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

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: e32cde8d2bd7 Merge tag 'sched_ext-for-6.12-rc1-fixes-1' of..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10ba6580580000
kernel config: https://syzkaller.appspot.com/x/.config?x=13af6e9c27c7bbbf
dashboard link: https://syzkaller.appspot.com/bug?extid=0a4fb8bbb7bab5f5c766
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/e728901b4154/disk-e32cde8d.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e662806fa232/vmlinux-e32cde8d.xz
kernel image: https://storage.googleapis.com/syzbot-assets/ed885d1a3f98/bzImage-e32cde8d.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0a4fb8...@syzkaller.appspotmail.com

loop0: detected capacity change from 0 to 512
==================================================================
BUG: KCSAN: data-race in fsnotify / fsnotify_put_mark

write to 0xffff888101441150 of 4 bytes by task 3257 on cpu 1:
fsnotify_detach_connector_from_object fs/notify/mark.c:330 [inline]
fsnotify_put_mark+0x2db/0x5d0 fs/notify/mark.c:393
__do_sys_inotify_rm_watch fs/notify/inotify/inotify_user.c:819 [inline]
__se_sys_inotify_rm_watch+0xf9/0x170 fs/notify/inotify/inotify_user.c:793
__x64_sys_inotify_rm_watch+0x31/0x40 fs/notify/inotify/inotify_user.c:793
x64_sys_call+0x1ae0/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:256
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888101441150 of 4 bytes by task 3892 on cpu 0:
fsnotify+0x36c/0x11a0 fs/notify/fsnotify.c:564
__fsnotify_parent+0x285/0x380 fs/notify/fsnotify.c:261
fsnotify_parent include/linux/fsnotify.h:96 [inline]
fsnotify_file include/linux/fsnotify.h:131 [inline]
fsnotify_close include/linux/fsnotify.h:412 [inline]
__fput+0x5a6/0x6d0 fs/file_table.c:417
__fput_sync+0x43/0x60 fs/file_table.c:516
__do_sys_close fs/open.c:1565 [inline]
__se_sys_close+0xf9/0x1a0 fs/open.c:1550
__x64_sys_close+0x1f/0x30 fs/open.c:1550
x64_sys_call+0x25cb/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:4
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00002008 -> 0x00000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 3892 Comm: syz.0.172 Tainted: G W 6.12.0-rc1-syzkaller-00031-ge32cde8d2bd7 #0
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
==================================================================
EXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: writeback.
ext4 filesystem being mounted at /47/bus supports timestamps until 2038-01-19 (0x7fffffff)


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.