[moderation] [fs?] KCSAN: data-race in fsnotify / fsnotify_detach_connector_from_object (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: bee0e7762ad2 Merge tag 'for-linus-iommufd' of git://git.ke..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=133730cae80000
kernel config: https://syzkaller.appspot.com/x/.config?x=ac34c1f29a8029df
dashboard link: https://syzkaller.appspot.com/bug?extid=7c0ddce2d1a4b4e14449
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/233be5f65dd2/disk-bee0e776.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/94423738a289/vmlinux-bee0e776.xz
kernel image: https://storage.googleapis.com/syzbot-assets/0b977463fa9a/bzImage-bee0e776.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7c0ddc...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in fsnotify / fsnotify_detach_connector_from_object

write to 0xffff888100c4f4c4 of 4 bytes by task 3322 on cpu 1:
fsnotify_detach_connector_from_object+0xcc/0x280 fs/notify/mark.c:253
fsnotify_put_mark+0x192/0x3b0 fs/notify/mark.c:316
__do_sys_inotify_rm_watch fs/notify/inotify/inotify_user.c:820 [inline]
__se_sys_inotify_rm_watch+0x105/0x180 fs/notify/inotify/inotify_user.c:794
__x64_sys_inotify_rm_watch+0x31/0x40 fs/notify/inotify/inotify_user.c:794
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff888100c4f4c4 of 4 bytes by task 2779 on cpu 0:
fsnotify+0x2b8/0x1150 fs/notify/fsnotify.c:532
__fsnotify_parent+0x307/0x480 fs/notify/fsnotify.c:230
fsnotify_parent include/linux/fsnotify.h:77 [inline]
fsnotify_file include/linux/fsnotify.h:100 [inline]
fsnotify_perm+0x33f/0x380 include/linux/fsnotify.h:125
security_file_open+0x53/0x70 security/security.c:2840
do_dentry_open+0x224/0xbd0 fs/open.c:935
vfs_open+0x4a/0x50 fs/open.c:1082
do_open fs/namei.c:3622 [inline]
path_openat+0x1819/0x1d70 fs/namei.c:3779
do_filp_open+0xf6/0x200 fs/namei.c:3809
do_sys_openat2+0xab/0x110 fs/open.c:1440
do_sys_open fs/open.c:1455 [inline]
__do_sys_openat fs/open.c:1471 [inline]
__se_sys_openat fs/open.c:1466 [inline]
__x64_sys_openat+0xf3/0x120 fs/open.c:1466
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x00002008 -> 0x00000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 2779 Comm: udevd Not tainted 6.7.0-rc4-syzkaller-00009-gbee0e7762ad2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
==================================================================


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