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BUG: KCSAN: data-race in generic_fillattr / touch_atime

write to 0xffff888104a71698 of 8 bytes by task 30058 on cpu 0:
 inode_set_atime_to_ts include/linux/fs.h:1620 [inline]
 inode_update_atime fs/inode.c:2157 [inline]
 inode_update_time fs/inode.c:2221 [inline]
 generic_update_time fs/inode.c:2254 [inline]
 touch_atime+0x1b9/0x300 fs/inode.c:2332
 file_accessed include/linux/fs.h:2272 [inline]
 shmem_file_read_iter+0x3ed/0x4b0 mm/shmem.c:3394
 new_sync_read fs/read_write.c:493 [inline]
 vfs_read+0x699/0x7c0 fs/read_write.c:574
 ksys_read+0xdc/0x1a0 fs/read_write.c:716
 __do_sys_read fs/read_write.c:725 [inline]
 __se_sys_read fs/read_write.c:723 [inline]
 __x64_sys_read+0x40/0x50 fs/read_write.c:723
 x64_sys_call+0x2886/0x3020 arch/x86/include/generated/asm/syscalls_64.h:1
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x136/0x3c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888104a71698 of 8 bytes by task 29065 on cpu 1:
 inode_get_atime_sec include/linux/fs.h:1601 [inline]
 inode_get_atime include/linux/fs.h:1611 [inline]
 generic_fillattr+0x168/0x340 fs/stat.c:96
 shmem_getattr+0x181/0x200 mm/shmem.c:1302
 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:551 [inline]
 __se_sys_newfstat+0x96/0x460 fs/stat.c:546
 __x64_sys_newfstat+0x31/0x40 fs/stat.c:546
 x64_sys_call+0x2773/0x3020 arch/x86/include/generated/asm/syscalls_64.h:6
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x136/0x3c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x000000006a41fa0d -> 0x000000006a41fa0e

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 29065 Comm: udevd Tainted: G        W           syzkaller #0 PREEMPT(lazy) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
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