[moderation] [fs?] KCSAN: data-race in fsnotify_destroy_mark / inotify_handle_inode_event (9)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: c369299895a5 Linux 7.0-rc5
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17038b52580000
kernel config: https://syzkaller.appspot.com/x/.config?x=3a78dd265deac3a9
dashboard link: https://syzkaller.appspot.com/bug?extid=c185466bef3fb295c0a3
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
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/e1a57b1f5815/disk-c3692998.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/1d507d4d26d8/vmlinux-c3692998.xz
kernel image: https://storage.googleapis.com/syzbot-assets/9325396a64ca/bzImage-c3692998.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c18546...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in fsnotify_destroy_mark / inotify_handle_inode_event

write to 0xffff888104c23184 of 4 bytes by task 11506 on cpu 1:
fsnotify_free_mark fs/notify/mark.c:584 [inline]
fsnotify_destroy_mark+0xeb/0x150 fs/notify/mark.c:602
__do_sys_inotify_rm_watch fs/notify/inotify/inotify_user.c:805 [inline]
__se_sys_inotify_rm_watch+0xe8/0x170 fs/notify/inotify/inotify_user.c:786
__x64_sys_inotify_rm_watch+0x31/0x40 fs/notify/inotify/inotify_user.c:786
x64_sys_call+0xc88/0x3020 arch/x86/include/generated/asm/syscalls_64.h:256
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x12c/0x370 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888104c23184 of 4 bytes by task 3311 on cpu 0:
inotify_handle_inode_event+0x34c/0x3d0 fs/notify/inotify/inotify_fsnotify.c:132
fsnotify_handle_inode_event+0x1c0/0x220 fs/notify/fsnotify.c:272
fsnotify_handle_event fs/notify/fsnotify.c:327 [inline]
send_to_group fs/notify/fsnotify.c:375 [inline]
fsnotify+0x15d0/0x1730 fs/notify/fsnotify.c:592
__fsnotify_parent+0x2f8/0x3a0 fs/notify/fsnotify.c:238
fsnotify_parent include/linux/fsnotify.h:96 [inline]
fsnotify_path include/linux/fsnotify.h:113 [inline]
fsnotify_file include/linux/fsnotify.h:127 [inline]
fsnotify_close include/linux/fsnotify.h:457 [inline]
__fput+0x1de/0x650 fs/file_table.c:455
fput_close_sync+0xad/0x190 fs/file_table.c:574
__do_sys_close fs/open.c:1509 [inline]
__se_sys_close fs/open.c:1494 [inline]
__x64_sys_close+0x55/0xf0 fs/open.c:1494
x64_sys_call+0x275d/0x3020 arch/x86/include/generated/asm/syscalls_64.h:4
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x12c/0x370 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000001 -> 0x00000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 3311 Comm: syz-executor Tainted: G W syzkaller #0 PREEMPT(full)
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
==================================================================


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