syzbot


KCSAN: data-race in pipe_release / pipe_wait_readable (10)

Status: moderation: reported on 2026/01/11 23:53
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+e99ed90904970f25484f@syzkaller.appspotmail.com
First crash: 48d, last: 12d
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision Error
7005ffbc-3cd2-4306-a9e6-4334035f959a assessment-kcsan Benign: ✅  KCSAN: data-race in pipe_release / pipe_wait_readable (10) 2026/01/12 15:06 2026/01/12 15:06 2026/01/12 15:28 dc57dbf3ee402bd8ad9c3037d56ee9d9940a9bc6
Similar bugs (9)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in pipe_release / pipe_wait_readable (5) fs 6 1 960d 960d 0/29 auto-obsoleted due to no activity on 2023/08/18 19:43
upstream KCSAN: data-race in pipe_release / pipe_wait_readable (7) fs 6 1 641d 641d 0/29 auto-obsoleted due to no activity on 2024/07/03 04:49
upstream KCSAN: data-race in pipe_release / pipe_wait_readable (9) fs 6 1 108d 108d 0/29 auto-obsoleted due to no activity on 2026/01/08 09:41
upstream KCSAN: data-race in pipe_release / pipe_wait_readable (6) fs 6 1 866d 866d 0/29 auto-obsoleted due to no activity on 2023/11/21 12:39
upstream KCSAN: data-race in pipe_release / pipe_wait_readable fs 6 1 1975d 1975d 0/29 auto-closed as invalid on 2020/11/06 19:13
upstream KCSAN: data-race in pipe_release / pipe_wait_readable (3) fs 6 1 1815d 1815d 0/29 auto-closed as invalid on 2021/04/15 21:34
upstream KCSAN: data-race in pipe_release / pipe_wait_readable (4) fs 6 2 1565d 1573d 0/29 auto-closed as invalid on 2021/12/21 16:44
upstream KCSAN: data-race in pipe_release / pipe_wait_readable (2) fs 6 1 1863d 1863d 0/29 auto-closed as invalid on 2021/02/26 20:27
upstream KCSAN: data-race in pipe_release / pipe_wait_readable (8) fs 6 1 587d 587d 0/29 auto-obsoleted due to no activity on 2024/08/26 01:03

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

read-write to 0xffff88811c8caeac of 4 bytes by task 15603 on cpu 1:
 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 0xffff88811c8caeac of 4 bytes by task 15604 on cpu 0:
 pipe_lock fs/pipe.c:90 [inline]
 pipe_wait_readable+0x1c2/0x210 fs/pipe.c:1077
 splice_from_pipe_next+0x21f/0x370 fs/splice.c:544
 iter_file_splice_write+0x1b4/0xa80 fs/splice.c:693
 do_splice_from fs/splice.c:938 [inline]
 do_splice+0x970/0x10b0 fs/splice.c:1351
 __do_splice fs/splice.c:1433 [inline]
 __do_sys_splice fs/splice.c:1636 [inline]
 __se_sys_splice+0x26c/0x3a0 fs/splice.c:1618
 __x64_sys_splice+0x78/0x90 fs/splice.c:1618
 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: 0 UID: 0 PID: 15604 Comm: syz.3.3119 Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/02/16 17:26 upstream 0f2acd3148e0 5d52cba5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in pipe_release / pipe_wait_readable
2026/01/11 23:53 upstream 755bc1335e3b d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in pipe_release / pipe_wait_readable
* Struck through repros no longer work on HEAD.