syzbot


kernel BUG in qlist_free_all (2)

Status: upstream: reported C repro on 2025/09/14 13:31
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+8715dd783e9b0bef43b1@syzkaller.appspotmail.com
Fix commit: 25718fdcbdd2 net: gro_cells: Use nested-BH locking for gro_cell
Patched on: [ci-qemu-gce-upstream-auto ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm32 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-snapshot-upstream-root ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-leak ci-upstream-kasan-badwrites-root ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-kmsan-gce-386-root ci-upstream-kmsan-gce-root ci-upstream-linux-next-kasan-gce-root ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci-upstream-rust-kasan-gce ci2-upstream-fs ci2-upstream-kcsan-gce], missing on: [ci-qemu-native-arm64-kvm ci-qemu2-riscv64 ci-upstream-gce-arm64 ci2-upstream-usb]
First crash: 43d, last: 8d12h
Cause bisection: introduced by (bisect log) :
commit 3253cb49cbad4772389d6ef55be75db1f97da910
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Thu Sep 4 14:25:25 2025 +0000

  softirq: Allow to drop the softirq-BKL lock on PREEMPT_RT

Crash: KASAN: slab-use-after-free Write in gro_cells_receive (log)
Repro: C syz .config
  
Discussions (2)
Title Replies (including bot) Last reply
[PATCH net] net: gro_cells: Use nested-BH locking for gro_cell 2 (2) 2025/10/14 01:10
[syzbot] [kernel?] kernel BUG in qlist_free_all (2) 0 (3) 2025/10/04 01:04
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream kernel BUG in qlist_free_all bcachefs -1 C done done 12 187d 335d 28/29 fixed on 2025/06/10 16:19

Sample crash report:
------------[ cut here ]------------
kernel BUG at arch/x86/mm/physaddr.c:28!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 0 UID: 0 PID: 5821 Comm: syz-executor Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:__phys_addr+0x173/0x180 arch/x86/mm/physaddr.c:28
Code: e8 72 22 49 00 48 c7 c7 90 ce 21 8d 48 89 de 4c 89 f2 e8 b0 03 39 03 e9 4d ff ff ff e8 56 22 49 00 90 0f 0b e8 4e 22 49 00 90 <0f> 0b e8 46 22 49 00 90 0f 0b 0f 1f 00 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90004aff658 EFLAGS: 00010293
RAX: ffffffff81740d22 RBX: 0000607fffc493c0 RCX: ffff88803980da00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffe8ffffc493c0 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1d6b7e7 R12: ffffea0000000000
R13: 0000000000000000 R14: 000000000000002e R15: 0000000000000001
FS:  000055557e606500(0000) GS:ffff888127022000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c007a73000 CR3: 000000003db40000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 virt_to_folio include/linux/mm.h:1180 [inline]
 virt_to_slab mm/slab.h:187 [inline]
 qlink_to_cache mm/kasan/quarantine.c:131 [inline]
 qlist_free_all+0x39/0x140 mm/kasan/quarantine.c:176
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:340
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4191 [inline]
 slab_alloc_node mm/slub.c:4240 [inline]
 kmem_cache_alloc_node_noprof+0x121/0x2f0 mm/slub.c:4292
 __alloc_skb+0x112/0x2d0 net/core/skbuff.c:659
 alloc_skb_fclone include/linux/skbuff.h:1386 [inline]
 tcp_stream_alloc_skb+0x3d/0x340 net/ipv4/tcp.c:892
 tcp_sendmsg_locked+0xf3e/0x5620 net/ipv4/tcp.c:1198
 tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1393
 sock_sendmsg_nosec net/socket.c:714 [inline]
 __sock_sendmsg+0x19c/0x270 net/socket.c:729
 sock_write_iter+0x27f/0x370 net/socket.c:1182
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x5d5/0xb40 fs/read_write.c:686
 ksys_write+0x14b/0x260 fs/read_write.c:738
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd359abd940
Code: 40 00 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 80 3d 21 ac 22 00 00 74 17 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 58 c3 0f 1f 80 00 00 00 00 48 83 ec 28 48 89
RSP: 002b:00007fffdda6c778 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000008f0d180 RCX: 00007fd359abd940
RDX: 00000000000000d8 RSI: 00007fd358767f28 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000007 R09: 000000000003fde8
R10: b07dc1dcfe8eb19c R11: 0000000000000202 R12: 00000000000000d8
R13: 000055557e61ac40 R14: 00007fffdda6cc40 R15: 00007fd358767f28
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__phys_addr+0x173/0x180 arch/x86/mm/physaddr.c:28
Code: e8 72 22 49 00 48 c7 c7 90 ce 21 8d 48 89 de 4c 89 f2 e8 b0 03 39 03 e9 4d ff ff ff e8 56 22 49 00 90 0f 0b e8 4e 22 49 00 90 <0f> 0b e8 46 22 49 00 90 0f 0b 0f 1f 00 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90004aff658 EFLAGS: 00010293
RAX: ffffffff81740d22 RBX: 0000607fffc493c0 RCX: ffff88803980da00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffe8ffffc493c0 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1d6b7e7 R12: ffffea0000000000
R13: 0000000000000000 R14: 000000000000002e R15: 0000000000000001
FS:  000055557e606500(0000) GS:ffff888127022000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c007a73000 CR3: 000000003db40000 CR4: 00000000003526f0

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/10/03 00:56 upstream 7f7072574127 49379ee0 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root kernel BUG in qlist_free_all
2025/10/02 19:41 upstream 7f7072574127 49379ee0 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root kernel BUG in qlist_free_all
2025/10/15 15:18 upstream 9b332cece987 19568248 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root kernel BUG in qlist_free_all
2025/10/03 21:36 upstream 9b0d551bcc05 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root kernel BUG in qlist_free_all
2025/09/10 13:28 upstream 9dd1835ecda5 fdeaa69b .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto kernel BUG in qlist_free_all
* Struck through repros no longer work on HEAD.