syzbot

==================================================================
BUG: KCSAN: data-race in fill_mg_cmtime / simple_rename_timestamp

write to 0xffff888103f7a6bc of 4 bytes by task 9083 on cpu 0:
 inode_set_mtime_to_ts include/linux/fs.h:1722 [inline]
 simple_rename_timestamp+0x53/0xd0 fs/libfs.c:821
 shmem_rename2+0x251/0x290 mm/shmem.c:4139
 vfs_rename+0x7f0/0xa40 fs/namei.c:5129
 do_renameat2+0x557/0xa10 fs/namei.c:5278
 __do_sys_rename fs/namei.c:5325 [inline]
 __se_sys_rename fs/namei.c:5323 [inline]
 __x64_sys_rename+0x58/0x70 fs/namei.c:5323
 x64_sys_call+0x1f9/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:83
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888103f7a6bc of 4 bytes by task 3604 on cpu 1:
 inode_get_mtime_nsec include/linux/fs.h:1708 [inline]
 inode_get_mtime include/linux/fs.h:1714 [inline]
 fill_mg_cmtime+0x5b/0x260 fs/stat.c:55
 generic_fillattr+0x24a/0x340 fs/stat.c:99
 shmem_getattr+0x181/0x200 mm/shmem.c:1294
 vfs_getattr_nosec+0x146/0x1e0 fs/stat.c:213
 vfs_getattr fs/stat.c:262 [inline]
 vfs_statx_path fs/stat.c:299 [inline]
 vfs_statx+0x113/0x390 fs/stat.c:356
 vfs_fstatat+0x115/0x170 fs/stat.c:375
 __do_sys_newfstatat fs/stat.c:542 [inline]
 __se_sys_newfstatat+0x55/0x260 fs/stat.c:536
 __x64_sys_newfstatat+0x55/0x70 fs/stat.c:536
 x64_sys_call+0x135a/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:263
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x04110bd8 -> 0x042b068d

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3604 Comm: udevd Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
==================================================================