syzbot

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BUG: KCSAN: data-race in touch_atime / touch_atime

write to 0xffff8881190266b8 of 4 bytes by task 14062 on cpu 0:
 inode_set_atime_to_ts include/linux/fs.h:1672 [inline]
 inode_update_timestamps fs/inode.c:2035 [inline]
 generic_update_time fs/inode.c:2057 [inline]
 inode_update_time fs/inode.c:2077 [inline]
 touch_atime+0x1e8/0x330 fs/inode.c:2149
 file_accessed include/linux/fs.h:2599 [inline]
 shmem_file_splice_read+0x582/0x5d0 mm/shmem.c:3623
 do_splice_read fs/splice.c:979 [inline]
 splice_direct_to_actor+0x26f/0x680 fs/splice.c:1083
 do_splice_direct_actor fs/splice.c:1201 [inline]
 do_splice_direct+0xda/0x150 fs/splice.c:1227
 do_sendfile+0x380/0x640 fs/read_write.c:1368
 __do_sys_sendfile64 fs/read_write.c:1429 [inline]
 __se_sys_sendfile64 fs/read_write.c:1415 [inline]
 __x64_sys_sendfile64+0x105/0x150 fs/read_write.c:1415
 x64_sys_call+0xb39/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd0/0x1a0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff8881190266b8 of 4 bytes by task 14063 on cpu 1:
 inode_get_atime_nsec include/linux/fs.h:1657 [inline]
 inode_get_atime include/linux/fs.h:1663 [inline]
 inode_update_timestamps fs/inode.c:2032 [inline]
 generic_update_time fs/inode.c:2057 [inline]
 inode_update_time fs/inode.c:2077 [inline]
 touch_atime+0x194/0x330 fs/inode.c:2149
 file_accessed include/linux/fs.h:2599 [inline]
 shmem_file_splice_read+0x582/0x5d0 mm/shmem.c:3623
 do_splice_read fs/splice.c:979 [inline]
 splice_direct_to_actor+0x26f/0x680 fs/splice.c:1083
 do_splice_direct_actor fs/splice.c:1201 [inline]
 do_splice_direct+0xda/0x150 fs/splice.c:1227
 do_sendfile+0x380/0x640 fs/read_write.c:1368
 __do_sys_sendfile64 fs/read_write.c:1429 [inline]
 __se_sys_sendfile64 fs/read_write.c:1415 [inline]
 __x64_sys_sendfile64+0x105/0x150 fs/read_write.c:1415
 x64_sys_call+0xb39/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd0/0x1a0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x28913eda -> 0x2929d9fd

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 14063 Comm: syz.3.3817 Not tainted 6.15.0-rc7-syzkaller-00142-g4856ebd99715 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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