[ OK ] Started Getty on tty4. [ OK ] Started Getty on tty3. [ OK ] Started Getty on tty2. [ OK ] Started Serial Getty on ttyS0. [ OK ] Started Getty on tty1. [ OK ] Reached target Login Prompts. [ OK ] Reached target Multi-User System. [ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... [ OK ] Started Update UTMP about System Runlevel Changes. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.208' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 64.059109][ C1] [ 64.061477][ C1] ======================================================== [ 64.068652][ C1] WARNING: possible irq lock inversion dependency detected [ 64.075834][ C1] 5.9.0-rc5-next-20200915-syzkaller #0 Not tainted [ 64.082412][ C1] -------------------------------------------------------- [ 64.089580][ C1] swapper/1/0 just changed the state of lock: [ 64.095715][ C1] ffff88809a05a108 (&group->lock){..-.}-{2:2}, at: _snd_pcm_stream_lock_irqsave+0x9f/0xd0 [ 64.105679][ C1] but this lock took another, SOFTIRQ-READ-unsafe lock in the past: [ 64.113622][ C1] (&card->ctl_files_rwlock){.+.+}-{2:2} [ 64.113634][ C1] [ 64.113634][ C1] [ 64.113634][ C1] and interrupts could create inverse lock ordering between them. [ 64.113634][ C1] [ 64.133540][ C1] [ 64.133540][ C1] other info that might help us debug this: [ 64.141571][ C1] Possible interrupt unsafe locking scenario: [ 64.141571][ C1] [ 64.149861][ C1] CPU0 CPU1 [ 64.155200][ C1] ---- ---- [ 64.160548][ C1] lock(&card->ctl_files_rwlock); [ 64.165685][ C1] local_irq_disable(); [ 64.172447][ C1] lock(&group->lock); [ 64.179099][ C1] lock(&card->ctl_files_rwlock); [ 64.186701][ C1] [ 64.190146][ C1] lock(&group->lock); [ 64.194457][ C1] [ 64.194457][ C1] *** DEADLOCK *** [ 64.194457][ C1] [ 64.202630][ C1] 1 lock held by swapper/1/0: [ 64.207367][ C1] #0: ffffc90000da8d80 ((&dpcm->timer)){+.-.}-{0:0}, at: call_timer_fn+0xd5/0x6b0 [ 64.216647][ C1] [ 64.216647][ C1] the shortest dependencies between 2nd lock and 1st lock: [ 64.226002][ C1] -> (&card->ctl_files_rwlock){.+.+}-{2:2} { [ 64.232050][ C1] HARDIRQ-ON-R at: [ 64.236115][ C1] lock_acquire+0x1f2/0xaa0 [ 64.242432][ C1] _raw_read_lock+0x5b/0x70 [ 64.248760][ C1] snd_ctl_notify.part.0+0x36/0x550 [ 64.255767][ C1] snd_ctl_notify+0x8f/0xb0 [ 64.262082][ C1] __snd_ctl_add_replace+0x638/0x800 [ 64.269606][ C1] snd_ctl_add_replace+0x76/0x130 [ 64.276530][ C1] snd_dummy_probe+0xbbf/0x1050 [ 64.283190][ C1] platform_drv_probe+0x87/0x140 [ 64.289924][ C1] really_probe+0x282/0x9f0 [ 64.296253][ C1] driver_probe_device+0xfe/0x1d0 [ 64.303191][ C1] __device_attach_driver+0x1c2/0x220 [ 64.310375][ C1] bus_for_each_drv+0x15f/0x1e0 [ 64.317052][ C1] __device_attach+0x228/0x470 [ 64.323636][ C1] bus_probe_device+0x1e4/0x290 [ 64.330284][ C1] device_add+0xb17/0x1c40 [ 64.336676][ C1] platform_device_add+0x34f/0x6d0 [ 64.343592][ C1] platform_device_register_full+0x38c/0x4e0 [ 64.351552][ C1] alsa_card_dummy_init+0x1cc/0x2e0 [ 64.358557][ C1] do_one_initcall+0x103/0x6f0 [ 64.365115][ C1] kernel_init_freeable+0x5e9/0x66d [ 64.372116][ C1] kernel_init+0xd/0x1c0 [ 64.378152][ C1] ret_from_fork+0x1f/0x30 [ 64.384357][ C1] SOFTIRQ-ON-R at: [ 64.388406][ C1] lock_acquire+0x1f2/0xaa0 [ 64.394705][ C1] _raw_read_lock+0x5b/0x70 [ 64.401005][ C1] snd_ctl_notify.part.0+0x36/0x550 [ 64.407994][ C1] snd_ctl_notify+0x8f/0xb0 [ 64.414290][ C1] __snd_ctl_add_replace+0x638/0x800 [ 64.421376][ C1] snd_ctl_add_replace+0x76/0x130 [ 64.428212][ C1] snd_dummy_probe+0xbbf/0x1050 [ 64.434943][ C1] platform_drv_probe+0x87/0x140 [ 64.441683][ C1] really_probe+0x282/0x9f0 [ 64.447988][ C1] driver_probe_device+0xfe/0x1d0 [ 64.454814][ C1] __device_attach_driver+0x1c2/0x220 [ 64.461986][ C1] bus_for_each_drv+0x15f/0x1e0 [ 64.468720][ C1] __device_attach+0x228/0x470 [ 64.475364][ C1] bus_probe_device+0x1e4/0x290 [ 64.482009][ C1] device_add+0xb17/0x1c40 [ 64.488248][ C1] platform_device_add+0x34f/0x6d0 [ 64.495182][ C1] platform_device_register_full+0x38c/0x4e0 [ 64.502968][ C1] alsa_card_dummy_init+0x1cc/0x2e0 [ 64.510097][ C1] do_one_initcall+0x103/0x6f0 [ 64.516668][ C1] kernel_init_freeable+0x5e9/0x66d [ 64.523663][ C1] kernel_init+0xd/0x1c0 [ 64.529719][ C1] ret_from_fork+0x1f/0x30 [ 64.535942][ C1] (null) at: [ 64.539924][ C1] general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN [ 64.551942][ C1] KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] [ 64.561375][ C1] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.9.0-rc5-next-20200915-syzkaller #0 [ 64.570460][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 64.580502][ C1] RIP: 0010:print_shortest_lock_dependencies.cold+0x110/0x2af [ 64.587932][ C1] Code: 48 8b 04 24 48 c1 e8 03 42 80 3c 20 00 74 09 48 8b 3c 24 e8 b1 21 d9 f9 48 8b 04 24 48 8b 00 48 8d 78 14 48 89 fa 48 c1 ea 03 <42> 0f b6 0c 22 48 89 fa 83 e2 07 83 c2 03 38 ca 7c 08 84 c9 0f 85 [ 64.609615][ C1] RSP: 0018:ffffc90000da8898 EFLAGS: 00010003 [ 64.615664][ C1] RAX: 0000000000000001 RBX: ffffffff8cbe3890 RCX: 0000000000000000 [ 64.623618][ C1] RDX: 0000000000000002 RSI: ffffffff815c26a7 RDI: 0000000000000015 [ 64.631584][ C1] RBP: ffffc90000da89c8 R08: 0000000000000004 R09: ffff8880ae720f8b [ 64.639565][ C1] R10: 0000000000000000 R11: 6c756e2820202020 R12: dffffc0000000000 [ 64.647512][ C1] R13: ffffffff8c9ee300 R14: 0000000000000009 R15: 0000000000000001 [ 64.655596][ C1] FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 [ 64.664521][ C1] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 64.671096][ C1] CR2: 0000000020000080 CR3: 000000009333b000 CR4: 00000000001506e0 [ 64.679329][ C1] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 64.687299][ C1] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 64.695416][ C1] Call Trace: [ 64.698696][ C1] [ 64.701540][ C1] print_irq_inversion_bug.part.0+0x2c6/0x2ee [ 64.707594][ C1] mark_lock.cold+0x38/0x10d [ 64.712185][ C1] ? lock_chain_count+0x20/0x20 [ 64.717024][ C1] ? lock_is_held_type+0xbb/0xf0 [ 64.721933][ C1] ? find_held_lock+0x2d/0x110 [ 64.726688][ C1] ? debug_object_activate+0x287/0x3e0 [ 64.732132][ C1] ? lock_downgrade+0x830/0x830 [ 64.737145][ C1] __lock_acquire+0x117d/0x55d0 [ 64.741979][ C1] ? lock_downgrade+0x830/0x830 [ 64.746807][ C1] ? lockdep_hardirqs_on_prepare+0x530/0x530 [ 64.752772][ C1] ? mark_lock+0xf7/0x2300 [ 64.757189][ C1] lock_acquire+0x1f2/0xaa0 [ 64.761822][ C1] ? _snd_pcm_stream_lock_irqsave+0x9f/0xd0 [ 64.767716][ C1] ? lock_release+0x890/0x890 [ 64.772376][ C1] ? find_held_lock+0x2d/0x110 [ 64.777122][ C1] ? loopback_jiffies_timer_function+0x188/0x220 [ 64.783527][ C1] ? _raw_spin_lock_irqsave+0xa9/0xd0 [ 64.788887][ C1] _raw_spin_lock_irqsave+0x94/0xd0 [ 64.794061][ C1] ? _snd_pcm_stream_lock_irqsave+0x9f/0xd0 [ 64.799943][ C1] _snd_pcm_stream_lock_irqsave+0x9f/0xd0 [ 64.806786][ C1] snd_pcm_period_elapsed+0x24/0x250 [ 64.812056][ C1] loopback_jiffies_timer_function+0x1a8/0x220 [ 64.818280][ C1] ? loopback_jiffies_timer_pos_update+0xf60/0xf60 [ 64.825130][ C1] call_timer_fn+0x1a5/0x6b0 [ 64.829866][ C1] ? add_timer_on+0x450/0x450 [ 64.834552][ C1] ? lock_downgrade+0x830/0x830 [ 64.839376][ C1] ? rwlock_bug.part.0+0x90/0x90 [ 64.844287][ C1] ? _raw_spin_unlock_irq+0x1f/0x80 [ 64.849546][ C1] ? loopback_jiffies_timer_pos_update+0xf60/0xf60 [ 64.856106][ C1] __run_timers.part.0+0x67c/0xa50 [ 64.861202][ C1] ? call_timer_fn+0x6b0/0x6b0 [ 64.866939][ C1] ? lapic_next_event+0x4d/0x80 [ 64.871765][ C1] ? clockevents_program_event+0x12b/0x350 [ 64.878067][ C1] ? kvm_sched_clock_read+0x14/0x40 [ 64.883252][ C1] ? sched_clock+0x2a/0x40 [ 64.887653][ C1] ? sched_clock_cpu+0x18/0x1b0 [ 64.892475][ C1] ? hrtimer_interrupt+0x6ea/0x930 [ 64.897572][ C1] run_timer_softirq+0xae/0x1a0 [ 64.904843][ C1] __do_softirq+0x202/0xa42 [ 64.909323][ C1] asm_call_on_stack+0xf/0x20 [ 64.914053][ C1] [ 64.917489][ C1] do_softirq_own_stack+0x9d/0xd0 [ 64.922503][ C1] irq_exit_rcu+0x235/0x280 [ 64.927156][ C1] sysvec_apic_timer_interrupt+0x51/0xf0 [ 64.932765][ C1] asm_sysvec_apic_timer_interrupt+0x12/0x20 [ 64.938718][ C1] RIP: 0010:native_safe_halt+0xe/0x10 [ 64.944249][ C1] Code: ff 4c 89 ef e8 b3 df ae f9 e9 8e fe ff ff 48 89 df e8 a6 df ae f9 eb 8a cc cc cc cc e9 07 00 00 00 0f 00 2d b4 5c 64 00 fb f4 90 e9 07 00 00 00 0f 00 2d a4 5c 64 00 f4 c3 cc cc 55 53 e8 19 [ 64.964212][ C1] RSP: 0018:ffffc90000d3fd10 EFLAGS: 00000293 [ 64.970267][ C1] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 1ffffffff15cb631 [ 64.978237][ C1] RDX: ffff8880a9632340 RSI: ffffffff88046c90 RDI: 0000000000000000 [ 64.986185][ C1] RBP: ffff8880a64e0064 R08: 0000000000000001 R09: 0000000000000001 [ 64.994370][ C1] R10: 0000000000000000 R11: 0000000000000001 R12: ffff8880a64e0064 [ 65.002336][ C1] R13: 1ffff920001a7fac R14: ffff8880a64e0065 R15: 0000000000000001 [ 65.010310][ C1] ? acpi_safe_halt+0x90/0x180 [ 65.015053][ C1] acpi_safe_halt+0x95/0x180 [ 65.019792][ C1] acpi_idle_do_entry+0x15c/0x1b0 [ 65.024991][ C1] acpi_idle_enter+0x403/0xac0 [ 65.029980][ C1] ? acpi_idle_enter_bm+0x2d0/0x2d0 [ 65.035170][ C1] cpuidle_enter_state+0x150/0xa70 [ 65.040348][ C1] cpuidle_enter+0x4a/0xa0 [ 65.044744][ C1] do_idle+0x48e/0x730 [ 65.048877][ C1] ? arch_cpu_idle_exit+0x70/0x70 [ 65.054484][ C1] cpu_startup_entry+0x14/0x20 [ 65.059240][ C1] secondary_startup_64_no_verify+0xa6/0xab [ 65.065115][ C1] Modules linked in: [ 65.068999][ C1] ---[ end trace 5c0dc2d58cf3e7df ]--- [ 65.074454][ C1] RIP: 0010:print_shortest_lock_dependencies.cold+0x110/0x2af [ 65.081885][ C1] Code: 48 8b 04 24 48 c1 e8 03 42 80 3c 20 00 74 09 48 8b 3c 24 e8 b1 21 d9 f9 48 8b 04 24 48 8b 00 48 8d 78 14 48 89 fa 48 c1 ea 03 <42> 0f b6 0c 22 48 89 fa 83 e2 07 83 c2 03 38 ca 7c 08 84 c9 0f 85 [ 65.101567][ C1] RSP: 0018:ffffc90000da8898 EFLAGS: 00010003 [ 65.107708][ C1] RAX: 0000000000000001 RBX: ffffffff8cbe3890 RCX: 0000000000000000 [ 65.115655][ C1] RDX: 0000000000000002 RSI: ffffffff815c26a7 RDI: 0000000000000015 [ 65.123611][ C1] RBP: ffffc90000da89c8 R08: 0000000000000004 R09: ffff8880ae720f8b [ 65.131582][ C1] R10: 0000000000000000 R11: 6c756e2820202020 R12: dffffc0000000000 [ 65.139533][ C1] R13: ffffffff8c9ee300 R14: 0000000000000009 R15: 0000000000000001 [ 65.147484][ C1] FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 [ 65.156403][ C1] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 65.162979][ C1] CR2: 0000000020000080 CR3: 000000009333b000 CR4: 00000000001506e0 [ 65.171006][ C1] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 65.179022][ C1] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 65.187097][ C1] Kernel panic - not syncing: Fatal exception in interrupt [ 65.195064][ C1] Kernel Offset: disabled [ 65.199385][ C1] Rebooting in 86400 seconds..