[moderation] [fs?] KCSAN: data-race in generic_fillattr / inode_update_timestamps (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 2c22dc1ee3a1 Merge tag 'mailbox-v6.13' of git://git.kernel..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15660f5f980000
kernel config: https://syzkaller.appspot.com/x/.config?x=db310a9aeec0c8cb
dashboard link: https://syzkaller.appspot.com/bug?extid=45b8a8c3f7a9139f15b4
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/0cb07ee98241/disk-2c22dc1e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ba989cf0a9bd/vmlinux-2c22dc1e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b7e2933ec9ca/bzImage-2c22dc1e.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+45b8a8...@syzkaller.appspotmail.com

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

write to 0xffff8881014469a4 of 4 bytes by task 15129 on cpu 1:
inode_set_mtime_to_ts include/linux/fs.h:1648 [inline]
inode_update_timestamps+0x139/0x250 fs/inode.c:2070
generic_update_time fs/inode.c:2105 [inline]
inode_update_time fs/inode.c:2125 [inline]
__file_update_time fs/inode.c:2353 [inline]
file_update_time+0x219/0x2b0 fs/inode.c:2383
blkdev_write_iter+0x31d/0x460 block/fops.c:711
do_iter_readv_writev+0x394/0x450
vfs_writev+0x2d4/0x880 fs/read_write.c:1050
do_pwritev fs/read_write.c:1146 [inline]
__do_sys_pwritev2 fs/read_write.c:1204 [inline]
__se_sys_pwritev2+0x100/0x1c0 fs/read_write.c:1195
__x64_sys_pwritev2+0x78/0x90 fs/read_write.c:1195
x64_sys_call+0x2afe/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:329
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 0xffff8881014469a4 of 4 bytes by task 13922 on cpu 0:
inode_get_mtime_nsec include/linux/fs.h:1634 [inline]
inode_get_mtime include/linux/fs.h:1640 [inline]
generic_fillattr+0x205/0x330 fs/stat.c:102
shmem_getattr+0x17b/0x200 mm/shmem.c:1177
vfs_getattr_nosec fs/stat.c:208 [inline]
vfs_getattr fs/stat.c:246 [inline]
vfs_fstat+0x19d/0x200 fs/stat.c:265
vfs_fstatat fs/stat.c:364 [inline]
__do_sys_newfstatat fs/stat.c:530 [inline]
__se_sys_newfstatat+0xb5/0x300 fs/stat.c:524
__x64_sys_newfstatat+0x55/0x70 fs/stat.c:524
x64_sys_call+0x236d/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:263
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: 0x0d379c01 -> 0x10765517

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 13922 Comm: udevd Not tainted 6.12.0-syzkaller-09435-g2c22dc1ee3a1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
==================================================================


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[syzbot]

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