syzbot

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BUG: KCSAN: data-race in fill_mg_cmtime / simple_rename_timestamp

write to 0xffff8881036f3544 of 4 bytes by task 18085 on cpu 1:
 inode_set_mtime_to_ts include/linux/fs.h:1716 [inline]
 simple_rename_timestamp+0x53/0xd0 fs/libfs.c:810
 shmem_rename2+0x251/0x290 mm/shmem.c:4074
 vfs_rename+0x7d6/0xa20 fs/namei.c:5128
 do_renameat2+0x764/0xab0 fs/namei.c:5277
 __do_sys_rename fs/namei.c:5324 [inline]
 __se_sys_rename fs/namei.c:5322 [inline]
 __x64_sys_rename+0x58/0x70 fs/namei.c:5322
 x64_sys_call+0x2aee/0x2fb0 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 0xffff8881036f3544 of 4 bytes by task 3487 on cpu 0:
 inode_get_mtime_nsec include/linux/fs.h:1702 [inline]
 inode_get_mtime include/linux/fs.h:1708 [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:1262
 vfs_getattr_nosec+0x143/0x1e0 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+0x2c22/0x2fb0 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: 0x1a1d916b -> 0x1a206384

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 3487 Comm: udevd Not tainted 6.15.0-syzkaller-13473-gc0c9379f235d #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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