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: 1d05h, last: 1d05h
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 913d 913d 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 594d 594d 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 60d 60d 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 818d 818d 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 1928d 1928d 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 1768d 1768d 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 1518d 1525d 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 1816d 1816d 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 540d 540d 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 0xffff88810d02796c of 4 bytes by task 5305 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:468
 ____fput+0x1c/0x30 fs/file_table.c:496
 task_work_run+0x131/0x1a0 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:44 [inline]
 exit_to_user_mode_loop+0x1fe/0x740 kernel/entry/common.c:75
 __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_work include/linux/entry-common.h:159 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
 do_syscall_64+0x1dd/0x2b0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88810d02796c of 4 bytes by task 5306 on cpu 1:
 pipe_lock fs/pipe.c:90 [inline]
 pipe_wait_readable+0x1c2/0x210 fs/pipe.c:1077
 splice_from_pipe_next+0x220/0x380 fs/splice.c:544
 iter_file_splice_write+0x1b1/0xa20 fs/splice.c:693
 do_splice_from fs/splice.c:938 [inline]
 do_splice+0x972/0x10b0 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+0x2e82/0x3000 arch/x86/include/generated/asm/syscalls_64.h:276
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xca/0x2b0 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: 5306 Comm: syz.0.612 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
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.