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

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 443b349019f2 samples/cgroup: add .gitignore file for gener..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=113c3c1de80000
kernel config: https://syzkaller.appspot.com/x/.config?x=e1bd33f45956bbc2
dashboard link: https://syzkaller.appspot.com/bug?extid=afc7c1600cf5007f6055
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/67d9d05341ce/disk-443b3490.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/fc7742b12b15/vmlinux-443b3490.xz
kernel image: https://storage.googleapis.com/syzbot-assets/7ab2f56e22ef/bzImage-443b3490.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+afc7c1...@syzkaller.appspotmail.com

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

write to 0xffff88814923c3e0 of 8 bytes by task 7014 on cpu 1:
inode_set_mtime_to_ts include/linux/fs.h:1571 [inline]
setattr_copy+0x1b9/0x2b0 fs/attr.c:313
shmem_setattr+0x52e/0x830 mm/shmem.c:1220
notify_change+0x866/0x8e0 fs/attr.c:499
vfs_utimes+0x2c6/0x3e0 fs/utimes.c:66
do_utimes_path fs/utimes.c:99 [inline]
do_utimes+0x14f/0x1f0 fs/utimes.c:145
__do_sys_utimensat fs/utimes.c:164 [inline]
__se_sys_utimensat fs/utimes.c:148 [inline]
__x64_sys_utimensat+0xc6/0x170 fs/utimes.c:148
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x59/0x120 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff88814923c3e0 of 8 bytes by task 5903 on cpu 0:
inode_get_mtime include/linux/fs.h:1565 [inline]
generic_fillattr+0x1a6/0x2f0 fs/stat.c:61
shmem_getattr+0x17b/0x200 mm/shmem.c:1139
vfs_getattr_nosec fs/stat.c:135 [inline]
vfs_getattr+0x198/0x1e0 fs/stat.c:176
vfs_statx+0x140/0x320 fs/stat.c:248
vfs_fstatat+0xcd/0x100 fs/stat.c:304
__do_sys_newfstatat fs/stat.c:468 [inline]
__se_sys_newfstatat+0x58/0x260 fs/stat.c:462
__x64_sys_newfstatat+0x55/0x60 fs/stat.c:462
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x59/0x120 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x0000000001bf2678 -> 0x000000000257bcf8

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 5903 Comm: udevd Tainted: G W 6.8.0-rc1-syzkaller-00037-g443b349019f2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
==================================================================
I/O error, dev loop0, sector 0 op 0x0:(READ) flags 0x80700 phys_seg 1 prio class 0


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[syzbot]

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