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

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 46452d3786a8 Merge tag 'sound-6.0-rc8' of git://git.kernel..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1302eaa8880000
kernel config: https://syzkaller.appspot.com/x/.config?x=a3b79d315aae1ae3
dashboard link: https://syzkaller.appspot.com/bug?extid=f2d61c1b2357c03fb539
compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13484b40880000
CC: [amir...@gmail.com ja...@suse.cz linux-...@vger.kernel.org linux-...@vger.kernel.org]

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/60d0206874bc/disk-46452d37.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/4e2c91bd93b7/vmlinux-46452d37.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+f2d61c...@syzkaller.appspotmail.com

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

write to 0xffff888101eb9324 of 4 bytes by task 1815 on cpu 0:
fsnotify_detach_connector_from_object+0x80/0x260 fs/notify/mark.c:253
fsnotify_put_mark+0x198/0x3b0 fs/notify/mark.c:316
__do_sys_inotify_rm_watch fs/notify/inotify/inotify_user.c:820 [inline]
__se_sys_inotify_rm_watch+0xff/0x170 fs/notify/inotify/inotify_user.c:794
__x64_sys_inotify_rm_watch+0x2d/0x40 fs/notify/inotify/inotify_user.c:794
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff888101eb9324 of 4 bytes by task 2085 on cpu 1:
fsnotify_event_needs_parent fs/notify/fsnotify.c:161 [inline]
__fsnotify_parent+0x126/0x470 fs/notify/fsnotify.c:202
fsnotify_parent include/linux/fsnotify.h:77 [inline]
fsnotify_file include/linux/fsnotify.h:99 [inline]
fsnotify_open include/linux/fsnotify.h:330 [inline]
do_sys_openat2+0x23a/0x2a0 fs/open.c:1318
do_sys_open fs/open.c:1329 [inline]
__do_sys_openat fs/open.c:1345 [inline]
__se_sys_openat fs/open.c:1340 [inline]
__x64_sys_openat+0xef/0x110 fs/open.c:1340
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x00002008 -> 0x00000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 2085 Comm: syz-executor.3 Not tainted 6.0.0-rc7-syzkaller-00042-g46452d3786a8-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022
==================================================================
loop3: detected capacity change from 0 to 87
FAT-fs (loop3): bogus sectors per cluster 116
FAT-fs (loop3): Can't find a valid FAT filesystem


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