============================================ WARNING: possible recursive locking detected 5.15.0-next-20211102-syzkaller #0 Not tainted -------------------------------------------- systemd-udevd/2939 is trying to acquire lock: ffffffff9075ddf0 (&port_lock_key){-.-.}-{2:2}, at: uart_write+0x12c/0x570 drivers/tty/serial/serial_core.c:577 but task is already holding lock: ffffffff9075ddf0 (&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 5 locks held by systemd-udevd/2939: #0: ffffffff8c3310d8 (tomoyo_ss){....}-{0:0}, at: tomoyo_check_open_permission+0xe8/0x380 security/tomoyo/file.c:761 #1: ffffffff8bb83a60 (rcu_read_lock){....}-{1:2}, at: ieee80211_iterate_active_interfaces_atomic+0x0/0x180 net/mac80211/util.c:1233 #2: ffff88801d16e630 (&i->lock){-.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:354 [inline] #2: ffff88801d16e630 (&i->lock){-.-.}-{2:2}, at: serial8250_interrupt+0x3a/0x200 drivers/tty/serial/8250/8250_core.c:116 #3: ffffffff9075ddf0 (&port_lock_key){-.-.}-{2:2}, at: serial8250_handle_irq.part.0+0x21/0x3d0 drivers/tty/serial/8250/8250_port.c:1908 #4: ffff88807d1d7098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref+0x1d/0x80 drivers/tty/tty_ldisc.c:273 stack backtrace: CPU: 1 PID: 2939 Comm: systemd-udevd Not tainted 5.15.0-next-20211102-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+0x4d/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 kernel/kcov.c:166 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:200 Code: 48 89 ef 5d e9 81 25 46 00 5d be 03 00 00 00 e9 d6 85 59 02 66 0f 1f 44 00 00 48 8b be b0 01 00 00 e8 b4 ff ff ff 31 c0 c3 90 <65> 8b 05 39 a5 8a 7e 89 c1 48 8b 34 24 81 e1 00 01 00 00 65 48 8b RSP: 0018:ffffc90000dc0cd0 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000200 RCX: 0000000000000100 RDX: ffff888079a4ba80 RSI: ffffffff8167cf3f RDI: 0000000000000003 RBP: 000000000000e690 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff8167cf35 R11: 0000000000000000 R12: 0000000000000000 R13: dffffc0000000000 R14: ffffffff8bba2ec8 R15: ffff888021a2a450 __seqprop_raw_spinlock_sequence include/linux/seqlock.h:276 [inline] timekeeping_get_delta kernel/time/timekeeping.c:252 [inline] timekeeping_get_ns kernel/time/timekeeping.c:386 [inline] ktime_get_with_offset+0x1f5/0x500 kernel/time/timekeeping.c:872 ktime_get_real include/linux/timekeeping.h:79 [inline] mac80211_hwsim_get_tsf_raw drivers/net/wireless/mac80211_hwsim.c:977 [inline] mac80211_hwsim_beacon_tx+0x2e6/0x930 drivers/net/wireless/mac80211_hwsim.c:1823 __iterate_interfaces+0x1e5/0x520 net/mac80211/util.c:793 ieee80211_iterate_active_interfaces_atomic+0x70/0x180 net/mac80211/util.c:829 mac80211_hwsim_beacon+0xcd/0x1c0 drivers/net/wireless/mac80211_hwsim.c:1861 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x609/0xe50 kernel/time/hrtimer.c:1749 hrtimer_run_softirq+0x17b/0x360 kernel/time/hrtimer.c:1766 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__sanitizer_cov_trace_pc+0x5c/0x60 kernel/kcov.c:210 Code: 82 88 15 00 00 83 f8 02 75 20 48 8b 8a 90 15 00 00 8b 92 8c 15 00 00 48 8b 01 48 83 c0 01 48 39 c2 76 07 48 89 34 c1 48 89 01 0f 1f 00 41 55 41 54 49 89 fc 55 48 bd eb 83 b5 80 46 86 c8 61 RSP: 0018:ffffc9000aeff5a8 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000009 RCX: 0000000000000000 RDX: ffff888079a4ba80 RSI: ffffffff8399b98a RDI: 0000000000000003 RBP: ffff88814a333580 R08: 0000000000000000 R09: 0000000000000009 R10: ffffffff8399b977 R11: 0000000000000010 R12: 0000000000000022 R13: 00000000000000a4 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_sys_open fs/open.c:1236 [inline] __se_sys_open fs/open.c:1232 [inline] __x64_sys_open+0x119/0x1c0 fs/open.c:1232 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: 0033:0x7fd3206bf9b1 Code: f7 d8 bf ff ff ff ff 64 89 02 eb cb 0f 1f 00 66 2e 0f 1f 84 00 00 00 00 00 80 3f 00 74 1b be 00 08 09 00 b8 02 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 1f 89 c7 e9 00 ff ff ff 48 8b 05 b1 54 2e 00 RSP: 002b:00007fff360ee1f8 EFLAGS: 00000202 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000562d87eabf30 RCX: 00007fd3206bf9b1 RDX: 00000000000000fd RSI: 0000000000090800 RDI: 0000562d87e71bf0 RBP: 00007fd321875710 R08: 0000562d87e772e0 R09: 0000000000001010 R10: 00007fd3209a5b58 R11: 0000000000000202 R12: 0000000000000000 R13: 0000562d87e71bf0 R14: 00000000000000fd R15: 0000562d87e71bf0 ---------------- Code disassembly (best guess): 0: 48 89 ef mov %rbp,%rdi 3: 5d pop %rbp 4: e9 81 25 46 00 jmpq 0x46258a 9: 5d pop %rbp a: be 03 00 00 00 mov $0x3,%esi f: e9 d6 85 59 02 jmpq 0x25985ea 14: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1) 1a: 48 8b be b0 01 00 00 mov 0x1b0(%rsi),%rdi 21: e8 b4 ff ff ff callq 0xffffffda 26: 31 c0 xor %eax,%eax 28: c3 retq 29: 90 nop * 2a: 65 8b 05 39 a5 8a 7e mov %gs:0x7e8aa539(%rip),%eax # 0x7e8aa56a <-- trapping instruction 31: 89 c1 mov %eax,%ecx 33: 48 8b 34 24 mov (%rsp),%rsi 37: 81 e1 00 01 00 00 and $0x100,%ecx 3d: 65 gs 3e: 48 rex.W 3f: 8b .byte 0x8b