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BUG: KCSAN: data-race in generic_fillattr / touch_atime

write to 0xffff88811ae7ac88 of 4 bytes by task 3668 on cpu 0:
 inode_set_atime_to_ts include/linux/fs.h:1624 [inline]
 inode_update_timestamps fs/inode.c:2126 [inline]
 generic_update_time fs/inode.c:2148 [inline]
 inode_update_time fs/inode.c:2168 [inline]
 touch_atime+0x1e8/0x340 fs/inode.c:2240
 file_accessed include/linux/fs.h:2254 [inline]
 filemap_read+0x960/0xa00 mm/filemap.c:2872
 blkdev_read_iter+0x22d/0x2e0 block/fops.c:856
 new_sync_read fs/read_write.c:491 [inline]
 vfs_read+0x64c/0x770 fs/read_write.c:572
 ksys_read+0xda/0x1a0 fs/read_write.c:715
 __do_sys_read fs/read_write.c:724 [inline]
 __se_sys_read fs/read_write.c:722 [inline]
 __x64_sys_read+0x40/0x50 fs/read_write.c:722
 x64_sys_call+0x2889/0x3000 arch/x86/include/generated/asm/syscalls_64.h:1
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd8/0x2c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88811ae7ac88 of 4 bytes by task 3538 on cpu 1:
 inode_get_atime_nsec include/linux/fs.h:1609 [inline]
 inode_get_atime include/linux/fs.h:1615 [inline]
 generic_fillattr+0x172/0x340 fs/stat.c:96
 shmem_getattr+0x181/0x200 mm/shmem.c:1274
 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+0x111f/0x3000 arch/x86/include/generated/asm/syscalls_64.h:263
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd8/0x2c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x2817822b -> 0x2896ac7d

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3538 Comm: udevd Tainted: G        W           syzkaller #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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