[moderation] [fs?] KCSAN: data-race in fsnotify_detach_connector_from_object / fsnotify_event_needs_parent

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 741e9d668aa5 Merge tag 'scsi-misc' of git://git.kernel.org..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12057959180000
kernel config: https://syzkaller.appspot.com/x/.config?x=f6807a59ab85347d
dashboard link: https://syzkaller.appspot.com/bug?extid=4115ff98aec2485b3195
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [amir...@gmail.com ja...@suse.cz linux-...@vger.kernel.org linux-...@vger.kernel.org]

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/7991c18f9658/disk-741e9d66.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ee798a879279/vmlinux-741e9d66.xz
kernel image: https://storage.googleapis.com/syzbot-assets/76910846e995/bzImage-741e9d66.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+4115ff...@syzkaller.appspotmail.com

EXT4-fs (loop4): unmounting filesystem 00000000-0000-0000-0000-000000000000.
==================================================================
BUG: KCSAN: data-race in fsnotify_detach_connector_from_object / fsnotify_event_needs_parent

write to 0xffff88810124a324 of 4 bytes by task 3626 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+0x6d/0x75

read to 0xffff88810124a324 of 4 bytes by task 3113 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+0x6d/0x75

value changed: 0x00002008 -> 0x00000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 3113 Comm: syz-executor.4 Not tainted 6.8.0-syzkaller-11339-g741e9d668aa5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
==================================================================


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