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BUG: KCSAN: data-race in atime_needs_update / touch_atime

write to 0xffff888104af1b18 of 4 bytes by task 15036 on cpu 1:
 inode_set_atime_to_ts include/linux/fs.h:1609 [inline]
 inode_update_timestamps fs/inode.c:2020 [inline]
 generic_update_time fs/inode.c:2042 [inline]
 inode_update_time fs/inode.c:2062 [inline]
 touch_atime+0x1f3/0x350 fs/inode.c:2134
 file_accessed include/linux/fs.h:2527 [inline]
 shmem_file_splice_read+0x561/0x5c0 mm/shmem.c:3358
 do_splice_read fs/splice.c:985 [inline]
 splice_direct_to_actor+0x269/0x670 fs/splice.c:1089
 do_splice_direct_actor fs/splice.c:1207 [inline]
 do_splice_direct+0xd7/0x150 fs/splice.c:1233
 do_sendfile+0x39b/0x970 fs/read_write.c:1388
 __do_sys_sendfile64 fs/read_write.c:1455 [inline]
 __se_sys_sendfile64 fs/read_write.c:1441 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1441
 x64_sys_call+0xed5/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888104af1b18 of 4 bytes by task 15033 on cpu 0:
 atime_needs_update+0x261/0x3e0
 touch_atime+0x4a/0x350 fs/inode.c:2117
 file_accessed include/linux/fs.h:2527 [inline]
 shmem_file_splice_read+0x561/0x5c0 mm/shmem.c:3358
 do_splice_read fs/splice.c:985 [inline]
 splice_direct_to_actor+0x269/0x670 fs/splice.c:1089
 do_splice_direct_actor fs/splice.c:1207 [inline]
 do_splice_direct+0xd7/0x150 fs/splice.c:1233
 do_sendfile+0x39b/0x970 fs/read_write.c:1388
 __do_sys_sendfile64 fs/read_write.c:1455 [inline]
 __se_sys_sendfile64 fs/read_write.c:1441 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1441
 x64_sys_call+0xed5/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x190b821c -> 0x19a4189d

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 15033 Comm: syz.2.3959 Not tainted 6.11.0-syzkaller-08833-gde5cb0dcb74c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
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