[moderation] [fs?] KCSAN: data-race in __dentry_kill / lookup_fast (11)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 4305ca0087dd Merge tag 'scsi-misc' of git://git.kernel.org..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=143f22c3980000
kernel config: https://syzkaller.appspot.com/x/.config?x=6163df0d7ac97a0b
dashboard link: https://syzkaller.appspot.com/bug?extid=511f4cd1b47514ec3075
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [bra...@kernel.org ja...@suse.cz 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/4b82775edafe/disk-4305ca00.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/926d7bf43c7c/vmlinux-4305ca00.xz
kernel image: https://storage.googleapis.com/syzbot-assets/368c211fcd88/bzImage-4305ca00.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+511f4c...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in __dentry_kill / lookup_fast

read-write to 0xffff888106a72240 of 4 bytes by task 16413 on cpu 1:
dentry_unlist fs/dcache.c:555 [inline]
__dentry_kill+0x22e/0x4c0 fs/dcache.c:624
dput+0x5c/0xd0 fs/dcache.c:852
path_put fs/namei.c:568 [inline]
terminate_walk+0xfb/0x280 fs/namei.c:692
path_openat+0x1979/0x1f10 fs/namei.c:3887
do_filp_open+0xf7/0x200 fs/namei.c:3913
do_sys_openat2+0xab/0x120 fs/open.c:1416
do_sys_open fs/open.c:1431 [inline]
__do_sys_openat fs/open.c:1447 [inline]
__se_sys_openat fs/open.c:1442 [inline]
__x64_sys_openat+0xf3/0x120 fs/open.c:1442
x64_sys_call+0x1ac/0x2e00 arch/x86/include/generated/asm/syscalls_64.h:258
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 0xffff888106a72240 of 4 bytes by task 16412 on cpu 0:
d_revalidate fs/namei.c:867 [inline]
lookup_fast+0xd9/0x2a0 fs/namei.c:1667
open_last_lookups fs/namei.c:3615 [inline]
path_openat+0x466/0x1f10 fs/namei.c:3883
do_filp_open+0xf7/0x200 fs/namei.c:3913
do_sys_openat2+0xab/0x120 fs/open.c:1416
do_sys_open fs/open.c:1431 [inline]
__do_sys_openat fs/open.c:1447 [inline]
__se_sys_openat fs/open.c:1442 [inline]
__x64_sys_openat+0xf3/0x120 fs/open.c:1442
x64_sys_call+0x1ac/0x2e00 arch/x86/include/generated/asm/syscalls_64.h:258
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: 0x0040000c -> 0x0000800c

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 16412 Comm: syz.4.3635 Not tainted 6.10.0-syzkaller-09061-g4305ca0087dd #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
==================================================================


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