[moderation] [fs?] KCSAN: data-race in do_fcntl / do_fcntl (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 5bbd9b249880 Merge tag 'v6.10-p4' of git://git.kernel.org/..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12a52361980000
kernel config: https://syzkaller.appspot.com/x/.config?x=7e87b541dc1fc960
dashboard link: https://syzkaller.appspot.com/bug?extid=31c0e4d3406d4483bb8f
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [alex....@gmail.com 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/ff5f8f9b9600/disk-5bbd9b24.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/9d83e00a503c/vmlinux-5bbd9b24.xz
kernel image: https://storage.googleapis.com/syzbot-assets/1bf6e142ccb0/bzImage-5bbd9b24.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+31c0e4...@syzkaller.appspotmail.com

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

write to 0xffff88810a1b336c of 4 bytes by task 8658 on cpu 1:
do_fcntl+0x7a7/0xe20 fs/fcntl.c:432
__do_sys_fcntl fs/fcntl.c:492 [inline]
__se_sys_fcntl+0xc4/0x190 fs/fcntl.c:477
__x64_sys_fcntl+0x43/0x50 fs/fcntl.c:477
x64_sys_call+0x292f/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:73
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

write to 0xffff88810a1b336c of 4 bytes by task 8654 on cpu 0:
do_fcntl+0x7a7/0xe20 fs/fcntl.c:432
__do_sys_fcntl fs/fcntl.c:492 [inline]
__se_sys_fcntl+0xc4/0x190 fs/fcntl.c:477
__x64_sys_fcntl+0x43/0x50 fs/fcntl.c:477
x64_sys_call+0x292f/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:73
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: 0x00000000 -> 0x00000021

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 8654 Comm: syz.3.1239 Not tainted 6.10.0-rc5-syzkaller-00200-g5bbd9b249880 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
==================================================================


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