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KCSAN: data-race in fasync_remove_entry / kill_fasync (10)

Status: auto-obsoleted due to no activity on 2023/08/01 22:11
Subsystems: fs
[Documentation on labels]
First crash: 844d, last: 844d
▶ ▼ Similar bugs (13)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in fasync_remove_entry / kill_fasync (2) fs 6 1 1882d 1882d 0/29 auto-closed as invalid on 2020/09/27 12:17
upstream KCSAN: data-race in fasync_remove_entry / kill_fasync (12) fs 6 1 344d 344d 0/29 auto-obsoleted due to no activity on 2025/01/04 10:04
upstream KCSAN: data-race in fasync_remove_entry / kill_fasync (4) fs 6 1 1614d 1614d 0/29 auto-closed as invalid on 2021/06/23 11:06
upstream KCSAN: data-race in fasync_remove_entry / kill_fasync (5) fs 6 2 1544d 1546d 0/29 auto-closed as invalid on 2021/08/31 22:21
upstream KCSAN: data-race in fasync_remove_entry / kill_fasync (9) fs 6 1 1063d 1063d 0/29 auto-obsoleted due to no activity on 2023/01/02 11:50
upstream KCSAN: data-race in fasync_remove_entry / kill_fasync (13) fs 6 1 277d 277d 0/29 auto-obsoleted due to no activity on 2025/03/11 12:00
upstream KCSAN: data-race in fasync_remove_entry / kill_fasync (3) fs 6 1 1765d 1765d 0/29 auto-closed as invalid on 2021/01/22 14:57
upstream KCSAN: data-race in fasync_remove_entry / kill_fasync (11) fs 6 3 427d 456d 0/29 auto-obsoleted due to no activity on 2024/09/21 19:37
upstream KCSAN: data-race in fasync_remove_entry / kill_fasync (6) fs 6 1 1483d 1483d 0/29 auto-closed as invalid on 2021/10/31 16:09
upstream KCSAN: data-race in fasync_remove_entry / kill_fasync (7) fs 6 4 1405d 1443d 0/29 auto-closed as invalid on 2022/01/18 10:05
upstream KCSAN: data-race in fasync_remove_entry / kill_fasync (8) fs 6 3 1349d 1358d 0/29 auto-closed as invalid on 2022/03/14 14:59
upstream KCSAN: data-race in fasync_remove_entry / kill_fasync fs 6 82 1936d 2094d 0/29 auto-closed as invalid on 2020/08/04 12:11
upstream KCSAN: data-race in fasync_remove_entry / kill_fasync (14) fs 6 2 50d 57d 0/29 moderation: reported on 2025/08/22 22:35

Sample crash report:
==================================================================
BUG: KCSAN: data-race in fasync_remove_entry / kill_fasync

write to 0xffff888109cb2358 of 8 bytes by task 14061 on cpu 1:
 fasync_remove_entry+0xd5/0x130 fs/fcntl.c:878
 fasync_helper+0x96/0xc0 fs/fcntl.c:977
 sock_fasync+0x60/0xd0 net/socket.c:1423
 __fput+0x5b2/0x600 fs/file_table.c:375
 ____fput+0x15/0x20 fs/file_table.c:406
 task_work_run+0x135/0x1a0 kernel/task_work.c:179
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xd1/0xe0 kernel/entry/common.c:171
 exit_to_user_mode_prepare+0x6c/0xb0 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
 syscall_exit_to_user_mode+0x26/0x140 kernel/entry/common.c:297
 do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff888109cb2358 of 8 bytes by task 14073 on cpu 0:
 kill_fasync+0x24/0x150 fs/fcntl.c:1016
 sock_wake_async+0xf5/0x120
 sk_wake_async include/net/sock.h:2530 [inline]
 unix_release_sock+0x483/0x780 net/unix/af_unix.c:636
 unix_release+0x52/0x70 net/unix/af_unix.c:1042
 __sock_release net/socket.c:654 [inline]
 sock_close+0x70/0x150 net/socket.c:1398
 __fput+0x303/0x600 fs/file_table.c:378
 ____fput+0x15/0x20 fs/file_table.c:406
 task_work_run+0x135/0x1a0 kernel/task_work.c:179
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xd1/0xe0 kernel/entry/common.c:171
 exit_to_user_mode_prepare+0x6c/0xb0 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
 syscall_exit_to_user_mode+0x26/0x140 kernel/entry/common.c:297
 do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0xffff88812d36e210 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 14073 Comm: syz-executor.2 Not tainted 6.4.0-syzkaller-01371-g04fc8904d5d1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/06/27 22:07 upstream 04fc8904d5d1 4cd5bb25 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in fasync_remove_entry / kill_fasync
* Struck through repros no longer work on HEAD.