), NULL, parent, GFP_KERNEL,
1026:				      parent->sk_type, 0);
1027:	}
 SourceFile:net/vmw_vsock/af_vsock.c]

gemini-3.1-pro-preview

							input: 13511
							output: 48
							thoughts: 11
						

Okay, here's my attempt at summarizing my thought process regarding `__vsock_create`, assuming I'm an expert in this field.

**Diving into `__vsock_create`**

Alright, time to dig into `__vsock_create`. My initial thought is to quickly refresh my understanding of where this function sits in the overall vsock architecture. Is this a user-space function? A kernel-space function? I need to remember the typical flow for vsock creation, the key data structures involved (like `struct vsock_sock`, `struct vsock_addr`, etc.), and how this function likely interacts with them. I'll need to think about the arguments this function takes – are they pointers, integers, what do they represent? What's the error handling like? Are there likely race conditions to watch out for, given that this function is probably operating on shared data structures? I need to understand this to determine how safe the system is. Is this called as part of a socket() implementation? Is it a helper for some other vsock functionality? Is it part of the initial connection setup? I will need to understand the implications of the context. Finally, I'm thinking about the possible return values – what are the potential success and failure scenarios, and what do those return codes mean in the broader context of a vsock application? Let's check the code and refresh my memory.

map[ContextFile:net/vmw_vsock/af_vsock.c IncludeLines:true Name:__vsock_create]

map[SourceCode: 882:	static struct sock *__vsock_create(struct net *net,
 883:					   struct socket *sock,
 884:					   struct sock *parent,
 885:					   gfp_t priority,
 886:					   unsigned short type,
 887:					   int kern)
 888:	{
 889:		struct sock *sk;
 890:		struct vsock_sock *psk;
 891:		struct vsock_sock *vsk;
 892:	
 893:		sk = sk_alloc(net, AF_VSOCK, priority, &vsock_proto, kern);
 894:		if (!sk)
 895:			return NULL;
 896:	
 897:		sock_init_data(sock, sk);
 898:	
 899:		/* sk->sk_type is normally set in sock_init_data, but only if sock is
 900:		 * non-NULL. We make sure that our sockets always have a type by
 901:		 * setting it here if needed.
 902:		 */
 903:		if (!sock)
 904:			sk->sk_type = type;
 905:	
 906:		vsk = vsock_sk(sk);
 907:		vsock_addr_init(&vsk->local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
 908:		vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
 909:	
 910:		sk->sk_destruct = vsock_sk_destruct;
 911:		sk->sk_backlog_rcv = vsock_queue_rcv_skb;
 912:		sock_reset_flag(sk, SOCK_DONE);
 913:	
 914:		INIT_LIST_HEAD(&vsk->bound_table);
 915:		INIT_LIST_HEAD(&vsk->connected_table);
 916:		vsk->listener = NULL;
 917:		INIT_LIST_HEAD(&vsk->pending_links);
 918:		INIT_LIST_HEAD(&vsk->accept_queue);
 919:		vsk->rejected = false;
 920:		vsk->sent_request = false;
 921:		vsk->ignore_connecting_rst = false;
 922:		vsk->peer_shutdown = 0;
 923:		INIT_DELAYED_WORK(&vsk->connect_work, vsock_connect_timeout);
 924:		INIT_DELAYED_WORK(&vsk->pending_work, vsock_pending_work);
 925:	
 926:		psk = parent ? vsock_sk(parent) : NULL;
 927:		if (parent) {
 928:			vsk->trusted = psk->trusted;
 929:			vsk->owner = get_cred(psk->owner);
 930:			vsk->connect_timeout = psk->connect_timeout;
 931:			vsk->buffer_size = psk->buffer_size;
 932:			vsk->buffer_min_size = psk->buffer_min_size;
 933:			vsk->buffer_max_size = psk->buffer_max_size;
 934:			security_sk_clone(parent, sk);
 935:		} else {
 936:			vsk->trusted = ns_capable_noaudit(&init_user_ns, CAP_NET_ADMIN);
 937:			vsk->owner = get_current_cred();
 938:			vsk->connect_timeout = VSOCK_DEFAULT_CONNECT_TIMEOUT;
 939:			vsk->buffer_size = VSOCK_DEFAULT_BUFFER_SIZE;
 940:			vsk->buffer_min_size = VSOCK_DEFAULT_BUFFER_MIN_SIZE;
 941:			vsk->buffer_max_size = VSOCK_DEFAULT_BUFFER_MAX_SIZE;
 942:		}
 943:	
 944:		return sk;
 945:	}
 SourceFile:net/vmw_vsock/af_vsock.c]

gemini-3.1-pro-preview

							input: 14999
							output: 49
							thoughts: 23
						

Here's my summary, as though I'm thinking through this process:

**Diving into the `sk_alloc` Function**

Okay, so I see this uses `sk_alloc`. That immediately flags a resource allocation concern. I need to understand what's happening at the low level. My immediate next step is to examine how this function interacts with memory management. We need to be confident of how this works.

The next thing on my mind is to understand the purpose of `vsock_assign_transport`. I need to figure out what it does within the context of the larger system. This looks like a central piece, so let's see how the elements are combined. Understanding this will be crucial to understand how resources are managed by this code.

map[ContextFile:net/vmw_vsock/af_vsock.c IncludeLines:true Name:vsock_assign_transport]

map[SourceCode: 540:	/* Assign a transport to a socket and call the .init transport callback.
 541:	 *
 542:	 * Note: for connection oriented socket this must be called when vsk->remote_addr
 543:	 * is set (e.g. during the connect() or when a connection request on a listener
 544:	 * socket is received).
 545:	 * The vsk->remote_addr is used to decide which transport to use:
 546:	 *  - remote CID == VMADDR_CID_LOCAL or g2h->local_cid or VMADDR_CID_HOST if
 547:	 *    g2h is not loaded, will use local transport;
 548:	 *  - remote CID <= VMADDR_CID_HOST or h2g is not loaded or remote flags field
 549:	 *    includes VMADDR_FLAG_TO_HOST flag value, will use guest->host transport;
 550:	 *  - remote CID > VMADDR_CID_HOST will use host->guest transport;
 551:	 */
 552:	int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk)
 553:	{
 554:		const struct vsock_transport *new_transport;
 555:		struct sock *sk = sk_vsock(vsk);
 556:		unsigned int remote_cid = vsk->remote_addr.svm_cid;
 557:		__u8 remote_flags;
 558:		int ret;
 559:	
 560:		/* If the packet is coming with the source and destination CIDs higher
 561:		 * than VMADDR_CID_HOST, then a vsock channel where all the packets are
 562:		 * forwarded to the host should be established. Then the host will
 563:		 * need to forward the packets to the guest.
 564:		 *
 565:		 * The flag is set on the (listen) receive path (psk is not NULL). On
 566:		 * the connect path the flag can be set by the user space application.
 567:		 */
 568:		if (psk && vsk->local_addr.svm_cid > VMADDR_CID_HOST &&
 569:		    vsk->remote_addr.svm_cid > VMADDR_CID_HOST)
 570:			vsk->remote_addr.svm_flags |= VMADDR_FLAG_TO_HOST;
 571:	
 572:		remote_flags = vsk->remote_addr.svm_flags;
 573:	
 574:		mutex_lock(&vsock_register_mutex);
 575:	
 576:		switch (sk->sk_type) {
 577:		case SOCK_DGRAM:
 578:			new_transport = transport_dgram;
 579:			break;
 580:		case SOCK_STREAM:
 581:		case SOCK_SEQPACKET:
 582:			if (vsock_use_local_transport(remote_cid))
 583:				new_transport = transport_local;
 584:			else if (remote_cid <= VMADDR_CID_HOST || !transport_h2g ||
 585:				 (remote_flags & VMADDR_FLAG_TO_HOST))
 586:				new_transport = transport_g2h;
 587:			else
 588:				new_transport = transport_h2g;
 589:			break;
 590:		default:
 591:			ret = -ESOCKTNOSUPPORT;
 592:			goto err;
 593:		}
 594:	
 595:		if (vsk->transport && vsk->transport == new_transport) {
 596:			ret = 0;
 597:			goto err;
 598:		}
 599:	
 600:		/* We increase the module refcnt to prevent the transport unloading
 601:		 * while there are open sockets assigned to it.
 602:		 */
 603:		if (!new_transport || !try_module_get(new_transport->module)) {
 604:			ret = -ENODEV;
 605:			goto err;
 606:		}
 607:	
 608:		/* It's safe to release the mutex after a successful try_module_get().
 609:		 * Whichever transport `new_transport` points at, it won't go away until
 610:		 * the last module_put() below or in vsock_deassign_transport().
 611:		 */
 612:		mutex_unlock(&vsock_register_mutex);
 613:	
 614:		if (vsk->transport) {
 615:			/* transport->release() must be called with sock lock acquired.
 616:			 * This path can only be taken during vsock_connect(), where we
 617:			 * have already held the sock lock. In the other cases, this
 618:			 * function is called on a new socket which is not assigned to
 619:			 * any transport.
 620:			 */
 621:			vsk->transport->release(vsk);
 622:			vsock_deassign_transport(vsk);
 623:	
 624:			/* transport's release() and destruct() can touch some socket
 625:			 * state, since we are reassigning the socket to a new transport
 626:			 * during vsock_connect(), let's reset these fields to have a
 627:			 * clean state.
 628:			 */
 629:			sock_reset_flag(sk, SOCK_DONE);
 630:			sk->sk_state = TCP_CLOSE;
 631:			vsk->peer_shutdown = 0;
 632:		}
 633:	
 634:		if (sk->sk_type == SOCK_SEQPACKET) {
 635:			if (!new_transport->seqpacket_allow ||
 636:			    !new_transport->seqpacket_allow(vsk, remote_cid)) {
 637:				module_put(new_transport->module);
 638:				return -ESOCKTNOSUPPORT;
 639:			}
 640:		}
 641:	
 642:		ret = new_transport->init(vsk, psk);
 643:		if (ret) {
 644:			module_put(new_transport->module);
 645:			return ret;
 646:		}
 647:	
 648:		vsk->transport = new_transport;
 649:	
 650:		return 0;
 651:	err:
 652:		mutex_unlock(&vsock_register_mutex);
 653:		return ret;
 654:	}
 SourceFile:net/vmw_vsock/af_vsock.c]

gemini-3.1-pro-preview

							input: 17097
							output: 50
							thoughts: 276
						

**My Analysis of the vsock Transport Assignment and Cleanup**

Okay, let's break this down. It seems the core of the vsock transport assignment happens within `vsock_assign_transport`. This function is pivotal because it kicks off the initialization process by calling `new_transport->init(vsk, psk)`. If that initialization is successful, then the `vsk->transport` pointer gets updated to point to the newly initialized transport.

Now, things get a bit more interesting when examining `virtio_transport_recv_listen`.  I see a crucial conditional check: `if (ret || vchild->transport != &t->transport)`.  The focus here is that if the return value, `ret`, indicates a failure *or* if the transport attached to the child socket, `vchild->transport`, does not match what the transport's target to which the child socket is pointing, it enters a cleanup routine.

Here's the problem I see developing: If `vsock_assign_transport` *succeeds*, yet this `vchild->transport` check *fails*, the cleanup triggers with `sock_put(child)`. That's where it goes sideways. Because `vsock_assign_transport` has *already* run `new_transport->init(vsk, psk)`. This init function is responsible for any memory allocation associated with the transport, like the `vvs` structure within `virtio_transport_do_socket_init`.

The critical point here is that `sock_put(child)` decreases the socket's reference count. If that count hits zero, it triggers `sk_destruct`, which for vsock sockets, is `vsock_sk_destruct`.

Essentially, if the child socket is getting dropped due to mismatch of transport, then we have a potential memory leak or use-after-free scenario. The allocated memory from the transport init *could* get prematurely freed when the socket's ref count hits 0, even though the transport might still be in use elsewhere. We need to look closely at the lifetime management of the `vvs` and associated transport-specific resources in this particular scenario. It requires further investigation to ensure that we're properly managing the memory associated with the transport when this condition is met.

map[ContextFile:net/vmw_vsock/af_vsock.c IncludeLines:true Name:vsock_sk_destruct]

map[SourceCode: 994:	static void vsock_sk_destruct(struct sock *sk)
 995:	{
 996:		struct vsock_sock *vsk = vsock_sk(sk);
 997:	
 998:		/* Flush MSG_ZEROCOPY leftovers. */
 999:		__skb_queue_purge(&sk->sk_error_queue);
1000:	
1001:		vsock_deassign_transport(vsk);
1002:	
1003:		/* When clearing these addresses, there's no need to set the family and
1004:		 * possibly register the address family with the kernel.
1005:		 */
1006:		vsock_addr_init(&vsk->local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
1007:		vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
1008:	
1009:		put_cred(vsk->owner);
1010:	}
 SourceFile:net/vmw_vsock/af_vsock.c]

gemini-3.1-pro-preview

							input: 18224
							output: 50
							thoughts: 13
						

Okay, let's dive into this. Here's my take on those thoughts, as if they're my own:

**Analyzing `vsock_deassign_transport`**

Alright, so the focus is `vsock_deassign_transport`, which immediately triggers some thoughts. We're talking about deassigning, so this is about tearing down a connection or resource allocation related to vsocks, I presume. Let's see what's involved in that process. I need to understand the implications of this action. What resources are being freed? Is there a risk of race conditions or data corruption if this isn't handled correctly? Are we talking about removing a specific transport, like a hypervisor-specific one, or a more general network transport within the vsock subsystem? Does it involve releasing memory, closing sockets, or signaling other subsystems? What locks or synchronization primitives are in place to ensure thread safety during the deallocation? I need to look for potential areas of concern and vulnerabilities related to resource leaks, use-after-free scenarios, or unexpected behavior if the transport is still in use elsewhere. The function name implies it's a critical part of the cleanup procedure. I'm going to have to analyze the code around `vsock_deassign_transport` to figure out the full scope of what it's doing.

map[ContextFile:net/vmw_vsock/af_vsock.c IncludeLines:true Name:vsock_deassign_transport]

map[SourceCode: 530:	static void vsock_deassign_transport(struct vsock_sock *vsk)
 531:	{
 532:		if (!vsk->transport)
 533:			return;
 534:	
 535:		vsk->transport->destruct(vsk);
 536:		module_put(vsk->transport->module);
 537:		vsk->transport = NULL;
 538:	}
 SourceFile:net/vmw_vsock/af_vsock.c]

gemini-3.1-pro-preview

							input: 18725
							output: 39
							thoughts: 378
						

**Debugging a Potential vsock Memory Leak**

Okay, let's break this down. My initial thought is: `vsock_deassign_transport` is calling `vsk->transport->destruct(vsk)`, which is expected. But, I need to trace where `vsk->transport` is actually assigned. Right, it's in `vsock_assign_transport`. Let me see... the critical section is the successful initialization of the new transport:

```c
	ret = new_transport->init(vsk, psk);
	if (ret) {
		module_put(new_transport->module);
		return ret;
	}

	vsk->transport = new_transport;
```

If `new_transport->init` returns successfully, `vsk->transport` gets assigned. Makes sense so far. Now, let me look at `virtio_transport_recv_listen`:

```c
	ret = vsock_assign_transport(vchild, vsk);
	/* Transport assigned (looking at remote_addr) must be the same
	 * where we received the request.
	 */
	if (ret || vchild->transport != &t->transport) {
		release_sock(child);
		virtio_transport_reset_no_sock(t, skb, sock_net(sk));
		sock_put(child);
		return ret;
	}
```

Okay, if `vchild->transport != &t->transport`, we call `sock_put(child)`. That `sock_put` should decrement the refcount. And since we already confirmed `vchild->transport` is set and valid, a call to `vsock_sk_destruct` will *correctly* call `vsock_deassign_transport`, which calls `vchild->transport->destruct(vchild)`. Therefore, that should *not* be the source of the leak... but something *is* wrong!

So, where am I missing something? I need to check the refcount of the socket and where it's created. Could `vsock_create_connected` be returning a socket with a refcount of 1? Let me go straight to `sk_alloc` and see.

map[ContextFile:net/core/sock.c IncludeLines:true Name:sk_alloc]

map[SourceCode:2288:	/**
2289:	 *	sk_alloc - All socket objects are allocated here
2290:	 *	@net: the applicable net namespace
2291:	 *	@family: protocol family
2292:	 *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
2293:	 *	@prot: struct proto associated with this new sock instance
2294:	 *	@kern: is this to be a kernel socket?
2295:	 */
2296:	struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
2297:			      struct proto *prot, int kern)
2298:	{
2299:		struct sock *sk;
2300:	
2301:		sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
2302:		if (sk) {
2303:			sk->sk_family = family;
2304:			/*
2305:			 * See comment in struct sock definition to understand
2306:			 * why we need sk_prot_creator -acme
2307:			 */
2308:			sk->sk_prot = sk->sk_prot_creator = prot;
2309:	
2310:			if (READ_ONCE(net->core.sysctl_bypass_prot_mem))
2311:				sk->sk_bypass_prot_mem = 1;
2312:	
2313:			sk->sk_kern_sock = kern;
2314:			sock_lock_init(sk);
2315:	
2316:			sk->sk_net_refcnt = kern ? 0 : 1;
2317:			if (likely(sk->sk_net_refcnt)) {
2318:				get_net_track(net, &sk->ns_tracker, priority);
2319:				sock_inuse_add(net, 1);
2320:			} else {
2321:				net_passive_inc(net);
2322:				__netns_tracker_alloc(net, &sk->ns_tracker,
2323:						      false, priority);
2324:			}
2325:	
2326:			sock_net_set(sk, net);
2327:			refcount_set(&sk->sk_wmem_alloc, SK_WMEM_ALLOC_BIAS);
2328:	
2329:			mem_cgroup_sk_alloc(sk);
2330:			cgroup_sk_alloc(&sk->sk_cgrp_data);
2331:			sock_update_classid(&sk->sk_cgrp_data);
2332:			sock_update_netprioidx(&sk->sk_cgrp_data);
2333:			sk_tx_queue_clear(sk);
2334:		}
2335:	
2336:		return sk;
2337:	}
 SourceFile:net/core/sock.c]

gemini-3.1-pro-preview

							input: 20451
							output: 41
							thoughts: 47
						

Okay, let me think this through.

**Analyzing Socket Initialization and Reference Counting**

Alright, I'm digging into this `sk_alloc` function and noticed something immediately. It appears that `sk_alloc` directly sets `sk_wmem_alloc` to 1. But that raises a question in my mind: what about the reference count, specifically `sk_refcnt`? I know that's crucial for socket lifecycle management. I seem to recall setting `sk_refcnt` elsewhere during initialization. Let me just think for a moment... Yes! That's it, `sock_init_data` is where that vital `sk_refcnt` is actually set. Okay, so `sk_alloc` does its thing with memory allocation and basic flags, and then `sock_init_data` handles the important reference count initialization, tying the two components together. That makes perfect sense. I will want to verify how the two are then intertwined.

map[ContextFile:net/core/sock.c IncludeLines:true Name:sock_init_data]

map[SourceCode:3767:	void sock_init_data(struct socket *sock, struct sock *sk)
3768:	{
3769:		kuid_t uid = sock ?
3770:			SOCK_INODE(sock)->i_uid :
3771:			make_kuid(sock_net(sk)->user_ns, 0);
3772:	
3773:		sock_init_data_uid(sock, sk, uid);
3774:	}
 SourceFile:net/core/sock.c]

gemini-3.1-pro-preview

							input: 20897
							output: 43
							thoughts: 13
						

Okay, here's my interpretation of that thought process, tailored for an expert audience, and written in the first person:

**Initial Assessment: Sock Initialization Data - UID Inspection**

Alright, the initial impulse here is to scrutinize the `sock_init_data_uid` function. Given the context (which I'm assuming is related to socket initialization), my brain is immediately keying in on user ID (`uid`) related data. This immediately brings up flags: possible security implications, privilege checks, potential for misconfiguration vulnerabilities, and the general integrity of the socket's context. I need to understand how this function is handling UID information during socket creation. I need to consider why this is even a function in the first place, or rather, what are the use-cases it is attempting to manage.

map[ContextFile:net/core/sock.c IncludeLines:true Name:sock_init_data_uid]

map[SourceCode:3696:	void sock_init_data_uid(struct socket *sock, struct sock *sk, kuid_t uid)
3697:	{
3698:		sk_init_common(sk);
3699:		sk->sk_send_head	=	NULL;
3700:	
3701:		timer_setup(&sk->sk_timer, NULL, 0);
3702:	
3703:		sk->sk_allocation	=	GFP_KERNEL;
3704:		sk->sk_rcvbuf		=	READ_ONCE(sysctl_rmem_default);
3705:		sk->sk_sndbuf		=	READ_ONCE(sysctl_wmem_default);
3706:		sk->sk_state		=	TCP_CLOSE;
3707:		sk->sk_use_task_frag	=	true;
3708:		sk_set_socket(sk, sock);
3709:	
3710:		sock_set_flag(sk, SOCK_ZAPPED);
3711:	
3712:		if (sock) {
3713:			sk->sk_type	=	sock->type;
3714:			RCU_INIT_POINTER(sk->sk_wq, &sock->wq);
3715:			sock->sk	=	sk;
3716:		} else {
3717:			RCU_INIT_POINTER(sk->sk_wq, NULL);
3718:		}
3719:		sk->sk_uid	=	uid;
3720:	
3721:		sk->sk_state_change	=	sock_def_wakeup;
3722:		sk->sk_data_ready	=	sock_def_readable;
3723:		sk->sk_write_space	=	sock_def_write_space;
3724:		sk->sk_error_report	=	sock_def_error_report;
3725:		sk->sk_destruct		=	sock_def_destruct;
3726:	
3727:		sk->sk_frag.page	=	NULL;
3728:		sk->sk_frag.offset	=	0;
3729:		sk->sk_peek_off		=	-1;
3730:	
3731:		sk->sk_peer_pid 	=	NULL;
3732:		sk->sk_peer_cred	=	NULL;
3733:		spin_lock_init(&sk->sk_peer_lock);
3734:	
3735:		sk->sk_write_pending	=	0;
3736:		sk->sk_rcvlowat		=	1;
3737:		sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
3738:		sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
3739:	
3740:		sk->sk_stamp = SK_DEFAULT_STAMP;
3741:	#if BITS_PER_LONG==32
3742:		seqlock_init(&sk->sk_stamp_seq);
3743:	#endif
3744:		atomic_set(&sk->sk_zckey, 0);
3745:	
3746:	#ifdef CONFIG_NET_RX_BUSY_POLL
3747:		sk->sk_napi_id		=	0;
3748:		sk->sk_ll_usec		=	READ_ONCE(sysctl_net_busy_read);
3749:	#endif
3750:	
3751:		sk->sk_max_pacing_rate = ~0UL;
3752:		sk->sk_pacing_rate = ~0UL;
3753:		WRITE_ONCE(sk->sk_pacing_shift, 10);
3754:		sk->sk_incoming_cpu = -1;
3755:	
3756:		sk_rx_queue_clear(sk);
3757:		/*
3758:		 * Before updating sk_refcnt, we must commit prior changes to memory
3759:		 * (Documentation/RCU/rculist_nulls.rst for details)
3760:		 */
3761:		smp_wmb();
3762:		refcount_set(&sk->sk_refcnt, 1);
3763:		sk_drops_reset(sk);
3764:	}
 SourceFile:net/core/sock.c]

gemini-3.1-pro-preview

							input: 22331
							output: 39
							thoughts: 668
						

**Analyzing a Potential Socket Leak in `virtio_transport_recv_listen`**

Okay, let's break this down. It seems we have a scenario where we could be leaking a socket in `virtio_transport_recv_listen`.  The first thing I see is that `sk_refcnt` is 1. We're in `virtio_transport_recv_listen` and we call `vsock_create_connected(sk)` which, if successful, creates a new connected socket `child`. The refcount on `child` starts at 1, from what I understand, because `__vsock_create` is called within `vsock_create_connected`, which calls `sk_alloc` and `sock_init_data`.

Now, the flow. We call `vsock_create_connected`, and then `sk_acceptq_added(sk)`. This increases the accept queue backlog. Then, we lock the socket, set the socket state to `TCP_ESTABLISHED` and initialize the local and remote addresses. Now, the critical part: we call `vsock_assign_transport`.

If this fails (or if the transport doesn't match what we expect), we release the socket. Specifically, we do `sock_put(child)`. This looks suspect. The important check is on `vsock_assign_transport`, if it fails then we call `sock_put(child)` which from my understanding should decrease `child`'s refcount to zero, which then frees the socket.

However, if `vsock_assign_transport` fails, we've already done `sk_acceptq_added(sk)`. This implies we incremented the `sk->sk_ack_backlog` on the listening socket (`sk`). But the thing is, `child` was NOT added to the accept queue. The code explicitly calls `vsock_enqueue_accept(sk, child)` to do that.  So, if `vsock_assign_transport` fails, the new socket `child` is never put in the accept queue.

Now, if `child` is then freed via `sock_put(child)`, what's being leaked? The bug report mentions `sk_prot_alloc`, `lsm_blob_alloc`, and `virtio_transport_do_socket_init` leaks, which point to memory associated with the socket itself. This indicates that `sock_put(child)` isn't properly freeing *everything*. Why would `sock_put(child)` NOT free the socket? This is the crux. I need to dive deeper into `sock_put` to understand the exact refcount behavior and potential for incomplete cleanup in this specific case.

map[ContextFile:include/net/sock.h IncludeLines:true Name:sock_put]

map[SourceCode:2003:	/* Ungrab socket and destroy it, if it was the last reference. */
2004:	static inline void sock_put(struct sock *sk)
2005:	{
2006:		if (refcount_dec_and_test(&sk->sk_refcnt))
2007:			sk_free(sk);
2008:	}
 SourceFile:include/net/sock.h]

gemini-3.1-pro-preview

							input: 23740
							output: 39
							thoughts: 14
						

Here's my attempt at summarizing the thought process, tailored for an expert audience:

**Sk_free and Its Relationship to __sk_free**

Okay, so I'm looking at `sk_free`. The name is familiar, obviously indicating it's the function for freeing a `sk_buff` structure. But what's intriguing is the function call within it: `__sk_free`. Hmm. That naming convention suggests a layered design, a level of abstraction. `sk_free` is likely a higher-level function, perhaps handling some sort of initial cleanup or checks before passing the task down to the "internals". 

My initial hunch is that `__sk_free` is the workhorse. It probably handles the actual memory deallocation, potentially freeing all the relevant fields and associated data within the `sk_buff`. `sk_free`, on the other hand, *might* be involved in synchronization, reference counting, or possibly even logging/statistics gathering regarding the freeing of the buffer. It could also be responsible for calling other cleanup functions based on flags set in the buffer. I'd need to dig deeper to confirm, but the pattern of `__` prefixes often signals internal helper functions in this codebase. Definitely worth a quick `grep` for the calls to `__sk_free` and `sk_free` to see where they're used and understand the broader context. Understanding the difference between these two calls will be critical for debugging any related issues.

map[ContextFile:net/core/sock.c IncludeLines:true Name:sk_free]

map[SourceCode:2426:	void sk_free(struct sock *sk)
2427:	{
2428:		/*
2429:		 * We subtract one from sk_wmem_alloc and can know if
2430:		 * some packets are still in some tx queue.
2431:		 * If not null, sock_wfree() will call __sk_free(sk) later
2432:		 */
2433:		if (refcount_dec_and_test(&sk->sk_wmem_alloc))
2434:			__sk_free(sk);
2435:	}
 SourceFile:net/core/sock.c]

gemini-3.1-pro-preview

							input: 24288
							output: 55
							thoughts: 272
						

**My Analysis of `sk_wmem_alloc` in the Context of Socket Lifecycle**

Okay, so I'm looking at `sk_wmem_alloc` here. Right, when `sk_alloc` is called, the value of `sk_wmem_alloc` gets set to 1. Specifically, `refcount_set(&sk->sk_wmem_alloc, SK_WMEM_ALLOC_BIAS)` happens, where `SK_WMEM_ALLOC_BIAS` is just the value 1.

The interesting bit here is what happens when that refcount hits zero. If I understand this correctly, then `refcount_dec_and_test(&sk->sk_wmem_alloc)` will decrement the counter to zero and then return *true*, which in turn triggers a call to `__sk_free(sk)`. That's the expected socket deallocation path when the memory reference count drops to zero.

Now, I'm trying to figure out if there are any other places where `sk_wmem_alloc` gets incremented. Specifically, I was wondering if `vsock_assign_transport` bumps the reference count. No, that's not it. Okay, then, what about `virtio_transport_do_socket_init`? Nope, that doesn't seem to touch it either.

Wait... hang on. What if `vchild->transport` doesn't match `t->transport`? The code then calls `sock_put(child)`. That should be where `sk_wmem_alloc` gets decremented, but only if the init path sets it to a higher value. But `vsock_assign_transport` *does* call `new_transport->init(vsk, psk)`. For the `virtio_transport`, that's `virtio_transport_do_socket_init`, which should be initializing the socket appropriately. So, the question remains: is the init function incrementing the value and therefore *increasing* the reference count to protect against premature deallocation? Still, the init is not the same as assignment. So it doesn't appear so!

map[ContextFile:net/vmw_vsock/virtio_transport_common.c IncludeLines:true Name:virtio_transport_do_socket_init]

map[SourceCode: 918:	int virtio_transport_do_socket_init(struct vsock_sock *vsk,
 919:					    struct vsock_sock *psk)
 920:	{
 921:		struct virtio_vsock_sock *vvs;
 922:	
 923:		vvs = kzalloc_obj(*vvs);
 924:		if (!vvs)
 925:			return -ENOMEM;
 926:	
 927:		vsk->trans = vvs;
 928:		vvs->vsk = vsk;
 929:		if (psk && psk->trans) {
 930:			struct virtio_vsock_sock *ptrans = psk->trans;
 931:	
 932:			vvs->peer_buf_alloc = ptrans->peer_buf_alloc;
 933:		}
 934:	
 935:		if (vsk->buffer_size > VIRTIO_VSOCK_MAX_BUF_SIZE)
 936:			vsk->buffer_size = VIRTIO_VSOCK_MAX_BUF_SIZE;
 937:	
 938:		vvs->buf_alloc = vsk->buffer_size;
 939:	
 940:		spin_lock_init(&vvs->rx_lock);
 941:		spin_lock_init(&vvs->tx_lock);
 942:		skb_queue_head_init(&vvs->rx_queue);
 943:	
 944:		return 0;
 945:	}
 SourceFile:net/vmw_vsock/virtio_transport_common.c]

gemini-3.1-pro-preview

							input: 25543
							output: 52
							thoughts: 275
						

**Analyzing Virtio Transport and Socket Initialization/Destruction**

Okay, let's break this down step-by-step. I'm looking at `virtio_transport_do_socket_init`, and it's clear that it allocates `vvs` (the Virtio transport specific data structure) and crucially sets `vsk->trans = vvs`. Now, if I understand the control flow correctly, `virtio_transport_recv_listen` has a check: `vchild->transport != &t->transport`. If that condition is met, it then calls `sock_put(child)`. The question then becomes: does `vsock_sk_destruct` properly handle the freeing of `vsk->trans`?

Let's see. `vsock_sk_destruct` calls `vsock_deassign_transport(vsk)`. That function is key. Inside `vsock_deassign_transport`, we have a call to `vsk->transport->destruct(vsk)`. This is where the transport-specific cleanup happens. But hold on, let me trace this back...

Ah, right, now it's becoming clearer. In `vsock_assign_transport`, there's a critical sequence. We have this:

```c
	ret = new_transport->init(vsk, psk);
	if (ret) {
		module_put(new_transport->module);
		return ret;
	}

	vsk->transport = new_transport;
```

So, if `new_transport->init` *succeeds*, only then does `vsk->transport` get assigned to `new_transport`. That makes sense. Therefore, `vsock_deassign_transport` *will* call `vsk->transport->destruct(vsk)`. This is the core principle.

Okay, and for the `virtio_transport` specifically, the `destruct` function should be `virtio_transport_destruct`. That seems right. This implies that the resources should be properly cleaned up. Let's make sure that that is actually the case though...

map[ContextFile:net/vmw_vsock/virtio_transport_common.c IncludeLines:true Name:virtio_transport_destruct]

map[SourceCode:1127:	void virtio_transport_destruct(struct vsock_sock *vsk)
1128:	{
1129:		struct virtio_vsock_sock *vvs = vsk->trans;
1130:	
1131:		virtio_transport_cancel_close_work(vsk, true);
1132:	
1133:		kfree(vvs);
1134:		vsk->trans = NULL;
1135:	}
 SourceFile:net/vmw_vsock/virtio_transport_common.c]

gemini-3.1-pro-preview

							input: 26498
							output: 53
							thoughts: 307
						

**Debugging a Memory Leak in vsock**

Okay, so I see `vvs` is being freed somewhere in the code. That's good, that's what's *supposed* to happen. But the bug report is screaming "memory leak", and it's pointing at `vvs`! That's...confounding. The report gives me this:

```
BUG: memory leak
unreferenced object 0xffff888128bfa8a0 (size 96):
  comm "kworker/0:1", pid 10, jiffies 4294944453
  backtrace (crc 1fd60988):
    virtio_transport_do_socket_init+0x2b/0xf0 net/vmw_vsock/virtio_transport_common.c:923
    vsock_assign_transport+0x309/0x3a0 net/vmw_vsock/af_vsock.c:642
    virtio_transport_recv_listen net/vmw_vsock/virtio_transport_common.c:1575 [inline]
```

Alright, the backtrace suggests the leak originates within the `virtio_transport_recv_listen` function, after initialization.  If `vvs` is leaking, it strongly suggests that the cleanup function, `vsock_sk_destruct`, *isn't* being called. That's the key. Now, why wouldn't `vsock_sk_destruct` be called? The most common reasons are that the socket reference count, `sk_refcnt`, isn't zero, or that `sk_wmem_alloc` isn't zero. That's where the resource management issues tend to live, in my experience. I need to go back and take another look at the logic in `virtio_transport_recv_listen`.  Let's see if we can find the condition that would cause that to happen.

map[ContextFile:net/vmw_vsock/virtio_transport_common.c IncludeLines:true Name:virtio_transport_recv_listen]

map[SourceCode:1528:	/* Handle server socket */
1529:	static int
1530:	virtio_transport_recv_listen(struct sock *sk, struct sk_buff *skb,
1531:				     struct virtio_transport *t)
1532:	{
1533:		struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
1534:		struct vsock_sock *vsk = vsock_sk(sk);
1535:		struct vsock_sock *vchild;
1536:		struct sock *child;
1537:		int ret;
1538:	
1539:		if (le16_to_cpu(hdr->op) != VIRTIO_VSOCK_OP_REQUEST) {
1540:			virtio_transport_reset_no_sock(t, skb, sock_net(sk));
1541:			return -EINVAL;
1542:		}
1543:	
1544:		if (sk_acceptq_is_full(sk)) {
1545:			virtio_transport_reset_no_sock(t, skb, sock_net(sk));
1546:			return -ENOMEM;
1547:		}
1548:	
1549:		/* __vsock_release() might have already flushed accept_queue.
1550:		 * Subsequent enqueues would lead to a memory leak.
1551:		 */
1552:		if (sk->sk_shutdown == SHUTDOWN_MASK) {
1553:			virtio_transport_reset_no_sock(t, skb, sock_net(sk));
1554:			return -ESHUTDOWN;
1555:		}
1556:	
1557:		child = vsock_create_connected(sk);
1558:		if (!child) {
1559:			virtio_transport_reset_no_sock(t, skb, sock_net(sk));
1560:			return -ENOMEM;
1561:		}
1562:	
1563:		sk_acceptq_added(sk);
1564:	
1565:		lock_sock_nested(child, SINGLE_DEPTH_NESTING);
1566:	
1567:		child->sk_state = TCP_ESTABLISHED;
1568:	
1569:		vchild = vsock_sk(child);
1570:		vsock_addr_init(&vchild->local_addr, le64_to_cpu(hdr->dst_cid),
1571:				le32_to_cpu(hdr->dst_port));
1572:		vsock_addr_init(&vchild->remote_addr, le64_to_cpu(hdr->src_cid),
1573:				le32_to_cpu(hdr->src_port));
1574:	
1575:		ret = vsock_assign_transport(vchild, vsk);
1576:		/* Transport assigned (looking at remote_addr) must be the same
1577:		 * where we received the request.
1578:		 */
1579:		if (ret || vchild->transport != &t->transport) {
1580:			release_sock(child);
1581:			virtio_transport_reset_no_sock(t, skb, sock_net(sk));
1582:			sock_put(child);
1583:			return ret;
1584:		}
1585:	
1586:		if (virtio_transport_space_update(child, skb))
1587:			child->sk_write_space(child);
1588:	
1589:		vsock_insert_connected(vchild);
1590:		vsock_enqueue_accept(sk, child);
1591:		virtio_transport_send_response(vchild, skb);
1592:	
1593:		release_sock(child);
1594:	
1595:		sk->sk_data_ready(sk);
1596:		return 0;
1597:	}
 SourceFile:net/vmw_vsock/virtio_transport_common.c]

gemini-3.1-pro-preview

							input: 28448
							output: 49
							thoughts: 221
						

**Analyzing a Potential Reference Count Issue in vsock_assign_transport**

Okay, so I'm looking at this `vsock_assign_transport` function, and something's bugging me. I see that `sk_acceptq_added(sk)` increments `sk->sk_ack_backlog`. If `vsock_assign_transport` fails, returning `ret`, we *don't* decrement `sk->sk_ack_backlog`. That seems problematic. It’s certainly a resource management issue, though probably not a straight-up memory leak of the `child` socket.

Hold on a second... what's this about `vchild->transport != &t->transport`? If this condition is true, we call `sock_put(child)`. That feels important. But, I don't recall off the top of my head whether `vsock_assign_transport` *itself* increments `sk_refcnt`. No, wait, it doesn't. OK, let's keep going.

Ah, yes, there's `lock_sock_nested(child, SINGLE_DEPTH_NESTING);` and then, later, `release_sock(child);`. Does *either* of those functions – `lock_sock` or `release_sock` – actually *touch* the reference count? No, that's not their function.

Alright, back to that `vchild->transport != &t->transport` check. This seems like the key. Let me just re-examine `vsock_assign_transport` and make sure I'm not missing anything crucial about the reference count management. Gotta be sure I haven't overlooked something.

map[ContextFile:net/vmw_vsock/af_vsock.c IncludeLines:true Name:vsock_assign_transport]

map[SourceCode: 540:	/* Assign a transport to a socket and call the .init transport callback.
 541:	 *
 542:	 * Note: for connection oriented socket this must be called when vsk->remote_addr
 543:	 * is set (e.g. during the connect() or when a connection request on a listener
 544:	 * socket is received).
 545:	 * The vsk->remote_addr is used to decide which transport to use:
 546:	 *  - remote CID == VMADDR_CID_LOCAL or g2h->local_cid or VMADDR_CID_HOST if
 547:	 *    g2h is not loaded, will use local transport;
 548:	 *  - remote CID <= VMADDR_CID_HOST or h2g is not loaded or remote flags field
 549:	 *    includes VMADDR_FLAG_TO_HOST flag value, will use guest->host transport;
 550:	 *  - remote CID > VMADDR_CID_HOST will use host->guest transport;
 551:	 */
 552:	int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk)
 553:	{
 554:		const struct vsock_transport *new_transport;
 555:		struct sock *sk = sk_vsock(vsk);
 556:		unsigned int remote_cid = vsk->remote_addr.svm_cid;
 557:		__u8 remote_flags;
 558:		int ret;
 559:	
 560:		/* If the packet is coming with the source and destination CIDs higher
 561:		 * than VMADDR_CID_HOST, then a vsock channel where all the packets are
 562:		 * forwarded to the host should be established. Then the host will
 563:		 * need to forward the packets to the guest.
 564:		 *
 565:		 * The flag is set on the (listen) receive path (psk is not NULL). On
 566:		 * the connect path the flag can be set by the user space application.
 567:		 */
 568:		if (psk && vsk->local_addr.svm_cid > VMADDR_CID_HOST &&
 569:		    vsk->remote_addr.svm_cid > VMADDR_CID_HOST)
 570:			vsk->remote_addr.svm_flags |= VMADDR_FLAG_TO_HOST;
 571:	
 572:		remote_flags = vsk->remote_addr.svm_flags;
 573:	
 574:		mutex_lock(&vsock_register_mutex);
 575:	
 576:		switch (sk->sk_type) {
 577:		case SOCK_DGRAM:
 578:			new_transport = transport_dgram;
 579:			break;
 580:		case SOCK_STREAM:
 581:		case SOCK_SEQPACKET:
 582:			if (vsock_use_local_transport(remote_cid))
 583:				new_transport = transport_local;
 584:			else if (remote_cid <= VMADDR_CID_HOST || !transport_h2g ||
 585:				 (remote_flags & VMADDR_FLAG_TO_HOST))
 586:				new_transport = transport_g2h;
 587:			else
 588:				new_transport = transport_h2g;
 589:			break;
 590:		default:
 591:			ret = -ESOCKTNOSUPPORT;
 592:			goto err;
 593:		}
 594:	
 595:		if (vsk->transport && vsk->transport == new_transport) {
 596:			ret = 0;
 597:			goto err;
 598:		}
 599:	
 600:		/* We increase the module refcnt to prevent the transport unloading
 601:		 * while there are open sockets assigned to it.
 602:		 */
 603:		if (!new_transport || !try_module_get(new_transport->module)) {
 604:			ret = -ENODEV;
 605:			goto err;
 606:		}
 607:	
 608:		/* It's safe to release the mutex after a successful try_module_get().
 609:		 * Whichever transport `new_transport` points at, it won't go away until
 610:		 * the last module_put() below or in vsock_deassign_transport().
 611:		 */
 612:		mutex_unlock(&vsock_register_mutex);
 613:	
 614:		if (vsk->transport) {
 615:			/* transport->release() must be called with sock lock acquired.
 616:			 * This path can only be taken during vsock_connect(), where we
 617:			 * have already held the sock lock. In the other cases, this
 618:			 * function is called on a new socket which is not assigned to
 619:			 * any transport.
 620:			 */
 621:			vsk->transport->release(vsk);
 622:			vsock_deassign_transport(vsk);
 623:	
 624:			/* transport's release() and destruct() can touch some socket
 625:			 * state, since we are reassigning the socket to a new transport
 626:			 * during vsock_connect(), let's reset these fields to have a
 627:			 * clean state.
 628:			 */
 629:			sock_reset_flag(sk, SOCK_DONE);
 630:			sk->sk_state = TCP_CLOSE;
 631:			vsk->peer_shutdown = 0;
 632:		}
 633:	
 634:		if (sk->sk_type == SOCK_SEQPACKET) {
 635:			if (!new_transport->seqpacket_allow ||
 636:			    !new_transport->seqpacket_allow(vsk, remote_cid)) {
 637:				module_put(new_transport->module);
 638:				return -ESOCKTNOSUPPORT;
 639:			}
 640:		}
 641:	
 642:		ret = new_transport->init(vsk, psk);
 643:		if (ret) {
 644:			module_put(new_transport->module);
 645:			return ret;
 646:		}
 647:	
 648:		vsk->transport = new_transport;
 649:	
 650:		return 0;
 651:	err:
 652:		mutex_unlock(&vsock_register_mutex);
 653:		return ret;
 654:	}
 SourceFile:net/vmw_vsock/af_vsock.c]

gemini-3.1-pro-preview

							input: 30947
							output: 40
							thoughts: 407
						

**Analyzing the Socket Lifecycle in `virtio_transport_recv_listen`**

Okay, let's break this down. I'm following the code path in `virtio_transport_recv_listen`. The first thing I see is that it calls `lock_sock_nested` on `child` with `SINGLE_DEPTH_NESTING`. Then, it calls `vsock_assign_transport` with the `vchild` and `vsk`. Now, if `vsock_assign_transport` fails (returns a non-zero value), *or* if the assigned transport doesn't match the expected transport (`vchild->transport != &t->transport`), we have a cleanup sequence: `release_sock(child)`, `virtio_transport_reset_no_sock(t, skb, sock_net(sk))`, and then `sock_put(child)`. Crucially, it then `return ret;`.

But that `sock_put` is what I'm focused on. If `vsock_assign_transport` succeeds, `vchild->transport` gets set to `new_transport`. And if `new_transport` doesn't match the original transport, the same cleanup happens: `release_sock(child)` and `sock_put(child)`.

Hold on... `sock_put(child)` drops the reference count, right? That means if it drops to zero, the socket will be freed via `sk_free(child)`. And `sk_free` then calls `__sk_free(child)` *if* `sk_wmem_alloc` is zero. Now, `sk_wmem_alloc` is initialized to 1 – the `SK_WMEM_ALLOC_BIAS`. So, *does* `sock_put` decrement `sk_wmem_alloc`? Nope. `sock_put` decrements `sk_refcnt`. Aha! If `sk_refcnt` hits zero, `sk_free` gets called. `sk_free` then decrements `sk_wmem_alloc`. Because `sk_wmem_alloc` started at 1, decrementing it *will* make it zero! So, *that* means `__sk_free` *is* called! This is where the magic happens and the socket resources are reclaimed. I should probably check that next.

map[ContextFile:net/core/sock.c IncludeLines:true Name:__sk_free]

map[SourceCode:2415:	static void __sk_free(struct sock *sk)
2416:	{
2417:		if (likely(sk->sk_net_refcnt))
2418:			sock_inuse_add(sock_net(sk), -1);
2419:	
2420:		if (unlikely(sk->sk_net_refcnt && sock_diag_has_destroy_listeners(sk)))
2421:			sock_diag_broadcast_destroy(sk);
2422:		else
2423:			sk_destruct(sk);
2424:	}
 SourceFile:net/core/sock.c]

gemini-3.1-pro-preview

							input: 32088
							output: 40
							thoughts: 27
						

Here's my thought process, as it flows from the code:

**Analyzing the Destruction Process**

Okay, so `__sk_free` is the function that's being called. It's supposed to handle the freeing of some sort of object, and it looks like it calls `sk_destruct(sk)` as part of that process.  I need to understand what `sk_destruct` actually *does*.  This is crucial for understanding the whole freeing operation, especially if memory management is involved (and it usually is!). I need to know what it does to the `sk` pointer. Does it simply invalidate it? Does it free memory? Does it potentially cause side effects? I have to go investigate what that `sk_destruct` function does right now.

map[ContextFile:net/core/sock.c IncludeLines:true Name:sk_destruct]

map[SourceCode:2400:	void sk_destruct(struct sock *sk)
2401:	{
2402:		bool use_call_rcu = sock_flag(sk, SOCK_RCU_FREE);
2403:	
2404:		if (rcu_access_pointer(sk->sk_reuseport_cb)) {
2405:			reuseport_detach_sock(sk);
2406:			use_call_rcu = true;
2407:		}
2408:	
2409:		if (use_call_rcu)
2410:			call_rcu(&sk->sk_rcu, __sk_destruct);
2411:		else
2412:			__sk_destruct(&sk->sk_rcu);
2413:	}
 SourceFile:net/core/sock.c]

gemini-3.1-pro-preview

							input: 32560
							output: 41
							thoughts: 19
						

Okay, here's my interpretation of that thought process, assuming I'm an expert in this area and thinking this through:

**Deconstructing a Socket in my Mind**

Alright, I'm thinking about the process of socket destruction, specifically focusing on how `__sk_destruct` handles it. The critical part is that `__sk_destruct` ultimately calls the socket's own destructor function. This means that the socket structure itself (`sk`) has a function pointer, `sk->sk_destruct`, and `__sk_destruct` uses this function pointer to call the specific destructor that is associated with that particular socket type. In essence, `__sk_destruct` defers the actual cleanup of the socket's resources and state to the socket-specific code. This is a crucial design pattern for flexibility and maintainability. It allows each socket implementation (TCP, UDP, etc.) to handle its own teardown without having to be intimately aware of the internals of the generic socket layer. I need to ensure that the appropriate `sk_destruct` function is correctly set up when the socket is created and ensure that the particular cleanup routines in that function do not trigger a critical vulnerability, for example.

Essentially, I'm thinking, "Okay, the *generic* destructor is just a dispatcher. The *real* cleanup happens through the specific function registered for this socket (`sk`)." That’s the key. Now, what are the implications of that?

map[ContextFile:net/core/sock.c IncludeLines:true Name:__sk_destruct]

map[SourceCode:2340:	/* Sockets having SOCK_RCU_FREE will call this function after one RCU
2341:	 * grace period. This is the case for UDP sockets and TCP listeners.
2342:	 */
2343:	static void __sk_destruct(struct rcu_head *head)
2344:	{
2345:		struct sock *sk = container_of(head, struct sock, sk_rcu);
2346:		struct net *net = sock_net(sk);
2347:		struct sk_filter *filter;
2348:	
2349:		if (sk->sk_destruct)
2350:			sk->sk_destruct(sk);
2351:	
2352:		filter = rcu_dereference_check(sk->sk_filter,
2353:					       refcount_read(&sk->sk_wmem_alloc) == 0);
2354:		if (filter) {
2355:			sk_filter_uncharge(sk, filter);
2356:			RCU_INIT_POINTER(sk->sk_filter, NULL);
2357:		}
2358:	
2359:		sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
2360:	
2361:	#ifdef CONFIG_BPF_SYSCALL
2362:		bpf_sk_storage_free(sk);
2363:	#endif
2364:	
2365:		if (atomic_read(&sk->sk_omem_alloc))
2366:			pr_debug("%s: optmem leakage (%d bytes) detected\n",
2367:				 __func__, atomic_read(&sk->sk_omem_alloc));
2368:	
2369:		if (sk->sk_frag.page) {
2370:			put_page(sk->sk_frag.page);
2371:			sk->sk_frag.page = NULL;
2372:		}
2373:	
2374:		/* We do not need to acquire sk->sk_peer_lock, we are the last user. */
2375:		put_cred(sk->sk_peer_cred);
2376:		put_pid(sk->sk_peer_pid);
2377:	
2378:		if (likely(sk->sk_net_refcnt)) {
2379:			put_net_track(net, &sk->ns_tracker);
2380:		} else {
2381:			__netns_tracker_free(net, &sk->ns_tracker, false);
2382:			net_passive_dec(net);
2383:		}
2384:		sk_prot_free(sk->sk_prot_creator, sk);
2385:	}
 SourceFile:net/core/sock.c]

gemini-3.1-pro-preview

							input: 33696
							output: 49
							thoughts: 1436
						

**Analyzing a Potential Memory Leak in the vsock Implementation**

Okay, let's break this down systematically. I see a bug report indicating a memory leak, specifically an unreferenced object. The backtrace points to `sk_prot_alloc`, which is called within `sk_alloc` and eventually within `__vsock_create`.  This function is itself called within `vsock_create_connected`, which is then called within `virtio_transport_recv_listen`. This smells like an issue with socket creation/destruction within the context of a listening vsock connection.

My initial line of thought, based on my understanding of how vsock sockets work, was to trace the socket destruction path. I noticed that `sk->sk_destruct` calls `vsock_sk_destruct`, which eventually leads to `virtio_transport_destruct` where the `vvs` struct is freed, and finally `sk_prot_free`, freeing the socket. I was expecting the memory leak to be there, but everything seemed to check out.

Then I focused on the specific context: `virtio_transport_recv_listen`.  This function seems to be handling incoming connections on a listening socket. It creates a "child" socket using `vsock_create_connected`, assigns it a transport, and potentially hands it off. I was thinking, let's see how `child` is being freed.

The critical part is the potential failure paths in `vsock_assign_transport`. If this fails, it *should* clean up after itself by calling `sock_put(child)`. The code seemed to account for failures in the `init` function of the transport, but I got concerned about the order of operations. What if the assignment itself failed *before* calling the init function?  But, it calls `new_transport->init` *before* the assignment is done, so that path seems clean.

I then revisited the code specifically looking for the leak.
The code does a check: `if (ret || vchild->transport != &t->transport)` and then calls `release_sock(child)` and `sock_put(child)`. This seems correct.

However, I remembered that `vsock_assign_transport` is called with a pre-existing transport, meaning the transport can be reassigned during `vsock_connect`. I went back and took a look.
In `vsock_assign_transport` I noticed the `if (vsk->transport)` block. It seemed to handle the case where a transport already exists for a socket and releases it before assigning a new one.  This could be the problem.

But the bug report indicates that `child` (a socket) is being leaked.  This means that the socket is never being properly freed. And that's where I realized what's happening. `vsock_create_connected` is being called to create the child socket. If `vsock_assign_transport` fails, we call `sock_put(child)` which is the correct cleanup. So `child` is being leaked because the initial failure. The backtrace definitely points to the socket, so that's the thing that's leaking, not a child object.

Alright, the bug report backtrace and my analysis seem to have converged: The socket itself, pointed to by `child`, is not being properly freed in certain failure scenarios within `virtio_transport_recv_listen`. It seems like I've found the root cause of this memory leak. Now, let's pinpoint the exact conditions and craft a patch to ensure proper socket cleanup.

map[ContextFile:net/vmw_vsock/af_vsock.c IncludeLines:true Name:vsock_create_connected]

map[SourceCode:1023:	struct sock *vsock_create_connected(struct sock *parent)
1024:	{
1025:		return __vsock_create(sock_net(parent), NULL, parent, GFP_KERNEL,
1026:				      parent->sk_type, 0);
1027:	}
 SourceFile:net/vmw_vsock/af_vsock.c]

gemini-3.1-pro-preview

							input: 36062
							output: 49
							thoughts: 627
						

**Analyzing vsock Connection Establishment**

Okay, let's break this down. It seems we're looking at the connection establishment process for vsock, specifically focusing on how a listening socket accepts a new connection. `__vsock_create` is called, which kicks things off with `sk_alloc`. That seems standard, allocating the socket structure and initializing its reference count (`sk_refcnt`) to 1. Then `sock_init_data` is called. Ah, and that function calls `sock_init_data_uid`, which also sets `sk_refcnt` to 1. So, right now, the `sk_refcnt` of the initial socket is 1.

Now, we get to the core logic within `virtio_transport_recv_listen`.  A child socket is created using `vsock_create_connected`, and if that fails, we have an error path using `virtio_transport_reset_no_sock` and return.  Assuming the child socket is created successfully, `sk_acceptq_added(sk)` is called.  Then the child socket is locked, its state is set to `TCP_ESTABLISHED`, and some address structures are initialized.  Then, there's `vsock_assign_transport`, which is crucial. If this succeeds, and more importantly, the transport assigned to the child socket matches the transport of the original listening socket (`vchild->transport != &t->transport`), we proceed.

If all the conditions for a successful connection have been met, we see a sequence of calls: `vsock_insert_connected`, `vsock_enqueue_accept`, and `virtio_transport_send_response`. And the child socket is released using `release_sock(child)`.

This is where things get interesting.  We're adding the child socket to the accept queue with `vsock_enqueue_accept`. This is a vital point for the connection establishment. I'm trying to figure out if there's a corresponding increment of the reference count of the child socket that's placed on the accept queue. Is there some ref counting happening within `vsock_enqueue_accept`? That would be essential to ensure the socket isn't prematurely freed while it's in the accept queue. The code snippet doesn't explicitly show any increase or decrease in the reference count. Without that increase, if something were to happen after `release_sock` it would create an issue!

map[ContextFile:net/vmw_vsock/af_vsock.c IncludeLines:true Name:vsock_enqueue_accept]

map[SourceCode: 499:	void vsock_enqueue_accept(struct sock *listener, struct sock *connected)
 500:	{
 501:		struct vsock_sock *vlistener;
 502:		struct vsock_sock *vconnected;
 503:	
 504:		vlistener = vsock_sk(listener);
 505:		vconnected = vsock_sk(connected);
 506:	
 507:		sock_hold(connected);
 508:		sock_hold(listener);
 509:		list_add_tail(&vconnected->accept_queue, &vlistener->accept_queue);
 510:	}
 SourceFile:net/vmw_vsock/af_vsock.c]

gemini-3.1-pro-preview

							input: 37469
							output: 49
							thoughts: 142
						

**Debugging a Possible Socket Leak**

Okay, let's break this down. My initial observation is that `vsock_enqueue_accept` calls `sock_hold(connected)`. This bumps the `sk_refcnt` of the socket to 2. However, if `vsock_enqueue_accept` doesn't get called (we hit an error instead), `sk_refcnt` stays at 1. Then, `sock_put(child)` should decrement it back to 0, and the socket gets freed. But wait, what happens if `vsock_assign_transport` fails? Same deal, `sock_put(child)` should drive the `sk_refcnt` to 0, releasing the resource. So, why am I seeing a leak? Time to investigate `vsock_insert_connected(vchild)`. That's where the problem is.

map[ContextFile:net/vmw_vsock/af_vsock.c IncludeLines:true Name:vsock_insert_connected]

map[SourceCode: 348:	void vsock_insert_connected(struct vsock_sock *vsk)
 349:	{
 350:		struct list_head *list = vsock_connected_sockets(
 351:			&vsk->remote_addr, &vsk->local_addr);
 352:	
 353:		spin_lock_bh(&vsock_table_lock);
 354:		__vsock_insert_connected(list, vsk);
 355:		spin_unlock_bh(&vsock_table_lock);
 356:	}
 SourceFile:net/vmw_vsock/af_vsock.c]

gemini-3.1-pro-preview

							input: 38036
							output: 50
							thoughts: 18
						

Okay, here's my interpretation of that thought process, from an expert's perspective:

**Diving Deep into vsock Connection Management**

Alright, let's get down to the nitty-gritty. I'm thinking about the low-level socket operations, specifically the virtual socket (vsock) implementation. My immediate concern is with the `__vsock_insert_connected` function. It's a critical piece within the vsock connection establishment procedure. The question burning in my mind is this: does this function, as its name suggests, correctly increment the socket's reference count (`sk_refcnt`) when handling a connected socket?

Why this is so critical? Because a missing increment here would be a *huge* problem. A failure to increase the reference count at the correct time in the connection establishment flow could lead to premature deallocation of the socket structure. That would inevitably lead to all sorts of nasty consequences: use-after-free vulnerabilities, corrupting kernel memory, system crashes... you name it. I'd expect it to increase the reference to the socket in order to prevent it from being freed before the connection is properly established and resources allocated. So, I need to check the code, and be sure.

map[ContextFile:net/vmw_vsock/af_vsock.c IncludeLines:true Name:__vsock_insert_connected]

map[SourceCode: 280:	static void __vsock_insert_connected(struct list_head *list,
 281:					     struct vsock_sock *vsk)
 282:	{
 283:		sock_hold(&vsk->sk);
 284:		list_add(&vsk->connected_table, list);
 285:	}
 SourceFile:net/vmw_vsock/af_vsock.c]

gemini-3.1-pro-preview

							input: 38492
							output: 51
							thoughts: 900
						

**Debugging a Potential vsock Memory Leak**

Okay, let's break this down. My initial thought was that `__vsock_insert_connected` increments `sk_refcnt` to 2 with `sock_hold(&vsk->sk)`. But the error path doesn't call that, so `sk_refcnt` should be 1, and `sock_put` should drop it to 0. So, why the leak? I need to dig deeper.

Aha! `vsock_assign_transport`. I need to re-examine this code block:

```c
	if (vsk->transport) {
		/* transport->release() must be called with sock lock acquired.
		 * This path can only be taken during vsock_connect(), where we
		 * have already held the sock lock. In the other cases, this
		 * function is called on a new socket which is not assigned to
		 * any transport.
		 */
		vsk->transport->release(vsk);
		vsock_deassign_transport(vsk);

		/* transport's release() and destruct() can touch some socket
		 * state, since we are reassigning the socket to a new transport
		 * during vsock_connect(), let's reset these fields to have a
		 * clean state.
		 */
		sock_reset_flag(sk, SOCK_DONE);
		sk->sk_state = TCP_CLOSE;
		vsk->peer_shutdown = 0;
	}
```

Wait, `vsock_assign_transport` is called with `vchild` and `vsk`. `vchild` is a *new* socket, so does it already have a `transport` set? No, I quickly verified that `__vsock_create` sets `vsk->transport = NULL` via `sk_alloc` with `__GFP_ZERO`.

Now, what if `vsock_assign_transport` *fails*? I remember this part:

```c
	ret = new_transport->init(vsk, psk);
	if (ret) {
		module_put(new_transport->module);
		return ret;
	}
```

If `new_transport->init` fails, it returns. But... what if `new_transport->init` *succeeds*, but then `vchild->transport != &t->transport`? The code then runs this logic:

```c
	ret = vsock_assign_transport(vchild, vsk);
	/* Transport assigned (looking at remote_addr) must be the same
	 * where we received the request.
	 */
	if (ret || vchild->transport != &t->transport) {
		release_sock(child);
		virtio_transport_reset_no_sock(t, skb, sock_net(sk));
		sock_put(child);
		return ret;
	}
```

That's the key! If the transports don't match, `sock_put(child)` *is* called. That means the `new_transport` wasn't `&t->transport`. It was, for example, `transport_local` or `transport_g2h`. In this situation, the `vchild->transport` gets set to `transport_local`, and we then call `sock_put(child)`. This drops the refcount to zero, which calls `sk_free`. `sk_free` then invokes `__sk_free`, which calls `sk_destruct`. And finally, `sk_destruct` calls `vsock_sk_destruct`, which then calls `vsock_deassign_transport` that does the heavy work. `vsock_deassign_transport` in turn calls `vsk->transport->destruct(vsk)`. In the case of `transport_local`, the `destruct` function is `virtio_transport_destruct`.

Ok, now I am on the right track. `transport_local` uses the loopback driver, so let's look at `vsock_loopback_transport`.

requested entity does not exist

map[ContextFile:net/vmw_vsock/vsock_loopback.c IncludeLines:true Name:vsock_loopback_transport]

map[SourceCode: SourceFile:]

gemini-3.1-pro-preview

							input: 40371
							output: 22
							thoughts: 11
						

Okay, here's my interpretation of that thought process, tailored for an expert audience, and written in the first person:

**Initial Investigation: The Search for `loopback_transport`**

Alright, so the immediate inclination is to dive into the problem by searching for `loopback_transport`. This suggests a potential area of concern or debugging, and my experience tells me that such a term usually references, or is at least *involved* in, some internal communication or data routing mechanism. It's a fairly specific term, so it's likely we're looking at something relatively niche, perhaps within a networking context, an inter-process communication system, or even something related to virtualization or testing setups. The key question is, *what* is using that transport and *why* am I even thinking about it at this moment? Knowing the context of the problem is paramount for understanding what to do next. Let's see what turns up.

no matches

map[Expression:struct vsock_transport.*loopback]

map[Output:]

gemini-3.1-pro-preview

							input: 40614
							output: 17
							thoughts: 10
						

Okay, here's my interpretation of that thought process, tailored for an expert audience, and written in the first person:

**Initial Investigation: "transport\_local"**

Alright, I see we're starting with `transport_local`. My immediate thought is, "Okay, this suggests a focus on some form of local transportation, likely within a specific system or context." This could be a module name, a variable, a function name, or even a configuration setting. My mind's already racing, considering the various domains this could apply to – is it related to logistics, containerization, networking, resource allocation, or something else entirely? The specificity implied by "local" makes me anticipate a limited scope, maybe an internal system component or a development environment configuration. Let's see what the search yields. I'm expecting a specific, rather than broad, result set.

map[Expression:transport_local]

map[Output:net/vmw_vsock/af_vsock.c=208=static const struct vsock_transport *transport_dgram;
net/vmw_vsock/af_vsock.c-209-/* Transport used for local communication */
net/vmw_vsock/af_vsock.c:210:static const struct vsock_transport *transport_local;
net/vmw_vsock/af_vsock.c-211-static DEFINE_MUTEX(vsock_register_mutex);
--
net/vmw_vsock/af_vsock.c=513=static bool vsock_use_local_transport(unsigned int remote_cid)
--
net/vmw_vsock/af_vsock.c-516-
net/vmw_vsock/af_vsock.c:517:	if (!transport_local)
net/vmw_vsock/af_vsock.c-518-		return false;
--
net/vmw_vsock/af_vsock.c=552=int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk)
--
net/vmw_vsock/af_vsock.c-582-		if (vsock_use_local_transport(remote_cid))
net/vmw_vsock/af_vsock.c:583:			new_transport = transport_local;
net/vmw_vsock/af_vsock.c-584-		else if (remote_cid <= VMADDR_CID_HOST || !transport_h2g ||
--
net/vmw_vsock/af_vsock.c=673=bool vsock_find_cid(unsigned int cid)
--
net/vmw_vsock/af_vsock.c-680-
net/vmw_vsock/af_vsock.c:681:	if (transport_local && cid == VMADDR_CID_LOCAL)
net/vmw_vsock/af_vsock.c-682-		return true;
--
net/vmw_vsock/af_vsock.c=2713=static long vsock_dev_do_ioctl(struct file *filp,
--
net/vmw_vsock/af_vsock.c-2728-		if (cid == VMADDR_CID_ANY)
net/vmw_vsock/af_vsock.c:2729:			cid = vsock_registered_transport_cid(&transport_local);
net/vmw_vsock/af_vsock.c-2730-
--
net/vmw_vsock/af_vsock.c=3013=int vsock_core_register(const struct vsock_transport *t, int features)
--
net/vmw_vsock/af_vsock.c-3023-	t_dgram = transport_dgram;
net/vmw_vsock/af_vsock.c:3024:	t_local = transport_local;
net/vmw_vsock/af_vsock.c-3025-
--
net/vmw_vsock/af_vsock.c-3060-	transport_dgram = t_dgram;
net/vmw_vsock/af_vsock.c:3061:	transport_local = t_local;
net/vmw_vsock/af_vsock.c-3062-
--
net/vmw_vsock/af_vsock.c=3069=void vsock_core_unregister(const struct vsock_transport *t)
--
net/vmw_vsock/af_vsock.c-3081-
net/vmw_vsock/af_vsock.c:3082:	if (transport_local == t)
net/vmw_vsock/af_vsock.c:3083:		transport_local = NULL;
net/vmw_vsock/af_vsock.c-3084-
]

gemini-3.1-pro-preview

							input: 41834
							output: 49
							thoughts: 12
						

Okay, let's dive into this. Here's my take on `vsock_core_register`, from the perspective of an expert:

**Delving into `vsock_core_register`**

Alright, so the task at hand is to analyze `vsock_core_register`. My initial thought is to immediately zoom in on its role within the broader vsock architecture. What is its exact function, and where does it fit into the bigger picture? I'm already anticipating questions about its purpose: is it for driver registration, endpoint binding, resource allocation, or something else entirely?

My experience tells me this will likely be a core function, probably responsible for initializing or making available the essential vsock core components. I'll need to look at its arguments. What data structures does it accept? Are there callbacks involved for handling incoming connections or data? Are there checks for resource availability, error conditions, and permission issues? Given my understanding of similar socket implementations, I’m mentally checking off potential responsibilities:

*   **Initialization:** What specific structures or modules are initialized here?
*   **Binding:** Does this function associate a vsock instance with a specific port or address family?
*   **Registration:** Is this the primary entry point for a new vsock instance, or is it part of a larger registration process?
*   **Callback:** Which are the callbacks for connection management or data transmission? How the data is delivered.
*   **Context:** Does the function configure context-specific parameters or create context objects for vsock operation?

I also need to immediately consider potential pitfalls. What are the likely race conditions? What locking mechanisms are in place (or *should* be in place) to protect shared resources? Are there any potential security vulnerabilities, like unchecked user input or insufficient access controls?

I’m already forming a mental checklist of related functions and data structures I'll need to explore next. `vsock_core_unregister`, `vsock_sendmsg`, `vsock_recvmsg`, and the various vsock socket structures and address families are likely candidates. The goal is to develop a robust understanding of the whole vsock framework, so the examination of `vsock_core_register` will be the foundation to begin.

map[ContextFile:net/vmw_vsock/af_vsock.c IncludeLines:true Name:vsock_core_register]

map[SourceCode:3013:	int vsock_core_register(const struct vsock_transport *t, int features)
3014:	{
3015:		const struct vsock_transport *t_h2g, *t_g2h, *t_dgram, *t_local;
3016:		int err = mutex_lock_interruptible(&vsock_register_mutex);
3017:	
3018:		if (err)
3019:			return err;
3020:	
3021:		t_h2g = transport_h2g;
3022:		t_g2h = transport_g2h;
3023:		t_dgram = transport_dgram;
3024:		t_local = transport_local;
3025:	
3026:		if (features & VSOCK_TRANSPORT_F_H2G) {
3027:			if (t_h2g) {
3028:				err = -EBUSY;
3029:				goto err_busy;
3030:			}
3031:			t_h2g = t;
3032:		}
3033:	
3034:		if (features & VSOCK_TRANSPORT_F_G2H) {
3035:			if (t_g2h) {
3036:				err = -EBUSY;
3037:				goto err_busy;
3038:			}
3039:			t_g2h = t;
3040:		}
3041:	
3042:		if (features & VSOCK_TRANSPORT_F_DGRAM) {
3043:			if (t_dgram) {
3044:				err = -EBUSY;
3045:				goto err_busy;
3046:			}
3047:			t_dgram = t;
3048:		}
3049:	
3050:		if (features & VSOCK_TRANSPORT_F_LOCAL) {
3051:			if (t_local) {
3052:				err = -EBUSY;
3053:				goto err_busy;
3054:			}
3055:			t_local = t;
3056:		}
3057:	
3058:		transport_h2g = t_h2g;
3059:		transport_g2h = t_g2h;
3060:		transport_dgram = t_dgram;
3061:		transport_local = t_local;
3062:	
3063:	err_busy:
3064:		mutex_unlock(&vsock_register_mutex);
3065:		return err;
3066:	}
 SourceFile:net/vmw_vsock/af_vsock.c]

gemini-3.1-pro-preview

							input: 43138
							output: 22
							thoughts: 13
						

**VSOCK Transport Flag Registration - A Quick Query**

Alright, so I'm thinking about this `VSOCK_TRANSPORT_F_LOCAL` flag. It's a key piece of the VSOCK puzzle, obviously, and I need to solidify my understanding of it. The real question that's bubbling up right now is: *who* actually registers that flag? Where in the system is that critical bit set? I need to understand the connection between the various components here - which driver, which subsystem, which module – does the work to declare that this transport supports local connections?

Knowing this will really help me determine the implications and understand the potential issues surrounding local VSOCK connections, and how they interact within the larger hypervisor-guest architecture that is in play. I am looking for the component, the function, the process – whatever the key to determining the component that takes responsibility for this. The documentation seems to be lacking the level of detail I need, so I will need to delve deeper.

map[Expression:VSOCK_TRANSPORT_F_LOCAL]

map[Output:include/net/af_vsock.h=93=struct vsock_transport_send_notify_data {
--
include/net/af_vsock.h-105-/* Transport provides local (loopback) communication */
include/net/af_vsock.h:106:#define VSOCK_TRANSPORT_F_LOCAL		0x00000008
include/net/af_vsock.h-107-
--
net/vmw_vsock/af_vsock.c=3013=int vsock_core_register(const struct vsock_transport *t, int features)
--
net/vmw_vsock/af_vsock.c-3049-
net/vmw_vsock/af_vsock.c:3050:	if (features & VSOCK_TRANSPORT_F_LOCAL) {
net/vmw_vsock/af_vsock.c-3051-		if (t_local) {
--
net/vmw_vsock/vsock_loopback.c=147=static int __init vsock_loopback_init(void)
--
net/vmw_vsock/vsock_loopback.c-159-	ret = vsock_core_register(&loopback_transport.transport,
net/vmw_vsock/vsock_loopback.c:160:				  VSOCK_TRANSPORT_F_LOCAL);
net/vmw_vsock/vsock_loopback.c-161-	if (ret)
]

gemini-3.1-pro-preview

							input: 43764
							output: 48
							thoughts: 29
						

Okay, here's my interpretation of those thoughts, presented as a first-person summary, keeping in mind my expertise:

**Diving into vsock_loopback.c and loopback_transport**

Alright, let's take a look at this `vsock_loopback.c` file. It appears to be registering `loopback_transport`. Interesting. My initial expectation is that this is how a virtual socket (vsock) implements a local communication path, likely within the same host or VM. The very name, `loopback_transport`, is telling; it suggests a mechanism for directing vsock traffic back onto itself. I'll need to examine the details within `loopback_transport` to understand the low-level data flow and how this registration fits within the overall vsock architecture. I expect to find some optimizations, bypassing networking stack overhead given that the communication is local. I'm keen to dissect this further!

map[ContextFile:net/vmw_vsock/vsock_loopback.c IncludeLines:true Name:loopback_transport]

map[SourceCode:  63:	static struct virtio_transport loopback_transport = {
  64:		.transport = {
  65:			.module                   = THIS_MODULE,
  66:	
  67:			.get_local_cid            = vsock_loopback_get_local_cid,
  68:	
  69:			.init                     = virtio_transport_do_socket_init,
  70:			.destruct                 = virtio_transport_destruct,
  71:			.release                  = virtio_transport_release,
  72:			.connect                  = virtio_transport_connect,
  73:			.shutdown                 = virtio_transport_shutdown,
  74:			.cancel_pkt               = vsock_loopback_cancel_pkt,
  75:	
  76:			.dgram_bind               = virtio_transport_dgram_bind,
  77:			.dgram_dequeue            = virtio_transport_dgram_dequeue,
  78:			.dgram_enqueue            = virtio_transport_dgram_enqueue,
  79:			.dgram_allow              = virtio_transport_dgram_allow,
  80:	
  81:			.stream_dequeue           = virtio_transport_stream_dequeue,
  82:			.stream_enqueue           = virtio_transport_stream_enqueue,
  83:			.stream_has_data          = virtio_transport_stream_has_data,
  84:			.stream_has_space         = virtio_transport_stream_has_space,
  85:			.stream_rcvhiwat          = virtio_transport_stream_rcvhiwat,
  86:			.stream_is_active         = virtio_transport_stream_is_active,
  87:			.stream_allow             = vsock_loopback_stream_allow,
  88:	
  89:			.seqpacket_dequeue        = virtio_transport_seqpacket_dequeue,
  90:			.seqpacket_enqueue        = virtio_transport_seqpacket_enqueue,
  91:			.seqpacket_allow          = vsock_loopback_seqpacket_allow,
  92:			.seqpacket_has_data       = virtio_transport_seqpacket_has_data,
  93:	
  94:			.msgzerocopy_allow        = vsock_loopback_msgzerocopy_allow,
  95:	
  96:			.notify_poll_in           = virtio_transport_notify_poll_in,
  97:			.notify_poll_out          = virtio_transport_notify_poll_out,
  98:			.notify_recv_init         = virtio_transport_notify_recv_init,
  99:			.notify_recv_pre_block    = virtio_transport_notify_recv_pre_block,
 100:			.notify_recv_pre_dequeue  = virtio_transport_notify_recv_pre_dequeue,
 101:			.notify_recv_post_dequeue = virtio_transport_notify_recv_post_dequeue,
 102:			.notify_send_init         = virtio_transport_notify_send_init,
 103:			.notify_send_pre_block    = virtio_transport_notify_send_pre_block,
 104:			.notify_send_pre_enqueue  = virtio_transport_notify_send_pre_enqueue,
 105:			.notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue,
 106:			.notify_buffer_size       = virtio_transport_notify_buffer_size,
 107:			.notify_set_rcvlowat      = virtio_transport_notify_set_rcvlowat,
 108:	
 109:			.unsent_bytes             = virtio_transport_unsent_bytes,
 110:	
 111:			.read_skb = virtio_transport_read_skb,
 112:		},
 113:	
 114:		.send_pkt = vsock_loopback_send_pkt,
 115:	};
 SourceFile:net/vmw_vsock/vsock_loopback.c]

gemini-3.1-pro-preview

							input: 45123
							output: 53
							thoughts: 1112
						

**Debugging a Potential vsock Memory Leak**

Okay, let's break this down. I'm looking at the `virtio_transport_recv_listen` function and trying to understand a possible memory leak in vsock. The core of the problem seems to be the comparison `vchild->transport != &t->transport`.

Initially, I thought, if the transport is `loopback_transport`, then `vchild->transport` *should* equal `&t->transport` because `t` would be `loopback_transport` and `vchild->transport` is the `loopback_transport` transport.  So, if the packet is loopback, they *should* be equal.  But what if `t` is `vhost_transport`? Then the transport pointers won't match, and the code calls `sock_put(child)`. That should *deallocate* the child socket.

Tracing through `sock_put`, I see the expected path:  `sock_put` decrements the reference count, leading to `sk_free`, which calls `sk_destruct`, then `vsock_sk_destruct`, which *should* call `virtio_transport_destruct`.  `virtio_transport_destruct` frees the transport-specific data. It *should* all be cleaned up. So I can't find a leak here.  I thought I found one.  But the code does the right thing.

Then, wait a minute, there's `vsock_assign_transport`. If it's called on a *new* socket, it doesn't have an existing transport, so there's no `release` call. But what if it *fails*? If `new_transport->init` returns an error, `vchild->transport` is set to NULL.  So there is no leak, still.

So, even if `vsock_assign_transport` fails, the `child` socket is correctly cleaned up, there is no leak. I'm missing something, still.

So, where is `sk_wmem_alloc` incremented? I need to check how the memory is actually allocated in the first place... Let's look at `virtio_transport_space_update` and see if that is the answer.

map[ContextFile:net/vmw_vsock/virtio_transport_common.c IncludeLines:true Name:virtio_transport_space_update]

map[SourceCode:1503:	static bool virtio_transport_space_update(struct sock *sk,
1504:						  struct sk_buff *skb)
1505:	{
1506:		struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
1507:		struct vsock_sock *vsk = vsock_sk(sk);
1508:		struct virtio_vsock_sock *vvs = vsk->trans;
1509:		bool space_available;
1510:	
1511:		/* Listener sockets are not associated with any transport, so we are
1512:		 * not able to take the state to see if there is space available in the
1513:		 * remote peer, but since they are only used to receive requests, we
1514:		 * can assume that there is always space available in the other peer.
1515:		 */
1516:		if (!vvs)
1517:			return true;
1518:	
1519:		/* buf_alloc and fwd_cnt is always included in the hdr */
1520:		spin_lock_bh(&vvs->tx_lock);
1521:		vvs->peer_buf_alloc = le32_to_cpu(hdr->buf_alloc);
1522:		vvs->peer_fwd_cnt = le32_to_cpu(hdr->fwd_cnt);
1523:		space_available = virtio_transport_has_space(vvs);
1524:		spin_unlock_bh(&vvs->tx_lock);
1525:		return space_available;
1526:	}
 SourceFile:net/vmw_vsock/virtio_transport_common.c]

gemini-3.1-pro-preview

							input: 47253
							output: 39
							thoughts: 192
						

**Analyzing Potential Reference Count Issues in Virtio vsock Connection Establishment**

Okay, hold on a second, no, that doesn't seem right. Wait a minute, what if the `sk_refcnt` is actually incremented somewhere? Let's trace this through. Okay, in `virtio_transport_recv_listen`…  I see it creates a new socket using `vsock_create_connected`, and then it checks if the new socket was successfully created. Okay, that looks fine. But then, *aha!* Here's something interesting: `sk_acceptq_added(sk)` and then `lock_sock_nested(child, SINGLE_DEPTH_NESTING)`.

Wait, wait, *that* call to `lock_sock_nested`! Does `lock_sock` increment the `sk_refcnt`? No, I don't think so, but I need to make sure. Does it do *something* else that could impact the lifecycle? Hang on, there's `release_sock(child)` further down.  Okay, so `release_sock` has to be considered. Does `release_sock` do something that might be connected with this? Let's check `release_sock`.

map[ContextFile:net/core/sock.c IncludeLines:true Name:release_sock]

map[SourceCode:3791:	void release_sock(struct sock *sk)
3792:	{
3793:		spin_lock_bh(&sk->sk_lock.slock);
3794:		if (sk->sk_backlog.tail)
3795:			__release_sock(sk);
3796:	
3797:		if (sk->sk_prot->release_cb)
3798:			INDIRECT_CALL_INET_1(sk->sk_prot->release_cb,
3799:					     tcp_release_cb, sk);
3800:	
3801:		sock_release_ownership(sk);
3802:		if (waitqueue_active(&sk->sk_lock.wq))
3803:			wake_up(&sk->sk_lock.wq);
3804:		spin_unlock_bh(&sk->sk_lock.slock);
3805:	}
 SourceFile:net/core/sock.c]

gemini-3.1-pro-preview

							input: 48019
							output: 49
							thoughts: 222
						

**Investigating a Potential Socket Leak**

Okay, so I'm diving into this code, and something's bugging me. I see `release_sock` being called, and I remember that function specifically handles processing the backlog, right? Specifically, if `sk->sk_backlog.tail` isn't null, it's going to call `__release_sock(sk)`. But... this `child` socket we're dealing with here, it's a newly created one. It shouldn't *have* anything in its backlog. That just doesn't make sense.

Hold on... *here* it is. In `virtio_transport_recv_listen`, there's this conditional check:

```c
	if (ret || vchild->transport != &t->transport) {
		release_sock(child);
		virtio_transport_reset_no_sock(t, skb, sock_net(sk));
		sock_put(child);
		return ret;
	}
```

Okay, if `vchild->transport != &t->transport`, we call `release_sock(child)` AND then `sock_put(child)`. But wait, is there a potential leak here? Is the *refcount* of `child` possibly not zero? Because if it isn't zero after that, then the socket isn't actually freed, it would only be *released*. And *that* would be bad. It would imply a leak.

Why would the refcount not be zero after `release_sock` and `sock_put`? I need to check the socket creation path – specifically, `vsock_create_connected` – to understand how the reference count is initially set and how it's handled. I need to track down why the socket isn't properly released.

map[ContextFile:net/vmw_vsock/af_vsock.c IncludeLines:true Name:vsock_create_connected]

map[SourceCode:1023:	struct sock *vsock_create_connected(struct sock *parent)
1024:	{
1025:		return __vsock_create(sock_net(parent), NULL, parent, GFP_KERNEL,
1026:				      parent->sk_type, 0);
1027:	}
 SourceFile:net/vmw_vsock/af_vsock.c]

gemini-3.1-pro-preview

							input: 48805
							output: 49
							thoughts: 273
						

**My Analysis of VSock Socket Creation**

Okay, so I'm diving into the `__vsock_create` function, and it immediately calls `sk_alloc`. Right, `sk_alloc` initializes the socket's reference count, `sk_refcnt`, to 1. That's standard socket management.

Now, looking at the code within `__vsock_create`, after potentially setting the parent VSock, it gets interesting. If a parent socket exists, it copies a bunch of properties:  `trusted`, the owner's credentials, the connect timeout and the buffer size parameters. But then, there's that `security_sk_clone(parent, sk)` call.

Hold on... I need to make sure I understand this ref count business, particularly since it seems like we *are not* incrementing the reference count in `security_sk_clone`. Hmm, is `sk_refcnt` ever 2? Let me make sure that it shouldn't be. 

Alright, so if `sock_put(child)` gets called, but `sk_refcnt` is 2, there is a problem. Where does the count go up? 

Let's check `vsock_assign_transport`.

map[ContextFile:net/vmw_vsock/af_vsock.c IncludeLines:true Name:vsock_assign_transport]

map[SourceCode: 540:	/* Assign a transport to a socket and call the .init transport callback.
 541:	 *
 542:	 * Note: for connection oriented socket this must be called when vsk->remote_addr
 543:	 * is set (e.g. during the connect() or when a connection request on a listener
 544:	 * socket is received).
 545:	 * The vsk->remote_addr is used to decide which transport to use:
 546:	 *  - remote CID == VMADDR_CID_LOCAL or g2h->local_cid or VMADDR_CID_HOST if
 547:	 *    g2h is not loaded, will use local transport;
 548:	 *  - remote CID <= VMADDR_CID_HOST or h2g is not loaded or remote flags field
 549:	 *    includes VMADDR_FLAG_TO_HOST flag value, will use guest->host transport;
 550:	 *  - remote CID > VMADDR_CID_HOST will use host->guest transport;
 551:	 */
 552:	int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk)
 553:	{
 554:		const struct vsock_transport *new_transport;
 555:		struct sock *sk = sk_vsock(vsk);
 556:		unsigned int remote_cid = vsk->remote_addr.svm_cid;
 557:		__u8 remote_flags;
 558:		int ret;
 559:	
 560:		/* If the packet is coming with the source and destination CIDs higher
 561:		 * than VMADDR_CID_HOST, then a vsock channel where all the packets are
 562:		 * forwarded to the host should be established. Then the host will
 563:		 * need to forward the packets to the guest.
 564:		 *
 565:		 * The flag is set on the (listen) receive path (psk is not NULL). On
 566:		 * the connect path the flag can be set by the user space application.
 567:		 */
 568:		if (psk && vsk->local_addr.svm_cid > VMADDR_CID_HOST &&
 569:		    vsk->remote_addr.svm_cid > VMADDR_CID_HOST)
 570:			vsk->remote_addr.svm_flags |= VMADDR_FLAG_TO_HOST;
 571:	
 572:		remote_flags = vsk->remote_addr.svm_flags;
 573:	
 574:		mutex_lock(&vsock_register_mutex);
 575:	
 576:		switch (sk->sk_type) {
 577:		case SOCK_DGRAM:
 578:			new_transport = transport_dgram;
 579:			break;
 580:		case SOCK_STREAM:
 581:		case SOCK_SEQPACKET:
 582:			if (vsock_use_local_transport(remote_cid))
 583:				new_transport = transport_local;
 584:			else if (remote_cid <= VMADDR_CID_HOST || !transport_h2g ||
 585:				 (remote_flags & VMADDR_FLAG_TO_HOST))
 586:				new_transport = transport_g2h;
 587:			else
 588:				new_transport = transport_h2g;
 589:			break;
 590:		default:
 591:			ret = -ESOCKTNOSUPPORT;
 592:			goto err;
 593:		}
 594:	
 595:		if (vsk->transport && vsk->transport == new_transport) {
 596:			ret = 0;
 597:			goto err;
 598:		}
 599:	
 600:		/* We increase the module refcnt to prevent the transport unloading
 601:		 * while there are open sockets assigned to it.
 602:		 */
 603:		if (!new_transport || !try_module_get(new_transport->module)) {
 604:			ret = -ENODEV;
 605:			goto err;
 606:		}
 607:	
 608:		/* It's safe to release the mutex after a successful try_module_get().
 609:		 * Whichever transport `new_transport` points at, it won't go away until
 610:		 * the last module_put() below or in vsock_deassign_transport().
 611:		 */
 612:		mutex_unlock(&vsock_register_mutex);
 613:	
 614:		if (vsk->transport) {
 615:			/* transport->release() must be called with sock lock acquired.
 616:			 * This path can only be taken during vsock_connect(), where we
 617:			 * have already held the sock lock. In the other cases, this
 618:			 * function is called on a new socket which is not assigned to
 619:			 * any transport.
 620:			 */
 621:			vsk->transport->release(vsk);
 622:			vsock_deassign_transport(vsk);
 623:	
 624:			/* transport's release() and destruct() can touch some socket
 625:			 * state, since we are reassigning the socket to a new transport
 626:			 * during vsock_connect(), let's reset these fields to have a
 627:			 * clean state.
 628:			 */
 629:			sock_reset_flag(sk, SOCK_DONE);
 630:			sk->sk_state = TCP_CLOSE;
 631:			vsk->peer_shutdown = 0;
 632:		}
 633:	
 634:		if (sk->sk_type == SOCK_SEQPACKET) {
 635:			if (!new_transport->seqpacket_allow ||
 636:			    !new_transport->seqpacket_allow(vsk, remote_cid)) {
 637:				module_put(new_transport->module);
 638:				return -ESOCKTNOSUPPORT;
 639:			}
 640:		}
 641:	
 642:		ret = new_transport->init(vsk, psk);
 643:		if (ret) {
 644:			module_put(new_transport->module);
 645:			return ret;
 646:		}
 647:	
 648:		vsk->transport = new_transport;
 649:	
 650:		return 0;
 651:	err:
 652:		mutex_unlock(&vsock_register_mutex);
 653:		return ret;
 654:	}
 SourceFile:net/vmw_vsock/af_vsock.c]

gemini-3.1-pro-preview

							input: 51259
							output: 49
							thoughts: 725
						

**Debugging a Potential Socket Leak**

Okay, let's break this down. It seems we're tracking down a potential socket leak, specifically in the vsock subsystem. The initial clue is in the error messages related to `sk_prot_alloc`, `lsm_blob_alloc`, and `virtio_transport_do_socket_init`. Those error messages point to *something* being leaked, likely the 'child' socket.

My first thought, tracing the code, is this. If `new_transport->init` fails, `module_put(new_transport->module)` will be called, so the `transport` initialization path is okay. Now, let's consider what happens in `vsock_assign_transport`. What if it succeeds, but the `vchild->transport` pointer doesn't match the expected `&t->transport`? `virtio_transport_recv_listen` does this:

```c
	if (ret || vchild->transport != &t->transport) {
		release_sock(child);
		virtio_transport_reset_no_sock(t, skb, sock_net(sk));
		sock_put(child);
		return ret;
	}
```

Wait, `release_sock(child)` is being called! Does that increment the socket refcount? No, it doesn't. Does it call `__release_sock(sk)`? Ah, yes, it does. But only if `sk->sk_backlog.tail` is not NULL. The thing is, this `child` socket is newly created, so its backlog *should* be empty. But, what if it's not? How could it *not* be empty? It's a brand new socket, not in a hash table! Nobody can find it to add to its backlog, so that's a dead end.

I'm thinking about the flow in `virtio_transport_recv_listen` and how the socket is handled.

```c
	child = vsock_create_connected(sk);
	if (!child) {
		virtio_transport_reset_no_sock(t, skb, sock_net(sk));
		return -ENOMEM;
	}

	sk_acceptq_added(sk);

	lock_sock_nested(child, SINGLE_DEPTH_NESTING);
```

Okay, `sk_acceptq_added(sk)` *does* increment `sk->sk_ack_backlog`. If we hit an error and return, we don't decrement that value. But wait, that's not the root cause! The bug report mentions `sk_prot_alloc` and friends, which strongly suggests that the `child` socket itself is the leaked resource.

Why is the `child` being leaked? Let's trace it carefully. `sock_put(child)` drops the `sk_refcnt` from 1 to 0. Then `sk_free(child)` is called. This frees `sk_wmem_alloc`. After that, `__sk_free(child)` is called, which then calls `sk_destruct(child)`. This in turn calls `vsock_sk_destruct(child)`. Finally, `vsock_sk_destruct` calls `vsock_deassign_transport(vchild)`, which calls `vchild->transport->destruct(vchild)`. `virtio_transport_destruct` frees `vchild->trans`. Then, `sk_prot_free` frees the `child` socket.

So, *everything* is freed! Where's the leak? I can't see it, every piece seems to be handled correctly, and the lifecycle *should* be complete.
Wait!

Am I absolutely sure the initial `sk_refcnt` is 1? I need to go back and check `vsock_create_connected` to be certain. Perhaps I'm missing something fundamental there, maybe something *else* is incrementing that count, or the allocation *itself* is problematic. I need to re-examine that function and the surrounding context for any potential refcount issues. Let's go.

map[ContextFile:net/vmw_vsock/af_vsock.c IncludeLines:true Name:vsock_create_connected]

map[SourceCode:1023:	struct sock *vsock_create_connected(struct sock *parent)
1024:	{
1025:		return __vsock_create(sock_net(parent), NULL, parent, GFP_KERNEL,
1026:				      parent->sk_type, 0);
1027:	}
 SourceFile:net/vmw_vsock/af_vsock.c]

gemini-3.1-pro-preview

							input: 53059
							output: 42
							thoughts: 1893
						

**Analyzing a Potential Reference Count Leak in `vsock` Socket Creation**

Okay, let's break this down. My initial inspection shows the `vsock` socket creation sequence involving `sk_alloc`, `sock_init_data`, and then `__vsock_create`.  I'm focusing on potential reference count issues here. I see `sk_refcnt` is initialized and incremented, as expected. I'm noting the standard socket initialization including function pointers like `sk_destruct` and `sk_backlog_rcv` are assigned.

The use of `INIT_DELAYED_WORK` immediately caught my attention. It doesn't appear to directly increment the reference count, but it introduces a delayed operation, a potential point for something to go wrong. Then I'm on to looking at `vsock_assign_transport` and the subsequent call to `new_transport->init`. For the `virtio_transport`, this boils down to `virtio_transport_do_socket_init`. This allocates memory for the transport-specific structure, `vvs`, and sets up locks and queues.  Crucially, it *doesn't* appear to affect `sk_refcnt`.

Now, the code path in `virtio_transport_recv_listen` is key. I'm focusing on the condition where `vchild->transport != &t->transport`.  If this condition is met, there's a call to `sock_put(child)`. The function `sock_put` decreases `sk_refcnt`. If the refcount drops to zero, the socket gets freed. The flow seems correct: `release_sock` and `sock_put`. But I'm going through the implications of this.

If `vchild->transport != &t->transport`, `sock_put(child)` should free the socket. Now, if it isn't freed it is not because of a refcount problem. I'm going back to basics. I check if there are other incrementers.  `vsock_assign_transport` doesn't seem to increase the refcount, but calls a `release` function if it had been assigned before.  For a new socket, this won't happen.

However, if `vchild->transport != &t->transport`, `virtio_transport_reset_no_sock` does not operate on the socket. This condition means that the transport has been changed. But if they're not equal, `vsock_deassign_transport` is called.

If `vsock_assign_transport` fails, it returns `ret`. If `vsock_assign_transport` succeeds, it returns 0. If it fails, the socket is freed through `release_sock` and `sock_put`. So that path is okay. I look at if `vchild->transport` is NULL.

I go through the situation when `vchild->transport` is equal to `&t->transport`. In this case, I'd expect the socket to be used. But this doesn't lead to any reference count problems or frees on the socket, from what I'm seeing.

Going back to the crux: The bug report says `virtio_transport_do_socket_init` is leaked. This implies `vsock_assign_transport` succeeded, because the `init` function wasn't called otherwise. Then `vchild->transport != &t->transport` must be true.  So `vchild->transport` was assigned to something else. But if that's true, it would call a `release` function. But there's a call to `sock_put(child)` in this scenario.

I'm now focused on the implication that `vchild->transport` *does* get set to `new_transport`.  If they're not equal, and we call `sock_put`, then `vsock_deassign_transport` *will* be called, and it *will* call `vchild->transport->destruct(vchild)`. I'm going to look at what calls `virtio_transport_destruct`.

Given that all `virtio` transports use `virtio_transport_destruct`, and `vvs` is allocated in `virtio_transport_do_socket_init`, why is `vvs` leaked? This strongly suggests that `virtio_transport_destruct` isn't being called, or isn't actually freeing the allocated memory. I need to investigate the function `virtio_transport_destruct` and understand under what circumstances it *doesn't* free the `vvs` struct. This is my next step.

map[ContextFile:drivers/vhost/vsock.c IncludeLines:true Name:vhost_transport]

map[SourceCode: 422:	static struct virtio_transport vhost_transport = {
 423:		.transport = {
 424:			.module                   = THIS_MODULE,
 425:	
 426:			.get_local_cid            = vhost_transport_get_local_cid,
 427:	
 428:			.init                     = virtio_transport_do_socket_init,
 429:			.destruct                 = virtio_transport_destruct,
 430:			.release                  = virtio_transport_release,
 431:			.connect                  = virtio_transport_connect,
 432:			.shutdown                 = virtio_transport_shutdown,
 433:			.cancel_pkt               = vhost_transport_cancel_pkt,
 434:	
 435:			.dgram_enqueue            = virtio_transport_dgram_enqueue,
 436:			.dgram_dequeue            = virtio_transport_dgram_dequeue,
 437:			.dgram_bind               = virtio_transport_dgram_bind,
 438:			.dgram_allow              = virtio_transport_dgram_allow,
 439:	
 440:			.stream_enqueue           = virtio_transport_stream_enqueue,
 441:			.stream_dequeue           = virtio_transport_stream_dequeue,
 442:			.stream_has_data          = virtio_transport_stream_has_data,
 443:			.stream_has_space         = virtio_transport_stream_has_space,
 444:			.stream_rcvhiwat          = virtio_transport_stream_rcvhiwat,
 445:			.stream_is_active         = virtio_transport_stream_is_active,
 446:			.stream_allow             = vhost_transport_stream_allow,
 447:	
 448:			.seqpacket_dequeue        = virtio_transport_seqpacket_dequeue,
 449:			.seqpacket_enqueue        = virtio_transport_seqpacket_enqueue,
 450:			.seqpacket_allow          = vhost_transport_seqpacket_allow,
 451:			.seqpacket_has_data       = virtio_transport_seqpacket_has_data,
 452:	
 453:			.msgzerocopy_allow        = vhost_transport_msgzerocopy_allow,
 454:	
 455:			.notify_poll_in           = virtio_transport_notify_poll_in,
 456:			.notify_poll_out          = virtio_transport_notify_poll_out,
 457:			.notify_recv_init         = virtio_transport_notify_recv_init,
 458:			.notify_recv_pre_block    = virtio_transport_notify_recv_pre_block,
 459:			.notify_recv_pre_dequeue  = virtio_transport_notify_recv_pre_dequeue,
 460:			.notify_recv_post_dequeue = virtio_transport_notify_recv_post_dequeue,
 461:			.notify_send_init         = virtio_transport_notify_send_init,
 462:			.notify_send_pre_block    = virtio_transport_notify_send_pre_block,
 463:			.notify_send_pre_enqueue  = virtio_transport_notify_send_pre_enqueue,
 464:			.notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue,
 465:			.notify_buffer_size       = virtio_transport_notify_buffer_size,
 466:			.notify_set_rcvlowat      = virtio_transport_notify_set_rcvlowat,
 467:	
 468:			.unsent_bytes             = virtio_transport_unsent_bytes,
 469:	
 470:			.read_skb = virtio_transport_read_skb,
 471:		},
 472:	
 473:		.send_pkt = vhost_transport_send_pkt,
 474:	};
 SourceFile:drivers/vhost/vsock.c]

gemini-3.1-pro-preview

							input: 57103
							output: 55
							thoughts: 111
						

**Debugging a `vvs` Leak in Virtio Transport**

Okay, so I've been tracing through this code, and it seems like every path eventually leads to a call to `virtio_transport_destruct`. That's good – I expected that. So, `virtio_transport_destruct` *is* being called, which should mean that the `vvs` structure is being freed. But we're still seeing a leak of `vvs` in the end. This doesn't make any sense. If `virtio_transport_destruct` frees it, how can it be leaking?

Wait a minute... could it be something related to the socket memory allocation? I'm wondering if the `sk_wmem_alloc` value isn't zero when it should be. Perhaps there's a scenario where memory isn't fully released? That would explain why `vvs` would be reported as leaked even after `virtio_transport_destruct` has been called. The question is, *why* would `sk_wmem_alloc` not be zero?

Alright, time to go back and investigate `virtio_transport_do_socket_init`. That's where the socket is initialized, so the issue must be related to that area. Let's see if something is going wrong there.

map[ContextFile:net/vmw_vsock/virtio_transport_common.c IncludeLines:true Name:virtio_transport_do_socket_init]

map[SourceCode: 918:	int virtio_transport_do_socket_init(struct vsock_sock *vsk,
 919:					    struct vsock_sock *psk)
 920:	{
 921:		struct virtio_vsock_sock *vvs;
 922:	
 923:		vvs = kzalloc_obj(*vvs);
 924:		if (!vvs)
 925:			return -ENOMEM;
 926:	
 927:		vsk->trans = vvs;
 928:		vvs->vsk = vsk;
 929:		if (psk && psk->trans) {
 930:			struct virtio_vsock_sock *ptrans = psk->trans;
 931:	
 932:			vvs->peer_buf_alloc = ptrans->peer_buf_alloc;
 933:		}
 934:	
 935:		if (vsk->buffer_size > VIRTIO_VSOCK_MAX_BUF_SIZE)
 936:			vsk->buffer_size = VIRTIO_VSOCK_MAX_BUF_SIZE;
 937:	
 938:		vvs->buf_alloc = vsk->buffer_size;
 939:	
 940:		spin_lock_init(&vvs->rx_lock);
 941:		spin_lock_init(&vvs->tx_lock);
 942:		skb_queue_head_init(&vvs->rx_queue);
 943:	
 944:		return 0;
 945:	}
 SourceFile:net/vmw_vsock/virtio_transport_common.c]

gemini-3.1-pro-preview

							input: 58022
							output: 41
							thoughts: 288
						

**Analyzing Potential Memory Leaks in vsock Implementation**

Okay, so I'm looking closely at this code snippet, specifically the connection handling within the vsock implementation. My initial concern is with the potential for memory leaks, and I'm trying to pinpoint where `sk_wmem_alloc` might not be handled correctly. First, I noticed that `virtio_transport_space_update` and its related function calls don't seem to increment `sk_wmem_alloc`, which is a red flag.

Then I moved onto looking at `virtio_transport_recv_listen`. This code segment, in particular:
```c
	if (virtio_transport_space_update(child, skb))
		child->sk_write_space(child);

	vsock_insert_connected(vchild);
	vsock_enqueue_accept(sk, child);
	virtio_transport_send_response(vchild, skb);

	release_sock(child);
```
I'm particularly interested in how the socket is handled after the initial connection setup. Then there is an important consideration when `vchild->transport != &t->transport`:

```c
	if (ret || vchild->transport != &t->transport) {
		release_sock(child);
		virtio_transport_reset_no_sock(t, skb, sock_net(sk));
		sock_put(child);
		return ret;
	}
```

Now, the `release_sock(child)` call is the focus. I need to understand exactly what `release_sock` does. Specifically, does it increment `sk_refcnt` or `sk_wmem_alloc`? Looking at the code, it doesn't appear to be touching either of those. That's a potential problem! Then there is `sock_put(child)` call after `release_sock(child)`. This is even more concerning.

The crucial question now becomes: What happens if `sock_put(child)` is called, but `sk_refcnt` is actually 2? Why would `sk_refcnt` be 2 at this point? This could lead to a double free, or a situation where the socket isn't properly cleaned up. I'm going to dig into how the `sk_refcnt` is managed in this context. I should check `lock_sock_nested` to find this, and get a clearer picture of socket reference counting and lock nesting behavior in this specific vsock scenario.

map[ContextFile:include/net/sock.h IncludeLines:true Name:lock_sock_nested]

map[SourceCode:3777:	void lock_sock_nested(struct sock *sk, int subclass)
3778:	{
3779:		/* The sk_lock has mutex_lock() semantics here. */
3780:		mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
3781:	
3782:		might_sleep();
3783:		spin_lock_bh(&sk->sk_lock.slock);
3784:		if (sock_owned_by_user_nocheck(sk))
3785:			__lock_sock(sk);
3786:		sk->sk_lock.owned = 1;
3787:		spin_unlock_bh(&sk->sk_lock.slock);
3788:	}
 SourceFile:net/core/sock.c]

gemini-3.1-pro-preview

							input: 59135
							output: 40
							thoughts: 940
						

**Debugging a Potential vsock Memory Leak**

Okay, let's break this down. My initial thought was, "No, `sk_refcnt` isn't being incremented". But then I started walking through the code, focusing on the `vsock_assign_transport` and related functions. I need to track the lifecycle of the socket and associated resources.

First, I considered the failure case of `new_transport->init`. If that fails, `vsk->transport` isn't set, so `vsock_deassign_transport` does nothing. This seemed correct. But, the failure should release anything allocated during init. `virtio_transport_do_socket_init` uses `kzalloc_obj`, which would cause it to error if it failed. So, no leak there, in the failure case.

The real puzzle is in the success path. If `new_transport->init` succeeds, `vsk->transport` *is* set. It looks like `vchild->transport` is then set and `sock_put(child)` is called. Then `vsock_sk_destruct` gets called and that calls `vsock_deassign_transport`, which calls the `transport->destruct` function, like `virtio_transport_destruct`. That seems to correctly free the `vvs` and then `sk_prot_free` frees the child socket. So far, so good. Everything seems to be freed. I thought I had it.

But the bug report indicates a memory leak. So I had to question my assumptions.

My train of thought jumped to checking if `vsock_sk_destruct` *is* even being called. I went back to the call chain: `sk_destruct` calls `vsock_sk_destruct`. `sk_destruct` is called from `__sk_free`, which is from `sk_free`, and finally, `sk_free` is called from `sock_put`. So that call chain checks out.

Okay, is `sock_put` even called? Yes, it is.

The critical thing, if everything is freeing, is to verify the reference counts. What is `sk_refcnt` before `sock_put` is called? I dove back into `sk_alloc` and `sock_init_data_uid`. `sk_alloc` sets `sk_net_refcnt` to 1. Then I found `sock_init_data_uid` which calls `refcount_set` and sets `sk->sk_refcnt` to 1. So, `sk_refcnt` *is* 1.

Then I verified the path again. `vsock_create_connected` calls `__vsock_create`. `__vsock_create` calls `sk_alloc`, and then `sock_init_data`. Then `virtio_transport_recv_listen` calls `sock_put(child)`. `sock_put` drops `sk_refcnt` to 0. Then `sk_free` is called, which drops `sk_wmem_alloc` from 1 to 0. Then `__sk_free` and `sk_destruct` and then `vsock_sk_destruct`. Everything is correctly deallocated.

So, if all of that is true, then THERE SHOULD BE NO MEMORY LEAK! I followed the code, the reference counts are correct and everything that gets allocated gets freed.

But the bug report says there IS a leak. So, what am I missing? I need to go back and check `sk_destruct` again. I need to be sure that I haven't skipped something critical.

map[ContextFile:net/core/sock.c IncludeLines:true Name:sk_destruct]

map[SourceCode:2400:	void sk_destruct(struct sock *sk)
2401:	{
2402:		bool use_call_rcu = sock_flag(sk, SOCK_RCU_FREE);
2403:	
2404:		if (rcu_access_pointer(sk->sk_reuseport_cb)) {
2405:			reuseport_detach_sock(sk);
2406:			use_call_rcu = true;
2407:		}
2408:	
2409:		if (use_call_rcu)
2410:			call_rcu(&sk->sk_rcu, __sk_destruct);
2411:		else
2412:			__sk_destruct(&sk->sk_rcu);
2413:	}
 SourceFile:net/core/sock.c]

gemini-3.1-pro-preview

							input: 61147
							output: 41
							thoughts: 12
						

Okay, here's my interpretation of that thought process, tailored for an expert audience, and written in the first person:

**Initial Assessment: A Destructor's Arrival**

Alright, the initial trigger is pretty clear. I'm immediately focused on the call to `__sk_destruct`. That's the signal, isn't it? It means we're in the midst of, or about to be in, a destruction sequence. The context is obviously critical here. Without further details, my mind's racing through the implications. I'm instantly thinking about:

*   **The Object Type:** What kind of object is being destructed? Is it a fundamental data structure, a service component, or something more complex? That dramatically influences the potential ramifications.
*   **The Scope of the Destruction:** Is this a single object, a collection, or a nested hierarchy? Are there any shared resources? Knowing the scope is crucial to avoid memory leaks or resource corruption.
*   **Destructor Implementation:** I'm immediately running through the possible behaviors of `__sk_destruct` . Is it doing simple cleanup, releasing memory, or managing complex dependencies? Is it properly handling exceptions? And, crucially, is it *correct*? The devils in the details.
*   **The Call Chain:** Where is this call coming from? The stack trace is what I'm looking for. Is this happening as part of a normal shutdown, a memory management event, or something more unexpected like an exception unwind? Knowing the call chain is key for debugging unexpected behavior.
*   **Possible Side Effects:** I have to consider the potential side effects of this call. Can it trigger other destruction routines? Does it impact other parts of the system? Are there any invariants that need to be maintained during this destruction process?
*   **Potential Problems:** I'm already mentally running through potential failure modes. Is there a possibility of double-freeing? Resource leaks? Unintended side effects? My main goal is to anticipate these problems and come up with a solution.

My brain is in high alert, going through the potential issues that may be happening. This is not the end, it is just the beginning.

map[ContextFile:net/core/sock.c IncludeLines:true Name:__sk_destruct]

map[SourceCode:2340:	/* Sockets having SOCK_RCU_FREE will call this function after one RCU
2341:	 * grace period. This is the case for UDP sockets and TCP listeners.
2342:	 */
2343:	static void __sk_destruct(struct rcu_head *head)
2344:	{
2345:		struct sock *sk = container_of(head, struct sock, sk_rcu);
2346:		struct net *net = sock_net(sk);
2347:		struct sk_filter *filter;
2348:	
2349:		if (sk->sk_destruct)
2350:			sk->sk_destruct(sk);
2351:	
2352:		filter = rcu_dereference_check(sk->sk_filter,
2353:					       refcount_read(&sk->sk_wmem_alloc) == 0);
2354:		if (filter) {
2355:			sk_filter_uncharge(sk, filter);
2356:			RCU_INIT_POINTER(sk->sk_filter, NULL);
2357:		}
2358:	
2359:		sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
2360:	
2361:	#ifdef CONFIG_BPF_SYSCALL
2362:		bpf_sk_storage_free(sk);
2363:	#endif
2364:	
2365:		if (atomic_read(&sk->sk_omem_alloc))
2366:			pr_debug("%s: optmem leakage (%d bytes) detected\n",
2367:				 __func__, atomic_read(&sk->sk_omem_alloc));
2368:	
2369:		if (sk->sk_frag.page) {
2370:			put_page(sk->sk_frag.page);
2371:			sk->sk_frag.page = NULL;
2372:		}
2373:	
2374:		/* We do not need to acquire sk->sk_peer_lock, we are the last user. */
2375:		put_cred(sk->sk_peer_cred);
2376:		put_pid(sk->sk_peer_pid);
2377:	
2378:		if (likely(sk->sk_net_refcnt)) {
2379:			put_net_track(net, &sk->ns_tracker);
2380:		} else {
2381:			__netns_tracker_free(net, &sk->ns_tracker, false);
2382:			net_passive_dec(net);
2383:		}
2384:		sk_prot_free(sk->sk_prot_creator, sk);
2385:	}
 SourceFile:net/core/sock.c]

gemini-3.1-pro-preview

							input: 62427
							output: 41
							thoughts: 25
						

Okay, here's my interpretation of those thoughts, tailored for an expert audience, presented in the first person:

**Decoding That `sk_prot_free` Call**

Alright, that `sk_prot_free` call just popped up in my mental model, and my first instinct is to zero in on what it's actually doing. I know `sk_prot_free` is a pretty common pattern in the kernel's networking code, and it's almost always a key function in resource management. So, *is* this the critical point where the socket is being deallocated? That's the question buzzing in my head. I need to quickly determine if this is the final goodbye to the socket structure itself.

map[ContextFile:net/core/sock.c IncludeLines:true Name:sk_prot_free]

map[SourceCode:2267:	static void sk_prot_free(struct proto *prot, struct sock *sk)
2268:	{
2269:		struct kmem_cache *slab;
2270:		struct module *owner;
2271:	
2272:		owner = prot->owner;
2273:		slab = prot->slab;
2274:	
2275:		cgroup_sk_free(&sk->sk_cgrp_data);
2276:		mem_cgroup_sk_free(sk);
2277:		security_sk_free(sk);
2278:	
2279:		sk_owner_put(sk);
2280:	
2281:		if (slab != NULL)
2282:			kmem_cache_free(slab, sk);
2283:		else
2284:			kfree(sk);
2285:		module_put(owner);
2286:	}
 SourceFile:net/core/sock.c]

gemini-3.1-pro-preview

							input: 62932
							output: 55
							thoughts: 1274
						

**Debugging a Potential Memory Leak in the Virtio-VSock Socket Handling**

Okay, so I'm trying to track down this potential memory leak. I can see that `release_sock` *should* free the socket. That's the expected behavior. So, why am I still seeing a leak? My first thought is to check if `sk_wmem_alloc` is incremented somewhere, but it should be zeroed when a socket is freed. I need to re-examine `virtio_transport_recv_listen`.

Let's look at the code again. I see `release_sock(child)` is called. My first thought is whether this function increments `sk_wmem_alloc`, but it doesn't. Okay, is `sk_refcnt` incremented somewhere? `lock_sock_nested` doesn't increment `sk_refcnt`, so that's not it. What about `vsock_assign_transport`? Nope, that doesn't increment `sk_refcnt` either. I need to make sure I am not missing something that could cause issues.

Okay, what about `virtio_transport_do_socket_init`? Nope. That's not the problem. Maybe `vsock_create_connected`? Wait... it calls `security_sk_clone`, but that also shouldn't be the issue.

Let me think a bit more broadly. If `sk_refcnt` isn't 1, there might be a problem. Checking `sk_alloc`, I see `sk_net_refcnt`, but that's not `sk_refcnt`. Ah, `sk_refcnt` is actually set to 1 in `sock_init_data_uid`. So, it *should* be 1.

Wait! Back to `virtio_transport_recv_listen`.

I see that `virtio_transport_reset_no_sock` is called in the error path. Okay, *that's* interesting. I need to look closely at `virtio_transport_reset_no_sock` to see if it's doing something unexpected with `child`. Let's check that function!

map[ContextFile:net/vmw_vsock/virtio_transport_common.c IncludeLines:true Name:virtio_transport_reset_no_sock]

map[SourceCode:1168:	/* Normally packets are associated with a socket.  There may be no socket if an
1169:	 * attempt was made to connect to a socket that does not exist.
1170:	 *
1171:	 * net refers to the namespace of whoever sent the invalid message. For
1172:	 * loopback, this is the namespace of the socket. For vhost, this is the
1173:	 * namespace of the VM (i.e., vhost_vsock).
1174:	 */
1175:	static int virtio_transport_reset_no_sock(const struct virtio_transport *t,
1176:						  struct sk_buff *skb, struct net *net)
1177:	{
1178:		struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
1179:		struct virtio_vsock_pkt_info info = {
1180:			.op = VIRTIO_VSOCK_OP_RST,
1181:			.type = le16_to_cpu(hdr->type),
1182:			.reply = true,
1183:	
1184:			/* Set sk owner to socket we are replying to (may be NULL for
1185:			 * non-loopback). This keeps a reference to the sock and
1186:			 * sock_net(sk) until the reply skb is freed.
1187:			 */
1188:			.vsk = vsock_sk(skb->sk),
1189:	
1190:			/* net is not defined here because we pass it directly to
1191:			 * t->send_pkt(), instead of relying on
1192:			 * virtio_transport_send_pkt_info() to pass it. It is not needed
1193:			 * by virtio_transport_alloc_skb().
1194:			 */
1195:		};
1196:		struct sk_buff *reply;
1197:	
1198:		/* Send RST only if the original pkt is not a RST pkt */
1199:		if (le16_to_cpu(hdr->op) == VIRTIO_VSOCK_OP_RST)
1200:			return 0;
1201:	
1202:		if (!t)
1203:			return -ENOTCONN;
1204:	
1205:		reply = virtio_transport_alloc_skb(&info, 0, false,
1206:						   le64_to_cpu(hdr->dst_cid),
1207:						   le32_to_cpu(hdr->dst_port),
1208:						   le64_to_cpu(hdr->src_cid),
1209:						   le32_to_cpu(hdr->src_port));
1210:		if (!reply)
1211:			return -ENOMEM;
1212:	
1213:		return t->send_pkt(reply, net);
1214:	}
 SourceFile:net/vmw_vsock/virtio_transport_common.c]

gemini-3.1-pro-preview

							input: 65565
							output: 53
							thoughts: 3079
						

**Analyzing a Potential Memory Leak in vsock Connection Handling**

Okay, so I'm diving into this vsock memory leak. The initial thought is, it can't just be a RST packet causing the issue. I need to trace through the socket's lifecycle to understand where this leak is coming from.

First, I need to know why the `sk_refcnt` of a socket isn't being decremented to zero. If it's not going down to zero, that means the socket isn't being properly freed. I start by re-examining `vsock_assign_transport`. I remember it increments a module refcount when a new transport is assigned. Then it calls the `init` function of this new transport.

I'm focused on the initialization sequence because it could be where something goes wrong and the socket reference isn't handled correctly. I check `virtio_transport_do_socket_init`, which allocates a `virtio_vsock_sock` struct. It doesn't seem to increment the socket's refcount directly, which is good.

I need to confirm that `sk_wmem_alloc` is decremented properly. `SK_WMEM_ALLOC_BIAS` is set to 1 in `sk_alloc`, so it should decrement to 0 and call `__sk_free`.

Next, I need to check for other places that might increment `sk_refcnt`. I quickly check `lock_sock_nested` but find nothing suspicious. It looks clean.

Okay, let's trace the path of the child socket. I need to make sure the socket's reference is being properly handled in the `virtio_transport_recv_listen` function. I check if `skb->sk` is equal to `child` which can only mean the socket has been used. The incoming packet is the `skb`, and the socket is the listening socket or NULL, not the `child`.

Now, if `vsock_assign_transport` fails, I confirm that `sock_put(child)` is called, which should decrement `sk_refcnt`. And `vsock_sk_destruct` is called.

If `vsock_assign_transport` succeeds, but there's a problem later, it should call `sock_put(child)`, which should decrement the refcount to zero.

I verify that the `transport` is set and later destructed. The `vsock_deassign_transport` function does call the `destruct` method. I'm going through the destructor chain, to check if everything is cleaned up properly. I confirmed that everything is being freed by checking all the possible paths. It looks like the destructor path is correct.

Now, I look for places where `sk_destruct` might not be called. I review that `sk_refcnt` is 0.

I recheck that the `sk_net_refcnt` is 1 when the socket is created. That ensures that the `sk_refcnt` is initialized to a reasonable value. `sock_put` should take care of decrementing it.

I confirm that there are no RCU delays, so the destructor should run immediately.

I need to make sure that the `sk_wmem_alloc` isn't an issue. It should decrement to 0 eventually. So that path is correct. I am not worried about that.

I am rechecking if `sk_refcnt` is being increased by `sk_acceptq_added`, but that is not the case because it only impacts `sk_ack_backlog` on the listener socket.

The next thing I check is if `sock_put(child)` is not being called. I check all of the conditions that cause `sock_put(child)` to be called, and it's being called in all the paths.

If `vchild->transport == &t->transport`, there's another path that might be causing problems. However, this is also handled properly when `child` is inserted in the accept queue. So that socket should be freed. The socket should be cleaned up.

If `vsock_assign_transport` fails, the `sock_put` should free `child` from all reference. No leak here. I keep confirming all the paths.

So, I re-examine. If there is no leak. I have to look into the bug report again. The bug report says `sk_prot_alloc` is leaked.

Okay, so I will now focus on the steps of the `child` that are related to `sk_prot_alloc` and see where this can be an issue. Let's trace it carefully, again.

map[ContextFile:net/vmw_vsock/virtio_transport_common.c IncludeLines:true Name:virtio_transport_recv_pkt]

map[SourceCode:1605:	/* We are under the virtio-vsock's vsock->rx_lock or vhost-vsock's vq->mutex
1606:	 * lock.
1607:	 */
1608:	void virtio_transport_recv_pkt(struct virtio_transport *t,
1609:				       struct sk_buff *skb, struct net *net)
1610:	{
1611:		struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
1612:		struct sockaddr_vm src, dst;
1613:		struct vsock_sock *vsk;
1614:		struct sock *sk;
1615:		bool space_available;
1616:	
1617:		vsock_addr_init(&src, le64_to_cpu(hdr->src_cid),
1618:				le32_to_cpu(hdr->src_port));
1619:		vsock_addr_init(&dst, le64_to_cpu(hdr->dst_cid),
1620:				le32_to_cpu(hdr->dst_port));
1621:	
1622:		trace_virtio_transport_recv_pkt(src.svm_cid, src.svm_port,
1623:						dst.svm_cid, dst.svm_port,
1624:						le32_to_cpu(hdr->len),
1625:						le16_to_cpu(hdr->type),
1626:						le16_to_cpu(hdr->op),
1627:						le32_to_cpu(hdr->flags),
1628:						le32_to_cpu(hdr->buf_alloc),
1629:						le32_to_cpu(hdr->fwd_cnt));
1630:	
1631:		if (!virtio_transport_valid_type(le16_to_cpu(hdr->type))) {
1632:			(void)virtio_transport_reset_no_sock(t, skb, net);
1633:			goto free_pkt;
1634:		}
1635:	
1636:		/* The socket must be in connected or bound table
1637:		 * otherwise send reset back
1638:		 */
1639:		sk = vsock_find_connected_socket_net(&src, &dst, net);
1640:		if (!sk) {
1641:			sk = vsock_find_bound_socket_net(&dst, net);
1642:			if (!sk) {
1643:				(void)virtio_transport_reset_no_sock(t, skb, net);
1644:				goto free_pkt;
1645:			}
1646:		}
1647:	
1648:		if (virtio_transport_get_type(sk) != le16_to_cpu(hdr->type)) {
1649:			(void)virtio_transport_reset_no_sock(t, skb, net);
1650:			sock_put(sk);
1651:			goto free_pkt;
1652:		}
1653:	
1654:		if (!skb_set_owner_sk_safe(skb, sk)) {
1655:			WARN_ONCE(1, "receiving vsock socket has sk_refcnt == 0\n");
1656:			goto free_pkt;
1657:		}
1658:	
1659:		vsk = vsock_sk(sk);
1660:	
1661:		lock_sock(sk);
1662:	
1663:		/* Check if sk has been closed or assigned to another transport before
1664:		 * lock_sock (note: listener sockets are not assigned to any transport)
1665:		 */
1666:		if (sock_flag(sk, SOCK_DONE) ||
1667:		    (sk->sk_state != TCP_LISTEN && vsk->transport != &t->transport)) {
1668:			(void)virtio_transport_reset_no_sock(t, skb, net);
1669:			release_sock(sk);
1670:			sock_put(sk);
1671:			goto free_pkt;
1672:		}
1673:	
1674:		space_available = virtio_transport_space_update(sk, skb);
1675:	
1676:		/* Update CID in case it has changed after a transport reset event */
1677:		if (vsk->local_addr.svm_cid != VMADDR_CID_ANY)
1678:			vsk->local_addr.svm_cid = dst.svm_cid;
1679:	
1680:		if (space_available)
1681:			sk->sk_write_space(sk);
1682:	
1683:		switch (sk->sk_state) {
1684:		case TCP_LISTEN:
1685:			virtio_transport_recv_listen(sk, skb, t);
1686:			kfree_skb(skb);
1687:			break;
1688:		case TCP_SYN_SENT:
1689:			virtio_transport_recv_connecting(sk, skb);
1690:			kfree_skb(skb);
1691:			break;
1692:		case TCP_ESTABLISHED:
1693:			virtio_transport_recv_connected(sk, skb);
1694:			break;
1695:		case TCP_CLOSING:
1696:			virtio_transport_recv_disconnecting(sk, skb);
1697:			kfree_skb(skb);
1698:			break;
1699:		default:
1700:			(void)virtio_transport_reset_no_sock(t, skb, net);
1701:			kfree_skb(skb);
1702:			break;
1703:		}
1704:	
1705:		release_sock(sk);
1706:	
1707:		/* Release refcnt obtained when we fetched this socket out of the
1708:		 * bound or connected list.
1709:		 */
1710:		sock_put(sk);
1711:		return;
1712:	
1713:	free_pkt:
1714:		kfree_skb(skb);
1715:	}
 SourceFile:net/vmw_vsock/virtio_transport_common.c]

gemini-3.1-pro-preview

							input: 71480
							output: 39
							thoughts: 1810
						

**Digging Deep into Virtio-VSOCK Socket Lifecycle**

Okay, so I'm really trying to pin down this potential memory leak in virtio-vsock. Let's break this down. First, in `virtio_transport_recv_pkt`, we have that `skb_set_owner_sk_safe` call. It assigns the listener socket (`sk`) to the socket buffer (`skb`). Then, `virtio_transport_recv_listen` comes into play. It creates a child socket with `vsock_create_connected`, and that's where things get interesting. We call `virtio_transport_reset_no_sock` when something goes wrong with the connection.

Now, `virtio_transport_reset_no_sock`, which is called if there's an error, also needs to be examined. Its job is to generate a RST packet. It seems that `info.vsk` is set to `vsock_sk(skb->sk)`, i.e. the listener socket. Then, `virtio_transport_alloc_skb` increments `sk_wmem_alloc` of the listener socket and not the newly created child socket, the one that is supposed to be connected. This seems fine, since the RST packet is being sent to the original socket.

But then, let's go back and look at the control flow in `virtio_transport_recv_listen`. It creates a child socket with `vsock_create_connected`. I've looked at the function code, and it allocates and initializes the child socket. Then, we increment `sk->sk_ack_backlog` with `sk_acceptq_added(sk)`, and free the child socket with `sock_put(child)` if the allocation fails. I checked. The `sk_ack_backlog` is an integer, so no leaks there. And we are sure to free the `child` socket.

Okay, let's get back to `vsock_assign_transport`. If it fails, `sock_put(child)` is called. But does it fail? The code checks `new_transport->init`, and if that fails, `ret` is returned, and `sock_put` is correctly called. The `virtio_transport_do_socket_init` function allocates the `vvs`. If it succeeds, the vsk's transport is assigned. Then `vchild->transport != &t->transport` is checked. If it's unequal, `sock_put(child)` is called, and `vsock_sk_destruct` calls `vsock_deassign_transport`, which calls `vchild->transport->destruct(vchild)`. `virtio_transport_destruct` frees the `vvs`. Then `sk_prot_free` frees `child`. So, it seems *everything* is freed.

So, how can this leak? Let's trace it back. The crucial function is `vsock_sk_destruct`. It purges leftover `MSG_ZEROCOPY` buffers and calls `vsock_deassign_transport` and clears the socket addresses. It also does `put_cred(vsk->owner)`. I see that `vsock_deassign_transport` is called. So, the teardown is there.

Okay, what's left? What if `sk_destruct` isn't called, because the socket's `sk_refcnt` isn't zero? Why would the reference count *not* be zero? `vsock_create_connected` calls `sk_alloc`, setting `sk_refcnt` to 1. Then it calls `sock_init_data`, still setting `sk_refcnt` to 1. Then, we look at the clone operation with `security_sk_clone`. *Does* this function increment the reference count? That's the missing piece! Let's check `security_sk_clone` to be sure.

map[ContextFile:security/security.c IncludeLines:true Name:security_sk_clone]

map[SourceCode:4414:	/**
4415:	 * security_sk_clone() - Clone a sock's LSM state
4416:	 * @sk: original sock
4417:	 * @newsk: target sock
4418:	 *
4419:	 * Clone/copy security structure.
4420:	 */
4421:	void security_sk_clone(const struct sock *sk, struct sock *newsk)
4422:	{
4423:		call_void_hook(sk_clone_security, sk, newsk);
4424:	}
 SourceFile:security/security.c]

gemini-3.1-pro-preview

							input: 74364
							output: 50
							thoughts: 725
						

**Analyzing Socket Reference Counting in virtio_transport_reset_no_sock**

Okay, so I'm digging into this code and trying to figure out if there's a reference counting issue. My initial thought was that `sk_refcnt` wasn't being incremented, which seems right, but let me check again, is it `sk_wmem_alloc`?

Hold on. What if `sk_wmem_alloc` is *not* zero? I recall that `sk_free` uses `refcount_dec_and_test` on `sk->sk_wmem_alloc`, and if the result of the decrement is zero, it calls `__sk_free`. So, where is `sk_wmem_alloc` incremented? I'm going to revisit `virtio_transport_recv_listen`.

Let's see... we create a `child` socket with `vsock_create_connected`, lock it, and then assign the transport with `vsock_assign_transport`. If either that fails, or if `vchild->transport` gets set to the wrong thing, then we call `release_sock(child)`, call `virtio_transport_reset_no_sock` and then call `sock_put(child)`. That `virtio_transport_reset_no_sock` call is what catches my eye.

Aha! `virtio_transport_reset_no_sock`. Let's look closely at this function. I see it creates a `virtio_vsock_pkt_info` struct, and crucially, it sets `.vsk` to `vsock_sk(skb->sk)`. I see that the `skb->sk` is the listener socket, `sk`. In that case, `info.vsk` would be `vsock_sk(sk)`. Then, inside `virtio_transport_alloc_skb`, we see `skb_set_owner_w(skb, sk_vsock(info->vsk))`. This increments `sk_wmem_alloc` of `skb->sk`. And we're using the listener socket `sk` there. So it's the listener socket's `sk_wmem_alloc` that gets incremented, not `child`s.

But, hang on, what if `child`'s `sk_wmem_alloc` is being incremented *somewhere else*? No, the `child` socket doesn't seem to be involved in `virtio_transport_reset_no_sock`.

What if we don't `sock_put(child)`? But, no, the code path shows that we do!

Now, what if `vsock_assign_transport` fails, but leaves `vchild->transport` set to a transport which does *not* have a destruct method? That would be a problem... but wait, all virtio transports have a `destruct` function.

What if `vchild->transport` is NOT a virtio transport? What if it's `transport_dgram`? Let's check that.

requested entity does not exist

map[ContextFile:net/vmw_vsock/vmci_transport.c IncludeLines:true Name:vmci_transport_dgram]

map[SourceCode: SourceFile:]

gemini-3.1-pro-preview

							input: 75833
							output: 18
							thoughts: 19
						

Okay, let's dive into this. Here's my thought process on what we're looking at, summarized as though I were examining this myself:

**Examining `transport_dgram` in `af_vsock.c`**

Alright, the objective is to check `transport_dgram` specifically within `af_vsock.c`. I need to understand what this function is doing within the context of the VSOCK address family, and in particular its role in datagram-oriented communication. I already know this is likely handling UDP-like semantics, but I want a deeper look at its implementation details. This likely is the core function for managing the send and receive logic of datagram sockets, considering the datagram nature. I'll be looking closely at how it handles connectionless communication, addressing, data transfer, and error handling. I'm keen to trace the data flow to ensure it matches my mental model of VSOCK communication, and to pinpoint any potential areas for optimization, or points where unexpected behavior might surface. I'll need to pay attention to any interaction with lower-level mechanisms, like the virtual machine's hypercall interface, to see how the datagram transport is achieved at a fundamental level. I'll also be searching for any concurrency issues.

map[Expression:transport_dgram]

map[Output:drivers/vhost/vsock.c=422=static struct virtio_transport vhost_transport = {
--
drivers/vhost/vsock.c-434-
drivers/vhost/vsock.c:435:		.dgram_enqueue            = virtio_transport_dgram_enqueue,
drivers/vhost/vsock.c:436:		.dgram_dequeue            = virtio_transport_dgram_dequeue,
drivers/vhost/vsock.c:437:		.dgram_bind               = virtio_transport_dgram_bind,
drivers/vhost/vsock.c:438:		.dgram_allow              = virtio_transport_dgram_allow,
drivers/vhost/vsock.c-439-
--
include/linux/virtio_vsock.h=206=int
include/linux/virtio_vsock.h:207:virtio_transport_dgram_dequeue(struct vsock_sock *vsk,
include/linux/virtio_vsock.h-208-			       struct msghdr *msg,
--
include/linux/virtio_vsock.h=260=bool virtio_transport_stream_allow(struct vsock_sock *vsk, u32 cid, u32 port);
include/linux/virtio_vsock.h:261:int virtio_transport_dgram_bind(struct vsock_sock *vsk,
include/linux/virtio_vsock.h-262-				struct sockaddr_vm *addr);
include/linux/virtio_vsock.h:263:bool virtio_transport_dgram_allow(struct vsock_sock *vsk, u32 cid, u32 port);
include/linux/virtio_vsock.h-264-
--
include/linux/virtio_vsock.h=275=int
include/linux/virtio_vsock.h:276:virtio_transport_dgram_enqueue(struct vsock_sock *vsk,
include/linux/virtio_vsock.h-277-			       struct sockaddr_vm *remote_addr,
--
net/vmw_vsock/af_vsock.c=206=static const struct vsock_transport *transport_g2h;
net/vmw_vsock/af_vsock.c-207-/* Transport used for DGRAM communication */
net/vmw_vsock/af_vsock.c:208:static const struct vsock_transport *transport_dgram;
net/vmw_vsock/af_vsock.c-209-/* Transport used for local communication */
--
net/vmw_vsock/af_vsock.c=552=int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk)
--
net/vmw_vsock/af_vsock.c-577-	case SOCK_DGRAM:
net/vmw_vsock/af_vsock.c:578:		new_transport = transport_dgram;
net/vmw_vsock/af_vsock.c-579-		break;
--
net/vmw_vsock/af_vsock.c=3013=int vsock_core_register(const struct vsock_transport *t, int features)
--
net/vmw_vsock/af_vsock.c-3022-	t_g2h = transport_g2h;
net/vmw_vsock/af_vsock.c:3023:	t_dgram = transport_dgram;
net/vmw_vsock/af_vsock.c-3024-	t_local = transport_local;
--
net/vmw_vsock/af_vsock.c-3059-	transport_g2h = t_g2h;
net/vmw_vsock/af_vsock.c:3060:	transport_dgram = t_dgram;
net/vmw_vsock/af_vsock.c-3061-	transport_local = t_local;
--
net/vmw_vsock/af_vsock.c=3069=void vsock_core_unregister(const struct vsock_transport *t)
--
net/vmw_vsock/af_vsock.c-3078-
net/vmw_vsock/af_vsock.c:3079:	if (transport_dgram == t)
net/vmw_vsock/af_vsock.c:3080:		transport_dgram = NULL;
net/vmw_vsock/af_vsock.c-3081-
--
net/vmw_vsock/virtio_transport.c=550=static struct virtio_transport virtio_transport = {
--
net/vmw_vsock/virtio_transport.c-562-
net/vmw_vsock/virtio_transport.c:563:		.dgram_bind               = virtio_transport_dgram_bind,
net/vmw_vsock/virtio_transport.c:564:		.dgram_dequeue            = virtio_transport_dgram_dequeue,
net/vmw_vsock/virtio_transport.c:565:		.dgram_enqueue            = virtio_transport_dgram_enqueue,
net/vmw_vsock/virtio_transport.c:566:		.dgram_allow              = virtio_transport_dgram_allow,
net/vmw_vsock/virtio_transport.c-567-
--
net/vmw_vsock/virtio_transport_common.c=854=int
net/vmw_vsock/virtio_transport_common.c:855:virtio_transport_dgram_dequeue(struct vsock_sock *vsk,
net/vmw_vsock/virtio_transport_common.c-856-			       struct msghdr *msg,
--
net/vmw_vsock/virtio_transport_common.c-860-}
net/vmw_vsock/virtio_transport_common.c:861:EXPORT_SYMBOL_GPL(virtio_transport_dgram_dequeue);
net/vmw_vsock/virtio_transport_common.c-862-
--
net/vmw_vsock/virtio_transport_common.c=1057=EXPORT_SYMBOL_GPL(virtio_transport_stream_is_active);
net/vmw_vsock/virtio_transport_common.c-1058-
net/vmw_vsock/virtio_transport_common.c:1059:int virtio_transport_dgram_bind(struct vsock_sock *vsk,
net/vmw_vsock/virtio_transport_common.c-1060-				struct sockaddr_vm *addr)
--
net/vmw_vsock/virtio_transport_common.c-1063-}
net/vmw_vsock/virtio_transport_common.c:1064:EXPORT_SYMBOL_GPL(virtio_transport_dgram_bind);
net/vmw_vsock/virtio_transport_common.c-1065-
net/vmw_vsock/virtio_transport_common.c:1066:bool virtio_transport_dgram_allow(struct vsock_sock *vsk, u32 cid, u32 port)
net/vmw_vsock/virtio_transport_common.c-1067-{
--
net/vmw_vsock/virtio_transport_common.c-1069-}
net/vmw_vsock/virtio_transport_common.c:1070:EXPORT_SYMBOL_GPL(virtio_transport_dgram_allow);
net/vmw_vsock/virtio_transport_common.c-1071-
--
net/vmw_vsock/virtio_transport_common.c=1100=int
net/vmw_vsock/virtio_transport_common.c:1101:virtio_transport_dgram_enqueue(struct vsock_sock *vsk,
net/vmw_vsock/virtio_transport_common.c-1102-			       struct sockaddr_vm *remote_addr,
--
net/vmw_vsock/virtio_transport_common.c-1107-}
net/vmw_vsock/virtio_transport_common.c:1108:EXPORT_SYMBOL_GPL(virtio_transport_dgram_enqueue);
net/vmw_vsock/virtio_transport_common.c-1109-
--
net/vmw_vsock/vmci_transport.c=1661=static void vmci_transport_release(struct vsock_sock *vsk)
--
net/vmw_vsock/vmci_transport.c-1670-
net/vmw_vsock/vmci_transport.c:1671:static int vmci_transport_dgram_bind(struct vsock_sock *vsk,
net/vmw_vsock/vmci_transport.c-1672-				     struct sockaddr_vm *addr)
--
net/vmw_vsock/vmci_transport.c-1701-
net/vmw_vsock/vmci_transport.c:1702:static int vmci_transport_dgram_enqueue(
net/vmw_vsock/vmci_transport.c-1703-	struct vsock_sock *vsk,
--
net/vmw_vsock/vmci_transport.c-1741-
net/vmw_vsock/vmci_transport.c:1742:static int vmci_transport_dgram_dequeue(struct vsock_sock *vsk,
net/vmw_vsock/vmci_transport.c-1743-					struct msghdr *msg, size_t len,
--
net/vmw_vsock/vmci_transport.c-1794-
net/vmw_vsock/vmci_transport.c:1795:static bool vmci_transport_dgram_allow(struct vsock_sock *vsk, u32 cid,
net/vmw_vsock/vmci_transport.c-1796-				       u32 port)
--
net/vmw_vsock/vmci_transport.c=2048=static struct vsock_transport vmci_transport = {
--
net/vmw_vsock/vmci_transport.c-2053-	.connect = vmci_transport_connect,
net/vmw_vsock/vmci_transport.c:2054:	.dgram_bind = vmci_transport_dgram_bind,
net/vmw_vsock/vmci_transport.c:2055:	.dgram_dequeue = vmci_transport_dgram_dequeue,
net/vmw_vsock/vmci_transport.c:2056:	.dgram_enqueue = vmci_transport_dgram_enqueue,
net/vmw_vsock/vmci_transport.c:2057:	.dgram_allow = vmci_transport_dgram_allow,
net/vmw_vsock/vmci_transport.c-2058-	.stream_dequeue = vmci_transport_stream_dequeue,
--
net/vmw_vsock/vsock_loopback.c=63=static struct virtio_transport loopback_transport = {
--
net/vmw_vsock/vsock_loopback.c-75-
net/vmw_vsock/vsock_loopback.c:76:		.dgram_bind               = virtio_transport_dgram_bind,
net/vmw_vsock/vsock_loopback.c:77:		.dgram_dequeue            = virtio_transport_dgram_dequeue,
net/vmw_vsock/vsock_loopback.c:78:		.dgram_enqueue            = virtio_transport_dgram_enqueue,
net/vmw_vsock/vsock_loopback.c:79:		.dgram_allow              = virtio_transport_dgram_allow,
net/vmw_vsock/vsock_loopback.c-80-
]

gemini-3.1-pro-preview

							input: 79214
							output: 48
							thoughts: 2980
						

**Analyzing a Potential vsock Leak**

Okay, so I'm diving into this vsock issue. First thought, `vmci_transport` uses `destruct`, good. The initial thought process is to trace through the lifecycle of a connected socket, specifically the child socket created by a listen socket. The goal is to identify a scenario where the child socket or its associated transport data isn't properly released.

The logic flow starts with `vsock_assign_transport`. I check if this fails early, before `init` is called on the transport, which prevents the issue. If `init` fails, it should clean up what it allocated. If `vsock_assign_transport` fails after `init`, `vsk->transport` wouldn't be set, and deallocation logic is also present in error paths. So far, so good.

Next, I consider multiple calls to `vsock_assign_transport`, but it only happens once during connect. I examine the reference counts and lifecycle of the child socket more closely. Specifically, `sk_acceptq_added` increments the backlog, but it doesn't seem to affect socket reference counts. Now I need to understand why a socket might not be freed. `sk_refcnt` should be 1, but I confirm that there are no obvious points in the code that increment the refcount of the `child` socket. LSMs, `lock_sock_nested` and `vsock_assign_transport` don't add additional refcounts. `virtio_transport_reset_no_sock` *does* set a socket owner, but it's the listener socket, not the child socket. Then I look at `skb_set_owner_sk_safe`, but the `skb->sk` is always the listener socket.

The next potential issue is `sk_wmem_alloc`. The listener and the `child` socket have separate `sk_wmem_alloc` fields. Now I consider a scenario where `child` is freed but the transport data `vvs` is not. That's a classic memory leak. I step back through the deallocation path: I check that `vsock_sk_destruct`, `sk_destruct` and `__sk_free` are called. Again, `sk_wmem_alloc` is unlikely to be incremented during the critical lifecycle of the child socket. 

Finally, I try to understand the entire logic flow of the receive path. If `ret` is 0 and the transport is correct, code execution *should* enqueue the `child` socket for accept and the `child` is released. If accept is not called, then the socket will be released when the listener is closed.

I think the analysis has to revolve around confirming `sock_put(child)` *is* called.

map[ContextFile:net/vmw_vsock/af_vsock.c IncludeLines:true Name:__vsock_release]

map[SourceCode: 952:	static void __vsock_release(struct sock *sk, int level)
 953:	{
 954:		struct vsock_sock *vsk;
 955:		struct sock *pending;
 956:	
 957:		vsk = vsock_sk(sk);
 958:		pending = NULL;	/* Compiler warning. */
 959:	
 960:		/* When "level" is SINGLE_DEPTH_NESTING, use the nested
 961:		 * version to avoid the warning "possible recursive locking
 962:		 * detected". When "level" is 0, lock_sock_nested(sk, level)
 963:		 * is the same as lock_sock(sk).
 964:		 */
 965:		lock_sock_nested(sk, level);
 966:	
 967:		/* Indicate to vsock_remove_sock() that the socket is being released and
 968:		 * can be removed from the bound_table. Unlike transport reassignment
 969:		 * case, where the socket must remain bound despite vsock_remove_sock()
 970:		 * being called from the transport release() callback.
 971:		 */
 972:		sock_set_flag(sk, SOCK_DEAD);
 973:	
 974:		if (vsk->transport)
 975:			vsk->transport->release(vsk);
 976:		else if (sock_type_connectible(sk->sk_type))
 977:			vsock_remove_sock(vsk);
 978:	
 979:		sock_orphan(sk);
 980:		sk->sk_shutdown = SHUTDOWN_MASK;
 981:	
 982:		skb_queue_purge(&sk->sk_receive_queue);
 983:	
 984:		/* Clean up any sockets that never were accepted. */
 985:		while ((pending = vsock_dequeue_accept(sk)) != NULL) {
 986:			__vsock_release(pending, SINGLE_DEPTH_NESTING);
 987:			sock_put(pending);
 988:		}
 989:	
 990:		release_sock(sk);
 991:		sock_put(sk);
 992:	}
 SourceFile:net/vmw_vsock/af_vsock.c]

gemini-3.1-pro-preview

							input: 83494
							output: 49
							thoughts: 4308
						

**Analyzing a Potential VSock Memory Leak**

Okay, so I've been carefully dissecting this VSock code, and initially, I thought it was solid – the accept queue flushes, calls to `__vsock_release` and `sock_put` looked clean, so no obvious leak. But then, I started poking around in the details and several scenarios emerged that needed deeper analysis.

My first concern was around `virtio_transport_recv_listen`, particularly when `vsock_assign_transport` fails after `virtio_transport_recv_listen` is called, but `vchild->transport` is NOT NULL. The critical point is that `vsk->transport` can ONLY be set if `init` in `vsock_assign_transport` succeeds. That prevents the initial worry.

Next I went through a scenario in which  `vsock_assign_transport` succeeds, but with the condition `vchild->transport != &t->transport`. In this case `sock_put(child)` should be called but is there a double free? No, I quickly determined that `vsock_assign_transport`, `virtio_transport_do_socket_init`, and `virtio_transport_reset_no_sock` do NOT increment `sk_refcnt`. And, critically, the code explicitly removes the socket from the connected table before calling `release_sock` and `sock_put`.

Then, I looked at a successful `vsock_assign_transport`, where `vchild->transport == &t->transport`.  The code adds the socket to the connected table, then to the accept queue, sends a response, and *should* release the socket via `release_sock` and `sk->sk_data_ready(sk)`. Even if `virtio_transport_send_response` fails, the error is ignored, and the socket *should* be cleaned up. So, nothing here.

Other cases I investigated, included `sk_acceptq_is_full`, `sk->sk_shutdown == SHUTDOWN_MASK`, and `vsock_create_connected` failures, and incrementing `sk_ack_backlog`, all seemed safe.

After a deep dive, I looked at the reproducer, and that's when things started to click. The reproducer calls `connect` before the `listen`, and I realized this causes the problem. Then, `virtio_transport_recv_listen` creates `child`. Because of the early `connect` call, the listening socket's `remote_addr` is set with the first `connect`'s value, which leads to `vsock_assign_transport` choosing `loopback_transport`. The child is added to the accept queue, and then `accept4` is called. That should free everything. I also thought about how things were cleaned up when the listener is closed.

I started to check `__vsock_release`, to ensure that it cleaned up the accepted sockets. The while loop that dequeues sockets from the accept queue and cleans them up is there. That loop calls `vsock_dequeue_accept`, then `__vsock_release`. I then checked that the release of the sockets was correct. Then I saw it! `__vsock_release` calls `sock_put` *twice* on the accepted socket, and that's the bug. When the socket is in the accept queue, its refcount is 2 (one from allocation, one from enqueueing). `vsock_dequeue_accept` *doesn't* decrement the refcount. Thus, there is a double put. Now I see where the memory leak is.

map[ContextFile:net/vmw_vsock/af_vsock.c IncludeLines:true Name:vsock_dequeue_accept]

map[SourceCode: 688:	static struct sock *vsock_dequeue_accept(struct sock *listener)
 689:	{
 690:		struct vsock_sock *vlistener;
 691:		struct vsock_sock *vconnected;
 692:	
 693:		vlistener = vsock_sk(listener);
 694:	
 695:		if (list_empty(&vlistener->accept_queue))
 696:			return NULL;
 697:	
 698:		vconnected = list_entry(vlistener->accept_queue.next,
 699:					struct vsock_sock, accept_queue);
 700:	
 701:		list_del_init(&vconnected->accept_queue);
 702:		sock_put(listener);
 703:		/* The caller will need a reference on the connected socket so we let
 704:		 * it call sock_put().
 705:		 */
 706:	
 707:		return sk_vsock(vconnected);
 708:	}
 SourceFile:net/vmw_vsock/af_vsock.c]

gemini-3.1-pro-preview

							input: 88949
							output: 47
							thoughts: 139
						

Okay, here's my breakdown of this logic, as I understand it:

**Deconstructing vsock Connection Acceptance**

Right, let me see... Okay, so `vsock_dequeue_accept` is the crucial piece here, and it's calling `sock_put(listener)`. That makes sense; it's releasing its hold on the *listener* socket. Ah, and it returns a `pending` socket with a reference count (`sk_refcnt`) of 2! Interesting...

Then, it looks like `__vsock_release` gets called, specifically with the `pending` socket. And, sure enough, `__vsock_release` itself then calls `sock_put(pending)`.  So, that drops the `sk_refcnt` of the `pending` socket down to 1. Excellent.

Now, the loop then calls `sock_put(pending)`. Boom! That decrements the reference count *again*, bringing `sk_refcnt` to a beautiful, clean 0!

Yep, looks like it's freed properly. That's good to know, confirming my initial assumption.

Hang on... I need to consider a potential wrinkle here. What about the case where `accept4` is used instead of `accept`? I should trace what that does.  It seems that `accept4` calls `vsock_accept`. I wonder how that impacts reference counting... I'll need to dig into `vsock_accept` to be sure.

map[ContextFile:net/vmw_vsock/af_vsock.c IncludeLines:true Name:vsock_accept]

map[SourceCode:1824:	static int vsock_accept(struct socket *sock, struct socket *newsock,
1825:				struct proto_accept_arg *arg)
1826:	{
1827:		struct sock *listener;
1828:		int err;
1829:		struct sock *connected;
1830:		struct vsock_sock *vconnected;
1831:		long timeout;
1832:		DEFINE_WAIT(wait);
1833:	
1834:		err = 0;
1835:		listener = sock->sk;
1836:	
1837:		lock_sock(listener);
1838:	
1839:		if (!sock_type_connectible(sock->type)) {
1840:			err = -EOPNOTSUPP;
1841:			goto out;
1842:		}
1843:	
1844:		if (listener->sk_state != TCP_LISTEN) {
1845:			err = -EINVAL;
1846:			goto out;
1847:		}
1848:	
1849:		/* Wait for children sockets to appear; these are the new sockets
1850:		 * created upon connection establishment.
1851:		 */
1852:		timeout = sock_rcvtimeo(listener, arg->flags & O_NONBLOCK);
1853:		prepare_to_wait(sk_sleep(listener), &wait, TASK_INTERRUPTIBLE);
1854:	
1855:		while ((connected = vsock_dequeue_accept(listener)) == NULL &&
1856:		       listener->sk_err == 0) {
1857:			release_sock(listener);
1858:			timeout = schedule_timeout(timeout);
1859:			finish_wait(sk_sleep(listener), &wait);
1860:			lock_sock(listener);
1861:	
1862:			if (signal_pending(current)) {
1863:				err = sock_intr_errno(timeout);
1864:				goto out;
1865:			} else if (timeout == 0) {
1866:				err = -EAGAIN;
1867:				goto out;
1868:			}
1869:	
1870:			prepare_to_wait(sk_sleep(listener), &wait, TASK_INTERRUPTIBLE);
1871:		}
1872:		finish_wait(sk_sleep(listener), &wait);
1873:	
1874:		if (listener->sk_err)
1875:			err = -listener->sk_err;
1876:	
1877:		if (connected) {
1878:			sk_acceptq_removed(listener);
1879:	
1880:			lock_sock_nested(connected, SINGLE_DEPTH_NESTING);
1881:			vconnected = vsock_sk(connected);
1882:	
1883:			/* If the listener socket has received an error, then we should
1884:			 * reject this socket and return.  Note that we simply mark the
1885:			 * socket rejected, drop our reference, and let the cleanup
1886:			 * function handle the cleanup; the fact that we found it in
1887:			 * the listener's accept queue guarantees that the cleanup
1888:			 * function hasn't run yet.
1889:			 */
1890:			if (err) {
1891:				vconnected->rejected = true;
1892:			} else {
1893:				newsock->state = SS_CONNECTED;
1894:				sock_graft(connected, newsock);
1895:	
1896:				set_bit(SOCK_CUSTOM_SOCKOPT,
1897:					&connected->sk_socket->flags);
1898:	
1899:				if (vsock_msgzerocopy_allow(vconnected->transport))
1900:					set_bit(SOCK_SUPPORT_ZC,
1901:						&connected->sk_socket->flags);
1902:			}
1903:	
1904:			release_sock(connected);
1905:			sock_put(connected);
1906:		}
1907:	
1908:	out:
1909:		release_sock(listener);
1910:		return err;
1911:	}
 SourceFile:net/vmw_vsock/af_vsock.c]

gemini-3.1-pro-preview

							input: 90678
							output: 47
							thoughts: 937
						

**Analyzing vsock Connection and Socket Lifecycle**

Okay, let me think this through, starting with the accept flow. I see that `vsock_accept` calls `sock_put(connected)`, and `sock_graft` sets `newsock->sk = connected`. The key question is, does `sock_graft` bump the reference count? No, it doesn't. Aha! Since `sock_put(connected)` decrements the `sk_refcnt` to 1, closing `newsock` drops it to zero, and the socket should be freed. No memory leak there! Good.

Now, what about the more complex listener side flow. Let's dig deeper: What if `virtio_transport_recv_listen` is called, and `vsock_assign_transport` succeeds, AND `vchild->transport == &t->transport`? `vsock_insert_connected(vchild)` is called. This function calls `sock_hold(&vsk->sk)`, so `sk_refcnt` becomes 2. Then `vsock_enqueue_accept` calls `sock_hold(child)`, increasing `sk_refcnt` to 3. The `accept` call removes it from the accept queue. `vsock_dequeue_accept` returns it, still with `sk_refcnt` at 3. `vsock_accept` decrements that with `sock_put(connected)`, making `sk_refcnt` now 2. Closing `newsock`. `vsock_release` calls `__vsock_release`, which calls `vsock_remove_sock(vsk)`. `vsock_remove_sock` removes it from the connected table and calls `sock_put(sk)`, so `sk_refcnt` drops to 1. Finally, `__vsock_release` calls `sock_put(sk)` again, and now the `sk_refcnt` hits zero. So, yes, it's freed! We're good.

Now, consider the edge cases: if `virtio_transport_recv_listen` is called and `vsock_assign_transport` fails? Then `sock_put(child)` gets called, dropping `sk_refcnt` from 1 to 0 and freeing it, as expected. Similarly, if `vchild->transport != &t->transport`, `sock_put(child)` gets called, dropping `sk_refcnt` from 1 to 0. It's freed.

Wait, back to the happy path: If `virtio_transport_recv_listen` is called, `vsock_assign_transport` succeeds, and `vchild->transport == &t->transport` but `vsock_insert_connected(vchild)` is NOT called? Wait, yes it IS called!

Hold on! Time to look closely at the reproducer:

```c
	syscall(__NR_socket, /*domain=*/0x28ul, /*type=*/1ul, /*proto=*/0);
	syscall(__NR_bind, /*fd=*/r[0], /*addr=*/0x200000000440ul, /*addrlen=*/0x10ul);
	syscall(__NR_connect, /*fd=*/r[0], /*addr=*/0x2000000001c0ul, /*addrlen=*/0x10ul);
	syscall(__NR_listen, /*fd=*/r[0], /*backlog=*/5);
```

**Aha!** The `connect` is called on `r[0]` BEFORE `listen`! That explains the issue. If `connect` is called, `vsock_connect` is invoked. `vsock_connect` sets `vsk->remote_addr`, then `vsock_assign_transport`, and sends the connection request. It then waits. But the `connect` call uses `port=-1, cid=VMADDR_CID_LOCAL`. No socket is listening on `port=-1`. So the connection request is rejected with a RST! `vsock_connect` returns an error, like `ECONNREFUSED`. Only THEN is `listen` called. `listen` will call `vsock_listen` after the initial connection has already failed. So the sockets are created and destroyed as a result of a failed attempt to connect to an non-existing socket. Not a leak!

map[ContextFile:net/vmw_vsock/af_vsock.c IncludeLines:true Name:vsock_listen]

map[SourceCode:1913:	static int vsock_listen(struct socket *sock, int backlog)
1914:	{
1915:		int err;
1916:		struct sock *sk;
1917:		struct vsock_sock *vsk;
1918:	
1919:		sk = sock->sk;
1920:	
1921:		lock_sock(sk);
1922:	
1923:		if (!sock_type_connectible(sk->sk_type)) {
1924:			err = -EOPNOTSUPP;
1925:			goto out;
1926:		}
1927:	
1928:		if (sock->state != SS_UNCONNECTED) {
1929:			err = -EINVAL;
1930:			goto out;
1931:		}
1932:	
1933:		vsk = vsock_sk(sk);
1934:	
1935:		if (!vsock_addr_bound(&vsk->local_addr)) {
1936:			err = -EINVAL;
1937:			goto out;
1938:		}
1939:	
1940:		sk->sk_max_ack_backlog = backlog;
1941:		sk->sk_state = TCP_LISTEN;
1942:	
1943:		err = 0;
1944:	
1945:	out:
1946:		release_sock(sk);
1947:		return err;
1948:	}
 SourceFile:net/vmw_vsock/af_vsock.c]

gemini-3.1-pro-preview

							input: 93082
							output: 15
							thoughts: 2002
						

**Analyzing a Potential vsock Memory Leak**

Okay, here's the breakdown of my thought process as I've been wrestling with this potential memory leak in the vsock code.  Let's see... the initial setup involves a `listen` socket and a connecting socket. The problem seems to occur if `accept4` fails.

First, I observed that the `listen` call may succeed even if the `connect` call fails initially, because the socket state isn't correctly checked, and I checked that the transport assignments seem to be set up correctly (loopback transport and local address set). Then, the `listen` socket (`r[0]`) receives the connection request, and a `child` socket is created and assigned the `loopback_transport`. The `child` socket is added to the accept queue. The process seems fine up to this point.

Then, the program calls `accept4`. The bug report points to the leak being `child` socket.

I considered what may cause an error. Could transport assignment fail? The code path assigns `virtio_transport_do_socket_init`, which allocates and initializes per-socket transport structures, and that seems to execute successfully (checked that `psk->trans` is not NULL). What about if `r[0]` is closed *before* `accept4`? The reproducer does not do this, so it doesn't seem possible.

My attention then shifted to the backtrace from the bug report: specifically, the `virtio_transport_recv_listen` function, which creates `child`. The code checks if `vsock_assign_transport` fails, but that's not the case. It also checks that the `transport` pointers are the same, which is fine. The code also calls `virtio_transport_space_update` and does other stuff, which looks correct.

Then I considered scenarios related to the accept queue, specifically: What if `vsock_insert_connected` is called, but `vsock_enqueue_accept` is *not*? The code executes them sequentially, so that is not likely. What if `virtio_transport_send_response` fails? The return value of the function is ignored!

Then the critical part: What if `child` is in the accept queue, but `accept4` is *not* called? In that case, `__vsock_release` should flush the queue and free the socket. That doesn't seem likely.

So, I focused on the scenario where `accept4` *is* called, but it *fails*. I scrutinized the `vsock_accept` function. If `accept4` fails (because of the error code `err` != 0), the `connected` socket, which is the child socket is *rejected*. In this case, `newsock` is *not* grafted to `connected` (the child socket). Now the `connected` variable (again, referring to the child socket) is removed from the accept queue. So, if `accept4` fails, the reference count of the socket becomes 1, and the socket leaks. Where does the `err` variable come from?  It is related to `listener->sk_err`, so the error is related to the listener.  If `listener->sk_err` is non-zero, then `err` becomes non-zero. The connection is rejected, and the socket leaks! This makes sense! If the accept fails, then the socket remains orphaned, with a reference count of 1.

So the likely scenario is: **An error on the listener (e.g., the listener socket somehow is in error state), such as `listener->sk_err` being non-zero, causes `accept4` to fail. As a consequence, the `child` (connected) socket is orphaned and its ref count drops to one, and it leaks.** That makes sense and seems to be the root of the problem. That also explains why the socket becomes unreferenced, as the error during the accept prevents the socket from being grafted. I think I've got it!

map[Expression:rejected]

map[Output:
Full output is too long, showing 500 out of 5825 lines.
Use more precise expression if possible.

[Documentation/ABI/testing/sysfs-block-device=27=Description:
 --
 Documentation/ABI/testing/sysfs-block-device-46-		  writing -2.
 Documentation/ABI/testing/sysfs-block-device:47:		- Values below -2 are rejected with -EINVAL
 Documentation/ABI/testing/sysfs-block-device-48-
 --
 Documentation/ABI/testing/sysfs-class-firmware=17=Description:	Write-only. For firmware uploads, write a "1" to this file to
 Documentation/ABI/testing/sysfs-class-firmware-18-		request that the transfer of firmware data to the lower-level
 Documentation/ABI/testing/sysfs-class-firmware:19:		device be canceled. This request will be rejected (EBUSY) if
 Documentation/ABI/testing/sysfs-class-firmware-20-		the update cannot be canceled (e.g. a FLASH write is in
 --
 Documentation/ABI/testing/sysfs-devices-system-cpu=611=Description:	Control Symmetric Multi Threading (SMT)
 --
 Documentation/ABI/testing/sysfs-devices-system-cpu-628-			 If control status is "forceoff" or "notsupported" writes
 Documentation/ABI/testing/sysfs-devices-system-cpu:629:			 are rejected. Note that enabling SMT on PowerPC skips
 Documentation/ABI/testing/sysfs-devices-system-cpu-630-			 offline cores.
 --
 Documentation/accel/qaic/qaic.rst=170=workloads. Attempts to access resources assigned to other clients will be
 Documentation/accel/qaic/qaic.rst:171:rejected.
 Documentation/accel/qaic/qaic.rst-172-
 --
 Documentation/admin-guide/cgroup-v2.rst=610=namespace of the process which is attempting the migration.  If either
 Documentation/admin-guide/cgroup-v2.rst:611:is not reachable, the migration is rejected with -ENOENT.
 Documentation/admin-guide/cgroup-v2.rst-612-
 --
 Documentation/admin-guide/cgroup-v2.rst=735=As allocations can't be over-committed, some configuration
 Documentation/admin-guide/cgroup-v2.rst:736:combinations are invalid and should be rejected.  Also, if the
 Documentation/admin-guide/cgroup-v2.rst-737-resource is mandatory for execution of processes, process migrations
 Documentation/admin-guide/cgroup-v2.rst:738:may be rejected.
 Documentation/admin-guide/cgroup-v2.rst-739-
 --
 Documentation/admin-guide/cgroup-v2.rst=1426=The following nested keys are defined.
 --
 Documentation/admin-guide/cgroup-v2.rst-1898-	reclaim inefficiency after disabling writeback (because the same
 Documentation/admin-guide/cgroup-v2.rst:1899:	pages might be rejected again and again).
 Documentation/admin-guide/cgroup-v2.rst-1900-
 --
 Documentation/admin-guide/cgroup-v2.rst=2449=Cpuset Interface Files
 --
 Documentation/admin-guide/cgroup-v2.rst-2569-	not allowed (the exclusivity rule).  A value that violates the
 Documentation/admin-guide/cgroup-v2.rst:2570:	exclusivity rule will be rejected with a write error.
 Documentation/admin-guide/cgroup-v2.rst-2571-
 --
 Documentation/admin-guide/hw-vuln/l1tf.rst=165=Guest mitigation mechanisms
 --
 Documentation/admin-guide/hw-vuln/l1tf.rst-321-			and offlined without restrictions. An attempt to
 Documentation/admin-guide/hw-vuln/l1tf.rst:322:			online a non-primary sibling is rejected
 Documentation/admin-guide/hw-vuln/l1tf.rst-323-
 Documentation/admin-guide/hw-vuln/l1tf.rst-324-	forceoff	Same as 'off' but the state cannot be controlled.
 Documentation/admin-guide/hw-vuln/l1tf.rst:325:			Attempts to write to the control file are rejected.
 Documentation/admin-guide/hw-vuln/l1tf.rst-326-
 --
 Documentation/admin-guide/hw-vuln/l1tf.rst-328-			not affected by the SMT implications of L1TF.
 Documentation/admin-guide/hw-vuln/l1tf.rst:329:			Attempts to write to the control file are rejected.
 Documentation/admin-guide/hw-vuln/l1tf.rst-330-	==============  ===================================================
 --
 Documentation/admin-guide/hw-vuln/l1tf.rst=445=line, then 'always' is enforced and the kvm-intel.vmentry_l1d_flush
 Documentation/admin-guide/hw-vuln/l1tf.rst:446:module parameter is ignored and writes to the sysfs file are rejected.
 Documentation/admin-guide/hw-vuln/l1tf.rst-447-
 --
 Documentation/admin-guide/laptops/disk-shock-protection.rst=54=cancel a previously set timeout and resume normal operation
 Documentation/admin-guide/laptops/disk-shock-protection.rst:55:immediately by specifying a timeout of 0. Values below -2 are rejected
 Documentation/admin-guide/laptops/disk-shock-protection.rst-56-with -EINVAL (see below for the special meaning of -1 and -2). If the
 --
 Documentation/admin-guide/md.rst=486=Each directory contains:
 --
 Documentation/admin-guide/md.rst-606-        array.  If a value less than the current component_size is
 Documentation/admin-guide/md.rst:607:        written, it will be rejected.
 Documentation/admin-guide/md.rst-608-
 --
 Documentation/admin-guide/mm/nommu-mmap.rst=216=The file->f_op->mmap() operation will be called to actually inaugurate the
 Documentation/admin-guide/mm/nommu-mmap.rst:217:mapping. It can be rejected at that point. Returning the ENOSYS error will
 Documentation/admin-guide/mm/nommu-mmap.rst-218-cause the mapping to be copied instead if NOMMU_MAP_COPY is specified.
 --
 Documentation/admin-guide/mm/nommu-mmap.rst=229=direct the call to the device-specific driver. Under such circumstances, the
 Documentation/admin-guide/mm/nommu-mmap.rst:230:mapping request will be rejected if NOMMU_MAP_COPY is not specified, and a
 Documentation/admin-guide/mm/nommu-mmap.rst-231-copy mapped otherwise.
 --
 Documentation/admin-guide/mm/transhuge.rst=234=support the following arguments::
 --
 Documentation/admin-guide/mm/transhuge.rst-247-		  a process level.
 Documentation/admin-guide/mm/transhuge.rst:248:		Note that MADV_COLLAPSE is currently always rejected if
 Documentation/admin-guide/mm/transhuge.rst-249-		madvise(..., MADV_NOHUGEPAGE) is set on an area.
 --
 Documentation/admin-guide/mm/zswap.rst=123=incompressible), users can observe reclaim inefficiency after disabling
 Documentation/admin-guide/mm/zswap.rst:124:writeback (because the same pages might be rejected again and again).
 Documentation/admin-guide/mm/zswap.rst-125-
 --
 Documentation/admin-guide/mm/zswap.rst=137=of pages stored, same-value filled pages and various counters for the reasons
 Documentation/admin-guide/mm/zswap.rst:138:pages are rejected.
 --
 Documentation/admin-guide/module-signing.rst=49=This has a number of options available:
 --
 Documentation/admin-guide/module-signing.rst-66-     Irrespective of the setting here, if the module has a signature block that
 Documentation/admin-guide/module-signing.rst:67:     cannot be parsed, it will be rejected out of hand.
 Documentation/admin-guide/module-signing.rst-68-
 --
 Documentation/admin-guide/module-signing.rst=274=a signature mismatch will not be permitted to load.
 Documentation/admin-guide/module-signing.rst-275-
 Documentation/admin-guide/module-signing.rst:276:Any module that has an unparsable signature will be rejected.
 Documentation/admin-guide/module-signing.rst-277-
 --
 Documentation/admin-guide/pm/cpuidle.rst=411=object corresponding to it, as follows:
 --
 Documentation/admin-guide/pm/cpuidle.rst-452-
 Documentation/admin-guide/pm/cpuidle.rst:453:``rejected``
 Documentation/admin-guide/pm/cpuidle.rst-454-	Total number of times a request to enter this idle state on the given
 Documentation/admin-guide/pm/cpuidle.rst:455:	CPU was rejected.
 Documentation/admin-guide/pm/cpuidle.rst-456-
 --
 Documentation/admin-guide/pm/cpuidle.rst=501=Generally, an interrupt received when trying to enter an idle state causes the
 Documentation/admin-guide/pm/cpuidle.rst:502:idle state entry request to be rejected, in which case the ``CPUIdle`` driver
 Documentation/admin-guide/pm/cpuidle.rst-503-may return an error code to indicate that this was the case. The :file:`usage`
 Documentation/admin-guide/pm/cpuidle.rst:504:and :file:`rejected` files report the number of times the given idle state
 Documentation/admin-guide/pm/cpuidle.rst:505:was entered successfully or rejected, respectively.
 Documentation/admin-guide/pm/cpuidle.rst-506-
 --
 Documentation/admin-guide/pm/cpuidle.rst=524=can be modified from user space by writing a string (representing a signed
 --
 Documentation/admin-guide/pm/cpuidle.rst-527-``<N>`` is allocated at the system initialization time.  Negative values
 Documentation/admin-guide/pm/cpuidle.rst:528:will be rejected in both cases and, also in both cases, the written integer
 Documentation/admin-guide/pm/cpuidle.rst-529-number will be interpreted as a requested PM QoS constraint in microseconds.
 --
 Documentation/admin-guide/pm/intel_pstate.rst=132=the EPP/EPB to a value different from 0 ("performance") via ``sysfs`` in this
 Documentation/admin-guide/pm/intel_pstate.rst:133:configuration will be rejected.
 Documentation/admin-guide/pm/intel_pstate.rst-134-
 --
 Documentation/admin-guide/reporting-issues.rst=114=After these preparations you'll now enter the main part:
 --
 Documentation/admin-guide/reporting-issues.rst-122-   ideally use a 'vanilla' build. Ignoring these advices will dramatically
 Documentation/admin-guide/reporting-issues.rst:123:   increase the risk your report will be rejected or ignored.
 Documentation/admin-guide/reporting-issues.rst-124-
 --
 Documentation/admin-guide/reporting-issues.rst=322=or heavily modified vendor kernel to the upstream Linux developers. But note,
 Documentation/admin-guide/reporting-issues.rst:323:those often get rejected or ignored, so consider yourself warned. But it's still
 Documentation/admin-guide/reporting-issues.rst-324-better than not reporting the issue at all: sometimes such reports directly or
 --
 Documentation/admin-guide/reporting-issues.rst=458=Make sure your kernel doesn't get enhanced
 --
 Documentation/admin-guide/reporting-issues.rst-464-
 Documentation/admin-guide/reporting-issues.rst:465:The risk your issue report gets ignored or rejected dramatically increases if
 Documentation/admin-guide/reporting-issues.rst-466-your kernel gets enhanced in any way. That's why you should remove or disable
 --
 Documentation/admin-guide/reporting-issues.rst=770=Install a fresh kernel for testing
 --
 Documentation/admin-guide/reporting-issues.rst-779-    ideally use a 'vanilla' built. Ignoring these advices will dramatically
 Documentation/admin-guide/reporting-issues.rst:780:    increase the risk your report will be rejected or ignored.*
 Documentation/admin-guide/reporting-issues.rst-781-
 --
 Documentation/admin-guide/reporting-issues.rst=788=earlier: doing so dramatically increases the risk that your issue report might
 Documentation/admin-guide/reporting-issues.rst:789:get rejected or simply ignored.
 Documentation/admin-guide/reporting-issues.rst-790-
 --
 Documentation/admin-guide/unicode.rst=97=adopted by the ConScript Unicode Registry and proposed (but ultimately
 Documentation/admin-guide/unicode.rst:98:rejected) for inclusion in Unicode Plane 1.  Thus, it remains as a
 Documentation/admin-guide/unicode.rst-99-Linux/CSUR private assignment in the Linux Zone.
 --
 Documentation/admin-guide/unicode.rst=186=The CSUR people are driving adding Tengwar and Cirth into Unicode
 Documentation/admin-guide/unicode.rst:187:Plane 1; the addition of Klingon to Unicode Plane 1 has been rejected
 Documentation/admin-guide/unicode.rst-188-and so the above encoding remains official.
 --
 Documentation/arch/arm64/asymmetric-32bit.rst=105=Explicit admission of a 32-bit deadline task to the default root domain
 Documentation/arch/arm64/asymmetric-32bit.rst:106:(e.g. by calling ``sched_setattr(2)``) is rejected on an asymmetric
 Documentation/arch/arm64/asymmetric-32bit.rst-107-32-bit system unless admission control is disabled by writing -1 to
 --
 Documentation/arch/arm64/gcs.rst=9=intended to be exhaustive.
 --
 Documentation/arch/arm64/gcs.rst-81-  values as used for PR_SET_SHADOW_STACK_STATUS.  Any future changes to the
 Documentation/arch/arm64/gcs.rst:82:  status of the specified GCS mode bits will be rejected.
 Documentation/arch/arm64/gcs.rst-83-
 --
 Documentation/arch/arm64/gcs.rst-102-  the stack will remain allocated for the lifetime of the thread.  At present
 Documentation/arch/arm64/gcs.rst:103:  any attempt to reenable GCS for the thread will be rejected, this may be
 Documentation/arch/arm64/gcs.rst-104-  revisited in future.
 --
 Documentation/arch/arm64/gcs.rst=180=When returning from a signal handler:
 --
 Documentation/arch/arm64/gcs.rst-197-* GCS may be disabled via signal return but any attempt to enable GCS via
 Documentation/arch/arm64/gcs.rst:198:  signal return will be rejected.
 Documentation/arch/arm64/gcs.rst-199-
 --
 Documentation/arch/powerpc/transactional_memory.rst=226=will not occur. If userspace constructs a sigcontext that enables TM
 Documentation/arch/powerpc/transactional_memory.rst:227:suspend, the sigcontext will be rejected by the kernel. This mode is
 Documentation/arch/powerpc/transactional_memory.rst-228-advertised to users with HWCAP2[PPC_FEATURE2_HTM_NO_SUSPEND] set.
 --
 Documentation/arch/sparc/oradax/dax-hv-api.txt=12=Chapter 36. Coprocessor services
 --
 Documentation/arch/sparc/oradax/dax-hv-api.txt-39-        machine, however, internal resource limitations within the virtual machine can cause CCB submissions
 Documentation/arch/sparc/oradax/dax-hv-api.txt:40:        to be temporarily rejected with EWOULDBLOCK. In such cases, guests should continue to attempt
 Documentation/arch/sparc/oradax/dax-hv-api.txt-41-        submissions until they succeed; waiting for an outstanding CCB to complete is not necessary, and would
 --
 Documentation/arch/sparc/oradax/dax-hv-api.txt-115-        node indicates N interrupts available, the guest may use any value from 0 to N - 1 (inclusive) in a CCB
 Documentation/arch/sparc/oradax/dax-hv-api.txt:116:        interrupt number field. Using values outside this range will result in the CCB being rejected for an invalid
 Documentation/arch/sparc/oradax/dax-hv-api.txt-117-        field value.
 --
 Documentation/arch/sparc/oradax/dax-hv-api.txt=224=bits set, and terminate at a CCB that has the Conditional bit set, but not the Pipeline bit.
 --
 Documentation/arch/sparc/oradax/dax-hv-api.txt-238-          for the submitting virtual processor. Virtual addresses which cannot be translated by the virtual machine
 Documentation/arch/sparc/oradax/dax-hv-api.txt:239:          will result in the CCB submission being rejected, with the causal virtual address indicated. The CCB
 Documentation/arch/sparc/oradax/dax-hv-api.txt-240-          may be resubmitted after inserting the translation, or the address may be translated by guest software and
 --
 Documentation/arch/sparc/oradax/dax-hv-api.txt-391-          value. The page size must be one of the sizes supported by the underlying virtual machine. Using a value
 Documentation/arch/sparc/oradax/dax-hv-api.txt:392:          that is not supported may result in the CCB submission being rejected or the generation of a CCB parsing
 Documentation/arch/sparc/oradax/dax-hv-api.txt-393-          error in the completion area.
 --
 Documentation/arch/sparc/oradax/dax-hv-api.txt=1127=Bits            Field Description
 --
 Documentation/arch/sparc/oradax/dax-hv-api.txt-1132-[13:12]         Alternate translation context for virtual addresses within CCBs:
 Documentation/arch/sparc/oradax/dax-hv-api.txt:1133:                 0b'00        CCBs requesting alternate context are rejected
 Documentation/arch/sparc/oradax/dax-hv-api.txt-1134-                 0b'01        Reserved
 --
 Documentation/arch/sparc/oradax/dax-hv-api.txt=1252=EUNAVAILABLE   The requested CCB operation could not be performed at this time. The
 --
 Documentation/arch/sparc/oradax/dax-hv-api.txt-1287-                                                the guest emulate the operation. The guest should expect all CCB
 Documentation/arch/sparc/oradax/dax-hv-api.txt:1288:                                                submissions to be similarly rejected in the near future.
 Documentation/arch/sparc/oradax/dax-hv-api.txt-1289-
 --
 Documentation/arch/x86/xstate.rst=152=are extended to control the guest permission:
 --
 Documentation/arch/x86/xstate.rst-169- first VCPU is created. Any attempt to change permission after that point
 Documentation/arch/x86/xstate.rst:170: is going to be rejected. So, the permission has to be requested before the
 Documentation/arch/x86/xstate.rst-171- first VCPU creation.
 --
 Documentation/bpf/bpf_design_QA.rst=103=There are also non-numerical limits that can cause the program
 Documentation/bpf/bpf_design_QA.rst:104:to be rejected. The verifier used to recognize only pointer + constant
 Documentation/bpf/bpf_design_QA.rst-105-expressions. Now it can recognize pointer + bounded_register.
 --
 Documentation/bpf/bpf_design_QA.rst=279=The kernel function protos will change and the bpf programs will be
 Documentation/bpf/bpf_design_QA.rst:280:rejected by the verifier.  Also, for example, some of the bpf-callable
 Documentation/bpf/bpf_design_QA.rst-281-kernel functions have already been used by other kernel tcp
 --
 Documentation/bpf/bpf_devel_QA.rst=106=from the current review queue. Likewise for cases where patches would
 Documentation/bpf/bpf_devel_QA.rst:107:get rejected or are not applicable to the BPF trees (but assigned to
 Documentation/bpf/bpf_devel_QA.rst-108-the 'bpf' delegate).
 --
 Documentation/bpf/bpf_prog_run.rst=66=run mode. Specifically:
 --
 Documentation/bpf/bpf_prog_run.rst-71-  it, etc). For this reason, setting the ``data_out`` or ``ctx_out`` attributes
 Documentation/bpf/bpf_prog_run.rst:72:  in the syscall parameters when running in this mode will be rejected. In
 Documentation/bpf/bpf_prog_run.rst-73-  addition, not all failures will be reported back to userspace directly;
 --
 Documentation/bpf/graph_ds_impl.rst=117=but that would result in programs with useful, common coding patterns being
 Documentation/bpf/graph_ds_impl.rst:118:rejected, e.g.:
 Documentation/bpf/graph_ds_impl.rst-119-
 --
 Documentation/bpf/graph_ds_impl.rst-132-
 Documentation/bpf/graph_ds_impl.rst:133:Both the read from and write to ``n->data`` would be rejected. The verifier
 Documentation/bpf/graph_ds_impl.rst-134-can do better, though, by taking advantage of two details:
 --
 Documentation/bpf/kfuncs.rst=538=procedure is followed for removal:
 --
 Documentation/bpf/kfuncs.rst-555-3. After the deprecation period the kfunc will be removed. At this point, BPF
 Documentation/bpf/kfuncs.rst:556:   programs calling the kfunc will be rejected by the verifier.
 Documentation/bpf/kfuncs.rst-557-
 --
 Documentation/bpf/ringbuf.rst=33=type ``BPF_MAP_TYPE_RINGBUF``. Two other alternatives considered, but
 Documentation/bpf/ringbuf.rst:34:ultimately rejected.
 Documentation/bpf/ringbuf.rst-35-
 --
 Documentation/bpf/verifier.rst=25=If register was never written to, it's not readable::
 --
 Documentation/bpf/verifier.rst-29-
 Documentation/bpf/verifier.rst:30:will be rejected, since R2 is unreadable at the start of the program.
 Documentation/bpf/verifier.rst-31-
 --
 Documentation/bpf/verifier.rst=44=is a correct program. If there was R1 instead of R6, it would have
 Documentation/bpf/verifier.rst:45:been rejected.
 Documentation/bpf/verifier.rst-46-
 --
 Documentation/bpf/verifier.rst=49=For example::
 --
 Documentation/bpf/verifier.rst-55-
 Documentation/bpf/verifier.rst:56:will be rejected, since R1 doesn't have a valid pointer type at the time of
 Documentation/bpf/verifier.rst-57-execution of instruction bpf_xadd.
 --
 Documentation/crypto/asymmetric-keys.rst=336=Several restriction methods are available:
 --
 Documentation/crypto/asymmetric-keys.rst-344-     If the builtin trusted keyring is not configured, all links will be
 Documentation/crypto/asymmetric-keys.rst:345:     rejected.  The ca_keys kernel parameter also affects which keys are used
 Documentation/crypto/asymmetric-keys.rst-346-     for signature verification.
 --
 Documentation/devicetree/bindings/input/azoteq,iqs7222.yaml=18=properties:
 --
 Documentation/devicetree/bindings/input/azoteq,iqs7222.yaml-296-              original point of contact across which the contact is permitted
 Documentation/devicetree/bindings/input/azoteq,iqs7222.yaml:297:              to travel before the gesture is rejected by the device.
 Documentation/devicetree/bindings/input/azoteq,iqs7222.yaml-298-
 --
 Documentation/driver-api/firmware/fallback-mechanisms.rst=252=Note that:
 --
 Documentation/driver-api/firmware/fallback-mechanisms.rst-269-   brute-force solution. There has been discussion to use the UEFI Platform
 Documentation/driver-api/firmware/fallback-mechanisms.rst:270:   Initialization (PI) spec's Firmware Volume protocol. This has been rejected
 Documentation/driver-api/firmware/fallback-mechanisms.rst-271-   because the FV Protocol relies on *internal* interfaces of the PI spec, and:
 --
 Documentation/driver-api/media/maintainer-entry-profile.rst=40=at linux-media@vger.kernel.org as plain text only e-mail. Emails with
 Documentation/driver-api/media/maintainer-entry-profile.rst:41:HTML will be automatically rejected by the mail server. It could be wise
 Documentation/driver-api/media/maintainer-entry-profile.rst-42-to also copy the sub-maintainer(s).
 --
 Documentation/driver-api/usb/error-codes.rst=29=USB-specific:
 --
 Documentation/driver-api/usb/error-codes.rst-74-
 Documentation/driver-api/usb/error-codes.rst:75:``-EHOSTUNREACH``	URB was rejected because the device is suspended.
 Documentation/driver-api/usb/error-codes.rst-76-
 --
 Documentation/fault-injection/fault-injection.rst=97=configuration of fault-injection capabilities.
 --
 Documentation/fault-injection/fault-injection.rst-152-	in the walked stacktrace lies within the required range, and
 Documentation/fault-injection/fault-injection.rst:153:	none lies within the rejected range.
 Documentation/fault-injection/fault-injection.rst-154-	Default required range is [0,ULONG_MAX) (whole of virtual address space).
 Documentation/fault-injection/fault-injection.rst:155:	Default rejected range is [0,0).
 Documentation/fault-injection/fault-injection.rst-156-
 --
 Documentation/filesystems/automount-support.rst=82=As an alternative, it is possible for userspace to request expiry of any
 Documentation/filesystems/automount-support.rst:83:mountpoint (though some will be rejected - the current process's idea of the
 Documentation/filesystems/automount-support.rst-84-rootfs for example). It does this by passing the MNT_EXPIRE flag to
 --
 Documentation/filesystems/befs.rst=57=is called patch-befs-xxx, you would do the following:
 --
 Documentation/filesystems/befs.rst-61-
 Documentation/filesystems/befs.rst:62:if the patching step fails (i.e. there are rejected hunks), you can try to
 Documentation/filesystems/befs.rst-63-figure it out yourself (it shouldn't be hard), or mail the maintainer
 --
 Documentation/filesystems/mount_api.rst=308=number of operations used by the new mount code for this purpose:
 --
 Documentation/filesystems/mount_api.rst-351-     the parameter should be discarded or an error to indicate that the
 Documentation/filesystems/mount_api.rst:352:     parameter should be rejected.
 Documentation/filesystems/mount_api.rst-353-
 --
 Documentation/filesystems/overlayfs.rst=447=least one data-only layer to enable redirection of data to a data-only layer.
 Documentation/filesystems/overlayfs.rst:448:In this case other forms of metacopy are rejected.  Note: this way, data-only
 Documentation/filesystems/overlayfs.rst-449-layers may be used together with "userxattr", in which case careful attention
 --
 Documentation/filesystems/xfs/xfs-online-fsck-design.rst=1641=Several other solutions to this problem were evaluated upon discovery of this
 Documentation/filesystems/xfs/xfs-online-fsck-design.rst:1642:flaw and rejected:
 Documentation/filesystems/xfs/xfs-online-fsck-design.rst-1643-
 --
 Documentation/gpu/amdgpu/display/mpo-overview.rst=59=hypothetical hardware that we are using as an example, we have an absolute
 Documentation/gpu/amdgpu/display/mpo-overview.rst:60:limit of 4 planes across all CRTCs. Atomic commits will be rejected for display
 Documentation/gpu/amdgpu/display/mpo-overview.rst-61-configurations using more than 4 planes. Again, it is important to stress that
 --
 Documentation/gpu/amdgpu/display/mpo-overview.rst=68=AMDGPU imposes restrictions on the use of DRM planes in the driver.
 Documentation/gpu/amdgpu/display/mpo-overview.rst-69-
 Documentation/gpu/amdgpu/display/mpo-overview.rst:70:Atomic commits will be rejected for commits which do not follow these
 Documentation/gpu/amdgpu/display/mpo-overview.rst-71-restrictions:
 --
 Documentation/gpu/drm-uapi.rst=332=After command submission, UMD should check if the submission was accepted or
 Documentation/gpu/drm-uapi.rst:333:rejected. After a reset, KMD should reject submissions, and UMD can issue an
 Documentation/gpu/drm-uapi.rst-334-ioctl to the KMD to check the reset status, and this can be checked more often
 --
 Documentation/gpu/drm-uapi.rst=412=device must be kept in 'wedged' state until the recovery is performed. New
 Documentation/gpu/drm-uapi.rst:413:accesses to the device (IOCTLs) should be rejected, preferably with an error
 Documentation/gpu/drm-uapi.rst-414-code that resembles the type of failure the device has encountered. This will
 --
 Documentation/gpu/drm-vm-bind-async.rst=111=out-syncobjs, so while theoretically possible the use of them is
 Documentation/gpu/drm-vm-bind-async.rst:112:questionable and should be rejected until there is a valuable use-case.
 Documentation/gpu/drm-vm-bind-async.rst-113-Note that this is not a limitation imposed by dma-fence rules, but
 --
 Documentation/gpu/todo.rst=776=There is support in place now for writing internal DRM clients making it
 Documentation/gpu/todo.rst:777:possible to pick up the bootsplash work that was rejected because it was written
 Documentation/gpu/todo.rst-778-for fbdev.
 --
 Documentation/hwmon/hwmon-kernel-api.rst=69=names. Device names including invalid characters (whitespace, '*', or '-')
 Documentation/hwmon/hwmon-kernel-api.rst:70:will be rejected. If NULL is passed as name parameter, the hardware monitoring
 Documentation/hwmon/hwmon-kernel-api.rst-71-device name will be derived from the parent device name.
 --
 Documentation/kernel-hacking/hacking.rst=723=make a neat patch, there's administrative work to be done:
 --
 Documentation/kernel-hacking/hacking.rst-728-   people to make sure you're not duplicating effort, or trying something
 Documentation/kernel-hacking/hacking.rst:729:   that's already been rejected.
 Documentation/kernel-hacking/hacking.rst-730-
 --
 Documentation/livepatch/livepatch.rst=320=are applied. The relevant entries are created under
 Documentation/livepatch/livepatch.rst:321:/sys/kernel/livepatch/<name>. The patch is rejected when any above
 Documentation/livepatch/livepatch.rst-322-operation fails.
 --
 Documentation/livepatch/livepatch.rst=411=The current Livepatch implementation has several limitations:
 --
 Documentation/livepatch/livepatch.rst-441-    the return address. The first user wins. Either the probe or the patch
 Documentation/livepatch/livepatch.rst:442:    is rejected when the handler is already in use by the other.
 Documentation/livepatch/livepatch.rst-443-
 --
 Documentation/maintainer/rebasing-and-merging.rst=140=Such merges need to be carefully thought about and well justified, or
 Documentation/maintainer/rebasing-and-merging.rst:141:there's a good chance that a subsequent pull request will be rejected.
 Documentation/maintainer/rebasing-and-merging.rst-142-
 --
 Documentation/mm/damon/design.rst=668=scheme's action to it depends on the last filter's allowance type.  If the last
 Documentation/mm/damon/design.rst:669:filter was for allowing, the part of memory will be rejected, and vice versa.
 Documentation/mm/damon/design.rst-670-
 --
 Documentation/netlabel/draft-ietf-cipso-ipsecurity-01.txt=450=a CIPSO host is authorized to handle.  All datagrams that have a label
 Documentation/netlabel/draft-ietf-cipso-ipsecurity-01.txt:451:greater than this maximum MUST be rejected by the CIPSO host.  This
 Documentation/netlabel/draft-ietf-cipso-ipsecurity-01.txt-452-parameter does not apply to CIPSO gateways or routers.  This parameter need
 --
 Documentation/netlabel/draft-ietf-cipso-ipsecurity-01.txt=468=a CIPSO host is authorized to handle.  All datagrams that have a label less
 Documentation/netlabel/draft-ietf-cipso-ipsecurity-01.txt:469:than this minimum MUST be rejected by the CIPSO host.  This parameter does
 Documentation/netlabel/draft-ietf-cipso-ipsecurity-01.txt-470-not apply to CIPSO gateways or routers.  This parameter need not be defined
 --
 Documentation/netlabel/draft-ietf-cipso-ipsecurity-01.txt=476=outgoing datagrams that have a label greater than this maximum MUST be
 Documentation/netlabel/draft-ietf-cipso-ipsecurity-01.txt:477:rejected by the CIPSO system.  The label within this parameter MUST be
 Documentation/netlabel/draft-ietf-cipso-ipsecurity-01.txt-478-less than or equal to the label within the HOST_LABEL_MAX parameter.  This
 --
 Documentation/netlabel/draft-ietf-cipso-ipsecurity-01.txt=483=outgoing datagrams that have a label less than this minimum MUST be
 Documentation/netlabel/draft-ietf-cipso-ipsecurity-01.txt:484:rejected by the CIPSO system.  The label within this parameter MUST be
 Documentation/netlabel/draft-ietf-cipso-ipsecurity-01.txt-485-greater than or equal to the label within the HOST_LABEL_MIN parameter.
 --
 Documentation/netlink/specs/ovs_flow.yaml=11=definitions:
 --
 Documentation/netlink/specs/ovs_flow.yaml-319-          ethertype should ever be given are ETH_P_MPLS_UC and ETH_P_MPLS_MC,
 Documentation/netlink/specs/ovs_flow.yaml:320:          indicating MPLS unicast or multicast. Other are rejected.
 Documentation/netlink/specs/ovs_flow.yaml-321-  -
 --
 Documentation/netlink/specs/ovs_flow.yaml-337-          ethertype should ever be given are ETH_P_MPLS_UC and ETH_P_MPLS_MC,
 Documentation/netlink/specs/ovs_flow.yaml:338:          indicating MPLS unicast or multicast. Other are rejected.
 Documentation/netlink/specs/ovs_flow.yaml-339-      -
 --
 Documentation/networking/device_drivers/ethernet/freescale/dpaa2/switch-driver.rst=182=When using the tc-flower classifier with the 802.1q protocol, only the
 Documentation/networking/device_drivers/ethernet/freescale/dpaa2/switch-driver.rst-183-''vlan_id'' key will be accepted. Mirroring based on any other fields from the
 Documentation/networking/device_drivers/ethernet/freescale/dpaa2/switch-driver.rst:184:802.1q protocol will be rejected::
 Documentation/networking/device_drivers/ethernet/freescale/dpaa2/switch-driver.rst-185-
 --
 Documentation/networking/devlink/ice.rst=227=preserving settings, and thus ``DEVLINK_FLASH_OVERWRITE_IDENTIFIERS`` on its
 Documentation/networking/devlink/ice.rst:228:own will be rejected. If no overwrite mask is provided, the firmware will be
 Documentation/networking/devlink/ice.rst-229-instructed to preserve all settings and identifying fields when updating.
 --
 Documentation/networking/dsa/dsa.rst=976=Bridge VLAN filtering
 --
 Documentation/networking/dsa/dsa.rst-984-  VLAN ID map/rules.  If there is no PVID programmed into the switch port,
 Documentation/networking/dsa/dsa.rst:985:  untagged frames must be rejected as well. When turned off the switch must
 Documentation/networking/dsa/dsa.rst-986-  accept any 802.1Q frames irrespective of their VLAN ID, and untagged frames are
 --
 Documentation/networking/ethtool-netlink.rst=442=MDI(-X) status and transceiver cannot be set, request with the corresponding
 Documentation/networking/ethtool-netlink.rst:443:attributes is rejected.
 Documentation/networking/ethtool-netlink.rst-444-
 --
 Documentation/networking/ethtool-netlink.rst=1113=Request contents:
 --
 Documentation/networking/ethtool-netlink.rst-1147-
 Documentation/networking/ethtool-netlink.rst:1148:Request is rejected if it attributes declared as unsupported by driver (i.e.
 Documentation/networking/ethtool-netlink.rst-1149-such that the corresponding bit in ``ethtool_ops::supported_coalesce_params``
 --
 Documentation/networking/ethtool-netlink.rst=2024=device needs at least 8 entries - the real table in use will end up being
 Documentation/networking/ethtool-netlink.rst-2025-``[0, 1, 0, 1, 0, 1, 0, 1]``. Most devices require the table size to be power
 Documentation/networking/ethtool-netlink.rst:2026:of 2, so tables which size is not a power of 2 will likely be rejected.
 Documentation/networking/ethtool-netlink.rst-2027-Using table of size 0 will reset the indirection table to the default.
 --
 Documentation/networking/j1939.rst=228=address being claimed. This serves as a base for filter schemes. By default,
 Documentation/networking/j1939.rst:229:packets with a destination that is not locally will be rejected.
 Documentation/networking/j1939.rst-230-
 --
 Documentation/networking/ppp_generic.rst=50=via the ppp_channel.ops pointer:
 --
 Documentation/networking/ppp_generic.rst-56-  later time when it can accept frames again, and the generic layer
 Documentation/networking/ppp_generic.rst:57:  will then attempt to retransmit the rejected frame(s).  If the frame
 Documentation/networking/ppp_generic.rst-58-  is accepted, the start_xmit() function should return 1.
 --
 Documentation/networking/ppp_generic.rst=66=The generic PPP layer provides seven functions to channels:
 --
 Documentation/networking/ppp_generic.rst-77-* ppp_output_wakeup() is called by a channel when it has previously
 Documentation/networking/ppp_generic.rst:78:  rejected a call to its start_xmit function, and can now accept more
 Documentation/networking/ppp_generic.rst-79-  packets.
 --
 Documentation/networking/rxrpc.rst=326=calls, to invoke certain actions and to report certain conditions.  These are:
 --
 Documentation/networking/rxrpc.rst-334-	RXRPC_NET_ERROR		-rt error num	Network error on call
 Documentation/networking/rxrpc.rst:335:	RXRPC_BUSY		-rt n/a		Call rejected (server busy)
 Documentation/networking/rxrpc.rst-336-	RXRPC_LOCAL_ERROR	-rt error num	Local error encountered
 --
 Documentation/networking/rxrpc.rst-378-     This is delivered to a client application to indicate that a call was
 Documentation/networking/rxrpc.rst:379:     rejected by the server due to the server being busy.  It will be
 Documentation/networking/rxrpc.rst:380:     associated with an RXRPC_USER_CALL_ID to indicate the rejected call.
 Documentation/networking/rxrpc.rst-381-
 --
 Documentation/networking/rxrpc.rst=795=The kernel interface functions are as follows:
 --
 Documentation/networking/rxrpc.rst-961-	RXRPC_SKB_MARK_FINAL_ACK	Final ACK received for an incoming call
 Documentation/networking/rxrpc.rst:962:	RXRPC_SKB_MARK_BUSY		Client call rejected as server busy
 Documentation/networking/rxrpc.rst-963-	RXRPC_SKB_MARK_REMOTE_ABORT	Call aborted by peer
 --
 Documentation/networking/tls-handshake.rst=180=parameter:
 --
 Documentation/networking/tls-handshake.rst-186-+------------+----------------------------------------------+
 Documentation/networking/tls-handshake.rst:187:|  -EACCESS  |  Remote peer rejected the handshake or       |
 Documentation/networking/tls-handshake.rst-188-|            |  authentication failed                       |
 --
 Documentation/process/howto.rst=322=revisions to it, and maintainers can mark patches as under review,
 Documentation/process/howto.rst:323:accepted, or rejected.  Most of these patchwork sites are listed at
 Documentation/process/howto.rst-324-https://patchwork.kernel.org/.
 --
 Documentation/process/maintainer-netdev.rst=133=Changes requested  patch has not passed the review, new revision is expected
 Documentation/process/maintainer-netdev.rst-134-                   with appropriate code and commit message changes
 Documentation/process/maintainer-netdev.rst:135:Rejected           patch has been rejected and new revision is not expected
 Documentation/process/maintainer-netdev.rst-136-Not applicable     patch is expected to be applied outside of the networking
 --
 Documentation/process/maintainer-netdev.rst=138=Awaiting upstream  patch should be reviewed and handled by appropriate
 --
 Documentation/process/maintainer-netdev.rst-141-                   will usually remain in this state, whether the sub-maintainer
 Documentation/process/maintainer-netdev.rst:142:                   requested changes, accepted or rejected the patch
 Documentation/process/maintainer-netdev.rst-143-Deferred           patch needs to be reposted later, usually due to dependency
 --
 Documentation/process/stable-kernel-rules.rst=172=The sender will receive an ACK when the patch has been accepted into the
 Documentation/process/stable-kernel-rules.rst:173:queue, or a NAK if the patch is rejected.  This response might take a few
]
]

gemini-3.1-pro-preview

							input: 107070
							output: 15
							thoughts: 877
						

**Vsock Socket Leak Analysis**

Okay, let's break this down. My initial thought was triggered by `vconnected->rejected = true` being set within `vsock_accept`. The question immediately arose: does `vsock_sk_destruct` handle the `rejected` flag? A quick check of `vsock_sk_destruct` reveals that it does *not*. No dice.

Next, I looked at `vsock_release`, figuring that might be the point of cleanup. Nope, no `rejected` check there either.

Aha! Now I see it. If `vconnected->rejected = true`, then `sock_put(connected)` is called. And `connected` is *not* grafted to `newsock`, and it is *not* in the accept queue. Meaning the reference count is decremented to 1. But... who holds that last reference?

Ah, right! `vsock_insert_connected` calls `sock_hold(&vsk->sk)`. Therefore, the `connected` socket is still in the connected table! Its `sk_refcnt` is now 1 because of the connected table. But here's the kicker: if it *is* in the connected table, who removes it?

Typically, `__vsock_release` handles the removal, specifically if there is no transport `vsock_remove_sock(vsk)` is called. However, `__vsock_release` is only called when the socket is closed! If `accept4` fails, `newsock` never gets grafted to `connected`. So, `connected` never gets closed! User space has no file descriptor for it, and it's not in the accept queue, so closing the listener doesn't flush it. This socket is effectively stuck in the connected table *forever*, and its `sk_refcnt` is 1. We have a leak!

Let's double-check this within `vsock_accept` to be sure. The code comment explicitly states "we simply mark the socket rejected, drop our reference, and let the cleanup function handle the cleanup; the fact that we found it in the listener's accept queue guarantees that the cleanup function hasn't run yet." My question is: What is this "cleanup function"?

Alright, time to search the code for all instances of `rejected` within `af_vsock.c`. Let's verify this leak scenario.

map[Expression:rejected]

map[Output:
Full output is too long, showing 500 out of 5825 lines.
Use more precise expression if possible.

[Documentation/ABI/testing/sysfs-block-device=27=Description:
 --
 Documentation/ABI/testing/sysfs-block-device-46-		  writing -2.
 Documentation/ABI/testing/sysfs-block-device:47:		- Values below -2 are rejected with -EINVAL
 Documentation/ABI/testing/sysfs-block-device-48-
 --
 Documentation/ABI/testing/sysfs-class-firmware=17=Description:	Write-only. For firmware uploads, write a "1" to this file to
 Documentation/ABI/testing/sysfs-class-firmware-18-		request that the transfer of firmware data to the lower-level
 Documentation/ABI/testing/sysfs-class-firmware:19:		device be canceled. This request will be rejected (EBUSY) if
 Documentation/ABI/testing/sysfs-class-firmware-20-		the update cannot be canceled (e.g. a FLASH write is in
 --
 Documentation/ABI/testing/sysfs-devices-system-cpu=611=Description:	Control Symmetric Multi Threading (SMT)
 --
 Documentation/ABI/testing/sysfs-devices-system-cpu-628-			 If control status is "forceoff" or "notsupported" writes
 Documentation/ABI/testing/sysfs-devices-system-cpu:629:			 are rejected. Note that enabling SMT on PowerPC skips
 Documentation/ABI/testing/sysfs-devices-system-cpu-630-			 offline cores.
 --
 Documentation/accel/qaic/qaic.rst=170=workloads. Attempts to access resources assigned to other clients will be
 Documentation/accel/qaic/qaic.rst:171:rejected.
 Documentation/accel/qaic/qaic.rst-172-
 --
 Documentation/admin-guide/cgroup-v2.rst=610=namespace of the process which is attempting the migration.  If either
 Documentation/admin-guide/cgroup-v2.rst:611:is not reachable, the migration is rejected with -ENOENT.
 Documentation/admin-guide/cgroup-v2.rst-612-
 --
 Documentation/admin-guide/cgroup-v2.rst=735=As allocations can't be over-committed, some configuration
 Documentation/admin-guide/cgroup-v2.rst:736:combinations are invalid and should be rejected.  Also, if the
 Documentation/admin-guide/cgroup-v2.rst-737-resource is mandatory for execution of processes, process migrations
 Documentation/admin-guide/cgroup-v2.rst:738:may be rejected.
 Documentation/admin-guide/cgroup-v2.rst-739-
 --
 Documentation/admin-guide/cgroup-v2.rst=1426=The following nested keys are defined.
 --
 Documentation/admin-guide/cgroup-v2.rst-1898-	reclaim inefficiency after disabling writeback (because the same
 Documentation/admin-guide/cgroup-v2.rst:1899:	pages might be rejected again and again).
 Documentation/admin-guide/cgroup-v2.rst-1900-
 --
 Documentation/admin-guide/cgroup-v2.rst=2449=Cpuset Interface Files
 --
 Documentation/admin-guide/cgroup-v2.rst-2569-	not allowed (the exclusivity rule).  A value that violates the
 Documentation/admin-guide/cgroup-v2.rst:2570:	exclusivity rule will be rejected with a write error.
 Documentation/admin-guide/cgroup-v2.rst-2571-
 --
 Documentation/admin-guide/hw-vuln/l1tf.rst=165=Guest mitigation mechanisms
 --
 Documentation/admin-guide/hw-vuln/l1tf.rst-321-			and offlined without restrictions. An attempt to
 Documentation/admin-guide/hw-vuln/l1tf.rst:322:			online a non-primary sibling is rejected
 Documentation/admin-guide/hw-vuln/l1tf.rst-323-
 Documentation/admin-guide/hw-vuln/l1tf.rst-324-	forceoff	Same as 'off' but the state cannot be controlled.
 Documentation/admin-guide/hw-vuln/l1tf.rst:325:			Attempts to write to the control file are rejected.
 Documentation/admin-guide/hw-vuln/l1tf.rst-326-
 --
 Documentation/admin-guide/hw-vuln/l1tf.rst-328-			not affected by the SMT implications of L1TF.
 Documentation/admin-guide/hw-vuln/l1tf.rst:329:			Attempts to write to the control file are rejected.
 Documentation/admin-guide/hw-vuln/l1tf.rst-330-	==============  ===================================================
 --
 Documentation/admin-guide/hw-vuln/l1tf.rst=445=line, then 'always' is enforced and the kvm-intel.vmentry_l1d_flush
 Documentation/admin-guide/hw-vuln/l1tf.rst:446:module parameter is ignored and writes to the sysfs file are rejected.
 Documentation/admin-guide/hw-vuln/l1tf.rst-447-
 --
 Documentation/admin-guide/laptops/disk-shock-protection.rst=54=cancel a previously set timeout and resume normal operation
 Documentation/admin-guide/laptops/disk-shock-protection.rst:55:immediately by specifying a timeout of 0. Values below -2 are rejected
 Documentation/admin-guide/laptops/disk-shock-protection.rst-56-with -EINVAL (see below for the special meaning of -1 and -2). If the
 --
 Documentation/admin-guide/md.rst=486=Each directory contains:
 --
 Documentation/admin-guide/md.rst-606-        array.  If a value less than the current component_size is
 Documentation/admin-guide/md.rst:607:        written, it will be rejected.
 Documentation/admin-guide/md.rst-608-
 --
 Documentation/admin-guide/mm/nommu-mmap.rst=216=The file->f_op->mmap() operation will be called to actually inaugurate the
 Documentation/admin-guide/mm/nommu-mmap.rst:217:mapping. It can be rejected at that point. Returning the ENOSYS error will
 Documentation/admin-guide/mm/nommu-mmap.rst-218-cause the mapping to be copied instead if NOMMU_MAP_COPY is specified.
 --
 Documentation/admin-guide/mm/nommu-mmap.rst=229=direct the call to the device-specific driver. Under such circumstances, the
 Documentation/admin-guide/mm/nommu-mmap.rst:230:mapping request will be rejected if NOMMU_MAP_COPY is not specified, and a
 Documentation/admin-guide/mm/nommu-mmap.rst-231-copy mapped otherwise.
 --
 Documentation/admin-guide/mm/transhuge.rst=234=support the following arguments::
 --
 Documentation/admin-guide/mm/transhuge.rst-247-		  a process level.
 Documentation/admin-guide/mm/transhuge.rst:248:		Note that MADV_COLLAPSE is currently always rejected if
 Documentation/admin-guide/mm/transhuge.rst-249-		madvise(..., MADV_NOHUGEPAGE) is set on an area.
 --
 Documentation/admin-guide/mm/zswap.rst=123=incompressible), users can observe reclaim inefficiency after disabling
 Documentation/admin-guide/mm/zswap.rst:124:writeback (because the same pages might be rejected again and again).
 Documentation/admin-guide/mm/zswap.rst-125-
 --
 Documentation/admin-guide/mm/zswap.rst=137=of pages stored, same-value filled pages and various counters for the reasons
 Documentation/admin-guide/mm/zswap.rst:138:pages are rejected.
 --
 Documentation/admin-guide/module-signing.rst=49=This has a number of options available:
 --
 Documentation/admin-guide/module-signing.rst-66-     Irrespective of the setting here, if the module has a signature block that
 Documentation/admin-guide/module-signing.rst:67:     cannot be parsed, it will be rejected out of hand.
 Documentation/admin-guide/module-signing.rst-68-
 --
 Documentation/admin-guide/module-signing.rst=274=a signature mismatch will not be permitted to load.
 Documentation/admin-guide/module-signing.rst-275-
 Documentation/admin-guide/module-signing.rst:276:Any module that has an unparsable signature will be rejected.
 Documentation/admin-guide/module-signing.rst-277-
 --
 Documentation/admin-guide/pm/cpuidle.rst=411=object corresponding to it, as follows:
 --
 Documentation/admin-guide/pm/cpuidle.rst-452-
 Documentation/admin-guide/pm/cpuidle.rst:453:``rejected``
 Documentation/admin-guide/pm/cpuidle.rst-454-	Total number of times a request to enter this idle state on the given
 Documentation/admin-guide/pm/cpuidle.rst:455:	CPU was rejected.
 Documentation/admin-guide/pm/cpuidle.rst-456-
 --
 Documentation/admin-guide/pm/cpuidle.rst=501=Generally, an interrupt received when trying to enter an idle state causes the
 Documentation/admin-guide/pm/cpuidle.rst:502:idle state entry request to be rejected, in which case the ``CPUIdle`` driver
 Documentation/admin-guide/pm/cpuidle.rst-503-may return an error code to indicate that this was the case. The :file:`usage`
 Documentation/admin-guide/pm/cpuidle.rst:504:and :file:`rejected` files report the number of times the given idle state
 Documentation/admin-guide/pm/cpuidle.rst:505:was entered successfully or rejected, respectively.
 Documentation/admin-guide/pm/cpuidle.rst-506-
 --
 Documentation/admin-guide/pm/cpuidle.rst=524=can be modified from user space by writing a string (representing a signed
 --
 Documentation/admin-guide/pm/cpuidle.rst-527-``<N>`` is allocated at the system initialization time.  Negative values
 Documentation/admin-guide/pm/cpuidle.rst:528:will be rejected in both cases and, also in both cases, the written integer
 Documentation/admin-guide/pm/cpuidle.rst-529-number will be interpreted as a requested PM QoS constraint in microseconds.
 --
 Documentation/admin-guide/pm/intel_pstate.rst=132=the EPP/EPB to a value different from 0 ("performance") via ``sysfs`` in this
 Documentation/admin-guide/pm/intel_pstate.rst:133:configuration will be rejected.
 Documentation/admin-guide/pm/intel_pstate.rst-134-
 --
 Documentation/admin-guide/reporting-issues.rst=114=After these preparations you'll now enter the main part:
 --
 Documentation/admin-guide/reporting-issues.rst-122-   ideally use a 'vanilla' build. Ignoring these advices will dramatically
 Documentation/admin-guide/reporting-issues.rst:123:   increase the risk your report will be rejected or ignored.
 Documentation/admin-guide/reporting-issues.rst-124-
 --
 Documentation/admin-guide/reporting-issues.rst=322=or heavily modified vendor kernel to the upstream Linux developers. But note,
 Documentation/admin-guide/reporting-issues.rst:323:those often get rejected or ignored, so consider yourself warned. But it's still
 Documentation/admin-guide/reporting-issues.rst-324-better than not reporting the issue at all: sometimes such reports directly or
 --
 Documentation/admin-guide/reporting-issues.rst=458=Make sure your kernel doesn't get enhanced
 --
 Documentation/admin-guide/reporting-issues.rst-464-
 Documentation/admin-guide/reporting-issues.rst:465:The risk your issue report gets ignored or rejected dramatically increases if
 Documentation/admin-guide/reporting-issues.rst-466-your kernel gets enhanced in any way. That's why you should remove or disable
 --
 Documentation/admin-guide/reporting-issues.rst=770=Install a fresh kernel for testing
 --
 Documentation/admin-guide/reporting-issues.rst-779-    ideally use a 'vanilla' built. Ignoring these advices will dramatically
 Documentation/admin-guide/reporting-issues.rst:780:    increase the risk your report will be rejected or ignored.*
 Documentation/admin-guide/reporting-issues.rst-781-
 --
 Documentation/admin-guide/reporting-issues.rst=788=earlier: doing so dramatically increases the risk that your issue report might
 Documentation/admin-guide/reporting-issues.rst:789:get rejected or simply ignored.
 Documentation/admin-guide/reporting-issues.rst-790-
 --
 Documentation/admin-guide/unicode.rst=97=adopted by the ConScript Unicode Registry and proposed (but ultimately
 Documentation/admin-guide/unicode.rst:98:rejected) for inclusion in Unicode Plane 1.  Thus, it remains as a
 Documentation/admin-guide/unicode.rst-99-Linux/CSUR private assignment in the Linux Zone.
 --
 Documentation/admin-guide/unicode.rst=186=The CSUR people are driving adding Tengwar and Cirth into Unicode
 Documentation/admin-guide/unicode.rst:187:Plane 1; the addition of Klingon to Unicode Plane 1 has been rejected
 Documentation/admin-guide/unicode.rst-188-and so the above encoding remains official.
 --
 Documentation/arch/arm64/asymmetric-32bit.rst=105=Explicit admission of a 32-bit deadline task to the default root domain
 Documentation/arch/arm64/asymmetric-32bit.rst:106:(e.g. by calling ``sched_setattr(2)``) is rejected on an asymmetric
 Documentation/arch/arm64/asymmetric-32bit.rst-107-32-bit system unless admission control is disabled by writing -1 to
 --
 Documentation/arch/arm64/gcs.rst=9=intended to be exhaustive.
 --
 Documentation/arch/arm64/gcs.rst-81-  values as used for PR_SET_SHADOW_STACK_STATUS.  Any future changes to the
 Documentation/arch/arm64/gcs.rst:82:  status of the specified GCS mode bits will be rejected.
 Documentation/arch/arm64/gcs.rst-83-
 --
 Documentation/arch/arm64/gcs.rst-102-  the stack will remain allocated for the lifetime of the thread.  At present
 Documentation/arch/arm64/gcs.rst:103:  any attempt to reenable GCS for the thread will be rejected, this may be
 Documentation/arch/arm64/gcs.rst-104-  revisited in future.
 --
 Documentation/arch/arm64/gcs.rst=180=When returning from a signal handler:
 --
 Documentation/arch/arm64/gcs.rst-197-* GCS may be disabled via signal return but any attempt to enable GCS via
 Documentation/arch/arm64/gcs.rst:198:  signal return will be rejected.
 Documentation/arch/arm64/gcs.rst-199-
 --
 Documentation/arch/powerpc/transactional_memory.rst=226=will not occur. If userspace constructs a sigcontext that enables TM
 Documentation/arch/powerpc/transactional_memory.rst:227:suspend, the sigcontext will be rejected by the kernel. This mode is
 Documentation/arch/powerpc/transactional_memory.rst-228-advertised to users with HWCAP2[PPC_FEATURE2_HTM_NO_SUSPEND] set.
 --
 Documentation/arch/sparc/oradax/dax-hv-api.txt=12=Chapter 36. Coprocessor services
 --
 Documentation/arch/sparc/oradax/dax-hv-api.txt-39-        machine, however, internal resource limitations within the virtual machine can cause CCB submissions
 Documentation/arch/sparc/oradax/dax-hv-api.txt:40:        to be temporarily rejected with EWOULDBLOCK. In such cases, guests should continue to attempt
 Documentation/arch/sparc/oradax/dax-hv-api.txt-41-        submissions until they succeed; waiting for an outstanding CCB to complete is not necessary, and would
 --
 Documentation/arch/sparc/oradax/dax-hv-api.txt-115-        node indicates N interrupts available, the guest may use any value from 0 to N - 1 (inclusive) in a CCB
 Documentation/arch/sparc/oradax/dax-hv-api.txt:116:        interrupt number field. Using values outside this range will result in the CCB being rejected for an invalid
 Documentation/arch/sparc/oradax/dax-hv-api.txt-117-        field value.
 --
 Documentation/arch/sparc/oradax/dax-hv-api.txt=224=bits set, and terminate at a CCB that has the Conditional bit set, but not the Pipeline bit.
 --
 Documentation/arch/sparc/oradax/dax-hv-api.txt-238-          for the submitting virtual processor. Virtual addresses which cannot be translated by the virtual machine
 Documentation/arch/sparc/oradax/dax-hv-api.txt:239:          will result in the CCB submission being rejected, with the causal virtual address indicated. The CCB
 Documentation/arch/sparc/oradax/dax-hv-api.txt-240-          may be resubmitted after inserting the translation, or the address may be translated by guest software and
 --
 Documentation/arch/sparc/oradax/dax-hv-api.txt-391-          value. The page size must be one of the sizes supported by the underlying virtual machine. Using a value
 Documentation/arch/sparc/oradax/dax-hv-api.txt:392:          that is not supported may result in the CCB submission being rejected or the generation of a CCB parsing
 Documentation/arch/sparc/oradax/dax-hv-api.txt-393-          error in the completion area.
 --
 Documentation/arch/sparc/oradax/dax-hv-api.txt=1127=Bits            Field Description
 --
 Documentation/arch/sparc/oradax/dax-hv-api.txt-1132-[13:12]         Alternate translation context for virtual addresses within CCBs:
 Documentation/arch/sparc/oradax/dax-hv-api.txt:1133:                 0b'00        CCBs requesting alternate context are rejected
 Documentation/arch/sparc/oradax/dax-hv-api.txt-1134-                 0b'01        Reserved
 --
 Documentation/arch/sparc/oradax/dax-hv-api.txt=1252=EUNAVAILABLE   The requested CCB operation could not be performed at this time. The
 --
 Documentation/arch/sparc/oradax/dax-hv-api.txt-1287-                                                the guest emulate the operation. The guest should expect all CCB
 Documentation/arch/sparc/oradax/dax-hv-api.txt:1288:                                                submissions to be similarly rejected in the near future.
 Documentation/arch/sparc/oradax/dax-hv-api.txt-1289-
 --
 Documentation/arch/x86/xstate.rst=152=are extended to control the guest permission:
 --
 Documentation/arch/x86/xstate.rst-169- first VCPU is created. Any attempt to change permission after that point
 Documentation/arch/x86/xstate.rst:170: is going to be rejected. So, the permission has to be requested before the
 Documentation/arch/x86/xstate.rst-171- first VCPU creation.
 --
 Documentation/bpf/bpf_design_QA.rst=103=There are also non-numerical limits that can cause the program
 Documentation/bpf/bpf_design_QA.rst:104:to be rejected. The verifier used to recognize only pointer + constant
 Documentation/bpf/bpf_design_QA.rst-105-expressions. Now it can recognize pointer + bounded_register.
 --
 Documentation/bpf/bpf_design_QA.rst=279=The kernel function protos will change and the bpf programs will be
 Documentation/bpf/bpf_design_QA.rst:280:rejected by the verifier.  Also, for example, some of the bpf-callable
 Documentation/bpf/bpf_design_QA.rst-281-kernel functions have already been used by other kernel tcp
 --
 Documentation/bpf/bpf_devel_QA.rst=106=from the current review queue. Likewise for cases where patches would
 Documentation/bpf/bpf_devel_QA.rst:107:get rejected or are not applicable to the BPF trees (but assigned to
 Documentation/bpf/bpf_devel_QA.rst-108-the 'bpf' delegate).
 --
 Documentation/bpf/bpf_prog_run.rst=66=run mode. Specifically:
 --
 Documentation/bpf/bpf_prog_run.rst-71-  it, etc). For this reason, setting the ``data_out`` or ``ctx_out`` attributes
 Documentation/bpf/bpf_prog_run.rst:72:  in the syscall parameters when running in this mode will be rejected. In
 Documentation/bpf/bpf_prog_run.rst-73-  addition, not all failures will be reported back to userspace directly;
 --
 Documentation/bpf/graph_ds_impl.rst=117=but that would result in programs with useful, common coding patterns being
 Documentation/bpf/graph_ds_impl.rst:118:rejected, e.g.:
 Documentation/bpf/graph_ds_impl.rst-119-
 --
 Documentation/bpf/graph_ds_impl.rst-132-
 Documentation/bpf/graph_ds_impl.rst:133:Both the read from and write to ``n->data`` would be rejected. The verifier
 Documentation/bpf/graph_ds_impl.rst-134-can do better, though, by taking advantage of two details:
 --
 Documentation/bpf/kfuncs.rst=538=procedure is followed for removal:
 --
 Documentation/bpf/kfuncs.rst-555-3. After the deprecation period the kfunc will be removed. At this point, BPF
 Documentation/bpf/kfuncs.rst:556:   programs calling the kfunc will be rejected by the verifier.
 Documentation/bpf/kfuncs.rst-557-
 --
 Documentation/bpf/ringbuf.rst=33=type ``BPF_MAP_TYPE_RINGBUF``. Two other alternatives considered, but
 Documentation/bpf/ringbuf.rst:34:ultimately rejected.
 Documentation/bpf/ringbuf.rst-35-
 --
 Documentation/bpf/verifier.rst=25=If register was never written to, it's not readable::
 --
 Documentation/bpf/verifier.rst-29-
 Documentation/bpf/verifier.rst:30:will be rejected, since R2 is unreadable at the start of the program.
 Documentation/bpf/verifier.rst-31-
 --
 Documentation/bpf/verifier.rst=44=is a correct program. If there was R1 instead of R6, it would have
 Documentation/bpf/verifier.rst:45:been rejected.
 Documentation/bpf/verifier.rst-46-
 --
 Documentation/bpf/verifier.rst=49=For example::
 --
 Documentation/bpf/verifier.rst-55-
 Documentation/bpf/verifier.rst:56:will be rejected, since R1 doesn't have a valid pointer type at the time of
 Documentation/bpf/verifier.rst-57-execution of instruction bpf_xadd.
 --
 Documentation/crypto/asymmetric-keys.rst=336=Several restriction methods are available:
 --
 Documentation/crypto/asymmetric-keys.rst-344-     If the builtin trusted keyring is not configured, all links will be
 Documentation/crypto/asymmetric-keys.rst:345:     rejected.  The ca_keys kernel parameter also affects which keys are used
 Documentation/crypto/asymmetric-keys.rst-346-     for signature verification.
 --
 Documentation/devicetree/bindings/input/azoteq,iqs7222.yaml=18=properties:
 --
 Documentation/devicetree/bindings/input/azoteq,iqs7222.yaml-296-              original point of contact across which the contact is permitted
 Documentation/devicetree/bindings/input/azoteq,iqs7222.yaml:297:              to travel before the gesture is rejected by the device.
 Documentation/devicetree/bindings/input/azoteq,iqs7222.yaml-298-
 --
 Documentation/driver-api/firmware/fallback-mechanisms.rst=252=Note that:
 --
 Documentation/driver-api/firmware/fallback-mechanisms.rst-269-   brute-force solution. There has been discussion to use the UEFI Platform
 Documentation/driver-api/firmware/fallback-mechanisms.rst:270:   Initialization (PI) spec's Firmware Volume protocol. This has been rejected
 Documentation/driver-api/firmware/fallback-mechanisms.rst-271-   because the FV Protocol relies on *internal* interfaces of the PI spec, and:
 --
 Documentation/driver-api/media/maintainer-entry-profile.rst=40=at linux-media@vger.kernel.org as plain text only e-mail. Emails with
 Documentation/driver-api/media/maintainer-entry-profile.rst:41:HTML will be automatically rejected by the mail server. It could be wise
 Documentation/driver-api/media/maintainer-entry-profile.rst-42-to also copy the sub-maintainer(s).
 --
 Documentation/driver-api/usb/error-codes.rst=29=USB-specific:
 --
 Documentation/driver-api/usb/error-codes.rst-74-
 Documentation/driver-api/usb/error-codes.rst:75:``-EHOSTUNREACH``	URB was rejected because the device is suspended.
 Documentation/driver-api/usb/error-codes.rst-76-
 --
 Documentation/fault-injection/fault-injection.rst=97=configuration of fault-injection capabilities.
 --
 Documentation/fault-injection/fault-injection.rst-152-	in the walked stacktrace lies within the required range, and
 Documentation/fault-injection/fault-injection.rst:153:	none lies within the rejected range.
 Documentation/fault-injection/fault-injection.rst-154-	Default required range is [0,ULONG_MAX) (whole of virtual address space).
 Documentation/fault-injection/fault-injection.rst:155:	Default rejected range is [0,0).
 Documentation/fault-injection/fault-injection.rst-156-
 --
 Documentation/filesystems/automount-support.rst=82=As an alternative, it is possible for userspace to request expiry of any
 Documentation/filesystems/automount-support.rst:83:mountpoint (though some will be rejected - the current process's idea of the
 Documentation/filesystems/automount-support.rst-84-rootfs for example). It does this by passing the MNT_EXPIRE flag to
 --
 Documentation/filesystems/befs.rst=57=is called patch-befs-xxx, you would do the following:
 --
 Documentation/filesystems/befs.rst-61-
 Documentation/filesystems/befs.rst:62:if the patching step fails (i.e. there are rejected hunks), you can try to
 Documentation/filesystems/befs.rst-63-figure it out yourself (it shouldn't be hard), or mail the maintainer
 --
 Documentation/filesystems/mount_api.rst=308=number of operations used by the new mount code for this purpose:
 --
 Documentation/filesystems/mount_api.rst-351-     the parameter should be discarded or an error to indicate that the
 Documentation/filesystems/mount_api.rst:352:     parameter should be rejected.
 Documentation/filesystems/mount_api.rst-353-
 --
 Documentation/filesystems/overlayfs.rst=447=least one data-only layer to enable redirection of data to a data-only layer.
 Documentation/filesystems/overlayfs.rst:448:In this case other forms of metacopy are rejected.  Note: this way, data-only
 Documentation/filesystems/overlayfs.rst-449-layers may be used together with "userxattr", in which case careful attention
 --
 Documentation/filesystems/xfs/xfs-online-fsck-design.rst=1641=Several other solutions to this problem were evaluated upon discovery of this
 Documentation/filesystems/xfs/xfs-online-fsck-design.rst:1642:flaw and rejected:
 Documentation/filesystems/xfs/xfs-online-fsck-design.rst-1643-
 --
 Documentation/gpu/amdgpu/display/mpo-overview.rst=59=hypothetical hardware that we are using as an example, we have an absolute
 Documentation/gpu/amdgpu/display/mpo-overview.rst:60:limit of 4 planes across all CRTCs. Atomic commits will be rejected for display
 Documentation/gpu/amdgpu/display/mpo-overview.rst-61-configurations using more than 4 planes. Again, it is important to stress that
 --
 Documentation/gpu/amdgpu/display/mpo-overview.rst=68=AMDGPU imposes restrictions on the use of DRM planes in the driver.
 Documentation/gpu/amdgpu/display/mpo-overview.rst-69-
 Documentation/gpu/amdgpu/display/mpo-overview.rst:70:Atomic commits will be rejected for commits which do not follow these
 Documentation/gpu/amdgpu/display/mpo-overview.rst-71-restrictions:
 --
 Documentation/gpu/drm-uapi.rst=332=After command submission, UMD should check if the submission was accepted or
 Documentation/gpu/drm-uapi.rst:333:rejected. After a reset, KMD should reject submissions, and UMD can issue an
 Documentation/gpu/drm-uapi.rst-334-ioctl to the KMD to check the reset status, and this can be checked more often
 --
 Documentation/gpu/drm-uapi.rst=412=device must be kept in 'wedged' state until the recovery is performed. New
 Documentation/gpu/drm-uapi.rst:413:accesses to the device (IOCTLs) should be rejected, preferably with an error
 Documentation/gpu/drm-uapi.rst-414-code that resembles the type of failure the device has encountered. This will
 --
 Documentation/gpu/drm-vm-bind-async.rst=111=out-syncobjs, so while theoretically possible the use of them is
 Documentation/gpu/drm-vm-bind-async.rst:112:questionable and should be rejected until there is a valuable use-case.
 Documentation/gpu/drm-vm-bind-async.rst-113-Note that this is not a limitation imposed by dma-fence rules, but
 --
 Documentation/gpu/todo.rst=776=There is support in place now for writing internal DRM clients making it
 Documentation/gpu/todo.rst:777:possible to pick up the bootsplash work that was rejected because it was written
 Documentation/gpu/todo.rst-778-for fbdev.
 --
 Documentation/hwmon/hwmon-kernel-api.rst=69=names. Device names including invalid characters (whitespace, '*', or '-')
 Documentation/hwmon/hwmon-kernel-api.rst:70:will be rejected. If NULL is passed as name parameter, the hardware monitoring
 Documentation/hwmon/hwmon-kernel-api.rst-71-device name will be derived from the parent device name.
 --
 Documentation/kernel-hacking/hacking.rst=723=make a neat patch, there's administrative work to be done:
 --
 Documentation/kernel-hacking/hacking.rst-728-   people to make sure you're not duplicating effort, or trying something
 Documentation/kernel-hacking/hacking.rst:729:   that's already been rejected.
 Documentation/kernel-hacking/hacking.rst-730-
 --
 Documentation/livepatch/livepatch.rst=320=are applied. The relevant entries are created under
 Documentation/livepatch/livepatch.rst:321:/sys/kernel/livepatch/<name>. The patch is rejected when any above
 Documentation/livepatch/livepatch.rst-322-operation fails.
 --
 Documentation/livepatch/livepatch.rst=411=The current Livepatch implementation has several limitations:
 --
 Documentation/livepatch/livepatch.rst-441-    the return address. The first user wins. Either the probe or the patch
 Documentation/livepatch/livepatch.rst:442:    is rejected when the handler is already in use by the other.
 Documentation/livepatch/livepatch.rst-443-
 --
 Documentation/maintainer/rebasing-and-merging.rst=140=Such merges need to be carefully thought about and well justified, or
 Documentation/maintainer/rebasing-and-merging.rst:141:there's a good chance that a subsequent pull request will be rejected.
 Documentation/maintainer/rebasing-and-merging.rst-142-
 --
 Documentation/mm/damon/design.rst=668=scheme's action to it depends on the last filter's allowance type.  If the last
 Documentation/mm/damon/design.rst:669:filter was for allowing, the part of memory will be rejected, and vice versa.
 Documentation/mm/damon/design.rst-670-
 --
 Documentation/netlabel/draft-ietf-cipso-ipsecurity-01.txt=450=a CIPSO host is authorized to handle.  All datagrams that have a label
 Documentation/netlabel/draft-ietf-cipso-ipsecurity-01.txt:451:greater than this maximum MUST be rejected by the CIPSO host.  This
 Documentation/netlabel/draft-ietf-cipso-ipsecurity-01.txt-452-parameter does not apply to CIPSO gateways or routers.  This parameter need
 --
 Documentation/netlabel/draft-ietf-cipso-ipsecurity-01.txt=468=a CIPSO host is authorized to handle.  All datagrams that have a label less
 Documentation/netlabel/draft-ietf-cipso-ipsecurity-01.txt:469:than this minimum MUST be rejected by the CIPSO host.  This parameter does
 Documentation/netlabel/draft-ietf-cipso-ipsecurity-01.txt-470-not apply to CIPSO gateways or routers.  This parameter need not be defined
 --
 Documentation/netlabel/draft-ietf-cipso-ipsecurity-01.txt=476=outgoing datagrams that have a label greater than this maximum MUST be
 Documentation/netlabel/draft-ietf-cipso-ipsecurity-01.txt:477:rejected by the CIPSO system.  The label within this parameter MUST be
 Documentation/netlabel/draft-ietf-cipso-ipsecurity-01.txt-478-less than or equal to the label within the HOST_LABEL_MAX parameter.  This
 --
 Documentation/netlabel/draft-ietf-cipso-ipsecurity-01.txt=483=outgoing datagrams that have a label less than this minimum MUST be
 Documentation/netlabel/draft-ietf-cipso-ipsecurity-01.txt:484:rejected by the CIPSO system.  The label within this parameter MUST be
 Documentation/netlabel/draft-ietf-cipso-ipsecurity-01.txt-485-greater than or equal to the label within the HOST_LABEL_MIN parameter.
 --
 Documentation/netlink/specs/ovs_flow.yaml=11=definitions:
 --
 Documentation/netlink/specs/ovs_flow.yaml-319-          ethertype should ever be given are ETH_P_MPLS_UC and ETH_P_MPLS_MC,
 Documentation/netlink/specs/ovs_flow.yaml:320:          indicating MPLS unicast or multicast. Other are rejected.
 Documentation/netlink/specs/ovs_flow.yaml-321-  -
 --
 Documentation/netlink/specs/ovs_flow.yaml-337-          ethertype should ever be given are ETH_P_MPLS_UC and ETH_P_MPLS_MC,
 Documentation/netlink/specs/ovs_flow.yaml:338:          indicating MPLS unicast or multicast. Other are rejected.
 Documentation/netlink/specs/ovs_flow.yaml-339-      -
 --
 Documentation/networking/device_drivers/ethernet/freescale/dpaa2/switch-driver.rst=182=When using the tc-flower classifier with the 802.1q protocol, only the
 Documentation/networking/device_drivers/ethernet/freescale/dpaa2/switch-driver.rst-183-''vlan_id'' key will be accepted. Mirroring based on any other fields from the
 Documentation/networking/device_drivers/ethernet/freescale/dpaa2/switch-driver.rst:184:802.1q protocol will be rejected::
 Documentation/networking/device_drivers/ethernet/freescale/dpaa2/switch-driver.rst-185-
 --
 Documentation/networking/devlink/ice.rst=227=preserving settings, and thus ``DEVLINK_FLASH_OVERWRITE_IDENTIFIERS`` on its
 Documentation/networking/devlink/ice.rst:228:own will be rejected. If no overwrite mask is provided, the firmware will be
 Documentation/networking/devlink/ice.rst-229-instructed to preserve all settings and identifying fields when updating.
 --
 Documentation/networking/dsa/dsa.rst=976=Bridge VLAN filtering
 --
 Documentation/networking/dsa/dsa.rst-984-  VLAN ID map/rules.  If there is no PVID programmed into the switch port,
 Documentation/networking/dsa/dsa.rst:985:  untagged frames must be rejected as well. When turned off the switch must
 Documentation/networking/dsa/dsa.rst-986-  accept any 802.1Q frames irrespective of their VLAN ID, and untagged frames are
 --
 Documentation/networking/ethtool-netlink.rst=442=MDI(-X) status and transceiver cannot be set, request with the corresponding
 Documentation/networking/ethtool-netlink.rst:443:attributes is rejected.
 Documentation/networking/ethtool-netlink.rst-444-
 --
 Documentation/networking/ethtool-netlink.rst=1113=Request contents:
 --
 Documentation/networking/ethtool-netlink.rst-1147-
 Documentation/networking/ethtool-netlink.rst:1148:Request is rejected if it attributes declared as unsupported by driver (i.e.
 Documentation/networking/ethtool-netlink.rst-1149-such that the corresponding bit in ``ethtool_ops::supported_coalesce_params``
 --
 Documentation/networking/ethtool-netlink.rst=2024=device needs at least 8 entries - the real table in use will end up being
 Documentation/networking/ethtool-netlink.rst-2025-``[0, 1, 0, 1, 0, 1, 0, 1]``. Most devices require the table size to be power
 Documentation/networking/ethtool-netlink.rst:2026:of 2, so tables which size is not a power of 2 will likely be rejected.
 Documentation/networking/ethtool-netlink.rst-2027-Using table of size 0 will reset the indirection table to the default.
 --
 Documentation/networking/j1939.rst=228=address being claimed. This serves as a base for filter schemes. By default,
 Documentation/networking/j1939.rst:229:packets with a destination that is not locally will be rejected.
 Documentation/networking/j1939.rst-230-
 --
 Documentation/networking/ppp_generic.rst=50=via the ppp_channel.ops pointer:
 --
 Documentation/networking/ppp_generic.rst-56-  later time when it can accept frames again, and the generic layer
 Documentation/networking/ppp_generic.rst:57:  will then attempt to retransmit the rejected frame(s).  If the frame
 Documentation/networking/ppp_generic.rst-58-  is accepted, the start_xmit() function should return 1.
 --
 Documentation/networking/ppp_generic.rst=66=The generic PPP layer provides seven functions to channels:
 --
 Documentation/networking/ppp_generic.rst-77-* ppp_output_wakeup() is called by a channel when it has previously
 Documentation/networking/ppp_generic.rst:78:  rejected a call to its start_xmit function, and can now accept more
 Documentation/networking/ppp_generic.rst-79-  packets.
 --
 Documentation/networking/rxrpc.rst=326=calls, to invoke certain actions and to report certain conditions.  These are:
 --
 Documentation/networking/rxrpc.rst-334-	RXRPC_NET_ERROR		-rt error num	Network error on call
 Documentation/networking/rxrpc.rst:335:	RXRPC_BUSY		-rt n/a		Call rejected (server busy)
 Documentation/networking/rxrpc.rst-336-	RXRPC_LOCAL_ERROR	-rt error num	Local error encountered
 --
 Documentation/networking/rxrpc.rst-378-     This is delivered to a client application to indicate that a call was
 Documentation/networking/rxrpc.rst:379:     rejected by the server due to the server being busy.  It will be
 Documentation/networking/rxrpc.rst:380:     associated with an RXRPC_USER_CALL_ID to indicate the rejected call.
 Documentation/networking/rxrpc.rst-381-
 --
 Documentation/networking/rxrpc.rst=795=The kernel interface functions are as follows:
 --
 Documentation/networking/rxrpc.rst-961-	RXRPC_SKB_MARK_FINAL_ACK	Final ACK received for an incoming call
 Documentation/networking/rxrpc.rst:962:	RXRPC_SKB_MARK_BUSY		Client call rejected as server busy
 Documentation/networking/rxrpc.rst-963-	RXRPC_SKB_MARK_REMOTE_ABORT	Call aborted by peer
 --
 Documentation/networking/tls-handshake.rst=180=parameter:
 --
 Documentation/networking/tls-handshake.rst-186-+------------+----------------------------------------------+
 Documentation/networking/tls-handshake.rst:187:|  -EACCESS  |  Remote peer rejected the handshake or       |
 Documentation/networking/tls-handshake.rst-188-|            |  authentication failed                       |
 --
 Documentation/process/howto.rst=322=revisions to it, and maintainers can mark patches as under review,
 Documentation/process/howto.rst:323:accepted, or rejected.  Most of these patchwork sites are listed at
 Documentation/process/howto.rst-324-https://patchwork.kernel.org/.
 --
 Documentation/process/maintainer-netdev.rst=133=Changes requested  patch has not passed the review, new revision is expected
 Documentation/process/maintainer-netdev.rst-134-                   with appropriate code and commit message changes
 Documentation/process/maintainer-netdev.rst:135:Rejected           patch has been rejected and new revision is not expected
 Documentation/process/maintainer-netdev.rst-136-Not applicable     patch is expected to be applied outside of the networking
 --
 Documentation/process/maintainer-netdev.rst=138=Awaiting upstream  patch should be reviewed and handled by appropriate
 --
 Documentation/process/maintainer-netdev.rst-141-                   will usually remain in this state, whether the sub-maintainer
 Documentation/process/maintainer-netdev.rst:142:                   requested changes, accepted or rejected the patch
 Documentation/process/maintainer-netdev.rst-143-Deferred           patch needs to be reposted later, usually due to dependency
 --
 Documentation/process/stable-kernel-rules.rst=172=The sender will receive an ACK when the patch has been accepted into the
 Documentation/process/stable-kernel-rules.rst:173:queue, or a NAK if the patch is rejected.  This response might take a few
]
]

gemini-3.1-pro-preview

							input: 119583
							output: 24
							thoughts: 19
						

Here's my thought process, summarized as you requested:

**Investigating Potential Rejection Issues in the VMware VSOCK Driver**

Okay, I need to troubleshoot something potentially related to rejection in the VMware VSOCK driver. My initial thought is to dive into the source code directly. The best starting point is to search the `net/vmw_vsock/` directory for instances of the word "rejected". This should quickly identify where rejection handling is implemented, or at least where related error messages and checks are performed. This keyword search is a solid preliminary step to locate the key areas of interest within the VSOCK code.

no matches

map[Expression:rejected.*net/vmw_vsock/]

map[Output:]

gemini-3.1-pro-preview

							input: 119769
							output: 15
							thoughts: 25
						

Okay, here's my interpretation of that thought process, assuming I'm an expert in this area and the context is kernel development:

**Finding the Source of Rejection in vsock**

Alright, I need to track down why a vsock connection might be getting rejected. The first place to look, given my familiarity with the architecture, is probably going to be the core networking code. I'm going to focus on the `net/vmw_vsock/af_vsock.c` file. That's the main vsock address family implementation, which should handle the connection setup and teardown. So, I'll start with a search for the term "rejected" within that specific file. Hopefully that will expose the specific code paths where a connection attempt might be denied and I can quickly dive into the relevant logic.

map[Expression:rejected]

map[Output:
Full output is too long, showing 500 out of 5825 lines.
Use more precise expression if possible.

[Documentation/ABI/testing/sysfs-block-device=27=Description:
 --
 Documentation/ABI/testing/sysfs-block-device-46-		  writing -2.
 Documentation/ABI/testing/sysfs-block-device:47:		- Values below -2 are rejected with -EINVAL
 Documentation/ABI/testing/sysfs-block-device-48-
 --
 Documentation/ABI/testing/sysfs-class-firmware=17=Description:	Write-only. For firmware uploads, write a "1" to this file to
 Documentation/ABI/testing/sysfs-class-firmware-18-		request that the transfer of firmware data to the lower-level
 Documentation/ABI/testing/sysfs-class-firmware:19:		device be canceled. This request will be rejected (EBUSY) if
 Documentation/ABI/testing/sysfs-class-firmware-20-		the update cannot be canceled (e.g. a FLASH write is in
 --
 Documentation/ABI/testing/sysfs-devices-system-cpu=611=Description:	Control Symmetric Multi Threading (SMT)
 --
 Documentation/ABI/testing/sysfs-devices-system-cpu-628-			 If control status is "forceoff" or "notsupported" writes
 Documentation/ABI/testing/sysfs-devices-system-cpu:629:			 are rejected. Note that enabling SMT on PowerPC skips
 Documentation/ABI/testing/sysfs-devices-system-cpu-630-			 offline cores.
 --
 Documentation/accel/qaic/qaic.rst=170=workloads. Attempts to access resources assigned to other clients will be
 Documentation/accel/qaic/qaic.rst:171:rejected.
 Documentation/accel/qaic/qaic.rst-172-
 --
 Documentation/admin-guide/cgroup-v2.rst=610=namespace of the process which is attempting the migration.  If either
 Documentation/admin-guide/cgroup-v2.rst:611:is not reachable, the migration is rejected with -ENOENT.
 Documentation/admin-guide/cgroup-v2.rst-612-
 --
 Documentation/admin-guide/cgroup-v2.rst=735=As allocations can't be over-committed, some configuration
 Documentation/admin-guide/cgroup-v2.rst:736:combinations are invalid and should be rejected.  Also, if the
 Documentation/admin-guide/cgroup-v2.rst-737-resource is mandatory for execution of processes, process migrations
 Documentation/admin-guide/cgroup-v2.rst:738:may be rejected.
 Documentation/admin-guide/cgroup-v2.rst-739-
 --
 Documentation/admin-guide/cgroup-v2.rst=1426=The following nested keys are defined.
 --
 Documentation/admin-guide/cgroup-v2.rst-1898-	reclaim inefficiency after disabling writeback (because the same
 Documentation/admin-guide/cgroup-v2.rst:1899:	pages might be rejected again and again).
 Documentation/admin-guide/cgroup-v2.rst-1900-
 --
 Documentation/admin-guide/cgroup-v2.rst=2449=Cpuset Interface Files
 --
 Documentation/admin-guide/cgroup-v2.rst-2569-	not allowed (the exclusivity rule).  A value that violates the
 Documentation/admin-guide/cgroup-v2.rst:2570:	exclusivity rule will be rejected with a write error.
 Documentation/admin-guide/cgroup-v2.rst-2571-
 --
 Documentation/admin-guide/hw-vuln/l1tf.rst=165=Guest mitigation mechanisms
 --
 Documentation/admin-guide/hw-vuln/l1tf.rst-321-			and offlined without restrictions. An attempt to
 Documentation/admin-guide/hw-vuln/l1tf.rst:322:			online a non-primary sibling is rejected
 Documentation/admin-guide/hw-vuln/l1tf.rst-323-
 Documentation/admin-guide/hw-vuln/l1tf.rst-324-	forceoff	Same as 'off' but the state cannot be controlled.
 Documentation/admin-guide/hw-vuln/l1tf.rst:325:			Attempts to write to the control file are rejected.
 Documentation/admin-guide/hw-vuln/l1tf.rst-326-
 --
 Documentation/admin-guide/hw-vuln/l1tf.rst-328-			not affected by the SMT implications of L1TF.
 Documentation/admin-guide/hw-vuln/l1tf.rst:329:			Attempts to write to the control file are rejected.
 Documentation/admin-guide/hw-vuln/l1tf.rst-330-	==============  ===================================================
 --
 Documentation/admin-guide/hw-vuln/l1tf.rst=445=line, then 'always' is enforced and the kvm-intel.vmentry_l1d_flush
 Documentation/admin-guide/hw-vuln/l1tf.rst:446:module parameter is ignored and writes to the sysfs file are rejected.
 Documentation/admin-guide/hw-vuln/l1tf.rst-447-
 --
 Documentation/admin-guide/laptops/disk-shock-protection.rst=54=cancel a previously set timeout and resume normal operation
 Documentation/admin-guide/laptops/disk-shock-protection.rst:55:immediately by specifying a timeout of 0. Values below -2 are rejected
 Documentation/admin-guide/laptops/disk-shock-protection.rst-56-with -EINVAL (see below for the special meaning of -1 and -2). If the
 --
 Documentation/admin-guide/md.rst=486=Each directory contains:
 --
 Documentation/admin-guide/md.rst-606-        array.  If a value less than the current component_size is
 Documentation/admin-guide/md.rst:607:        written, it will be rejected.
 Documentation/admin-guide/md.rst-608-
 --
 Documentation/admin-guide/mm/nommu-mmap.rst=216=The file->f_op->mmap() operation will be called to actually inaugurate the
 Documentation/admin-guide/mm/nommu-mmap.rst:217:mapping. It can be rejected at that point. Returning the ENOSYS error will
 Documentation/admin-guide/mm/nommu-mmap.rst-218-cause the mapping to be copied instead if NOMMU_MAP_COPY is specified.
 --
 Documentation/admin-guide/mm/nommu-mmap.rst=229=direct the call to the device-specific driver. Under such circumstances, the
 Documentation/admin-guide/mm/nommu-mmap.rst:230:mapping request will be rejected if NOMMU_MAP_COPY is not specified, and a
 Documentation/admin-guide/mm/nommu-mmap.rst-231-copy mapped otherwise.
 --
 Documentation/admin-guide/mm/transhuge.rst=234=support the following arguments::
 --
 Documentation/admin-guide/mm/transhuge.rst-247-		  a process level.
 Documentation/admin-guide/mm/transhuge.rst:248:		Note that MADV_COLLAPSE is currently always rejected if
 Documentation/admin-guide/mm/transhuge.rst-249-		madvise(..., MADV_NOHUGEPAGE) is set on an area.
 --
 Documentation/admin-guide/mm/zswap.rst=123=incompressible), users can observe reclaim inefficiency after disabling
 Documentation/admin-guide/mm/zswap.rst:124:writeback (because the same pages might be rejected again and again).
 Documentation/admin-guide/mm/zswap.rst-125-
 --
 Documentation/admin-guide/mm/zswap.rst=137=of pages stored, same-value filled pages and various counters for the reasons
 Documentation/admin-guide/mm/zswap.rst:138:pages are rejected.
 --
 Documentation/admin-guide/module-signing.rst=49=This has a number of options available:
 --
 Documentation/admin-guide/module-signing.rst-66-     Irrespective of the setting here, if the module has a signature block that
 Documentation/admin-guide/module-signing.rst:67:     cannot be parsed, it will be rejected out of hand.
 Documentation/admin-guide/module-signing.rst-68-
 --
 Documentation/admin-guide/module-signing.rst=274=a signature mismatch will not be permitted to load.
 Documentation/admin-guide/module-signing.rst-275-
 Documentation/admin-guide/module-signing.rst:276:Any module that has an unparsable signature will be rejected.
 Documentation/admin-guide/module-signing.rst-277-
 --
 Documentation/admin-guide/pm/cpuidle.rst=411=object corresponding to it, as follows:
 --
 Documentation/admin-guide/pm/cpuidle.rst-452-
 Documentation/admin-guide/pm/cpuidle.rst:453:``rejected``
 Documentation/admin-guide/pm/cpuidle.rst-454-	Total number of times a request to enter this idle state on the given
 Documentation/admin-guide/pm/cpuidle.rst:455:	CPU was rejected.
 Documentation/admin-guide/pm/cpuidle.rst-456-
 --
 Documentation/admin-guide/pm/cpuidle.rst=501=Generally, an interrupt received when trying to enter an idle state causes the
 Documentation/admin-guide/pm/cpuidle.rst:502:idle state entry request to be rejected, in which case the ``CPUIdle`` driver
 Documentation/admin-guide/pm/cpuidle.rst-503-may return an error code to indicate that this was the case. The :file:`usage`
 Documentation/admin-guide/pm/cpuidle.rst:504:and :file:`rejected` files report the number of times the given idle state
 Documentation/admin-guide/pm/cpuidle.rst:505:was entered successfully or rejected, respectively.
 Documentation/admin-guide/pm/cpuidle.rst-506-
 --
 Documentation/admin-guide/pm/cpuidle.rst=524=can be modified from user space by writing a string (representing a signed
 --
 Documentation/admin-guide/pm/cpuidle.rst-527-``<N>`` is allocated at the system initialization time.  Negative values
 Documentation/admin-guide/pm/cpuidle.rst:528:will be rejected in both cases and, also in both cases, the written integer
 Documentation/admin-guide/pm/cpuidle.rst-529-number will be interpreted as a requested PM QoS constraint in microseconds.
 --
 Documentation/admin-guide/pm/intel_pstate.rst=132=the EPP/EPB to a value different from 0 ("performance") via ``sysfs`` in this
 Documentation/admin-guide/pm/intel_pstate.rst:133:configuration will be rejected.
 Documentation/admin-guide/pm/intel_pstate.rst-134-
 --
 Documentation/admin-guide/reporting-issues.rst=114=After these preparations you'll now enter the main part:
 --
 Documentation/admin-guide/reporting-issues.rst-122-   ideally use a 'vanilla' build. Ignoring these advices will dramatically
 Documentation/admin-guide/reporting-issues.rst:123:   increase the risk your report will be rejected or ignored.
 Documentation/admin-guide/reporting-issues.rst-124-
 --
 Documentation/admin-guide/reporting-issues.rst=322=or heavily modified vendor kernel to the upstream Linux developers. But note,
 Documentation/admin-guide/reporting-issues.rst:323:those often get rejected or ignored, so consider yourself warned. But it's still
 Documentation/admin-guide/reporting-issues.rst-324-better than not reporting the issue at all: sometimes such reports directly or
 --
 Documentation/admin-guide/reporting-issues.rst=458=Make sure your kernel doesn't get enhanced
 --
 Documentation/admin-guide/reporting-issues.rst-464-
 Documentation/admin-guide/reporting-issues.rst:465:The risk your issue report gets ignored or rejected dramatically increases if
 Documentation/admin-guide/reporting-issues.rst-466-your kernel gets enhanced in any way. That's why you should remove or disable
 --
 Documentation/admin-guide/reporting-issues.rst=770=Install a fresh kernel for testing
 --
 Documentation/admin-guide/reporting-issues.rst-779-    ideally use a 'vanilla' built. Ignoring these advices will dramatically
 Documentation/admin-guide/reporting-issues.rst:780:    increase the risk your report will be rejected or ignored.*
 Documentation/admin-guide/reporting-issues.rst-781-
 --
 Documentation/admin-guide/reporting-issues.rst=788=earlier: doing so dramatically increases the risk that your issue report might
 Documentation/admin-guide/reporting-issues.rst:789:get rejected or simply ignored.
 Documentation/admin-guide/reporting-issues.rst-790-
 --
 Documentation/admin-guide/unicode.rst=97=adopted by the ConScript Unicode Registry and proposed (but ultimately
 Documentation/admin-guide/unicode.rst:98:rejected) for inclusion in Unicode Plane 1.  Thus, it remains as a
 Documentation/admin-guide/unicode.rst-99-Linux/CSUR private assignment in the Linux Zone.
 --
 Documentation/admin-guide/unicode.rst=186=The CSUR people are driving adding Tengwar and Cirth into Unicode
 Documentation/admin-guide/unicode.rst:187:Plane 1; the addition of Klingon to Unicode Plane 1 has been rejected
 Documentation/admin-guide/unicode.rst-188-and so the above encoding remains official.
 --
 Documentation/arch/arm64/asymmetric-32bit.rst=105=Explicit admission of a 32-bit deadline task to the default root domain
 Documentation/arch/arm64/asymmetric-32bit.rst:106:(e.g. by calling ``sched_setattr(2)``) is rejected on an asymmetric
 Documentation/arch/arm64/asymmetric-32bit.rst-107-32-bit system unless admission control is disabled by writing -1 to
 --
 Documentation/arch/arm64/gcs.rst=9=intended to be exhaustive.
 --
 Documentation/arch/arm64/gcs.rst-81-  values as used for PR_SET_SHADOW_STACK_STATUS.  Any future changes to the
 Documentation/arch/arm64/gcs.rst:82:  status of the specified GCS mode bits will be rejected.
 Documentation/arch/arm64/gcs.rst-83-
 --
 Documentation/arch/arm64/gcs.rst-102-  the stack will remain allocated for the lifetime of the thread.  At present
 Documentation/arch/arm64/gcs.rst:103:  any attempt to reenable GCS for the thread will be rejected, this may be
 Documentation/arch/arm64/gcs.rst-104-  revisited in future.
 --
 Documentation/arch/arm64/gcs.rst=180=When returning from a signal handler:
 --
 Documentation/arch/arm64/gcs.rst-197-* GCS may be disabled via signal return but any attempt to enable GCS via
 Documentation/arch/arm64/gcs.rst:198:  signal return will be rejected.
 Documentation/arch/arm64/gcs.rst-199-
 --
 Documentation/arch/powerpc/transactional_memory.rst=226=will not occur. If userspace constructs a sigcontext that enables TM
 Documentation/arch/powerpc/transactional_memory.rst:227:suspend, the sigcontext will be rejected by the kernel. This mode is
 Documentation/arch/powerpc/transactional_memory.rst-228-advertised to users with HWCAP2[PPC_FEATURE2_HTM_NO_SUSPEND] set.
 --
 Documentation/arch/sparc/oradax/dax-hv-api.txt=12=Chapter 36. Coprocessor services
 --
 Documentation/arch/sparc/oradax/dax-hv-api.txt-39-        machine, however, internal resource limitations within the virtual machine can cause CCB submissions
 Documentation/arch/sparc/oradax/dax-hv-api.txt:40:        to be temporarily rejected with EWOULDBLOCK. In such cases, guests should continue to attempt
 Documentation/arch/sparc/oradax/dax-hv-api.txt-41-        submissions until they succeed; waiting for an outstanding CCB to complete is not necessary, and would
 --
 Documentation/arch/sparc/oradax/dax-hv-api.txt-115-        node indicates N interrupts available, the guest may use any value from 0 to N - 1 (inclusive) in a CCB
 Documentation/arch/sparc/oradax/dax-hv-api.txt:116:        interrupt number field. Using values outside this range will result in the CCB being rejected for an invalid
 Documentation/arch/sparc/oradax/dax-hv-api.txt-117-        field value.
 --
 Documentation/arch/sparc/oradax/dax-hv-api.txt=224=bits set, and terminate at a CCB that has the Conditional bit set, but not the Pipeline bit.
 --
 Documentation/arch/sparc/oradax/dax-hv-api.txt-238-          for the submitting virtual processor. Virtual addresses which cannot be translated by the virtual machine
 Documentation/arch/sparc/oradax/dax-hv-api.txt:239:          will result in the CCB submission being rejected, with the causal virtual address indicated. The CCB
 Documentation/arch/sparc/oradax/dax-hv-api.txt-240-          may be resubmitted after inserting the translation, or the address may be translated by guest software and
 --
 Documentation/arch/sparc/oradax/dax-hv-api.txt-391-          value. The page size must be one of the sizes supported by the underlying virtual machine. Using a value
 Documentation/arch/sparc/oradax/dax-hv-api.txt:392:          that is not supported may result in the CCB submission being rejected or the generation of a CCB parsing
 Documentation/arch/sparc/oradax/dax-hv-api.txt-393-          error in the completion area.
 --
 Documentation/arch/sparc/oradax/dax-hv-api.txt=1127=Bits            Field Description
 --
 Documentation/arch/sparc/oradax/dax-hv-api.txt-1132-[13:12]         Alternate translation context for virtual addresses within CCBs:
 Documentation/arch/sparc/oradax/dax-hv-api.txt:1133:                 0b'00        CCBs requesting alternate context are rejected
 Documentation/arch/sparc/oradax/dax-hv-api.txt-1134-                 0b'01        Reserved
 --
 Documentation/arch/sparc/oradax/dax-hv-api.txt=1252=EUNAVAILABLE   The requested CCB operation could not be performed at this time. The
 --
 Documentation/arch/sparc/oradax/dax-hv-api.txt-1287-                                                the guest emulate the operation. The guest should expect all CCB
 Documentation/arch/sparc/oradax/dax-hv-api.txt:1288:                                                submissions to be similarly rejected in the near future.
 Documentation/arch/sparc/oradax/dax-hv-api.txt-1289-
 --
 Documentation/arch/x86/xstate.rst=152=are extended to control the guest permission:
 --
 Documentation/arch/x86/xstate.rst-169- first VCPU is created. Any attempt to change permission after that point
 Documentation/arch/x86/xstate.rst:170: is going to be rejected. So, the permission has to be requested before the
 Documentation/arch/x86/xstate.rst-171- first VCPU creation.
 --
 Documentation/bpf/bpf_design_QA.rst=103=There are also non-numerical limits that can cause the program
 Documentation/bpf/bpf_design_QA.rst:104:to be rejected. The verifier used to recognize only pointer + constant
 Documentation/bpf/bpf_design_QA.rst-105-expressions. Now it can recognize pointer + bounded_register.
 --
 Documentation/bpf/bpf_design_QA.rst=279=The kernel function protos will change and the bpf programs will be
 Documentation/bpf/bpf_design_QA.rst:280:rejected by the verifier.  Also, for example, some of the bpf-callable
 Documentation/bpf/bpf_design_QA.rst-281-kernel functions have already been used by other kernel tcp
 --
 Documentation/bpf/bpf_devel_QA.rst=106=from the current review queue. Likewise for cases where patches would
 Documentation/bpf/bpf_devel_QA.rst:107:get rejected or are not applicable to the BPF trees (but assigned to
 Documentation/bpf/bpf_devel_QA.rst-108-the 'bpf' delegate).
 --
 Documentation/bpf/bpf_prog_run.rst=66=run mode. Specifically:
 --
 Documentation/bpf/bpf_prog_run.rst-71-  it, etc). For this reason, setting the ``data_out`` or ``ctx_out`` attributes
 Documentation/bpf/bpf_prog_run.rst:72:  in the syscall parameters when running in this mode will be rejected. In
 Documentation/bpf/bpf_prog_run.rst-73-  addition, not all failures will be reported back to userspace directly;
 --
 Documentation/bpf/graph_ds_impl.rst=117=but that would result in programs with useful, common coding patterns being
 Documentation/bpf/graph_ds_impl.rst:118:rejected, e.g.:
 Documentation/bpf/graph_ds_impl.rst-119-
 --
 Documentation/bpf/graph_ds_impl.rst-132-
 Documentation/bpf/graph_ds_impl.rst:133:Both the read from and write to ``n->data`` would be rejected. The verifier
 Documentation/bpf/graph_ds_impl.rst-134-can do better, though, by taking advantage of two details:
 --
 Documentation/bpf/kfuncs.rst=538=procedure is followed for removal:
 --
 Documentation/bpf/kfuncs.rst-555-3. After the deprecation period the kfunc will be removed. At this point, BPF
 Documentation/bpf/kfuncs.rst:556:   programs calling the kfunc will be rejected by the verifier.
 Documentation/bpf/kfuncs.rst-557-
 --
 Documentation/bpf/ringbuf.rst=33=type ``BPF_MAP_TYPE_RINGBUF``. Two other alternatives considered, but
 Documentation/bpf/ringbuf.rst:34:ultimately rejected.
 Documentation/bpf/ringbuf.rst-35-
 --
 Documentation/bpf/verifier.rst=25=If register was never written to, it's not readable::
 --
 Documentation/bpf/verifier.rst-29-
 Documentation/bpf/verifier.rst:30:will be rejected, since R2 is unreadable at the start of the program.
 Documentation/bpf/verifier.rst-31-
 --
 Documentation/bpf/verifier.rst=44=is a correct program. If there was R1 instead of R6, it would have
 Documentation/bpf/verifier.rst:45:been rejected.
 Documentation/bpf/verifier.rst-46-
 --
 Documentation/bpf/verifier.rst=49=For example::
 --
 Documentation/bpf/verifier.rst-55-
 Documentation/bpf/verifier.rst:56:will be rejected, since R1 doesn't have a valid pointer type at the time of
 Documentation/bpf/verifier.rst-57-execution of instruction bpf_xadd.
 --
 Documentation/crypto/asymmetric-keys.rst=336=Several restriction methods are available:
 --
 Documentation/crypto/asymmetric-keys.rst-344-     If the builtin trusted keyring is not configured, all links will be
 Documentation/crypto/asymmetric-keys.rst:345:     rejected.  The ca_keys kernel parameter also affects which keys are used
 Documentation/crypto/asymmetric-keys.rst-346-     for signature verification.
 --
 Documentation/devicetree/bindings/input/azoteq,iqs7222.yaml=18=properties:
 --
 Documentation/devicetree/bindings/input/azoteq,iqs7222.yaml-296-              original point of contact across which the contact is permitted
 Documentation/devicetree/bindings/input/azoteq,iqs7222.yaml:297:              to travel before the gesture is rejected by the device.
 Documentation/devicetree/bindings/input/azoteq,iqs7222.yaml-298-
 --
 Documentation/driver-api/firmware/fallback-mechanisms.rst=252=Note that:
 --
 Documentation/driver-api/firmware/fallback-mechanisms.rst-269-   brute-force solution. There has been discussion to use the UEFI Platform
 Documentation/driver-api/firmware/fallback-mechanisms.rst:270:   Initialization (PI) spec's Firmware Volume protocol. This has been rejected
 Documentation/driver-api/firmware/fallback-mechanisms.rst-271-   because the FV Protocol relies on *internal* interfaces of the PI spec, and:
 --
 Documentation/driver-api/media/maintainer-entry-profile.rst=40=at linux-media@vger.kernel.org as plain text only e-mail. Emails with
 Documentation/driver-api/media/maintainer-entry-profile.rst:41:HTML will be automatically rejected by the mail server. It could be wise
 Documentation/driver-api/media/maintainer-entry-profile.rst-42-to also copy the sub-maintainer(s).
 --
 Documentation/driver-api/usb/error-codes.rst=29=USB-specific:
 --
 Documentation/driver-api/usb/error-codes.rst-74-
 Documentation/driver-api/usb/error-codes.rst:75:``-EHOSTUNREACH``	URB was rejected because the device is suspended.
 Documentation/driver-api/usb/error-codes.rst-76-
 --
 Documentation/fault-injection/fault-injection.rst=97=configuration of fault-injection capabilities.
 --
 Documentation/fault-injection/fault-injection.rst-152-	in the walked stacktrace lies within the required range, and
 Documentation/fault-injection/fault-injection.rst:153:	none lies within the rejected range.
 Documentation/fault-injection/fault-injection.rst-154-	Default required range is [0,ULONG_MAX) (whole of virtual address space).
 Documentation/fault-injection/fault-injection.rst:155:	Default rejected range is [0,0).
 Documentation/fault-injection/fault-injection.rst-156-
 --
 Documentation/filesystems/automount-support.rst=82=As an alternative, it is possible for userspace to request expiry of any
 Documentation/filesystems/automount-support.rst:83:mountpoint (though some will be rejected - the current process's idea of the
 Documentation/filesystems/automount-support.rst-84-rootfs for example). It does this by passing the MNT_EXPIRE flag to
 --
 Documentation/filesystems/befs.rst=57=is called patch-befs-xxx, you would do the following:
 --
 Documentation/filesystems/befs.rst-61-
 Documentation/filesystems/befs.rst:62:if the patching step fails (i.e. there are rejected hunks), you can try to
 Documentation/filesystems/befs.rst-63-figure it out yourself (it shouldn't be hard), or mail the maintainer
 --
 Documentation/filesystems/mount_api.rst=308=number of operations used by the new mount code for this purpose:
 --
 Documentation/filesystems/mount_api.rst-351-     the parameter should be discarded or an error to indicate that the
 Documentation/filesystems/mount_api.rst:352:     parameter should be rejected.
 Documentation/filesystems/mount_api.rst-353-
 --
 Documentation/filesystems/overlayfs.rst=447=least one data-only layer to enable redirection of data to a data-only layer.
 Documentation/filesystems/overlayfs.rst:448:In this case other forms of metacopy are rejected.  Note: this way, data-only
 Documentation/filesystems/overlayfs.rst-449-layers may be used together with "userxattr", in which case careful attention
 --
 Documentation/filesystems/xfs/xfs-online-fsck-design.rst=1641=Several other solutions to this problem were evaluated upon discovery of this
 Documentation/filesystems/xfs/xfs-online-fsck-design.rst:1642:flaw and rejected:
 Documentation/filesystems/xfs/xfs-online-fsck-design.rst-1643-
 --
 Documentation/gpu/amdgpu/display/mpo-overview.rst=59=hypothetical hardware that we are using as an example, we have an absolute
 Documentation/gpu/amdgpu/display/mpo-overview.rst:60:limit of 4 planes across all CRTCs. Atomic commits will be rejected for display
 Documentation/gpu/amdgpu/display/mpo-overview.rst-61-configurations using more than 4 planes. Again, it is important to stress that
 --
 Documentation/gpu/amdgpu/display/mpo-overview.rst=68=AMDGPU imposes restrictions on the use of DRM planes in the driver.
 Documentation/gpu/amdgpu/display/mpo-overview.rst-69-
 Documentation/gpu/amdgpu/display/mpo-overview.rst:70:Atomic commits will be rejected for commits which do not follow these
 Documentation/gpu/amdgpu/display/mpo-overview.rst-71-restrictions:
 --
 Documentation/gpu/drm-uapi.rst=332=After command submission, UMD should check if the submission was accepted or
 Documentation/gpu/drm-uapi.rst:333:rejected. After a reset, KMD should reject submissions, and UMD can issue an
 Documentation/gpu/drm-uapi.rst-334-ioctl to the KMD to check the reset status, and this can be checked more often
 --
 Documentation/gpu/drm-uapi.rst=412=device must be kept in 'wedged' state until the recovery is performed. New
 Documentation/gpu/drm-uapi.rst:413:accesses to the device (IOCTLs) should be rejected, preferably with an error
 Documentation/gpu/drm-uapi.rst-414-code that resembles the type of failure the device has encountered. This will
 --
 Documentation/gpu/drm-vm-bind-async.rst=111=out-syncobjs, so while theoretically possible the use of them is
 Documentation/gpu/drm-vm-bind-async.rst:112:questionable and should be rejected until there is a valuable use-case.
 Documentation/gpu/drm-vm-bind-async.rst-113-Note that this is not a limitation imposed by dma-fence rules, but
 --
 Documentation/gpu/todo.rst=776=There is support in place now for writing internal DRM clients making it
 Documentation/gpu/todo.rst:777:possible to pick up the bootsplash work that was rejected because it was written
 Documentation/gpu/todo.rst-778-for fbdev.
 --
 Documentation/hwmon/hwmon-kernel-api.rst=69=names. Device names including invalid characters (whitespace, '*', or '-')
 Documentation/hwmon/hwmon-kernel-api.rst:70:will be rejected. If NULL is passed as name parameter, the hardware monitoring
 Documentation/hwmon/hwmon-kernel-api.rst-71-device name will be derived from the parent device name.
 --
 Documentation/kernel-hacking/hacking.rst=723=make a neat patch, there's administrative work to be done:
 --
 Documentation/kernel-hacking/hacking.rst-728-   people to make sure you're not duplicating effort, or trying something
 Documentation/kernel-hacking/hacking.rst:729:   that's already been rejected.
 Documentation/kernel-hacking/hacking.rst-730-
 --
 Documentation/livepatch/livepatch.rst=320=are applied. The relevant entries are created under
 Documentation/livepatch/livepatch.rst:321:/sys/kernel/livepatch/<name>. The patch is rejected when any above
 Documentation/livepatch/livepatch.rst-322-operation fails.
 --
 Documentation/livepatch/livepatch.rst=411=The current Livepatch implementation has several limitations:
 --
 Documentation/livepatch/livepatch.rst-441-    the return address. The first user wins. Either the probe or the patch
 Documentation/livepatch/livepatch.rst:442:    is rejected when the handler is already in use by the other.
 Documentation/livepatch/livepatch.rst-443-
 --
 Documentation/maintainer/rebasing-and-merging.rst=140=Such merges need to be carefully thought about and well justified, or
 Documentation/maintainer/rebasing-and-merging.rst:141:there's a good chance that a subsequent pull request will be rejected.
 Documentation/maintainer/rebasing-and-merging.rst-142-
 --
 Documentation/mm/damon/design.rst=668=scheme's action to it depends on the last filter's allowance type.  If the last
 Documentation/mm/damon/design.rst:669:filter was for allowing, the part of memory will be rejected, and vice versa.
 Documentation/mm/damon/design.rst-670-
 --
 Documentation/netlabel/draft-ietf-cipso-ipsecurity-01.txt=450=a CIPSO host is authorized to handle.  All datagrams that have a label
 Documentation/netlabel/draft-ietf-cipso-ipsecurity-01.txt:451:greater than this maximum MUST be rejected by the CIPSO host.  This
 Documentation/netlabel/draft-ietf-cipso-ipsecurity-01.txt-452-parameter does not apply to CIPSO gateways or routers.  This parameter need
 --
 Documentation/netlabel/draft-ietf-cipso-ipsecurity-01.txt=468=a CIPSO host is authorized to handle.  All datagrams that have a label less
 Documentation/netlabel/draft-ietf-cipso-ipsecurity-01.txt:469:than this minimum MUST be rejected by the CIPSO host.  This parameter does
 Documentation/netlabel/draft-ietf-cipso-ipsecurity-01.txt-470-not apply to CIPSO gateways or routers.  This parameter need not be defined
 --
 Documentation/netlabel/draft-ietf-cipso-ipsecurity-01.txt=476=outgoing datagrams that have a label greater than this maximum MUST be
 Documentation/netlabel/draft-ietf-cipso-ipsecurity-01.txt:477:rejected by the CIPSO system.  The label within this parameter MUST be
 Documentation/netlabel/draft-ietf-cipso-ipsecurity-01.txt-478-less than or equal to the label within the HOST_LABEL_MAX parameter.  This
 --
 Documentation/netlabel/draft-ietf-cipso-ipsecurity-01.txt=483=outgoing datagrams that have a label less than this minimum MUST be
 Documentation/netlabel/draft-ietf-cipso-ipsecurity-01.txt:484:rejected by the CIPSO system.  The label within this parameter MUST be
 Documentation/netlabel/draft-ietf-cipso-ipsecurity-01.txt-485-greater than or equal to the label within the HOST_LABEL_MIN parameter.
 --
 Documentation/netlink/specs/ovs_flow.yaml=11=definitions:
 --
 Documentation/netlink/specs/ovs_flow.yaml-319-          ethertype should ever be given are ETH_P_MPLS_UC and ETH_P_MPLS_MC,
 Documentation/netlink/specs/ovs_flow.yaml:320:          indicating MPLS unicast or multicast. Other are rejected.
 Documentation/netlink/specs/ovs_flow.yaml-321-  -
 --
 Documentation/netlink/specs/ovs_flow.yaml-337-          ethertype should ever be given are ETH_P_MPLS_UC and ETH_P_MPLS_MC,
 Documentation/netlink/specs/ovs_flow.yaml:338:          indicating MPLS unicast or multicast. Other are rejected.
 Documentation/netlink/specs/ovs_flow.yaml-339-      -
 --
 Documentation/networking/device_drivers/ethernet/freescale/dpaa2/switch-driver.rst=182=When using the tc-flower classifier with the 802.1q protocol, only the
 Documentation/networking/device_drivers/ethernet/freescale/dpaa2/switch-driver.rst-183-''vlan_id'' key will be accepted. Mirroring based on any other fields from the
 Documentation/networking/device_drivers/ethernet/freescale/dpaa2/switch-driver.rst:184:802.1q protocol will be rejected::
 Documentation/networking/device_drivers/ethernet/freescale/dpaa2/switch-driver.rst-185-
 --
 Documentation/networking/devlink/ice.rst=227=preserving settings, and thus ``DEVLINK_FLASH_OVERWRITE_IDENTIFIERS`` on its
 Documentation/networking/devlink/ice.rst:228:own will be rejected. If no overwrite mask is provided, the firmware will be
 Documentation/networking/devlink/ice.rst-229-instructed to preserve all settings and identifying fields when updating.
 --
 Documentation/networking/dsa/dsa.rst=976=Bridge VLAN filtering
 --
 Documentation/networking/dsa/dsa.rst-984-  VLAN ID map/rules.  If there is no PVID programmed into the switch port,
 Documentation/networking/dsa/dsa.rst:985:  untagged frames must be rejected as well. When turned off the switch must
 Documentation/networking/dsa/dsa.rst-986-  accept any 802.1Q frames irrespective of their VLAN ID, and untagged frames are
 --
 Documentation/networking/ethtool-netlink.rst=442=MDI(-X) status and transceiver cannot be set, request with the corresponding
 Documentation/networking/ethtool-netlink.rst:443:attributes is rejected.
 Documentation/networking/ethtool-netlink.rst-444-
 --
 Documentation/networking/ethtool-netlink.rst=1113=Request contents:
 --
 Documentation/networking/ethtool-netlink.rst-1147-
 Documentation/networking/ethtool-netlink.rst:1148:Request is rejected if it attributes declared as unsupported by driver (i.e.
 Documentation/networking/ethtool-netlink.rst-1149-such that the corresponding bit in ``ethtool_ops::supported_coalesce_params``
 --
 Documentation/networking/ethtool-netlink.rst=2024=device needs at least 8 entries - the real table in use will end up being
 Documentation/networking/ethtool-netlink.rst-2025-``[0, 1, 0, 1, 0, 1, 0, 1]``. Most devices require the table size to be power
 Documentation/networking/ethtool-netlink.rst:2026:of 2, so tables which size is not a power of 2 will likely be rejected.
 Documentation/networking/ethtool-netlink.rst-2027-Using table of size 0 will reset the indirection table to the default.
 --
 Documentation/networking/j1939.rst=228=address being claimed. This serves as a base for filter schemes. By default,
 Documentation/networking/j1939.rst:229:packets with a destination that is not locally will be rejected.
 Documentation/networking/j1939.rst-230-
 --
 Documentation/networking/ppp_generic.rst=50=via the ppp_channel.ops pointer:
 --
 Documentation/networking/ppp_generic.rst-56-  later time when it can accept frames again, and the generic layer
 Documentation/networking/ppp_generic.rst:57:  will then attempt to retransmit the rejected frame(s).  If the frame
 Documentation/networking/ppp_generic.rst-58-  is accepted, the start_xmit() function should return 1.
 --
 Documentation/networking/ppp_generic.rst=66=The generic PPP layer provides seven functions to channels:
 --
 Documentation/networking/ppp_generic.rst-77-* ppp_output_wakeup() is called by a channel when it has previously
 Documentation/networking/ppp_generic.rst:78:  rejected a call to its start_xmit function, and can now accept more
 Documentation/networking/ppp_generic.rst-79-  packets.
 --
 Documentation/networking/rxrpc.rst=326=calls, to invoke certain actions and to report certain conditions.  These are:
 --
 Documentation/networking/rxrpc.rst-334-	RXRPC_NET_ERROR		-rt error num	Network error on call
 Documentation/networking/rxrpc.rst:335:	RXRPC_BUSY		-rt n/a		Call rejected (server busy)
 Documentation/networking/rxrpc.rst-336-	RXRPC_LOCAL_ERROR	-rt error num	Local error encountered
 --
 Documentation/networking/rxrpc.rst-378-     This is delivered to a client application to indicate that a call was
 Documentation/networking/rxrpc.rst:379:     rejected by the server due to the server being busy.  It will be
 Documentation/networking/rxrpc.rst:380:     associated with an RXRPC_USER_CALL_ID to indicate the rejected call.
 Documentation/networking/rxrpc.rst-381-
 --
 Documentation/networking/rxrpc.rst=795=The kernel interface functions are as follows:
 --
 Documentation/networking/rxrpc.rst-961-	RXRPC_SKB_MARK_FINAL_ACK	Final ACK received for an incoming call
 Documentation/networking/rxrpc.rst:962:	RXRPC_SKB_MARK_BUSY		Client call rejected as server busy
 Documentation/networking/rxrpc.rst-963-	RXRPC_SKB_MARK_REMOTE_ABORT	Call aborted by peer
 --
 Documentation/networking/tls-handshake.rst=180=parameter:
 --
 Documentation/networking/tls-handshake.rst-186-+------------+----------------------------------------------+
 Documentation/networking/tls-handshake.rst:187:|  -EACCESS  |  Remote peer rejected the handshake or       |
 Documentation/networking/tls-handshake.rst-188-|            |  authentication failed                       |
 --
 Documentation/process/howto.rst=322=revisions to it, and maintainers can mark patches as under review,
 Documentation/process/howto.rst:323:accepted, or rejected.  Most of these patchwork sites are listed at
 Documentation/process/howto.rst-324-https://patchwork.kernel.org/.
 --
 Documentation/process/maintainer-netdev.rst=133=Changes requested  patch has not passed the review, new revision is expected
 Documentation/process/maintainer-netdev.rst-134-                   with appropriate code and commit message changes
 Documentation/process/maintainer-netdev.rst:135:Rejected           patch has been rejected and new revision is not expected
 Documentation/process/maintainer-netdev.rst-136-Not applicable     patch is expected to be applied outside of the networking
 --
 Documentation/process/maintainer-netdev.rst=138=Awaiting upstream  patch should be reviewed and handled by appropriate
 --
 Documentation/process/maintainer-netdev.rst-141-                   will usually remain in this state, whether the sub-maintainer
 Documentation/process/maintainer-netdev.rst:142:                   requested changes, accepted or rejected the patch
 Documentation/process/maintainer-netdev.rst-143-Deferred           patch needs to be reposted later, usually due to dependency
 --
 Documentation/process/stable-kernel-rules.rst=172=The sender will receive an ACK when the patch has been accepted into the
 Documentation/process/stable-kernel-rules.rst:173:queue, or a NAK if the patch is rejected.  This response might take a few
]
]

gemini-3.1-pro-preview

							input: 131088
							output: 49
							thoughts: 12
						

Okay, here's my attempt at summarizing that thought process, keeping in mind I'm speaking to a fellow expert:

**Investigating `vsock_pending_work`**

Alright, time to dive in. My immediate thought is, "Let's check `vsock_pending_work`." That variable, specifically, is where the rubber meets the road when it comes to understanding the current state of asynchronous VSOCK operations. I'm probably looking for clues about pending connection requests, data waiting to be transmitted or received, or maybe even pending disconnect events. It's the central point I'd investigate when trying to figure out why some VSOCK interaction isn't behaving as I expect. It's the likely bottleneck or indicator of trouble. I need to understand what's in there, what the implications of the current values are, and how that relates to the overall flow of VSOCK data. Where is this variable used and how is it updated? What state is driving that process? This will likely provide a good foundation to understand the broader VSOCK issues at hand.

map[ContextFile:net/vmw_vsock/af_vsock.c IncludeLines:true Name:vsock_pending_work]

map[SourceCode: 732:	static void vsock_pending_work(struct work_struct *work)
 733:	{
 734:		struct sock *sk;
 735:		struct sock *listener;
 736:		struct vsock_sock *vsk;
 737:		bool cleanup;
 738:	
 739:		vsk = container_of(work, struct vsock_sock, pending_work.work);
 740:		sk = sk_vsock(vsk);
 741:		listener = vsk->listener;
 742:		cleanup = true;
 743:	
 744:		lock_sock(listener);
 745:		lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
 746:	
 747:		if (vsock_is_pending(sk)) {
 748:			vsock_remove_pending(listener, sk);
 749:	
 750:			sk_acceptq_removed(listener);
 751:		} else if (!vsk->rejected) {
 752:			/* We are not on the pending list and accept() did not reject
 753:			 * us, so we must have been accepted by our user process.  We
 754:			 * just need to drop our references to the sockets and be on
 755:			 * our way.
 756:			 */
 757:			cleanup = false;
 758:			goto out;
 759:		}
 760:	
 761:		/* We need to remove ourself from the global connected sockets list so
 762:		 * incoming packets can't find this socket, and to reduce the reference
 763:		 * count.
 764:		 */
 765:		vsock_remove_connected(vsk);
 766:	
 767:		sk->sk_state = TCP_CLOSE;
 768:	
 769:	out:
 770:		release_sock(sk);
 771:		release_sock(listener);
 772:		if (cleanup)
 773:			sock_put(sk);
 774:	
 775:		sock_put(sk);
 776:		sock_put(listener);
 777:	}
 SourceFile:net/vmw_vsock/af_vsock.c]

gemini-3.1-pro-preview

							input: 132023
							output: 49
							thoughts: 58
						

Okay, here's my breakdown of what's going through my mind as I approach this `vsock` issue:

**Delving into the `vsock_pending_work` Rabbit Hole**

Right, `vsock_pending_work`. That's where I need to start. I know that function is scheduled somehow, and my immediate thought is *how*? Aha, `vsock_add_pending`! The name rings a bell, and it certainly sounds like the right place to look. Does `vsock_add_pending` actually *get* called, though? That's the critical question. Now, I need to confirm that `vsock_add_pending` is indeed being invoked in the right circumstances. Let's dig into its code and see what we can find. I need to understand its call paths and where it's being used within the larger `vsock` framework.

map[ContextFile:net/vmw_vsock/af_vsock.c IncludeLines:true Name:vsock_add_pending]

map[SourceCode: 475:	void vsock_add_pending(struct sock *listener, struct sock *pending)
 476:	{
 477:		struct vsock_sock *vlistener;
 478:		struct vsock_sock *vpending;
 479:	
 480:		vlistener = vsock_sk(listener);
 481:		vpending = vsock_sk(pending);
 482:	
 483:		sock_hold(pending);
 484:		sock_hold(listener);
 485:		list_add_tail(&vpending->pending_links, &vlistener->pending_links);
 486:	}
 SourceFile:net/vmw_vsock/af_vsock.c]

gemini-3.1-pro-preview

							input: 132535
							output: 47
							thoughts: 2356
						

**Analysis of vsock Memory Leak Vulnerability**

Okay, so here's what I've figured out. `virtio_transport_recv_listen` doesn't use `vsock_add_pending` as I initially thought; it calls `vsock_enqueue_accept` instead. That means the `child` socket isn't added to the pending list. Consequently, `vsock_pending_work` isn't scheduled if `accept4` fails. If `accept4` fails, the `vconnected->rejected = true` flag gets set, but the socket remains in the connected table, and `vsock_pending_work` is never executed. This means the connected socket is never removed, and it leaks.

Then, looking at the `vsock_accept` function, if an error occurs (`err` is non-zero), the code sets `vconnected->rejected = true`. However, the socket was already in the accept queue. If accept fails who cleans the socket? It is removed from the accept queue by `vsock_dequeue_accept`. However, the socket is still in the connected table, because `vsock_insert_connected` added it, which increased its refcount. And nothing ever removes it from the connected table! It's a leak!

So, the reproducer calls `accept4(r[0], NULL, NULL, 0)`. Does that fail? The issue is that `r[0]` is the *listener* socket. Was its `sk_err` set? Hold on, `connect` was called on `r[0]` *before* `listen`! The `connect` failed with `ECONNREFUSED`! The `listen` call doesn't clear the `sk_err` flag. So, when `accept4` is called, `vsock_accept` sees `listener->sk_err`, and sets `err` to `-listener->sk_err`, which is `-ECONNREFUSED`. Then, `vsock_accept` sets `vconnected->rejected = true`, and calls `sock_put(connected)`, but still returns the negative error. The `connected` socket is leaked.

Bingo! That's it! If a socket's `sk_err` is set, and it's a listener, `accept` will dequeue a socket, set `rejected = true`, and decrease the reference. However, for virtio-vsock, the socket is *already* in the connected table, *not* in the pending list! This stops the `vsock_pending_work` from being scheduled, and therefore, it's *never* removed from the connected table. It's leaked.

Here's the sequence of events. `virtio_transport_recv_listen` inserts `child` into the connected table and then enqueues it to the accept queue. If `accept` fails due to `listener->sk_err`, the `accept` function dequeues `child`, sets `rejected = true` and drops the accept queue's reference, but `child` is still in the connected table, with its `sk_refcnt` at 1 (held by the connected table) meaning it is a memory leak.

So, is this exploitable? It's a memory leak, so yes, it can be exploited. Can it be triggered by an unprivileged user? Absolutely. The reproducer uses `socket(AF_VSOCK)`, `bind`, `connect`, `listen`, `accept4` - all available to unprivileged users. No capabilities, user namespaces aren't necessary. It causes a Denial of Service, due to the memory leak, and can lead to OOM. No privilege escalation or memory corruption, only a memory leak.

Let me just double-check, does `listen` clear `sk_err`? Nope, the `vsock_listen` function doesn't clear it.

And `connect`? The `vsk->transport->connect(vsk)` sends a connection request. If it receives a RST, `virtio_transport_recv_pkt` calls `virtio_transport_recv_connecting`. And that sets `sk->sk_err = ECONNREFUSED`. So the connect can cause the sk_err.

So the sequence is:
1.  `socket(AF_VSOCK)`
2.  `bind()`
3.  `connect()` - leads to ECONNREFUSED which sets `sk->sk_err`
4.  `listen()` - leaves sk_err as ECONNREFUSED
5.  `socket(AF_VSOCK)`
6.  `connect()` - triggers a new socket and listener socket setup.
7.  `accept4()` - fails and causes the leak

Finally, the child socket is never closed because it was

map[ContextFile:net/vmw_vsock/af_vsock.c IncludeLines:true Name:vsock_create]

map[SourceCode:2652:	static int vsock_create(struct net *net, struct socket *sock,
2653:				int protocol, int kern)
2654:	{
2655:		struct vsock_sock *vsk;
2656:		struct sock *sk;
2657:		int ret;
2658:	
2659:		if (!sock)
2660:			return -EINVAL;
2661:	
2662:		if (protocol && protocol != PF_VSOCK)
2663:			return -EPROTONOSUPPORT;
2664:	
2665:		switch (sock->type) {
2666:		case SOCK_DGRAM:
2667:			sock->ops = &vsock_dgram_ops;
2668:			break;
2669:		case SOCK_STREAM:
2670:			sock->ops = &vsock_stream_ops;
2671:			break;
2672:		case SOCK_SEQPACKET:
2673:			sock->ops = &vsock_seqpacket_ops;
2674:			break;
2675:		default:
2676:			return -ESOCKTNOSUPPORT;
2677:		}
2678:	
2679:		sock->state = SS_UNCONNECTED;
2680:	
2681:		sk = __vsock_create(net, sock, NULL, GFP_KERNEL, 0, kern);
2682:		if (!sk)
2683:			return -ENOMEM;
2684:	
2685:		vsk = vsock_sk(sk);
2686:	
2687:		if (sock->type == SOCK_DGRAM) {
2688:			ret = vsock_assign_transport(vsk, NULL);
2689:			if (ret < 0) {
2690:				sock->sk = NULL;
2691:				sock_put(sk);
2692:				return ret;
2693:			}
2694:		}
2695:	
2696:		/* SOCK_DGRAM doesn't have 'setsockopt' callback set in its
2697:		 * proto_ops, so there is no handler for custom logic.
2698:		 */
2699:		if (sock_type_connectible(sock->type))
2700:			set_bit(SOCK_CUSTOM_SOCKOPT, &sk->sk_socket->flags);
2701:	
2702:		vsock_insert_unbound(vsk);
2703:	
2704:		return 0;
2705:	}
 SourceFile:net/vmw_vsock/af_vsock.c]

gemini-3.1-pro-preview

							input: 136714
							output: 66
							thoughts: 242
						

**My Assessment of the VSOCK Vulnerability**

Okay, so looking at this `vsock_create` function, it's immediately clear there are *zero* privilege checks. That's a huge red flag. This means that an unprivileged user can create `AF_VSOCK` sockets and potentially trigger this memory leak.

Let's break down the implications:

*   **Exploitable:** False – It's a denial of service, not a code execution vulnerability.
*   **DenialOfService:** True – Absolutely. We can crash the system.
*   **Unprivileged:** True – Critically, this can be done without root.
*   **UserNamespace:** True – This means it can be triggered within a user namespace, increasing the attack surface.
*   **VMGuestTrigger:** True – Wait, is this even *possible* within a VM guest? Ah, right, `AF_VSOCK` is used for guest-host communication. Okay, that makes sense.
*   **VMHostTrigger:** True – And for the host-guest direction, too. This broadens the impact significantly.
*   **NetworkTrigger:** False – No, it doesn't involve external network connections.
*   **RemoteTrigger:** False – Same, no remote component.
*   **PeripheralTrigger:** False – Not triggered by any external devices.
*   **FilesystemTrigger:** False – No filesystem interaction involved.

And just to confirm the critical aspect, it can be triggered locally. The reproducer leverages `VMADDR_CID_LOCAL`, the loopback address. This is great, as it doesn't even need a vhost-vsock or virtio-vsock device configured, meaning that so long as the `vsock_loopback` module is enabled (which is very common), then the attack is valid.

Right, I'm confident in these findings. Time to call the `set-results` tool.

map[DenialOfService:true Exploitable:false FilesystemTrigger:false NetworkTrigger:false PeripheralTrigger:false RemoteTrigger:false Unprivileged:true UserNamespace:true VMGuestTrigger:true VMHostTrigger:true]

map[DenialOfService:true Exploitable:false FilesystemTrigger:false NetworkTrigger:false PeripheralTrigger:false RemoteTrigger:false Unprivileged:true UserNamespace:true VMGuestTrigger:true VMHostTrigger:true]

gemini-3.1-pro-preview

							input: 137500
							output: 667
							thoughts: 410
						

**My Analysis Concluded: The VSOCK Memory Leak**

Alright, the analysis is done, and it's time to summarize this fascinating bug. My focus is entirely on this insidious memory leak I've uncovered in the `vsock` implementation. It seems pretty straightforward, once you understand the sequence of events.

It all starts with a connection attempt. We set up a `vsock` socket and bind it. Then, we try to connect to an invalid port – a deliberate failure, essentially. This sets the socket's error code, `sk_err`, to `ECONNREFUSED`, which is expected. The problem begins when we call `listen()` on this same socket. The socket transitions to `TCP_LISTEN`, but, critically, the error code isn't cleared. That's our first red flag.

The next part involves a successful connection attempt. A second socket is created and connects to our "listening" socket. This is where things get interesting. The listening socket happily accepts the connection, spawns a child socket, and inserts it into the connected table, incrementing its reference count. Then, the child gets enqueued in the accept queue, which is another increment to the refcount. So, the socket is hanging around with two refcounts.

Here's the critical point: the subsequent call to `accept4()` is where the leak is revealed. The `vsock_accept()` function dequeues the child socket from the accept queue. However, it *sees* that `listener->sk_err` still contains the `ECONNREFUSED` error from the initial *failed* connection attempt. Because of this error, `vsock_accept()` rejects the connection, sets `vconnected->rejected = true`, and *drops* the accept queue's reference to the child socket. Then, and this is the core of the problem, it *returns the error* without grafting the child socket to a new file descriptor.

Now, because it was never grafted to a file descriptor, it's never closed by the user-space. And, because it was removed from the accept queue, it won't be cleaned up when the listening socket closes. The child socket just sits there, forever in the connected table with a refcount of 1, never freed. That's a memory leak, plain and simple.

The implications are clear: This leak, while not leading to memory corruption or privilege escalation, is a Denial of Service vulnerability. An unprivileged user can trigger it locally on any system with `AF_VSOCK` support – that means hosts and VM guests are both at risk. With the loopback transport, it's essentially a local attack. We're looking at a manageable but very real vulnerability.

map[Explanation:**Bug Analysis:**

The bug is a memory leak of a `vsock` child socket. It occurs due to an
unhandled error path when `accept()` is called on a listening socket that has a
pending error (`sk_err`).

Here is the sequence of events triggered by the reproducer:
1. An unprivileged user creates a `vsock` socket (`r[0]`), binds it, and
attempts to `connect()` to an invalid port on the local CID
(`VMADDR_CID_LOCAL`).
2. The connection attempt fails (receives a RST), which sets `sk->sk_err =
ECONNREFUSED` on `r[0]`.
3. The user then calls `listen()` on `r[0]`. The `listen()` syscall successfully
transitions the socket to the `TCP_LISTEN` state but **does not clear the
`sk_err` field**.
4. The user creates a second socket (`r[1]`) and connects it to the listening
socket `r[0]`.
5. The listening socket receives the connection request, creates a child socket,
inserts it into the global connected table (incrementing its refcount), and
enqueues it into the accept queue (incrementing its refcount again).
6. The user calls `accept4()` on `r[0]`. `vsock_accept()` dequeues the child
socket from the accept queue. However, it checks `listener->sk_err` and finds it
set to `ECONNREFUSED`.
7. Because of this error, `vsock_accept()` rejects the connection: it sets
`vconnected->rejected = true`, drops the accept queue's reference to the child
socket, and returns the error without grafting the child socket to a new file
descriptor.

Since the child socket was never grafted to a file descriptor, it will never be
closed by user space. Furthermore, because it was removed from the accept queue,
it will not be cleaned up when the listening socket is eventually closed. The
child socket remains in the connected table indefinitely with a refcount of 1,
resulting in a memory leak of the socket structure and its associated transport
data (e.g., `virtio_vsock_sock`).

**Security Impact:**

* **Exploitable:** No. This is a pure memory leak. It does not lead to memory
corruption, use-after-free, or privilege escalation.
* **Denial Of Service:** Yes. An attacker can repeatedly trigger this leak to
consume kernel memory, eventually leading to an Out-Of-Memory (OOM) condition
and system crash.
* **Accessible From Unprivileged Processes:** Yes. Creating `AF_VSOCK` sockets
and calling `bind`, `connect`, `listen`, and `accept` does not require any
special capabilities.
* **Accessible From User Namespaces:** Yes.
* **VM Guest / Host Trigger:** Yes. The bug can be triggered locally on any
system that supports `AF_VSOCK` (including VM guests and hosts). The reproducer
uses the `VMADDR_CID_LOCAL` (loopback) transport, meaning it doesn't even
require a configured external vsock device to be triggered.]