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

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: bee0e7762ad2 Merge tag 'for-linus-iommufd' of git://git.ke..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16dbc0d4e80000
kernel config: https://syzkaller.appspot.com/x/.config?x=ac34c1f29a8029df
dashboard link: https://syzkaller.appspot.com/bug?extid=ec3c00269c1c4e69e4a1
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/233be5f65dd2/disk-bee0e776.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/94423738a289/vmlinux-bee0e776.xz
kernel image: https://storage.googleapis.com/syzbot-assets/0b977463fa9a/bzImage-bee0e776.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ec3c00...@syzkaller.appspotmail.com

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

write to 0xffff888124cad280 of 8 bytes by task 3302 on cpu 1:
inode_set_atime_to_ts include/linux/fs.h:1537 [inline]
inode_update_timestamps+0x4d1/0x560 fs/inode.c:1914
generic_update_time fs/inode.c:1936 [inline]
inode_update_time fs/inode.c:1956 [inline]
touch_atime+0x15c/0x2d0 fs/inode.c:2028
do_readlinkat+0x164/0x210 fs/stat.c:505
__do_sys_readlink fs/stat.c:527 [inline]
__se_sys_readlink fs/stat.c:524 [inline]
__x64_sys_readlink+0x47/0x50 fs/stat.c:524
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff888124cad280 of 8 bytes by task 6050 on cpu 0:
inode_get_atime include/linux/fs.h:1531 [inline]
generic_fillattr+0x16f/0x2f0 fs/stat.c:60
shmem_getattr+0x17b/0x200 mm/shmem.c:1121
vfs_getattr_nosec fs/stat.c:135 [inline]
vfs_getattr+0x198/0x1e0 fs/stat.c:176
vfs_statx+0x12f/0x2f0 fs/stat.c:248
vfs_fstatat+0xcd/0x100 fs/stat.c:299
__do_sys_newfstatat fs/stat.c:463 [inline]
__se_sys_newfstatat+0x58/0x260 fs/stat.c:457
__x64_sys_newfstatat+0x55/0x60 fs/stat.c:457
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x0000000026333a89 -> 0x0000000027646789

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 6050 Comm: udevd Not tainted 6.7.0-rc4-syzkaller-00009-gbee0e7762ad2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
==================================================================


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[syzbot]

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