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BUG: KCSAN: data-race in __tty_hangup / tty_hung_up_p

write to 0xffff888102a92c28 of 8 bytes by task 14935 on cpu 1:
 __tty_hangup+0x16a/0x460 drivers/tty/tty_io.c:615
 tty_vhangup+0x21/0x30 drivers/tty/tty_io.c:697
 pty_close+0x25b/0x2d0 drivers/tty/pty.c:79
 tty_release+0x285/0x910 drivers/tty/tty_io.c:1679
 __fput+0x1e1/0x520 fs/file_table.c:280
 ____fput+0x1f/0x30 fs/file_table.c:313
 task_work_run+0xf6/0x130 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x2b4/0x2c0 arch/x86/entry/common.c:163
 prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:274 [inline]
 do_syscall_64+0x353/0x370 arch/x86/entry/common.c:300
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff888102a92c28 of 8 bytes by task 14945 on cpu 0:
 tty_hung_up_p+0x2b/0x60 drivers/tty/tty_io.c:747
 n_tty_write+0x1a1/0x9f0 drivers/tty/n_tty.c:2327
 do_tty_write drivers/tty/tty_io.c:961 [inline]
 tty_write+0x2fb/0x4e0 drivers/tty/tty_io.c:1045
 __vfs_write+0x67/0xc0 fs/read_write.c:494
 __kernel_write+0xb8/0x240 fs/read_write.c:515
 write_pipe_buf+0xb6/0xf0 fs/splice.c:794
 splice_from_pipe_feed fs/splice.c:500 [inline]
 __splice_from_pipe+0x248/0x480 fs/splice.c:624
 splice_from_pipe+0xbb/0x100 fs/splice.c:659
 default_file_splice_write+0x45/0x90 fs/splice.c:806
 do_splice_from fs/splice.c:848 [inline]
 do_splice+0x497/0xbe0 fs/splice.c:1155
 __do_sys_splice fs/splice.c:1425 [inline]
 __se_sys_splice fs/splice.c:1405 [inline]
 __x64_sys_splice+0x20a/0x220 fs/splice.c:1405
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 14945 Comm: syz-executor.5 Not tainted 5.4.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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