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BUG: KCSAN: data-race in fill_mg_cmtime / shmem_symlink

write to 0xffff88810376fb14 of 4 bytes by task 3974 on cpu 1:
 inode_set_mtime_to_ts include/linux/fs.h:1706 [inline]
 shmem_symlink+0x392/0x3e0 mm/shmem.c:4131
 vfs_symlink+0xca/0x1d0 fs/namei.c:4723
 do_symlinkat+0xe3/0x370 fs/namei.c:4749
 __do_sys_symlink fs/namei.c:4770 [inline]
 __se_sys_symlink fs/namei.c:4768 [inline]
 __x64_sys_symlink+0x50/0x60 fs/namei.c:4768
 x64_sys_call+0x2a77/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:89
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0x1a0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88810376fb14 of 4 bytes by task 3954 on cpu 0:
 inode_get_mtime_nsec include/linux/fs.h:1692 [inline]
 inode_get_mtime include/linux/fs.h:1698 [inline]
 fill_mg_cmtime+0x58/0x280 fs/stat.c:55
 generic_fillattr+0x241/0x330 fs/stat.c:99
 shmem_getattr+0x17b/0x200 mm/shmem.c:1262
 vfs_getattr_nosec+0x141/0x1d0 fs/stat.c:210
 vfs_getattr fs/stat.c:259 [inline]
 vfs_statx_path fs/stat.c:296 [inline]
 vfs_statx+0x145/0x2f0 fs/stat.c:353
 vfs_fstatat+0xd9/0x150 fs/stat.c:372
 __do_sys_newfstatat fs/stat.c:536 [inline]
 __se_sys_newfstatat+0x58/0x260 fs/stat.c:530
 __x64_sys_newfstatat+0x55/0x70 fs/stat.c:530
 x64_sys_call+0x2d6f/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:263
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0x1a0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x378d87ff -> 0x380c0072

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 3954 Comm: udevd Not tainted 6.15.0-rc2-syzkaller-00488-g6fea5fabd332 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
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