syzbot


KCSAN: data-race in pipe_poll / pipe_release (13)

Status: moderation: reported on 2026/04/19 19:15
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+e30a8943954071025142@syzkaller.appspotmail.com
First crash: 2d07h, last: 2d07h
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision Error
f3cdf4f3-7a7c-4e90-b96a-d0e872909b30 assessment-kcsan Benign: ✅  Confident: ✅  KCSAN: data-race in pipe_poll / pipe_release (13) 2026/04/19 19:14 2026/04/19 19:14 2026/04/19 19:35 303e2802d4760a2024848e19b613070c0df2a791
Similar bugs (12)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in pipe_poll / pipe_release (5) fs 6 1 720d 720d 0/29 auto-obsoleted due to no activity on 2024/06/05 09:41
upstream KCSAN: data-race in pipe_poll / pipe_release (10) fs 6 4 341d 363d 0/29 auto-obsoleted due to no activity on 2025/07/10 18:23
upstream KCSAN: data-race in pipe_poll / pipe_release (11) fs 6 4 210d 285d 0/29 auto-obsoleted due to no activity on 2025/11/18 14:55
upstream KCSAN: data-race in pipe_poll / pipe_release (2) fs 6 1 1953d 1953d 0/29 auto-closed as invalid on 2021/01/19 18:58
upstream KCSAN: data-race in pipe_poll / pipe_release (6) fs 6 1 649d 649d 0/29 auto-obsoleted due to no activity on 2024/08/15 20:31
upstream KCSAN: data-race in pipe_poll / pipe_release (9) fs 6 2 446d 447d 0/29 auto-obsoleted due to no activity on 2025/03/27 08:52
upstream KCSAN: data-race in pipe_poll / pipe_release (12) fs 6 1 149d 149d 0/29 auto-obsoleted due to no activity on 2026/01/19 01:31
upstream KCSAN: data-race in pipe_poll / pipe_release (3) fs 6 1 1517d 1517d 0/29 auto-closed as invalid on 2022/04/01 01:04
upstream KCSAN: data-race in pipe_poll / pipe_release (4) fs 6 1 776d 776d 0/29 auto-obsoleted due to no activity on 2024/04/10 23:01
upstream KCSAN: data-race in pipe_poll / pipe_release fs 6 3 2283d 2349d 0/29 auto-closed as invalid on 2020/03/30 06:30
upstream KCSAN: data-race in pipe_poll / pipe_release (7) fs 6 1 614d 613d 0/29 auto-obsoleted due to no activity on 2024/09/20 00:08
upstream KCSAN: data-race in pipe_poll / pipe_release (8) fs 6 2 542d 569d 0/29 auto-obsoleted due to no activity on 2024/12/21 16:47

Sample crash report:
==================================================================
BUG: KCSAN: data-race in pipe_poll / pipe_release

write to 0xffff88812e1fbd20 of 4 bytes by task 11018 on cpu 1:
 pipe_release+0xb6/0x1d0 fs/pipe.c:733
 __fput+0x29b/0x630 fs/file_table.c:510
 ____fput+0x1c/0x30 fs/file_table.c:538
 task_work_run+0x130/0x1a0 kernel/task_work.c:233
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x4ae/0x1530 kernel/exit.c:975
 do_group_exit+0x138/0x140 kernel/exit.c:1117
 __do_sys_exit_group kernel/exit.c:1128 [inline]
 __se_sys_exit_group kernel/exit.c:1126 [inline]
 __x64_sys_exit_group+0x1f/0x20 kernel/exit.c:1126
 x64_sys_call+0x3008/0x3020 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88812e1fbd20 of 4 bytes by task 3302 on cpu 0:
 pipe_poll+0x16d/0x250 fs/pipe.c:691
 vfs_poll include/linux/poll.h:82 [inline]
 select_poll_one fs/select.c:480 [inline]
 do_select+0x94e/0xfa0 fs/select.c:536
 core_sys_select+0x45d/0x730 fs/select.c:677
 do_pselect fs/select.c:759 [inline]
 __do_sys_pselect6 fs/select.c:798 [inline]
 __se_sys_pselect6+0x23c/0x2a0 fs/select.c:789
 __x64_sys_pselect6+0x78/0x90 fs/select.c:789
 x64_sys_call+0x8d5/0x3020 arch/x86/include/generated/asm/syscalls_64.h:271
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000001 -> 0x00000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 3302 Comm: syz-executor Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/04/19 19:14 upstream faeab166167f 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in pipe_poll / pipe_release
* Struck through repros no longer work on HEAD.