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KCSAN: data-race in fsnotify_detach_connector_from_object / fsnotify_event_needs_parent

Status: moderation: reported on 2024/03/17 12:49
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+4115ff98aec2485b3195@syzkaller.appspotmail.com
First crash: 27d, last: 7d08h

Sample crash report:
==================================================================
BUG: KCSAN: data-race in fsnotify_detach_connector_from_object / fsnotify_event_needs_parent

write to 0xffff88810121baa4 of 4 bytes by task 15893 on cpu 0:
 fsnotify_detach_connector_from_object+0xcc/0x280 fs/notify/mark.c:253
 fsnotify_put_mark+0x198/0x3c0 fs/notify/mark.c:316
 __do_sys_inotify_rm_watch fs/notify/inotify/inotify_user.c:819 [inline]
 __se_sys_inotify_rm_watch+0x105/0x180 fs/notify/inotify/inotify_user.c:793
 __x64_sys_inotify_rm_watch+0x31/0x40 fs/notify/inotify/inotify_user.c:793
 do_syscall_64+0xd3/0x1d0
 entry_SYSCALL_64_after_hwframe+0x72/0x7a

read to 0xffff88810121baa4 of 4 bytes by task 8533 on cpu 1:
 fsnotify_event_needs_parent+0x47/0x100 fs/notify/fsnotify.c:161
 __fsnotify_parent+0x178/0x370 fs/notify/fsnotify.c:208
 fsnotify_parent include/linux/fsnotify.h:83 [inline]
 fsnotify_file include/linux/fsnotify.h:106 [inline]
 fsnotify_close include/linux/fsnotify.h:387 [inline]
 __fput+0x1ff/0x660 fs/file_table.c:408
 __fput_sync+0x44/0x60 fs/file_table.c:507
 __do_sys_close fs/open.c:1556 [inline]
 __se_sys_close+0x101/0x1b0 fs/open.c:1541
 __x64_sys_close+0x1f/0x30 fs/open.c:1541
 do_syscall_64+0xd3/0x1d0
 entry_SYSCALL_64_after_hwframe+0x72/0x7a

value changed: 0x00002008 -> 0x00000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 8533 Comm: syz-executor.0 Tainted: G        W          6.9.0-rc2-syzkaller-00385-g104db052b62d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
==================================================================

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/04/06 08:00 upstream 104db052b62d ca620dd8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_detach_connector_from_object / fsnotify_event_needs_parent
2024/04/02 05:24 upstream 026e680b0a08 6baf5069 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_detach_connector_from_object / fsnotify_event_needs_parent
2024/03/17 12:48 upstream 741e9d668aa5 d615901c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in fsnotify_detach_connector_from_object / fsnotify_event_needs_parent
* Struck through repros no longer work on HEAD.