syzbot

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BUG: KCSAN: data-race in file_update_time / inode_update_timestamps

write to 0xffff88810691baf0 of 4 bytes by task 21383 on cpu 0:
 inode_set_ctime_to_ts include/linux/fs.h:1678 [inline]
 inode_set_ctime_current fs/inode.c:2662 [inline]
 inode_update_timestamps+0xaf/0x280 fs/inode.c:1995
 generic_update_time fs/inode.c:2034 [inline]
 inode_update_time fs/inode.c:2054 [inline]
 __file_update_time fs/inode.c:2243 [inline]
 file_update_time+0x220/0x2b0 fs/inode.c:2273
 pipe_write+0xa7b/0xd20 fs/pipe.c:607
 new_sync_write fs/read_write.c:590 [inline]
 vfs_write+0x76a/0x910 fs/read_write.c:683
 ksys_write+0xeb/0x1b0 fs/read_write.c:736
 __do_sys_write fs/read_write.c:748 [inline]
 __se_sys_write fs/read_write.c:745 [inline]
 __x64_sys_write+0x42/0x50 fs/read_write.c:745
 x64_sys_call+0x27dd/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:2
 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 0xffff88810691baf0 of 4 bytes by task 21379 on cpu 1:
 inode_get_ctime_nsec include/linux/fs.h:1663 [inline]
 inode_get_ctime include/linux/fs.h:1669 [inline]
 inode_needs_update_time fs/inode.c:2226 [inline]
 file_update_time+0xfe/0x2b0 fs/inode.c:2269
 pipe_write+0xa7b/0xd20 fs/pipe.c:607
 new_sync_write fs/read_write.c:590 [inline]
 vfs_write+0x76a/0x910 fs/read_write.c:683
 ksys_write+0xeb/0x1b0 fs/read_write.c:736
 __do_sys_write fs/read_write.c:748 [inline]
 __se_sys_write fs/read_write.c:745 [inline]
 __x64_sys_write+0x42/0x50 fs/read_write.c:745
 x64_sys_call+0x27dd/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:2
 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: 0x2e569cb1 -> 0x3adaf535

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 21379 Comm: syz.0.6246 Not tainted 6.12.0-rc2-syzkaller-00006-g87d6aab2389e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
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