[moderation] [fs?] KCSAN: data-race in may_open / setattr_copy (5)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: ac865f00af29 Merge tag 'pci-v6.7-fixes-2' of git://git.ker..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=170ae861e80000
kernel config: https://syzkaller.appspot.com/x/.config?x=17e138c8fc533c5e
dashboard link: https://syzkaller.appspot.com/bug?extid=dc376fb8f84c2b05b852
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [bra...@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/1634cde30dc8/disk-ac865f00.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/9e9d023f69df/vmlinux-ac865f00.xz
kernel image: https://storage.googleapis.com/syzbot-assets/0d96fda8112c/bzImage-ac865f00.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+dc376f...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in may_open / setattr_copy

write to 0xffff88811e9aa3c0 of 2 bytes by task 24 on cpu 0:
setattr_copy+0x29d/0x2b0 fs/attr.c:321
shmem_setattr+0x52e/0x830 mm/shmem.c:1219
notify_change+0x866/0x8e0 fs/attr.c:499
handle_remove drivers/base/devtmpfs.c:337 [inline]
handle drivers/base/devtmpfs.c:386 [inline]
devtmpfs_work_loop+0x828/0x8e0 drivers/base/devtmpfs.c:399
devtmpfsd+0x43/0x50 drivers/base/devtmpfs.c:441
kthread+0x1d7/0x210 kernel/kthread.c:388
ret_from_fork+0x48/0x60 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242

read to 0xffff88811e9aa3c0 of 2 bytes by task 22541 on cpu 1:
may_open+0x42/0x340 fs/namei.c:3223
do_open fs/namei.c:3620 [inline]
path_openat+0x1789/0x1d70 fs/namei.c:3779
do_filp_open+0xf6/0x200 fs/namei.c:3809
do_sys_openat2+0xab/0x110 fs/open.c:1437
do_sys_open fs/open.c:1452 [inline]
__do_sys_openat fs/open.c:1468 [inline]
__se_sys_openat fs/open.c:1463 [inline]
__x64_sys_openat+0xf3/0x120 fs/open.c:1463
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x6180 -> 0x6000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 22541 Comm: udevd Not tainted 6.7.0-rc8-syzkaller-00024-gac865f00af29 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
==================================================================
udevd[22541]: inotify_add_watch(7, /dev/loop1, 10) failed: No such file or directory
udevd[22541]: inotify_add_watch(7, /dev/loop2, 10) failed: No such file or directory


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[syzbot]

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