============================================
WARNING: possible recursive locking detected
5.16.0-rc1-syzkaller #0 Not tainted
--------------------------------------------
systemd-udevd/2969 is trying to acquire lock:
ffffffff90790430 (&port_lock_key){-.-.}-{2:2}, at: uart_write+0x12c/0x570 drivers/tty/serial/serial_core.c:577
but task is already holding lock:
ffffffff90790430 (&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 systemd-udevd/2969:
#0: ffffffff8c3599f8 (tomoyo_ss){....}-{0:0}, at: tomoyo_path_perm+0x1c1/0x400 security/tomoyo/file.c:847
#1: ffff88806cbd46b0 (&i->lock){-.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:349 [inline]
#1: ffff88806cbd46b0 (&i->lock){-.-.}-{2:2}, at: serial8250_interrupt+0x3a/0x200 drivers/tty/serial/8250/8250_core.c:116
#2: ffffffff90790430 (&port_lock_key){-.-.}-{2:2}, at: serial8250_handle_irq.part.0+0x21/0x3d0 drivers/tty/serial/8250/8250_port.c:1908
#3: ffff88801e058098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref+0x1d/0x80 drivers/tty/tty_ldisc.c:273
stack backtrace:
CPU: 0 PID: 2969 Comm: systemd-udevd 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:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:check_kcov_mode+0x0/0x40 kernel/kcov.c:166
Code: 48 89 df e8 02 bd 46 00 e9 59 fe ff ff 48 8b 7c 24 08 e8 f3 bc 46 00 e9 61 fd ff ff cc cc cc cc cc cc cc cc cc cc cc cc cc cc <65> 8b 05 c9 8c 8a 7e 89 c2 81 e2 00 01 00 00 a9 00 01 ff 00 74 10
RSP: 0018:ffffc900027df850 EFLAGS: 00000206
RAX: 0000000000000000 RBX: 000000000000000c RCX: ffff888014de9d00
RDX: ffff888014de9d00 RSI: ffff888014de9d00 RDI: 0000000000000003
RBP: ffff88807eed8100 R08: 0000000000000000 R09: 000000000000000c
R10: ffffffff83a3517a R11: 0000000000000010 R12: 0000000000000002
R13: 000000000000011d R14: dffffc0000000000 R15: 0000000000000000
write_comp_data kernel/kcov.c:221 [inline]
__sanitizer_cov_trace_const_cmp1+0x22/0x80 kernel/kcov.c:273
tomoyo_domain_quota_is_ok+0x32a/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_path_perm+0x2f0/0x400 security/tomoyo/file.c:838
security_inode_getattr+0xcf/0x140 security/security.c:1334
vfs_getattr fs/stat.c:157 [inline]
vfs_statx+0x164/0x390 fs/stat.c:225
vfs_fstatat fs/stat.c:243 [inline]
vfs_lstat include/linux/fs.h:3358 [inline]
__do_sys_newlstat+0x91/0x110 fs/stat.c:398
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fec4f590335
Code: 69 db 2b 00 64 c7 00 16 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 83 ff 01 48 89 f0 77 30 48 89 c7 48 89 d6 b8 06 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 03 f3 c3 90 48 8b 15 31 db 2b 00 f7 d8 64 89
RSP: 002b:00007ffe16e8f9c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000006
RAX: ffffffffffffffda RBX: 000056502e70cf70 RCX: 00007fec4f590335
RDX: 00007ffe16e8fa00 RSI: 00007ffe16e8fa00 RDI: 000056502e70bf70
RBP: 00007ffe16e8fac0 R08: 00007fec4f84f178 R09: 0000000000001010
R10: 0000000000000020 R11: 0000000000000246 R12: 000056502e70bf70
R13: 000056502e70bf8a R14: 000056502e7d8af5 R15: 000056502e7d8afa
----------------
Code disassembly (best guess):
0: 48 89 df mov %rbx,%rdi
3: e8 02 bd 46 00 callq 0x46bd0a
8: e9 59 fe ff ff jmpq 0xfffffe66
d: 48 8b 7c 24 08 mov 0x8(%rsp),%rdi
12: e8 f3 bc 46 00 callq 0x46bd0a
17: e9 61 fd ff ff jmpq 0xfffffd7d
1c: cc int3
1d: cc int3
1e: cc int3
1f: cc int3
20: cc int3
21: cc int3
22: cc int3
23: cc int3
24: cc int3
25: cc int3
26: cc int3
27: cc int3
28: cc int3
29: cc int3
* 2a: 65 8b 05 c9 8c 8a 7e mov %gs:0x7e8a8cc9(%rip),%eax # 0x7e8a8cfa <-- trapping instruction
31: 89 c2 mov %eax,%edx
33: 81 e2 00 01 00 00 and $0x100,%edx
39: a9 00 01 ff 00 test $0xff0100,%eax
3e: 74 10 je 0x50