syzbot


BUG: corrupted list in io_poll_remove_entries

Status: upstream: reported C repro on 2026/02/09 18:26
Subsystems: media
[Documentation on labels]
Reported-by: syzbot+ab12f0c08dd7ab8d057c@syzkaller.appspotmail.com
First crash: 3d18h, last: 1d01h
Cause bisection: failed (error log, bisect log)
  
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [io-uring?] BUG: corrupted list in io_poll_remove_entries 5 (7) 2026/02/12 00:14
Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: use-after-free Read in io_poll_remove_entries io-uring 19 C done done 751 1043d 1423d 0/29 auto-obsoleted due to no activity on 2023/07/04 23:32
linux-6.1 general protection fault in io_poll_remove_entries 11 C done 21 1046d 1065d 3/3 fixed on 2023/05/02 21:55
upstream KASAN: slab-use-after-free Read in io_poll_remove_entries comedi 19 C 12 198d 207d 29/29 fixed on 2025/09/04 16:57
upstream KASAN: slab-use-after-free Read in io_poll_remove_entries (2) io-uring 19 1 77d 75d 0/29 closed as invalid on 2025/12/19 03:22
linux-5.15 KASAN: use-after-free Read in io_poll_remove_entries origin:lts-only 19 C error 5 172d 199d 0/3 auto-obsoleted due to no activity on 2025/12/08 02:55
Last patch testing requests (1)
Created Duration User Patch Repo Result
2026/02/09 20:18 30m axboe@kernel.dk patch upstream OK log

Sample crash report:
list_del corruption. prev->next should be ffff88807dc6c3f0, but was ffff888146b205c8. (prev=ffff888146b205c8)
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:62!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 5969 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
RIP: 0010:__list_del_entry_valid_or_report+0x14a/0x1d0 lib/list_debug.c:62
Code: 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 8d 00 00 00 48 8b 55 00 48 89 e9 48 89 de 48 c7 c7 40 3d fa 8b e8 37 b0 32 fc 90 <0f> 0b 4c 89 e7 e8 3c 24 5d fd 48 89 ea 48 b8 00 00 00 00 00 fc ff
RSP: 0018:ffffc90003bffaa8 EFLAGS: 00010082
RAX: 000000000000006d RBX: ffff88807dc6c3f0 RCX: 0000000000000000
RDX: 000000000000006d RSI: ffffffff81e5d6c9 RDI: fffff5200077ff46
RBP: ffff888146b205c8 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000080000001 R11: 0000000000000000 R12: ffff88807dc6c2b0
R13: ffff88807dc6c408 R14: ffff88807dc6c3f0 R15: ffff88807dc6c3c8
FS:  0000000000000000(0000) GS:ffff8881245d9000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f60e56708c0 CR3: 000000006b065000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __list_del_entry_valid include/linux/list.h:132 [inline]
 __list_del_entry include/linux/list.h:223 [inline]
 list_del_init include/linux/list.h:295 [inline]
 io_poll_remove_waitq io_uring/poll.c:149 [inline]
 io_poll_remove_entry io_uring/poll.c:166 [inline]
 io_poll_remove_entries.part.0+0x156/0x7e0 io_uring/poll.c:197
 io_poll_remove_entries io_uring/poll.c:177 [inline]
 io_poll_task_func+0x39e/0xe30 io_uring/poll.c:343
 io_handle_tw_list+0x194/0x580 io_uring/io_uring.c:1122
 tctx_task_work_run+0x57/0x2b0 io_uring/io_uring.c:1182
 tctx_task_work+0x7a/0xd0 io_uring/io_uring.c:1200
 task_work_run+0x150/0x240 kernel/task_work.c:233
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x829/0x2a30 kernel/exit.c:971
 do_group_exit+0xd5/0x2a0 kernel/exit.c:1112
 __do_sys_exit_group kernel/exit.c:1123 [inline]
 __se_sys_exit_group kernel/exit.c:1121 [inline]
 __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1121
 x64_sys_call+0x14fd/0x1510 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f60e579aeb9
Code: Unable to access opcode bytes at 0x7f60e579ae8f.
RSP: 002b:00007ffc2d47ddf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f60e579aeb9
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000003 R08: 0000000000000000 R09: 00007f60e59e1280
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f60e59e1280 R14: 0000000000000003 R15: 00007ffc2d47deb0
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__list_del_entry_valid_or_report+0x14a/0x1d0 lib/list_debug.c:62
Code: 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 8d 00 00 00 48 8b 55 00 48 89 e9 48 89 de 48 c7 c7 40 3d fa 8b e8 37 b0 32 fc 90 <0f> 0b 4c 89 e7 e8 3c 24 5d fd 48 89 ea 48 b8 00 00 00 00 00 fc ff
RSP: 0018:ffffc90003bffaa8 EFLAGS: 00010082
RAX: 000000000000006d RBX: ffff88807dc6c3f0 RCX: 0000000000000000
RDX: 000000000000006d RSI: ffffffff81e5d6c9 RDI: fffff5200077ff46
RBP: ffff888146b205c8 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000080000001 R11: 0000000000000000 R12: ffff88807dc6c2b0
R13: ffff88807dc6c408 R14: ffff88807dc6c3f0 R15: ffff88807dc6c3c8
FS:  0000000000000000(0000) GS:ffff8881245d9000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f60e56708c0 CR3: 000000006b065000 CR4: 00000000003526f0

Crashes (7):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/02/08 17:56 upstream e7aa57247700 4c131dc4 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root BUG: corrupted list in io_poll_remove_entries
2026/02/08 16:52 upstream e7aa57247700 4c131dc4 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root BUG: corrupted list in io_poll_remove_entries
2026/02/08 15:10 upstream e7aa57247700 4c131dc4 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root BUG: corrupted list in io_poll_remove_entries
2026/02/08 14:08 upstream e7aa57247700 4c131dc4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root BUG: corrupted list in io_poll_remove_entries
2026/02/08 14:08 upstream e7aa57247700 4c131dc4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root BUG: corrupted list in io_poll_remove_entries
2026/02/08 14:07 upstream e7aa57247700 4c131dc4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root BUG: corrupted list in io_poll_remove_entries
2026/02/11 07:51 linux-next fd9678829d6d 441e25b7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root BUG: corrupted list in io_poll_remove_entries
* Struck through repros no longer work on HEAD.