------------[ cut here ]------------ ====================================================== WARNING: possible circular locking dependency detected 5.15.153-syzkaller #0 Not tainted ------------------------------------------------------ kworker/u4:1/144 is trying to acquire lock: ffffffff8c7fbf78 ((console_sem).lock){-.-.}-{2:2}, at: down_trylock+0x1c/0xa0 kernel/locking/semaphore.c:138 but task is already holding lock: ffff8880b9b2a218 (hrtimer_bases.lock){-.-.}-{2:2}, at: __run_hrtimer kernel/time/hrtimer.c:1690 [inline] ffff8880b9b2a218 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_run_queues+0x662/0xcf0 kernel/time/hrtimer.c:1750 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (hrtimer_bases.lock){-.-.}-{2:2}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 lock_hrtimer_base kernel/time/hrtimer.c:173 [inline] hrtimer_start_range_ns+0xd8/0xc50 kernel/time/hrtimer.c:1297 hrtimer_start_expires include/linux/hrtimer.h:434 [inline] do_start_rt_bandwidth kernel/sched/rt.c:69 [inline] start_rt_bandwidth kernel/sched/rt.c:80 [inline] inc_rt_group kernel/sched/rt.c:1207 [inline] inc_rt_tasks kernel/sched/rt.c:1251 [inline] __enqueue_rt_entity kernel/sched/rt.c:1321 [inline] enqueue_rt_entity kernel/sched/rt.c:1368 [inline] enqueue_task_rt+0x5a0/0xbf0 kernel/sched/rt.c:1398 enqueue_task+0x181/0x3a0 kernel/sched/core.c:1977 activate_task kernel/sched/core.c:2005 [inline] ttwu_do_activate+0x1cf/0x430 kernel/sched/core.c:3614 sched_ttwu_pending+0x34e/0x730 kernel/sched/core.c:3689 __sysvec_call_function_single+0x9a/0x250 arch/x86/kernel/smp.c:248 sysvec_call_function_single+0x89/0xb0 arch/x86/kernel/smp.c:243 asm_sysvec_call_function_single+0x16/0x20 arch/x86/include/asm/idtentry.h:646 native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline] arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] acpi_safe_halt drivers/acpi/processor_idle.c:109 [inline] acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:570 acpi_idle_enter+0x352/0x4f0 drivers/acpi/processor_idle.c:705 cpuidle_enter_state+0x521/0xef0 drivers/cpuidle/cpuidle.c:237 cpuidle_enter+0x59/0x90 drivers/cpuidle/cpuidle.c:351 call_cpuidle kernel/sched/idle.c:158 [inline] cpuidle_idle_call kernel/sched/idle.c:239 [inline] do_idle+0x3e4/0x670 kernel/sched/idle.c:306 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:403 start_secondary+0x371/0x500 arch/x86/kernel/smpboot.c:281 secondary_startup_64_no_verify+0xb1/0xbb -> #3 (&rt_b->rt_runtime_lock){-.-.}-{2:2}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 __enable_runtime kernel/sched/rt.c:840 [inline] rq_online_rt+0x123/0x300 kernel/sched/rt.c:2331 set_rq_online kernel/sched/core.c:9037 [inline] sched_cpu_activate+0x508/0x6b0 kernel/sched/core.c:9144 cpuhp_invoke_callback+0x49f/0x820 kernel/cpu.c:191 cpuhp_thread_fun+0x3ee/0x790 kernel/cpu.c:822 smpboot_thread_fn+0x51b/0x9d0 kernel/smpboot.c:164 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 -> #2 (&rq->__lock){-.-.}-{2:2}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 _raw_spin_lock_nested+0x2d/0x40 kernel/locking/spinlock.c:368 raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475 raw_spin_rq_lock kernel/sched/sched.h:1326 [inline] rq_lock kernel/sched/sched.h:1621 [inline] task_fork_fair+0x5d/0x350 kernel/sched/fair.c:11480 sched_cgroup_fork+0x2d3/0x330 kernel/sched/core.c:4466 copy_process+0x224a/0x3ef0 kernel/fork.c:2320 kernel_clone+0x210/0x960 kernel/fork.c:2604 kernel_thread+0x168/0x1e0 kernel/fork.c:2656 rest_init+0x21/0x330 init/main.c:704 start_kernel+0x48c/0x535 init/main.c:1138 secondary_startup_64_no_verify+0xb1/0xbb -> #1 (&p->pi_lock){-.-.}-{2:2}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 try_to_wake_up+0xae/0x1300 kernel/sched/core.c:4030 up+0x6e/0x90 kernel/locking/semaphore.c:190 __up_console_sem+0x11a/0x1e0 kernel/printk/printk.c:256 console_unlock+0x1145/0x12b0 kernel/printk/printk.c:2754 vprintk_emit+0xbf/0x150 kernel/printk/printk.c:2268 _printk+0xd1/0x111 kernel/printk/printk.c:2293 addrconf_notify+0xa80/0xf30 net/ipv6/addrconf.c:3657 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0xd0/0x170 kernel/notifier.c:391 call_netdevice_notifiers_info net/core/dev.c:2018 [inline] netdev_state_change+0x1a3/0x250 net/core/dev.c:1409 linkwatch_do_dev+0x10c/0x160 net/core/link_watch.c:167 __linkwatch_run_queue+0x4ca/0x7f0 net/core/link_watch.c:213 linkwatch_event+0x48/0x50 net/core/link_watch.c:252 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 -> #0 ((console_sem).lock){-.-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 down_trylock+0x1c/0xa0 kernel/locking/semaphore.c:138 __down_trylock_console_sem+0x105/0x250 kernel/printk/printk.c:239 console_trylock kernel/printk/printk.c:2569 [inline] console_trylock_spinning+0x8a/0x3f0 kernel/printk/printk.c:1867 vprintk_emit+0xa6/0x150 kernel/printk/printk.c:2267 _printk+0xd1/0x111 kernel/printk/printk.c:2293 report_bug+0x1e5/0x2e0 lib/bug.c:195 handle_bug+0x3d/0x70 arch/x86/kernel/traps.c:239 exc_invalid_op+0x16/0x40 arch/x86/kernel/traps.c:259 asm_exc_invalid_op+0x16/0x20 arch/x86/include/asm/idtentry.h:566 copy_from_user_nofault+0x15c/0x1c0 bpf_probe_read_user_common kernel/trace/bpf_trace.c:157 [inline] ____bpf_probe_read_user kernel/trace/bpf_trace.c:166 [inline] bpf_probe_read_user+0x26/0x70 kernel/trace/bpf_trace.c:163 bpf_prog_690f12e098ef46de+0x32/0xb70 bpf_dispatcher_nop_func include/linux/bpf.h:785 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1880 [inline] bpf_trace_run2+0x19e/0x340 kernel/trace/bpf_trace.c:1917 trace_hrtimer_start include/trace/events/timer.h:199 [inline] debug_activate kernel/time/hrtimer.c:476 [inline] enqueue_hrtimer+0x324/0x390 kernel/time/hrtimer.c:1084 __run_hrtimer kernel/time/hrtimer.c:1703 [inline] __hrtimer_run_queues+0x6b6/0xcf0 kernel/time/hrtimer.c:1750 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1812 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline] __sysvec_apic_timer_interrupt+0x139/0x470 arch/x86/kernel/apic/apic.c:1102 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1096 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 __mutex_trylock_common+0x1c/0x2e0 kernel/locking/mutex.c:98 __mutex_trylock kernel/locking/mutex.c:146 [inline] __mutex_lock_common+0x1e8/0x25a0 kernel/locking/mutex.c:598 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 commit_echoes drivers/tty/n_tty.c:775 [inline] n_tty_receive_char+0x5d0/0xb60 drivers/tty/n_tty.c:1411 n_tty_receive_buf_standard drivers/tty/n_tty.c:1560 [inline] __receive_buf drivers/tty/n_tty.c:1577 [inline] n_tty_receive_buf_common+0x1786/0x6ac0 drivers/tty/n_tty.c:1674 tty_port_default_receive_buf+0x6a/0x90 drivers/tty/tty_port.c:39 receive_buf drivers/tty/tty_buffer.c:471 [inline] flush_to_ldisc+0x2b9/0x540 drivers/tty/tty_buffer.c:523 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 other info that might help us debug this: Chain exists of: (console_sem).lock --> &rt_b->rt_runtime_lock --> hrtimer_bases.lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(hrtimer_bases.lock); lock(&rt_b->rt_runtime_lock); lock(hrtimer_bases.lock); lock((console_sem).lock); *** DEADLOCK *** 8 locks held by kworker/u4:1/144: #0: ffff888011c79138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc900010bfd20 ((work_completion)(&buf->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 #2: ffff888073a7c8b8 (&port->buf.lock/1){+.+.}-{3:3}, at: flush_to_ldisc+0x34/0x540 drivers/tty/tty_buffer.c:495 #3: ffff88801a6bb098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref+0x18/0x80 drivers/tty/tty_ldisc.c:273 #4: ffff88801a6bb2e8 (&o_tty->termios_rwsem/1){++++}-{3:3}, at: n_tty_receive_buf_common+0x88/0x6ac0 drivers/tty/n_tty.c:1637 #5: ffffc9000110e378 (&ldata->output_lock){+.+.}-{3:3}, at: commit_echoes drivers/tty/n_tty.c:775 [inline] #5: ffffc9000110e378 (&ldata->output_lock){+.+.}-{3:3}, at: n_tty_receive_char+0x5d0/0xb60 drivers/tty/n_tty.c:1411 #6: ffff8880b9b2a218 (hrtimer_bases.lock){-.-.}-{2:2}, at: __run_hrtimer kernel/time/hrtimer.c:1690 [inline] #6: ffff8880b9b2a218 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_run_queues+0x662/0xcf0 kernel/time/hrtimer.c:1750 #7: ffffffff8c91f720 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311 stack backtrace: CPU: 1 PID: 144 Comm: kworker/u4:1 Not tainted 5.15.153-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Workqueue: events_unbound flush_to_ldisc Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 check_noncircular+0x2f8/0x3b0 kernel/locking/lockdep.c:2133 check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 down_trylock+0x1c/0xa0 kernel/locking/semaphore.c:138 __down_trylock_console_sem+0x105/0x250 kernel/printk/printk.c:239 console_trylock kernel/printk/printk.c:2569 [inline] console_trylock_spinning+0x8a/0x3f0 kernel/printk/printk.c:1867 vprintk_emit+0xa6/0x150 kernel/printk/printk.c:2267 _printk+0xd1/0x111 kernel/printk/printk.c:2293 report_bug+0x1e5/0x2e0 lib/bug.c:195 handle_bug+0x3d/0x70 arch/x86/kernel/traps.c:239 exc_invalid_op+0x16/0x40 arch/x86/kernel/traps.c:259 asm_exc_invalid_op+0x16/0x20 arch/x86/include/asm/idtentry.h:566 RIP: 0010:copy_from_user_nofault+0x15c/0x1c0 mm/maccess.c:226 Code: db 48 c7 c0 f2 ff ff ff 48 0f 44 c5 eb 0c e8 6b dc d5 ff 48 c7 c0 f2 ff ff ff 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 54 dc d5 ff <0f> 0b e9 1e ff ff ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c ef fe ff RSP: 0018:ffffc90000dd0be8 EFLAGS: 00010046 RAX: ffffffff81aa5d5c RBX: 0000000000000000 RCX: ffff888017248000 RDX: 0000000080010003 RSI: 0000000000000000 RDI: 0000000000000000 RBP: dffffc0000000000 R08: ffffffff81aa5c6d R09: fffffbfff1f7a019 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: ffffc90000dd0c48 bpf_probe_read_user_common kernel/trace/bpf_trace.c:157 [inline] ____bpf_probe_read_user kernel/trace/bpf_trace.c:166 [inline] bpf_probe_read_user+0x26/0x70 kernel/trace/bpf_trace.c:163 bpf_prog_690f12e098ef46de+0x32/0xb70 bpf_dispatcher_nop_func include/linux/bpf.h:785 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1880 [inline] bpf_trace_run2+0x19e/0x340 kernel/trace/bpf_trace.c:1917 trace_hrtimer_start include/trace/events/timer.h:199 [inline] debug_activate kernel/time/hrtimer.c:476 [inline] enqueue_hrtimer+0x324/0x390 kernel/time/hrtimer.c:1084 __run_hrtimer kernel/time/hrtimer.c:1703 [inline] __hrtimer_run_queues+0x6b6/0xcf0 kernel/time/hrtimer.c:1750 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1812 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline] __sysvec_apic_timer_interrupt+0x139/0x470 arch/x86/kernel/apic/apic.c:1102 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1096 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__mutex_trylock_common+0x1c/0x2e0 kernel/locking/mutex.c:98 Code: 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 81 ec a0 00 00 00 89 74 24 24 <49> 89 fc 65 48 8b 04 25 28 00 00 00 48 89 84 24 80 00 00 00 49 be RSP: 0018:ffffc900010bf680 EFLAGS: 00000282 RAX: cc0c55d73cea9700 RBX: dffffc0000000000 RCX: ffffffff816344b2 RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffffc9000110e310 RBP: ffffc900010bf750 R08: dffffc0000000000 R09: fffffbfff1f7a02d R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000 R13: ffffc9000110e310 R14: ffffc9000110e378 R15: 0000000000000000 __mutex_trylock kernel/locking/mutex.c:146 [inline] __mutex_lock_common+0x1e8/0x25a0 kernel/locking/mutex.c:598 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 commit_echoes drivers/tty/n_tty.c:775 [inline] n_tty_receive_char+0x5d0/0xb60 drivers/tty/n_tty.c:1411 n_tty_receive_buf_standard drivers/tty/n_tty.c:1560 [inline] __receive_buf drivers/tty/n_tty.c:1577 [inline] n_tty_receive_buf_common+0x1786/0x6ac0 drivers/tty/n_tty.c:1674 tty_port_default_receive_buf+0x6a/0x90 drivers/tty/tty_port.c:39 receive_buf drivers/tty/tty_buffer.c:471 [inline] flush_to_ldisc+0x2b9/0x540 drivers/tty/tty_buffer.c:523 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 WARNING: CPU: 1 PID: 144 at mm/maccess.c:226 copy_from_user_nofault+0x15c/0x1c0 Modules linked in: CPU: 1 PID: 144 Comm: kworker/u4:1 Not tainted 5.15.153-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Workqueue: events_unbound flush_to_ldisc RIP: 0010:copy_from_user_nofault+0x15c/0x1c0 mm/maccess.c:226 Code: db 48 c7 c0 f2 ff ff ff 48 0f 44 c5 eb 0c e8 6b dc d5 ff 48 c7 c0 f2 ff ff ff 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 54 dc d5 ff <0f> 0b e9 1e ff ff ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c ef fe ff RSP: 0018:ffffc90000dd0be8 EFLAGS: 00010046 RAX: ffffffff81aa5d5c RBX: 0000000000000000 RCX: ffff888017248000 RDX: 0000000080010003 RSI: 0000000000000000 RDI: 0000000000000000 RBP: dffffc0000000000 R08: ffffffff81aa5c6d R09: fffffbfff1f7a019 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: ffffc90000dd0c48 FS: 0000000000000000(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020002000 CR3: 00000000624e5000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: bpf_probe_read_user_common kernel/trace/bpf_trace.c:157 [inline] ____bpf_probe_read_user kernel/trace/bpf_trace.c:166 [inline] bpf_probe_read_user+0x26/0x70 kernel/trace/bpf_trace.c:163 bpf_prog_690f12e098ef46de+0x32/0xb70 bpf_dispatcher_nop_func include/linux/bpf.h:785 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1880 [inline] bpf_trace_run2+0x19e/0x340 kernel/trace/bpf_trace.c:1917 trace_hrtimer_start include/trace/events/timer.h:199 [inline] debug_activate kernel/time/hrtimer.c:476 [inline] enqueue_hrtimer+0x324/0x390 kernel/time/hrtimer.c:1084 __run_hrtimer kernel/time/hrtimer.c:1703 [inline] __hrtimer_run_queues+0x6b6/0xcf0 kernel/time/hrtimer.c:1750 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1812 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline] __sysvec_apic_timer_interrupt+0x139/0x470 arch/x86/kernel/apic/apic.c:1102 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1096 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:__mutex_trylock_common+0x1c/0x2e0 kernel/locking/mutex.c:98 Code: 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 81 ec a0 00 00 00 89 74 24 24 <49> 89 fc 65 48 8b 04 25 28 00 00 00 48 89 84 24 80 00 00 00 49 be RSP: 0018:ffffc900010bf680 EFLAGS: 00000282 RAX: cc0c55d73cea9700 RBX: dffffc0000000000 RCX: ffffffff816344b2 RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffffc9000110e310 RBP: ffffc900010bf750 R08: dffffc0000000000 R09: fffffbfff1f7a02d R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000 R13: ffffc9000110e310 R14: ffffc9000110e378 R15: 0000000000000000 __mutex_trylock kernel/locking/mutex.c:146 [inline] __mutex_lock_common+0x1e8/0x25a0 kernel/locking/mutex.c:598 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 commit_echoes drivers/tty/n_tty.c:775 [inline] n_tty_receive_char+0x5d0/0xb60 drivers/tty/n_tty.c:1411 n_tty_receive_buf_standard drivers/tty/n_tty.c:1560 [inline] __receive_buf drivers/tty/n_tty.c:1577 [inline] n_tty_receive_buf_common+0x1786/0x6ac0 drivers/tty/n_tty.c:1674 tty_port_default_receive_buf+0x6a/0x90 drivers/tty/tty_port.c:39 receive_buf drivers/tty/tty_buffer.c:471 [inline] flush_to_ldisc+0x2b9/0x540 drivers/tty/tty_buffer.c:523 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 ---------------- Code disassembly (best guess): 0: 00 66 2e add %ah,0x2e(%rsi) 3: 0f 1f 84 00 00 00 00 nopl 0x0(%rax,%rax,1) a: 00 b: 0f 1f 00 nopl (%rax) e: 55 push %rbp f: 48 89 e5 mov %rsp,%rbp 12: 41 57 push %r15 14: 41 56 push %r14 16: 41 55 push %r13 18: 41 54 push %r12 1a: 53 push %rbx 1b: 48 83 e4 e0 and $0xffffffffffffffe0,%rsp 1f: 48 81 ec a0 00 00 00 sub $0xa0,%rsp 26: 89 74 24 24 mov %esi,0x24(%rsp) * 2a: 49 89 fc mov %rdi,%r12 <-- trapping instruction 2d: 65 48 8b 04 25 28 00 mov %gs:0x28,%rax 34: 00 00 36: 48 89 84 24 80 00 00 mov %rax,0x80(%rsp) 3d: 00 3e: 49 rex.WB 3f: be .byte 0xbe