[v5.15] BUG: corrupted list in io_poll_remove_entries
0 views
Skip to first unread message
syzbot
Feb 22, 2026, 4:37:34 AM (3 days ago) Feb 22
to syzkaller...@googlegroups.com
Hello,
syzbot found the following issue on:
HEAD commit: 3330a8d33e08 Linux 5.15.201
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1602dd94580000
kernel config: https://syzkaller.appspot.com/x/.config?x=353ae28c40b35af5
dashboard link: https://syzkaller.appspot.com/bug?extid=c0e02e47f6a27ef4d2b0
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/b65fe19af112/disk-3330a8d3.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/351948519a0d/vmlinux-3330a8d3.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a3b3f8477595/bzImage-3330a8d3.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c0e02e...@syzkaller.appspotmail.com
list_del corruption. prev->next should be ffff88801e2378f0, but was ffff88802a0e85c8
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:61!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 4288 Comm: kworker/0:9 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: events io_fallback_req_func
RIP: 0010:__list_del_entry_valid+0x107/0x120 lib/list_debug.c:59
Code: 48 89 de e8 0b 6e c9 05 0f 0b 48 c7 c7 40 fc 79 8a 48 89 de e8 fa 6d c9 05 0f 0b 48 c7 c7 a0 fc 79 8a 48 89 de e8 e9 6d c9 05 <0f> 0b 48 c7 c7 00 fd 79 8a 48 89 de e8 d8 6d c9 05 0f 0b 00 00 cc
RSP: 0018:ffffc9000335fac8 EFLAGS: 00010046
RAX: 0000000000000054 RBX: ffff88801e2378f0 RCX: 1f705b129ed33b00
RDX: 0000000000000000 RSI: 0000000080000001 RDI: 0000000000000000
RBP: ffff88802a0e8588 R08: ffff8880b9033d7f R09: 1ffff110172067af
R10: dffffc0000000000 R11: ffffed10172067b0 R12: dffffc0000000000
R13: ffff88801e2378f0 R14: ffff88802a0e85c8 R15: ffff88802a0e85c8
FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f73deec7000 CR3: 0000000060133000 CR4: 00000000003526f0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000300
DR3: 0000000080000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
__list_del_entry include/linux/list.h:132 [inline]
list_del_init include/linux/list.h:204 [inline]
io_poll_remove_entry io_uring/io_uring.c:5579 [inline]
io_poll_remove_entries+0x193/0x4a0 io_uring/io_uring.c:5606
io_poll_task_func+0xfe/0x280 io_uring/io_uring.c:5708
io_fallback_req_func+0x100/0x210 io_uring/io_uring.c:1280
process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
</TASK>
Modules linked in:
---[ end trace 3c027d3336a655cb ]---
RIP: 0010:__list_del_entry_valid+0x107/0x120 lib/list_debug.c:59
Code: 48 89 de e8 0b 6e c9 05 0f 0b 48 c7 c7 40 fc 79 8a 48 89 de e8 fa 6d c9 05 0f 0b 48 c7 c7 a0 fc 79 8a 48 89 de e8 e9 6d c9 05 <0f> 0b 48 c7 c7 00 fd 79 8a 48 89 de e8 d8 6d c9 05 0f 0b 00 00 cc
RSP: 0018:ffffc9000335fac8 EFLAGS: 00010046
RAX: 0000000000000054 RBX: ffff88801e2378f0 RCX: 1f705b129ed33b00
RDX: 0000000000000000 RSI: 0000000080000001 RDI: 0000000000000000
RBP: ffff88802a0e8588 R08: ffff8880b9033d7f R09: 1ffff110172067af
R10: dffffc0000000000 R11: ffffed10172067b0 R12: dffffc0000000000
R13: ffff88801e2378f0 R14: ffff88802a0e85c8 R15: ffff88802a0e85c8
FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f73deec7000 CR3: 0000000060133000 CR4: 00000000003526f0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000300
DR3: 0000000080000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
syzbot found the following issue on:
HEAD commit: 3330a8d33e08 Linux 5.15.201
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1602dd94580000
kernel config: https://syzkaller.appspot.com/x/.config?x=353ae28c40b35af5
dashboard link: https://syzkaller.appspot.com/bug?extid=c0e02e47f6a27ef4d2b0
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/b65fe19af112/disk-3330a8d3.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/351948519a0d/vmlinux-3330a8d3.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a3b3f8477595/bzImage-3330a8d3.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c0e02e...@syzkaller.appspotmail.com
list_del corruption. prev->next should be ffff88801e2378f0, but was ffff88802a0e85c8
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:61!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 4288 Comm: kworker/0:9 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: events io_fallback_req_func
RIP: 0010:__list_del_entry_valid+0x107/0x120 lib/list_debug.c:59
Code: 48 89 de e8 0b 6e c9 05 0f 0b 48 c7 c7 40 fc 79 8a 48 89 de e8 fa 6d c9 05 0f 0b 48 c7 c7 a0 fc 79 8a 48 89 de e8 e9 6d c9 05 <0f> 0b 48 c7 c7 00 fd 79 8a 48 89 de e8 d8 6d c9 05 0f 0b 00 00 cc
RSP: 0018:ffffc9000335fac8 EFLAGS: 00010046
RAX: 0000000000000054 RBX: ffff88801e2378f0 RCX: 1f705b129ed33b00
RDX: 0000000000000000 RSI: 0000000080000001 RDI: 0000000000000000
RBP: ffff88802a0e8588 R08: ffff8880b9033d7f R09: 1ffff110172067af
R10: dffffc0000000000 R11: ffffed10172067b0 R12: dffffc0000000000
R13: ffff88801e2378f0 R14: ffff88802a0e85c8 R15: ffff88802a0e85c8
FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f73deec7000 CR3: 0000000060133000 CR4: 00000000003526f0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000300
DR3: 0000000080000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
__list_del_entry include/linux/list.h:132 [inline]
list_del_init include/linux/list.h:204 [inline]
io_poll_remove_entry io_uring/io_uring.c:5579 [inline]
io_poll_remove_entries+0x193/0x4a0 io_uring/io_uring.c:5606
io_poll_task_func+0xfe/0x280 io_uring/io_uring.c:5708
io_fallback_req_func+0x100/0x210 io_uring/io_uring.c:1280
process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
</TASK>
Modules linked in:
---[ end trace 3c027d3336a655cb ]---
RIP: 0010:__list_del_entry_valid+0x107/0x120 lib/list_debug.c:59
Code: 48 89 de e8 0b 6e c9 05 0f 0b 48 c7 c7 40 fc 79 8a 48 89 de e8 fa 6d c9 05 0f 0b 48 c7 c7 a0 fc 79 8a 48 89 de e8 e9 6d c9 05 <0f> 0b 48 c7 c7 00 fd 79 8a 48 89 de e8 d8 6d c9 05 0f 0b 00 00 cc
RSP: 0018:ffffc9000335fac8 EFLAGS: 00010046
RAX: 0000000000000054 RBX: ffff88801e2378f0 RCX: 1f705b129ed33b00
RDX: 0000000000000000 RSI: 0000000080000001 RDI: 0000000000000000
RBP: ffff88802a0e8588 R08: ffff8880b9033d7f R09: 1ffff110172067af
R10: dffffc0000000000 R11: ffffed10172067b0 R12: dffffc0000000000
R13: ffff88801e2378f0 R14: ffff88802a0e85c8 R15: ffff88802a0e85c8
FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f73deec7000 CR3: 0000000060133000 CR4: 00000000003526f0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000300
DR3: 0000000080000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
syzbot
Feb 22, 2026, 6:05:31 AM (3 days ago) Feb 22
to syzkaller...@googlegroups.com
syzbot has found a reproducer for the following issue on:
HEAD commit: 3330a8d33e08 Linux 5.15.201
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1636d95a580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16d5eeaa580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/b65fe19af112/disk-3330a8d3.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/351948519a0d/vmlinux-3330a8d3.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a3b3f8477595/bzImage-3330a8d3.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c0e02e...@syzkaller.appspotmail.com
list_del corruption. prev->next should be ffff88807cf588f0, but was ffff88802aa345c8
RAX: 0000000000000054 RBX: ffff88807cf588f0 RCX: 1393da159bc1da00
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
task_work_run+0x125/0x1a0 kernel/task_work.c:188
exit_task_work include/linux/task_work.h:33 [inline]
do_exit+0x626/0x20c0 kernel/exit.c:883
do_group_exit+0x12e/0x300 kernel/exit.c:997
__do_sys_exit_group kernel/exit.c:1008 [inline]
__se_sys_exit_group kernel/exit.c:1006 [inline]
__x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1006
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f78d04f5629
Code: Unable to access opcode bytes at RIP 0x7f78d04f55ff.
RSP: 002b:00007ffd64067708 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f78d04f5629
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000003 R08: 0000000000000000 R09: 00007f78d073e3e0
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f78d073e3e0 R14: 0000000000000003 R15: 00007ffd640677c0
</TASK>
Modules linked in:
---[ end trace 690635bab7d10448 ]---
RAX: 0000000000000054 RBX: ffff88807cf588f0 RCX: 1393da159bc1da00
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
HEAD commit: 3330a8d33e08 Linux 5.15.201
git tree: linux-5.15.y
kernel config: https://syzkaller.appspot.com/x/.config?x=353ae28c40b35af5
dashboard link: https://syzkaller.appspot.com/bug?extid=c0e02e47f6a27ef4d2b0
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1652dd94580000
dashboard link: https://syzkaller.appspot.com/bug?extid=c0e02e47f6a27ef4d2b0
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16d5eeaa580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/b65fe19af112/disk-3330a8d3.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/351948519a0d/vmlinux-3330a8d3.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a3b3f8477595/bzImage-3330a8d3.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c0e02e...@syzkaller.appspotmail.com
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:61!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 4373 Comm: syz.0.17 Not tainted syzkaller #0
kernel BUG at lib/list_debug.c:61!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:__list_del_entry_valid+0x107/0x120 lib/list_debug.c:59
Code: 48 89 de e8 0b 6e c9 05 0f 0b 48 c7 c7 40 fc 79 8a 48 89 de e8 fa 6d c9 05 0f 0b 48 c7 c7 a0 fc 79 8a 48 89 de e8 e9 6d c9 05 <0f> 0b 48 c7 c7 00 fd 79 8a 48 89 de e8 d8 6d c9 05 0f 0b 00 00 cc
RSP: 0018:ffffc900031cfbc8 EFLAGS: 00010046
Code: 48 89 de e8 0b 6e c9 05 0f 0b 48 c7 c7 40 fc 79 8a 48 89 de e8 fa 6d c9 05 0f 0b 48 c7 c7 a0 fc 79 8a 48 89 de e8 e9 6d c9 05 <0f> 0b 48 c7 c7 00 fd 79 8a 48 89 de e8 d8 6d c9 05 0f 0b 00 00 cc
RAX: 0000000000000054 RBX: ffff88807cf588f0 RCX: 1393da159bc1da00
RDX: 0000000000000000 RSI: 0000000080000001 RDI: 0000000000000000
RBP: ffff88802aa34588 R08: ffff8880b9033d7f R09: 1ffff110172067af
R10: dffffc0000000000 R11: ffffed10172067b0 R12: dffffc0000000000
R13: ffff88807cf588f0 R14: ffff88802aa345c8 R15: ffff88802aa345c8
FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000556c39005950 CR3: 000000000c08e000 CR4: 00000000003506f0
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
__list_del_entry include/linux/list.h:132 [inline]
list_del_init include/linux/list.h:204 [inline]
io_poll_remove_entry io_uring/io_uring.c:5579 [inline]
io_poll_remove_entries+0x193/0x4a0 io_uring/io_uring.c:5606
io_poll_task_func+0xfe/0x280 io_uring/io_uring.c:5708
tctx_task_work+0x2d9/0x5e0 io_uring/io_uring.c:2209
<TASK>
__list_del_entry include/linux/list.h:132 [inline]
list_del_init include/linux/list.h:204 [inline]
io_poll_remove_entry io_uring/io_uring.c:5579 [inline]
io_poll_remove_entries+0x193/0x4a0 io_uring/io_uring.c:5606
io_poll_task_func+0xfe/0x280 io_uring/io_uring.c:5708
task_work_run+0x125/0x1a0 kernel/task_work.c:188
exit_task_work include/linux/task_work.h:33 [inline]
do_exit+0x626/0x20c0 kernel/exit.c:883
do_group_exit+0x12e/0x300 kernel/exit.c:997
__do_sys_exit_group kernel/exit.c:1008 [inline]
__se_sys_exit_group kernel/exit.c:1006 [inline]
__x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1006
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f78d04f5629
Code: Unable to access opcode bytes at RIP 0x7f78d04f55ff.
RSP: 002b:00007ffd64067708 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f78d04f5629
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000003 R08: 0000000000000000 R09: 00007f78d073e3e0
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f78d073e3e0 R14: 0000000000000003 R15: 00007ffd640677c0
</TASK>
Modules linked in:
---[ end trace 690635bab7d10448 ]---
RIP: 0010:__list_del_entry_valid+0x107/0x120 lib/list_debug.c:59
Code: 48 89 de e8 0b 6e c9 05 0f 0b 48 c7 c7 40 fc 79 8a 48 89 de e8 fa 6d c9 05 0f 0b 48 c7 c7 a0 fc 79 8a 48 89 de e8 e9 6d c9 05 <0f> 0b 48 c7 c7 00 fd 79 8a 48 89 de e8 d8 6d c9 05 0f 0b 00 00 cc
RSP: 0018:ffffc900031cfbc8 EFLAGS: 00010046
Code: 48 89 de e8 0b 6e c9 05 0f 0b 48 c7 c7 40 fc 79 8a 48 89 de e8 fa 6d c9 05 0f 0b 48 c7 c7 a0 fc 79 8a 48 89 de e8 e9 6d c9 05 <0f> 0b 48 c7 c7 00 fd 79 8a 48 89 de e8 d8 6d c9 05 0f 0b 00 00 cc
RAX: 0000000000000054 RBX: ffff88807cf588f0 RCX: 1393da159bc1da00
RDX: 0000000000000000 RSI: 0000000080000001 RDI: 0000000000000000
RBP: ffff88802aa34588 R08: ffff8880b9033d7f R09: 1ffff110172067af
R10: dffffc0000000000 R11: ffffed10172067b0 R12: dffffc0000000000
R13: ffff88807cf588f0 R14: ffff88802aa345c8 R15: ffff88802aa345c8
FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000556c39005950 CR3: 000000000c08e000 CR4: 00000000003506f0
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
Reply all
Reply to author
Forward
0 new messages