============================================
WARNING: possible recursive locking detected
5.16.0-rc1-syzkaller #0 Not tainted
--------------------------------------------
syz-executor.4/30945 is trying to acquire lock:
ffffffff9078b430 (&port_lock_key){-.-.}-{2:2}, at: uart_write+0x12c/0x570 drivers/tty/serial/serial_core.c:577
but task is already holding lock:
ffffffff9078b430 (&port_lock_key){-.-.}-{2:2}, at: serial8250_handle_irq.part.0+0x21/0x3d0 drivers/tty/serial/8250/8250_port.c:1908
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.4/30945:
 #0: ffffffff8c359b78 (tomoyo_ss){....}-{0:0}, at: tomoyo_check_open_permission+0xe8/0x380 security/tomoyo/file.c:761
 #1: ffff88807f20f530 (&i->lock){-.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline]
 #1: ffff88807f20f530 (&i->lock){-.-.}-{2:2}, at: serial8250_interrupt+0x3a/0x200 drivers/tty/serial/8250/8250_core.c:116
 #2: ffffffff9078b430 (&port_lock_key){-.-.}-{2:2}, at: serial8250_handle_irq.part.0+0x21/0x3d0 drivers/tty/serial/8250/8250_port.c:1908
 #3: ffff8880713aa098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref+0x1d/0x80 drivers/tty/tty_ldisc.c:273
stack backtrace:
CPU: 1 PID: 30945 Comm: syz-executor.4 Not tainted 5.16.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 print_deadlock_bug kernel/locking/lockdep.c:2956 [inline]
 check_deadlock kernel/locking/lockdep.c:2999 [inline]
 validate_chain kernel/locking/lockdep.c:3788 [inline]
 __lock_acquire.cold+0x149/0x3ab kernel/locking/lockdep.c:5027
 lock_acquire kernel/locking/lockdep.c:5637 [inline]
 lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5602
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162
 uart_write+0x12c/0x570 drivers/tty/serial/serial_core.c:577
 n_hdlc_send_frames+0x24b/0x490 drivers/tty/n_hdlc.c:290
 tty_wakeup+0xe1/0x120 drivers/tty/tty_io.c:534
 tty_port_default_wakeup+0x26/0x40 drivers/tty/tty_port.c:51
 serial8250_tx_chars+0x4f3/0xad0 drivers/tty/serial/8250/8250_port.c:1845
 serial8250_handle_irq.part.0+0x328/0x3d0 drivers/tty/serial/8250/8250_port.c:1932
 serial8250_handle_irq drivers/tty/serial/8250/8250_port.c:1905 [inline]
 serial8250_default_handle_irq+0xb2/0x220 drivers/tty/serial/8250/8250_port.c:1949
 serial8250_interrupt+0xfd/0x200 drivers/tty/serial/8250/8250_core.c:126
 __handle_irq_event_percpu+0x303/0x8f0 kernel/irq/handle.c:158
 handle_irq_event_percpu kernel/irq/handle.c:198 [inline]
 handle_irq_event+0x102/0x280 kernel/irq/handle.c:215
 handle_edge_irq+0x25f/0xd00 kernel/irq/chip.c:822
 generic_handle_irq_desc include/linux/irqdesc.h:158 [inline]
 handle_irq arch/x86/kernel/irq.c:231 [inline]
 __common_interrupt+0x9d/0x210 arch/x86/kernel/irq.c:250
 common_interrupt+0xa4/0xc0 arch/x86/kernel/irq.c:240
 
 
 asm_common_interrupt+0x1e/0x40 arch/x86/include/asm/idtentry.h:629
RIP: 0010:__sanitizer_cov_trace_pc+0x3c/0x60 kernel/kcov.c:203
Code: 00 65 48 8b 14 25 40 70 02 00 a9 00 01 ff 00 74 0e 85 c9 74 35 8b 82 a4 15 00 00 85 c0 74 2b 8b 82 80 15 00 00 83 f8 02 75 20 <48> 8b 8a 88 15 00 00 8b 92 84 15 00 00 48 8b 01 48 83 c0 01 48 39
RSP: 0018:ffffc90003c9f588 EFLAGS: 00000246
RAX: 0000000000000002 RBX: 0000000000000006 RCX: 0000000000000000
RDX: ffff88807c8f5700 RSI: ffffffff83a3079a RDI: 0000000000000003
RBP: ffff88807ccf4d80 R08: 0000000000000000 R09: 0000000000000006
R10: ffffffff83a30787 R11: 0000000000000010 R12: 0000000000000010
R13: 000000000000014b R14: dffffc0000000000 R15: 0000000000000000
 tomoyo_domain_quota_is_ok+0x31a/0x550 security/tomoyo/util.c:1092
 tomoyo_supervisor+0x2f2/0xf00 security/tomoyo/common.c:2089
 tomoyo_audit_path_log security/tomoyo/file.c:168 [inline]
 tomoyo_path_permission security/tomoyo/file.c:587 [inline]
 tomoyo_path_permission+0x270/0x3a0 security/tomoyo/file.c:573
 tomoyo_check_open_permission+0x33e/0x380 security/tomoyo/file.c:777
 tomoyo_file_open security/tomoyo/tomoyo.c:311 [inline]
 tomoyo_file_open+0xa3/0xd0 security/tomoyo/tomoyo.c:306
 security_file_open+0x45/0xb0 security/security.c:1635
 do_dentry_open+0x353/0x1250 fs/open.c:809
 do_open fs/namei.c:3426 [inline]
 path_openat+0x1cad/0x2750 fs/namei.c:3559
 do_filp_open+0x1aa/0x400 fs/namei.c:3586
 do_sys_openat2+0x16d/0x4d0 fs/open.c:1212
 do_sys_open fs/open.c:1228 [inline]
 __do_compat_sys_open fs/open.c:1279 [inline]
 __se_compat_sys_open fs/open.c:1277 [inline]
 __ia32_compat_sys_open+0x119/0x1c0 fs/open.c:1277
 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
 __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178
 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c
RIP: 0023:0xf6e68549
Code: 03 74 c0 01 10 05 03 74 b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000f44625fc EFLAGS: 00000296 ORIG_RAX: 0000000000000005
RAX: ffffffffffffffda RBX: 0000000020000400 RCX: 000000000014103e
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 
----------------
Code disassembly (best guess):
   0:	00 65 48             	add    %ah,0x48(%rbp)
   3:	8b 14 25 40 70 02 00 	mov    0x27040,%edx
   a:	a9 00 01 ff 00       	test   $0xff0100,%eax
   f:	74 0e                	je     0x1f
  11:	85 c9                	test   %ecx,%ecx
  13:	74 35                	je     0x4a
  15:	8b 82 a4 15 00 00    	mov    0x15a4(%rdx),%eax
  1b:	85 c0                	test   %eax,%eax
  1d:	74 2b                	je     0x4a
  1f:	8b 82 80 15 00 00    	mov    0x1580(%rdx),%eax
  25:	83 f8 02             	cmp    $0x2,%eax
  28:	75 20                	jne    0x4a
* 2a:	48 8b 8a 88 15 00 00 	mov    0x1588(%rdx),%rcx <-- trapping instruction
  31:	8b 92 84 15 00 00    	mov    0x1584(%rdx),%edx
  37:	48 8b 01             	mov    (%rcx),%rax
  3a:	48 83 c0 01          	add    $0x1,%rax
  3e:	48                   	rex.W
  3f:	39                   	.byte 0x39