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BUG: KCSAN: data-race in atime_needs_update / touch_atime

read to 0xffff88810642e598 of 4 bytes by task 6592 on cpu 0:
 atime_needs_update+0x261/0x3e0
 touch_atime+0x4a/0x350 fs/inode.c:2109
 file_accessed include/linux/fs.h:2528 [inline]
 filemap_splice_read+0x8a5/0x910 mm/filemap.c:2977
 ext4_file_splice_read+0x8f/0xb0 fs/ext4/file.c:158
 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

write to 0xffff88810642e598 of 4 bytes by task 6597 on cpu 1:
 inode_set_atime_to_ts include/linux/fs.h:1610 [inline]
 inode_update_timestamps fs/inode.c:2012 [inline]
 generic_update_time fs/inode.c:2034 [inline]
 inode_update_time fs/inode.c:2054 [inline]
 touch_atime+0x1f3/0x350 fs/inode.c:2126
 file_accessed include/linux/fs.h:2528 [inline]
 filemap_read+0x5f8/0x680 mm/filemap.c:2713
 generic_file_read_iter+0x78/0x330 mm/filemap.c:2833
 ext4_file_read_iter+0x1cc/0x290
 copy_splice_read+0x3a0/0x5d0 fs/splice.c:365
 do_splice_read fs/splice.c:984 [inline]
 splice_direct_to_actor+0x28b/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: 0x2895d03c -> 0x292e66bd

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 6597 Comm: syz.4.908 Not tainted 6.12.0-rc1-syzkaller-00042-gf23aa4c0761a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
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