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

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 5c24e4e9e708 Merge tag 'hid-for-linus-2024020101' of git:/..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14670838180000
kernel config: https://syzkaller.appspot.com/x/.config?x=4aab723d3dfffc44
dashboard link: https://syzkaller.appspot.com/bug?extid=2fb2065ce74d09b92949
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [bra...@kernel.org chuck...@oracle.com ja...@suse.cz jla...@kernel.org linux-...@vger.kernel.org linux-...@vger.kernel.org vi...@zeniv.linux.org.uk]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/939a791831ca/disk-5c24e4e9.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/0ffa996f3841/vmlinux-5c24e4e9.xz
kernel image: https://storage.googleapis.com/syzbot-assets/00a87458e25f/bzImage-5c24e4e9.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2fb206...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in do_fcntl / do_fcntl

read-write to 0xffff888137108648 of 4 bytes by task 13328 on cpu 0:
setfl fs/fcntl.c:81 [inline]
do_fcntl+0xde9/0xeb0 fs/fcntl.c:342
__do_sys_fcntl fs/fcntl.c:456 [inline]
__se_sys_fcntl+0xc4/0x180 fs/fcntl.c:441
__x64_sys_fcntl+0x43/0x50 fs/fcntl.c:441
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff888137108648 of 4 bytes by task 13327 on cpu 1:
setfl fs/fcntl.c:73 [inline]
do_fcntl+0xc55/0xeb0 fs/fcntl.c:342
__do_sys_fcntl fs/fcntl.c:456 [inline]
__se_sys_fcntl+0xc4/0x180 fs/fcntl.c:441
__x64_sys_fcntl+0x43/0x50 fs/fcntl.c:441
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x00048000 -> 0x0004cc00

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 13327 Comm: syz-executor.1 Not tainted 6.8.0-rc2-syzkaller-00084-g5c24e4e9e708 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
==================================================================


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[syzbot]

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