syzbot


KCSAN: data-race in pipe_lock / pipe_release (17)

Status: moderation: reported on 2026/02/27 23:55
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+ce000bbda60a56aa1370@syzkaller.appspotmail.com
First crash: 2d20h, last: 2d20h
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision Error
6f47a0f4-faa1-42af-b929-8c2afd23600f assessment-kcsan Benign: ✅  Confident: ✅  KCSAN: data-race in pipe_lock / pipe_release (17) 2026/02/27 23:54 2026/02/27 23:54 2026/02/28 00:04 305c0ec5cd886e2d13738e28e1b2df9b0ec20fc9
Similar bugs (16)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in pipe_lock / pipe_release (5) fs 6 1 1539d 1539d 0/29 auto-closed as invalid on 2022/01/18 04:35
upstream KCSAN: data-race in pipe_lock / pipe_release (8) fs 6 1 1287d 1287d 0/29 auto-closed as invalid on 2022/09/27 07:59
upstream KCSAN: data-race in pipe_lock / pipe_release (16) fs 6 5 60d 222d 0/29 auto-obsoleted due to no activity on 2026/02/26 17:04
upstream KCSAN: data-race in pipe_lock / pipe_release (13) fs 6 1 742d 742d 0/29 auto-obsoleted due to no activity on 2024/03/25 04:35
upstream KCSAN: data-race in pipe_lock / pipe_release (15) fs 6 3 402d 474d 0/29 auto-obsoleted due to no activity on 2025/03/21 15:25
upstream KCSAN: data-race in pipe_lock / pipe_release (4) fs 6 1 1800d 1800d 0/29 auto-closed as invalid on 2021/05/02 03:19
upstream KCSAN: data-race in pipe_lock / pipe_release (11) fs 6 1 888d 888d 0/29 auto-obsoleted due to no activity on 2023/10/31 07:05
upstream KCSAN: data-race in pipe_lock / pipe_release (14) fs 6 2 631d 633d 0/29 auto-obsoleted due to no activity on 2024/07/14 01:56
upstream KCSAN: data-race in pipe_lock / pipe_release (6) fs 6 2 1466d 1468d 0/29 auto-closed as invalid on 2022/04/01 19:16
upstream KCSAN: data-race in pipe_lock / pipe_release (9) fs 6 6 1032d 1162d 0/29 auto-obsoleted due to no activity on 2023/06/09 03:35
upstream KCSAN: data-race in pipe_lock / pipe_release fs 6 2 2066d 2083d 0/29 auto-closed as invalid on 2020/08/09 18:16
upstream KCSAN: data-race in pipe_lock / pipe_release (3) fs 6 1 1958d 1958d 0/29 auto-closed as invalid on 2020/11/25 12:55
upstream KCSAN: data-race in pipe_lock / pipe_release (12) fs 6 1 796d 796d 0/29 auto-obsoleted due to no activity on 2024/01/31 07:04
upstream KCSAN: data-race in pipe_lock / pipe_release (7) fs 6 2 1398d 1426d 0/29 auto-closed as invalid on 2022/06/08 19:34
upstream KCSAN: data-race in pipe_lock / pipe_release (10) fs 6 2 969d 990d 0/29 auto-obsoleted due to no activity on 2023/08/10 23:17
upstream KCSAN: data-race in pipe_lock / pipe_release (2) fs 6 1 2008d 2008d 0/29 auto-closed as invalid on 2020/10/06 00:08

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

read-write to 0xffff88811df94bac of 4 bytes by task 6865 on cpu 0:
 put_pipe_info fs/pipe.c:714 [inline]
 pipe_release+0x16a/0x1d0 fs/pipe.c:744
 __fput+0x29b/0x650 fs/file_table.c:469
 ____fput+0x1c/0x30 fs/file_table.c:497
 task_work_run+0x130/0x1a0 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
 exit_to_user_mode_loop+0x1f4/0x6f0 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
 do_syscall_64+0x249/0x370 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88811df94bac of 4 bytes by task 6867 on cpu 1:
 pipe_lock+0x17/0x50 fs/pipe.c:90
 splice_file_to_pipe+0x2e/0x390 fs/splice.c:1287
 do_splice+0xc46/0x10b0 fs/splice.c:1374
 __do_splice fs/splice.c:1431 [inline]
 __do_sys_splice fs/splice.c:1634 [inline]
 __se_sys_splice+0x26c/0x3a0 fs/splice.c:1616
 __x64_sys_splice+0x78/0x90 fs/splice.c:1616
 x64_sys_call+0x16ef/0x3020 arch/x86/include/generated/asm/syscalls_64.h:276
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x370 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000002 -> 0x00000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 6867 Comm: syz.2.1159 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/02/27 23:54 upstream a75cb869a8cc 2cf092b8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in pipe_lock / pipe_release
* Struck through repros no longer work on HEAD.