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KCSAN: data-race in fsnotify_detach_mark / fsnotify_handle_inode_event (4)

Status: moderation: reported on 2025/05/29 06:50
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+21ccf00ef85c17ca9d58@syzkaller.appspotmail.com
First crash: 285d, last: 12d
✨ AI Jobs (2)
ID Workflow Result Correct Bug Created Started Finished Revision Error
0414ec70-f49b-4321-8820-5227f96060d3 repro KCSAN: data-race in fsnotify_detach_mark / fsnotify_handle_inode_event (4) 2026/03/06 13:26 2026/03/06 13:26 2026/03/06 13:31 31e9c887f7dc24e04b3ca70d0d54fc34141844b0
7465f176-d000-4ffd-b3ba-b1b1046207e3 assessment-kcsan Benign: ✅  KCSAN: data-race in fsnotify_detach_mark / fsnotify_handle_inode_event (4) 2026/01/09 16:22 2026/01/09 16:22 2026/01/09 16:45 7519916073b761ced56a7b15fdeeb4674e8dc125
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in fsnotify_detach_mark / fsnotify_handle_inode_event (3) fs 6 24 398d 557d 0/29 auto-obsoleted due to no activity on 2025/04/01 19:34
upstream KCSAN: data-race in fsnotify_detach_mark / fsnotify_handle_inode_event (2) fs 6 3 603d 611d 0/29 auto-obsoleted due to no activity on 2024/08/19 04:23
upstream KCSAN: data-race in fsnotify_detach_mark / fsnotify_handle_inode_event fs 6 226 688d 823d 0/29 auto-obsoleted due to no activity on 2024/05/18 20:42

Sample crash report:
==================================================================
BUG: KCSAN: data-race in fsnotify_detach_mark / fsnotify_handle_inode_event

write to 0xffff88811e5ac594 of 4 bytes by task 3303 on cpu 0:
 fsnotify_detach_mark+0xb9/0x160 fs/notify/mark.c:558
 fsnotify_destroy_mark+0x6f/0x150 fs/notify/mark.c:600
 __do_sys_inotify_rm_watch fs/notify/inotify/inotify_user.c:805 [inline]
 __se_sys_inotify_rm_watch+0xe8/0x170 fs/notify/inotify/inotify_user.c:786
 __x64_sys_inotify_rm_watch+0x31/0x40 fs/notify/inotify/inotify_user.c:786
 x64_sys_call+0xc88/0x3020 arch/x86/include/generated/asm/syscalls_64.h:256
 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

read to 0xffff88811e5ac594 of 4 bytes by task 9427 on cpu 1:
 fsnotify_handle_inode_event+0x125/0x220 fs/notify/fsnotify.c:264
 fsnotify_handle_event fs/notify/fsnotify.c:327 [inline]
 send_to_group fs/notify/fsnotify.c:375 [inline]
 fsnotify+0x15d0/0x1730 fs/notify/fsnotify.c:592
 __fsnotify_parent+0x2f8/0x3a0 fs/notify/fsnotify.c:238
 fsnotify_parent include/linux/fsnotify.h:96 [inline]
 fsnotify_path include/linux/fsnotify.h:113 [inline]
 fsnotify_file include/linux/fsnotify.h:127 [inline]
 fsnotify_close include/linux/fsnotify.h:457 [inline]
 __fput+0x1de/0x650 fs/file_table.c:455
 fput_close_sync+0xad/0x190 fs/file_table.c:574
 __do_sys_close fs/open.c:1509 [inline]
 __se_sys_close fs/open.c:1494 [inline]
 __x64_sys_close+0x55/0xf0 fs/open.c:1494
 x64_sys_call+0x275d/0x3020 arch/x86/include/generated/asm/syscalls_64.h:4
 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: 0x00000003 -> 0x00000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 9427 Comm: syz.1.438 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
==================================================================

Crashes (31):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/02/26 16:34 upstream f4d0ec0aa20d ffa54287 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_detach_mark / fsnotify_handle_inode_event
2026/02/26 03:57 upstream d9d32e5bd5a4 e0f78d93 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_detach_mark / fsnotify_handle_inode_event
2026/02/07 05:54 upstream 2687c848e578 f20fc9f9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_detach_mark / fsnotify_handle_inode_event
2026/02/06 09:25 upstream 8fdb05de0e2d f03c4191 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_detach_mark / fsnotify_handle_inode_event
2026/02/05 07:40 upstream f14faaf3a1fb ea10c935 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_detach_mark / fsnotify_handle_inode_event
2026/01/31 00:12 upstream 4d310797262f c75a2f6e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_detach_mark / fsnotify_handle_inode_event
2026/01/24 22:34 upstream 62085877ae65 40acda8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_detach_mark / fsnotify_handle_inode_event
2026/01/20 13:15 upstream 24d479d26b25 06648d9c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_detach_mark / fsnotify_handle_inode_event
2026/01/14 09:35 upstream c537e12daeec d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_detach_mark / fsnotify_handle_inode_event
2025/12/28 12:35 upstream d26143bb38e2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_detach_mark / fsnotify_handle_inode_event
2025/12/23 05:14 upstream b927546677c8 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_detach_mark / fsnotify_handle_inode_event
2025/12/02 00:29 upstream 1d18101a644e d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_detach_mark / fsnotify_handle_inode_event
2025/11/16 17:08 upstream 7254a2b52279 f7988ea4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_detach_mark / fsnotify_handle_inode_event
2025/11/14 00:59 upstream 2ccec5944606 07e030de .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_detach_mark / fsnotify_handle_inode_event
2025/10/24 10:42 upstream 6fab32bb6508 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_detach_mark / fsnotify_handle_inode_event
2025/10/22 03:08 upstream 552c50713f27 252fbbad .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_detach_mark / fsnotify_handle_inode_event
2025/10/05 04:28 upstream d104e3d17f7b 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_detach_mark / fsnotify_handle_inode_event
2025/10/03 19:46 upstream 9b0d551bcc05 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_detach_mark / fsnotify_handle_inode_event
2025/09/15 00:23 upstream 79e8447ec662 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_detach_mark / fsnotify_handle_inode_event
2025/09/13 22:18 upstream 5cd64d4f9268 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_detach_mark / fsnotify_handle_inode_event
2025/08/14 16:41 upstream 0cc53520e68b 5d8c2ac2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_detach_mark / fsnotify_handle_inode_event
2025/08/10 06:05 upstream 561c80369df0 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_detach_mark / fsnotify_handle_inode_event
2025/08/09 11:08 upstream 2988dfed8a5d 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_detach_mark / fsnotify_handle_inode_event
2025/08/05 10:10 upstream 7e161a991ea7 37880f40 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_detach_mark / fsnotify_handle_inode_event
2025/08/02 10:42 upstream 0905809b38bd 7368264b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_detach_mark / fsnotify_handle_inode_event
2025/07/19 23:54 upstream bf61759db409 7117feec .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_detach_mark / fsnotify_handle_inode_event
2025/07/12 09:03 upstream 379f604cc3dc 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_detach_mark / fsnotify_handle_inode_event
2025/06/30 08:24 upstream d0b3b7b22dfa fc9d8ee5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_detach_mark / fsnotify_handle_inode_event
2025/06/27 17:47 upstream 67a993863163 803ce19b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_detach_mark / fsnotify_handle_inode_event
2025/06/25 03:37 upstream 7595b66ae9de 26d77996 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_detach_mark / fsnotify_handle_inode_event
2025/05/29 06:49 upstream 90b83efa6701 3d2f584d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_detach_mark / fsnotify_handle_inode_event
* Struck through repros no longer work on HEAD.