syzbot

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BUG: KCSAN: data-race in generic_fillattr / touch_atime

write to 0xffff88811a9840f0 of 4 bytes by task 3688 on cpu 0:
 inode_set_atime_to_ts include/linux/fs.h:1805 [inline]
 inode_update_timestamps fs/inode.c:2076 [inline]
 generic_update_time fs/inode.c:2098 [inline]
 inode_update_time fs/inode.c:2118 [inline]
 touch_atime+0x1e8/0x340 fs/inode.c:2190
 file_accessed include/linux/fs.h:2673 [inline]
 iterate_dir+0x28b/0x330 fs/readdir.c:111
 __do_sys_getdents64 fs/readdir.c:410 [inline]
 __se_sys_getdents64+0x88/0x1b0 fs/readdir.c:396
 __x64_sys_getdents64+0x43/0x50 fs/readdir.c:396
 x64_sys_call+0x2dae/0x3000 arch/x86/include/generated/asm/syscalls_64.h:218
 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 0xffff88811a9840f0 of 4 bytes by task 3502 on cpu 1:
 inode_get_atime_nsec include/linux/fs.h:1790 [inline]
 inode_get_atime include/linux/fs.h:1796 [inline]
 generic_fillattr+0x172/0x340 fs/stat.c:96
 shmem_getattr+0x181/0x200 mm/shmem.c:1257
 vfs_getattr_nosec+0x146/0x1e0 fs/stat.c:213
 vfs_getattr fs/stat.c:262 [inline]
 vfs_fstat fs/stat.c:281 [inline]
 __do_sys_newfstat fs/stat.c:555 [inline]
 __se_sys_newfstat+0x96/0x2e0 fs/stat.c:550
 __x64_sys_newfstat+0x31/0x40 fs/stat.c:550
 x64_sys_call+0x2768/0x3000 arch/x86/include/generated/asm/syscalls_64.h:6
 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: 0x2fa9fa57 -> 0x31af4c54

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3502 Comm: udevd Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
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