audit: type=1800 audit(1667921296.004:12): pid=10193 uid=0 auid=4294967295 ses=4294967295 op="collect_data" cause="failed(directio)" comm="syz-executor.3" name="bus" dev="sda1" ino=13963 res=0
============================================
WARNING: possible recursive locking detected
4.14.298-syzkaller #0 Not tainted
--------------------------------------------
syz-executor.3/10189 is trying to acquire lock:
 (&port_lock_key){-.-.}, at: [<ffffffff835ae379>] uart_write+0x109/0x560 drivers/tty/serial/serial_core.c:611

but task is already holding lock:
 (&port_lock_key){-.-.}, at: [<ffffffff835c9810>] serial8250_handle_irq.part.0+0x20/0x330 drivers/tty/serial/8250/8250_port.c:1891

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&port_lock_key);
  lock(&port_lock_key);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

4 locks held by syz-executor.3/10189:
 #0:  (&u->iolock){+.+.}, at: [<ffffffff8632a674>] unix_dgram_recvmsg+0x1e4/0xc60 net/unix/af_unix.c:2146
 #1:  (&(&i->lock)->rlock){-.-.}, at: [<ffffffff835b6b9a>] spin_lock include/linux/spinlock.h:317 [inline]
 #1:  (&(&i->lock)->rlock){-.-.}, at: [<ffffffff835b6b9a>] serial8250_interrupt+0x3a/0x210 drivers/tty/serial/8250/8250_core.c:119
 #2:  (&port_lock_key){-.-.}, at: [<ffffffff835c9810>] serial8250_handle_irq.part.0+0x20/0x330 drivers/tty/serial/8250/8250_port.c:1891
 #3:  (&tty->ldisc_sem){++++}, at: [<ffffffff8355bd9b>] tty_ldisc_ref+0x1b/0x80 drivers/tty/tty_ldisc.c:305

stack backtrace:
CPU: 1 PID: 10189 Comm: syz-executor.3 Not tainted 4.14.298-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x281 lib/dump_stack.c:58
 print_deadlock_bug kernel/locking/lockdep.c:1800 [inline]
 check_deadlock kernel/locking/lockdep.c:1847 [inline]
 validate_chain kernel/locking/lockdep.c:2448 [inline]
 __lock_acquire.cold+0x180/0x97c kernel/locking/lockdep.c:3491
 lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x8c/0xc0 kernel/locking/spinlock.c:160
 uart_write+0x109/0x560 drivers/tty/serial/serial_core.c:611
 n_hdlc_send_frames+0x241/0x410 drivers/tty/n_hdlc.c:404
 n_hdlc_tty_wakeup+0x95/0xb0 drivers/tty/n_hdlc.c:480
 tty_wakeup+0xc3/0xf0 drivers/tty/tty_io.c:533
 tty_port_default_wakeup+0x26/0x40 drivers/tty/tty_port.c:49
 serial8250_tx_chars+0x3fe/0xc70 drivers/tty/serial/8250/8250_port.c:1828
 serial8250_handle_irq.part.0+0x28d/0x330 drivers/tty/serial/8250/8250_port.c:1915
 serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1888 [inline]
 serial8250_default_handle_irq+0x8a/0x1f0 drivers/tty/serial/8250/8250_port.c:1931
 serial8250_interrupt+0xf3/0x210 drivers/tty/serial/8250/8250_core.c:129
 __handle_irq_event_percpu+0xee/0x7f0 kernel/irq/handle.c:147
 handle_irq_event_percpu kernel/irq/handle.c:187 [inline]
 handle_irq_event+0xed/0x240 kernel/irq/handle.c:204
 handle_edge_irq+0x224/0xc40 kernel/irq/chip.c:770
 generic_handle_irq_desc include/linux/irqdesc.h:159 [inline]
 handle_irq+0x35/0x50 arch/x86/kernel/irq_64.c:87
 do_IRQ+0x93/0x1d0 arch/x86/kernel/irq.c:230
 common_interrupt+0x93/0x93 arch/x86/entry/entry_64.S:578
 </IRQ>