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KCSAN: data-race in fsnotify_destroy_mark / inotify_handle_inode_event (9)

Status: moderation: reported on 2026/03/23 19:35
Subsystems: fs
Labels: prio:low
[Documentation on labels]
Reported-by: syzbot+c185466bef3fb295c0a3@syzkaller.appspotmail.com
First crash: 67d, last: 54d
▶ ▼ ✨ AI Jobs (5)
ID Workflow Result Correct Bug Created Started Finished Revision Error
3ab94885-c15b-4510-bb19-cb6d0081c1a4 assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ✅ UserNamespace: ✅ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ KCSAN: data-race in fsnotify_destroy_mark / inotify_handle_inode_event (9) 2026/05/24 16:33 2026/05/24 16:33 2026/05/24 17:00 c69befb30ac10e158cc9d1557b508ee3f0eca1de
9c2fab05-ae3f-4464-a5ae-303eb1c403ac assessment-kcsan Benign: ✅ Confident: ✅ ❓ KCSAN: data-race in fsnotify_destroy_mark / inotify_handle_inode_event (9) 2026/03/31 12:12 2026/03/31 12:25 2026/03/31 12:26 d0af506ef4609d1bffbbbbae776b857a63d84b20
34253091-9671-48a0-9397-e885b73c80ea assessment-kcsan Benign: ✅ Confident: ✅ ❓ KCSAN: data-race in fsnotify_destroy_mark / inotify_handle_inode_event (9) 2026/03/31 12:12 2026/03/31 12:14 2026/03/31 12:17 d0af506ef4609d1bffbbbbae776b857a63d84b20
0d8f4d24-a8bb-45ea-9eb0-dbb1648db2bc assessment-kcsan Benign: ✅ Confident: ✅ ❓ KCSAN: data-race in fsnotify_destroy_mark / inotify_handle_inode_event (9) 2026/03/26 00:03 2026/03/26 00:03 2026/03/26 00:27 c6143aacd8e1a01f2482ab5eec709f9949710cee
41bb13bd-1c74-4bda-aadc-ac6f182c9b3b assessment-kcsan 💥 KCSAN: data-race in fsnotify_destroy_mark / inotify_handle_inode_event (9) 2026/03/24 09:40 2026/03/24 09:40 2026/03/24 09:40 971831e4896625f799f350fe4439dc0774b7154a+ unexpected git log output: "warning: unable to access '/root/.config/git/attributes': Permission denied\nwarning: unable to access '/root/.config/git/attributes': Permission denied\nc369299895a591d96745d6492d4888259b004a9e\nLinux 7.0-rc5\ntorvalds@linux-foundation.org\nLinus Torvalds\nSun Mar 22 14:42:17 2026 -0700\nec69c9e88315c4be70c283f18c2ff130da6320b5\nSun Mar 22 14:42:17 2026 -0700\n"
▶ ▼ Similar bugs (8)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in fsnotify_destroy_mark / inotify_handle_inode_event (6) fs 6 2 747d 780d 0/29 auto-obsoleted due to no activity on 2024/06/17 10:51
upstream KCSAN: data-race in fsnotify_destroy_mark / inotify_handle_inode_event (8) fs 6 1 485d 485d 0/29 auto-obsoleted due to no activity on 2025/03/27 02:07
upstream KCSAN: data-race in fsnotify_destroy_mark / inotify_handle_inode_event fs 6 1 1396d 1396d 0/29 auto-closed as invalid on 2022/09/07 06:46
upstream KCSAN: data-race in fsnotify_destroy_mark / inotify_handle_inode_event (4) fs 6 1 1042d 1042d 0/29 auto-obsoleted due to no activity on 2023/08/27 10:05
upstream KCSAN: data-race in fsnotify_destroy_mark / inotify_handle_inode_event (7) fs 6 1 687d 687d 0/29 auto-obsoleted due to no activity on 2024/08/15 15:27
upstream KCSAN: data-race in fsnotify_destroy_mark / inotify_handle_inode_event (2) fs 6 1 1301d 1301d 0/29 auto-obsoleted due to no activity on 2022/12/10 20:40
upstream KCSAN: data-race in fsnotify_destroy_mark / inotify_handle_inode_event (3) fs 6 1 1148d 1148d 0/29 auto-obsoleted due to no activity on 2023/05/12 13:04
upstream KCSAN: data-race in fsnotify_destroy_mark / inotify_handle_inode_event (5) fs 6 3 942d 953d 0/29 auto-obsoleted due to no activity on 2023/12/04 18:59

Sample crash report:
EXT4-fs (loop4): unmounting filesystem 00000000-0000-0000-0000-000000000000.
==================================================================
BUG: KCSAN: data-race in fsnotify_destroy_mark / inotify_handle_inode_event

write to 0xffff888104be8a94 of 4 bytes by task 3283 on cpu 1:
 fsnotify_free_mark fs/notify/mark.c:584 [inline]
 fsnotify_destroy_mark+0xeb/0x150 fs/notify/mark.c:602
 __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 0xffff888104be8a94 of 4 bytes by task 3314 on cpu 0:
 inotify_handle_inode_event+0x34c/0x3d0 fs/notify/inotify/inotify_fsnotify.c:132
 fsnotify_handle_inode_event+0x1c0/0x220 fs/notify/fsnotify.c:272
 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: 0x00000001 -> 0x00000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 3314 Comm: syz-executor Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/04/05 14:37 upstream 3aae9383f42f 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_destroy_mark / inotify_handle_inode_event
2026/03/23 19:34 upstream c369299895a5 4933dba2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_destroy_mark / inotify_handle_inode_event
* Struck through repros no longer work on HEAD.