syzbot
general protection fault in bus_remove_device
Status:
premoderation: reported C repro on 2026/08/03 16:19
Reported-by: syzbot+e2271ab938eb2746b343@syzkaller.appspotmail.com
First crash: 3d03h, last: 3d01h
Sample crash report:
usb 1-1: 1:1 : UAC_AS_GENERAL descriptor not found
usb 1-1: selecting invalid altsetting 0
usb 1-1: USB disconnect, device number 2
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000004: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027]
CPU: 0 UID: 0 PID: 10 Comm: kworker/0:1 Not tainted syzkaller #0 7f3b23dcf55806c758f3cdeb9210fc77c27c120f
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: usb_hub_wq hub_event
RIP: 0010:klist_put lib/klist.c:212 [inline]
RIP: 0010:klist_del lib/klist.c:230 [inline]
RIP: 0010:klist_remove+0x15e/0x330 lib/klist.c:249
Code: be 00 00 00 00 00 fc ff df 43 80 3c 34 00 74 08 48 89 df e8 84 5f 45 fc 4c 8b 3b 49 83 e7 fe 49 8d 7f 20 48 89 f8 48 c1 e8 03 <42> 80 3c 30 00 74 05 e8 66 5f 45 fc 49 8b 47 20 48 89 44 24 18 4c
RSP: 0018:ffffc900000a7600 EFLAGS: 00010202
RAX: 0000000000000004 RBX: ffff888106245a48 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: ffffffff87e34540 RDI: 0000000000000020
RBP: ffffc900000a76e8 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000014eb0 R12: 1ffff11020c48b49
R13: 1ffff92000014ec4 R14: dffffc0000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbd7b0483a8 CR3: 00000001305ea000 CR4: 00000000003526b0
Call Trace:
<TASK>
__device_release_driver drivers/base/dd.c:1280 [inline]
device_release_driver_internal+0x739/0x830 drivers/base/dd.c:1295
device_release_driver+0x1d/0x30 drivers/base/dd.c:1318
bus_remove_device+0x34f/0x370 drivers/base/bus.c:576
device_del+0x583/0xcf0 drivers/base/core.c:3881
usb_disable_device+0x3af/0x770 drivers/usb/core/message.c:1476
usb_disconnect+0x331/0x950 drivers/usb/core/hub.c:2353
hub_port_connect drivers/usb/core/hub.c:5414 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5714 [inline]
port_event drivers/usb/core/hub.c:5878 [inline]
hub_event+0x1ad5/0x4360 drivers/usb/core/hub.c:5960
process_one_work kernel/workqueue.c:3273 [inline]
process_scheduled_works+0x7f7/0x1060 kernel/workqueue.c:3354
worker_thread+0xc99/0x13f0 kernel/workqueue.c:3435
kthread+0x2c7/0x360 kernel/kthread.c:389
ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:klist_put lib/klist.c:212 [inline]
RIP: 0010:klist_del lib/klist.c:230 [inline]
RIP: 0010:klist_remove+0x15e/0x330 lib/klist.c:249
Code: be 00 00 00 00 00 fc ff df 43 80 3c 34 00 74 08 48 89 df e8 84 5f 45 fc 4c 8b 3b 49 83 e7 fe 49 8d 7f 20 48 89 f8 48 c1 e8 03 <42> 80 3c 30 00 74 05 e8 66 5f 45 fc 49 8b 47 20 48 89 44 24 18 4c
----------------
Code disassembly (best guess):
0: be 00 00 00 00 mov $0x0,%esi
5: 00 fc add %bh,%ah
7: ff lcall (bad)
8: df 43 80 filds -0x80(%rbx)
b: 3c 34 cmp $0x34,%al
d: 00 74 08 48 add %dh,0x48(%rax,%rcx,1)
11: 89 df mov %ebx,%edi
13: e8 84 5f 45 fc call 0xfc455f9c
18: 4c 8b 3b mov (%rbx),%r15
1b: 49 83 e7 fe and $0xfffffffffffffffe,%r15
1f: 49 8d 7f 20 lea 0x20(%r15),%rdi
23: 48 89 f8 mov %rdi,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 80 3c 30 00 cmpb $0x0,(%rax,%r14,1) <-- trapping instruction
2f: 74 05 je 0x36
31: e8 66 5f 45 fc call 0xfc455f9c
36: 49 8b 47 20 mov 0x20(%r15),%rax
3a: 48 89 44 24 18 mov %rax,0x18(%rsp)
3f: 4c rex.WR
* Struck through repros no longer work on HEAD.