[ OK ] Started Getty on tty4. [ OK ] Started Getty on tty3. [ OK ] Started Getty on tty2. [ OK ] Started Getty on tty1. [ OK ] Started Serial Getty on ttyS0. [ 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 '10.128.15.201' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 68.863347][ C1] [ 68.865806][ C1] ======================================================== [ 68.872981][ C1] WARNING: possible irq lock inversion dependency detected [ 68.880160][ C1] 5.9.0-rc4-next-20200911-syzkaller #0 Not tainted [ 68.886652][ C1] -------------------------------------------------------- [ 68.893831][ C1] swapper/1/0 just changed the state of lock: [ 68.899888][ C1] ffff88809a2ac908 (&group->lock){..-.}-{2:2}, at: _snd_pcm_stream_lock_irqsave+0x9f/0xd0 [ 68.909783][ C1] but this lock took another, SOFTIRQ-READ-unsafe lock in the past: [ 68.917757][ C1] (&card->ctl_files_rwlock){.+.+}-{2:2} [ 68.917773][ C1] [ 68.917773][ C1] [ 68.917773][ C1] and interrupts could create inverse lock ordering between them. [ 68.917773][ C1] [ 68.937841][ C1] [ 68.937841][ C1] other info that might help us debug this: [ 68.945898][ C1] Possible interrupt unsafe locking scenario: [ 68.945898][ C1] [ 68.954214][ C1] CPU0 CPU1 [ 68.959580][ C1] ---- ---- [ 68.964929][ C1] lock(&card->ctl_files_rwlock); [ 68.970038][ C1] local_irq_disable(); [ 68.976835][ C1] lock(&group->lock); [ 68.983542][ C1] lock(&card->ctl_files_rwlock); [ 68.991159][ C1] [ 68.994616][ C1] lock(&group->lock); [ 68.998942][ C1] [ 68.998942][ C1] *** DEADLOCK *** [ 68.998942][ C1] [ 69.007185][ C1] 1 lock held by swapper/1/0: [ 69.011839][ C1] #0: ffffc90000da8d80 ((&dpcm->timer)){+.-.}-{0:0}, at: call_timer_fn+0xd5/0x6b0 [ 69.021140][ C1] [ 69.021140][ C1] the shortest dependencies between 2nd lock and 1st lock: [ 69.030517][ C1] -> (&card->ctl_files_rwlock){.+.+}-{2:2} { [ 69.036594][ C1] HARDIRQ-ON-R at: [ 69.040679][ C1] lock_acquire+0x1f2/0xaa0 [ 69.047046][ C1] _raw_read_lock+0x5b/0x70 [ 69.053382][ C1] snd_ctl_notify.part.0+0x36/0x550 [ 69.060418][ C1] snd_ctl_notify+0x8f/0xb0 [ 69.066744][ C1] __snd_ctl_add_replace+0x638/0x800 [ 69.073857][ C1] snd_ctl_add_replace+0x76/0x130 [ 69.080727][ C1] snd_dummy_probe+0xbbf/0x1050 [ 69.087412][ C1] platform_drv_probe+0x87/0x140 [ 69.094183][ C1] really_probe+0x282/0x9f0 [ 69.100511][ C1] driver_probe_device+0xfe/0x1d0 [ 69.107365][ C1] __device_attach_driver+0x1c2/0x220 [ 69.114553][ C1] bus_for_each_drv+0x15f/0x1e0 [ 69.121231][ C1] __device_attach+0x228/0x470 [ 69.128793][ C1] bus_probe_device+0x1e4/0x290 [ 69.135644][ C1] device_add+0xb17/0x1c40 [ 69.141876][ C1] platform_device_add+0x34f/0x6d0 [ 69.148813][ C1] platform_device_register_full+0x38c/0x4e0 [ 69.156620][ C1] alsa_card_dummy_init+0x1cc/0x2e0 [ 69.163648][ C1] do_one_initcall+0x103/0x6f0 [ 69.170243][ C1] kernel_init_freeable+0x5e9/0x66d [ 69.177307][ C1] kernel_init+0xd/0x1c0 [ 69.183387][ C1] ret_from_fork+0x1f/0x30 [ 69.189608][ C1] SOFTIRQ-ON-R at: [ 69.193684][ C1] lock_acquire+0x1f2/0xaa0 [ 69.200017][ C1] _raw_read_lock+0x5b/0x70 [ 69.206338][ C1] snd_ctl_notify.part.0+0x36/0x550 [ 69.213972][ C1] snd_ctl_notify+0x8f/0xb0 [ 69.220738][ C1] __snd_ctl_add_replace+0x638/0x800 [ 69.227905][ C1] snd_ctl_add_replace+0x76/0x130 [ 69.234757][ C1] snd_dummy_probe+0xbbf/0x1050 [ 69.241424][ C1] platform_drv_probe+0x87/0x140 [ 69.248201][ C1] really_probe+0x282/0x9f0 [ 69.254540][ C1] driver_probe_device+0xfe/0x1d0 [ 69.261441][ C1] __device_attach_driver+0x1c2/0x220 [ 69.268694][ C1] bus_for_each_drv+0x15f/0x1e0 [ 69.275375][ C1] __device_attach+0x228/0x470 [ 69.281955][ C1] bus_probe_device+0x1e4/0x290 [ 69.288621][ C1] device_add+0xb17/0x1c40 [ 69.295230][ C1] platform_device_add+0x34f/0x6d0 [ 69.302170][ C1] platform_device_register_full+0x38c/0x4e0 [ 69.309978][ C1] alsa_card_dummy_init+0x1cc/0x2e0 [ 69.317946][ C1] do_one_initcall+0x103/0x6f0 [ 69.324568][ C1] kernel_init_freeable+0x5e9/0x66d [ 69.331687][ C1] kernel_init+0xd/0x1c0 [ 69.337762][ C1] ret_from_fork+0x1f/0x30 [ 69.343984][ C1] (null) at: [ 69.347546][ C1] general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN [ 69.359270][ C1] KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] [ 69.368029][ C1] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.9.0-rc4-next-20200911-syzkaller #0 [ 69.377136][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 69.387211][ C1] RIP: 0010:print_shortest_lock_dependencies.cold+0x110/0x2af [ 69.394655][ C1] Code: 48 8b 04 24 48 c1 e8 03 42 80 3c 20 00 74 09 48 8b 3c 24 e8 5b 11 da 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 [ 69.414270][ C1] RSP: 0018:ffffc90000da8898 EFLAGS: 00010003 [ 69.420328][ C1] RAX: 0000000000000001 RBX: ffffffff8cbde5b0 RCX: 0000000000000000 [ 69.428387][ C1] RDX: 0000000000000002 RSI: ffffffff815c0ec7 RDI: 0000000000000015 [ 69.436359][ C1] RBP: ffffc90000da89c8 R08: 0000000000000004 R09: ffff8880ae720f8b [ 69.444335][ C1] R10: 0000000000000000 R11: 6c756e2820202020 R12: dffffc0000000000 [ 69.452306][ C1] R13: ffffffff8c9e73f8 R14: 0000000000000009 R15: 0000000000000001 [ 69.460272][ C1] FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 [ 69.469202][ C1] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 69.475783][ C1] CR2: 0000000000000040 CR3: 0000000009c8e000 CR4: 00000000001506e0 [ 69.483760][ C1] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 69.491731][ C1] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 69.499701][ C1] Call Trace: [ 69.502989][ C1] [ 69.505831][ C1] print_irq_inversion_bug.part.0+0x2c6/0x2ee [ 69.511905][ C1] mark_lock.cold+0x38/0x10d [ 69.516493][ C1] ? lock_chain_count+0x20/0x20 [ 69.521326][ C1] ? lock_is_held_type+0xbb/0xf0 [ 69.526284][ C1] ? find_held_lock+0x2d/0x110 [ 69.531050][ C1] ? debug_object_activate+0x287/0x3e0 [ 69.536527][ C1] ? lock_downgrade+0x830/0x830 [ 69.541367][ C1] __lock_acquire+0x117d/0x55d0 [ 69.546212][ C1] ? lock_downgrade+0x830/0x830 [ 69.551069][ C1] ? lockdep_hardirqs_on_prepare+0x530/0x530 [ 69.557053][ C1] ? mark_lock+0xf7/0x2300 [ 69.561479][ C1] lock_acquire+0x1f2/0xaa0 [ 69.565992][ C1] ? _snd_pcm_stream_lock_irqsave+0x9f/0xd0 [ 69.571879][ C1] ? lock_release+0x890/0x890 [ 69.576550][ C1] ? find_held_lock+0x2d/0x110 [ 69.581312][ C1] ? loopback_jiffies_timer_function+0x188/0x220 [ 69.587645][ C1] ? _raw_spin_lock_irqsave+0xa9/0xd0 [ 69.593028][ C1] _raw_spin_lock_irqsave+0x94/0xd0 [ 69.598237][ C1] ? _snd_pcm_stream_lock_irqsave+0x9f/0xd0 [ 69.604145][ C1] _snd_pcm_stream_lock_irqsave+0x9f/0xd0 [ 69.609880][ C1] snd_pcm_period_elapsed+0x24/0x250 [ 69.615180][ C1] loopback_jiffies_timer_function+0x1a8/0x220 [ 69.621342][ C1] ? loopback_jiffies_timer_pos_update+0xf60/0xf60 [ 69.627834][ C1] call_timer_fn+0x1a5/0x6b0 [ 69.632426][ C1] ? add_timer_on+0x450/0x450 [ 69.637097][ C1] ? lock_downgrade+0x830/0x830 [ 69.641943][ C1] ? _raw_spin_unlock_irq+0x1f/0x80 [ 69.647156][ C1] ? loopback_jiffies_timer_pos_update+0xf60/0xf60 [ 69.653665][ C1] __run_timers.part.0+0x67c/0xa50 [ 69.658769][ C1] ? call_timer_fn+0x6b0/0x6b0 [ 69.663527][ C1] ? lapic_next_event+0x4d/0x80 [ 69.668386][ C1] ? clockevents_program_event+0x12b/0x350 [ 69.674206][ C1] ? kvm_sched_clock_read+0x14/0x40 [ 69.679400][ C1] ? sched_clock+0x2a/0x40 [ 69.683821][ C1] ? sched_clock_cpu+0x18/0x1b0 [ 69.688685][ C1] ? hrtimer_interrupt+0x6ea/0x930 [ 69.693807][ C1] run_timer_softirq+0xae/0x1a0 [ 69.698670][ C1] __do_softirq+0x202/0xa42 [ 69.703171][ C1] asm_call_on_stack+0xf/0x20 [ 69.707855][ C1] [ 69.710806][ C1] do_softirq_own_stack+0x9d/0xd0 [ 69.715838][ C1] irq_exit_rcu+0x235/0x280 [ 69.720363][ C1] sysvec_apic_timer_interrupt+0x51/0xf0 [ 69.725993][ C1] asm_sysvec_apic_timer_interrupt+0x12/0x20 [ 69.731977][ C1] RIP: 0010:native_safe_halt+0xe/0x10 [ 69.737350][ C1] Code: ff 4c 89 ef e8 93 d9 af f9 e9 8e fe ff ff 48 89 df e8 86 d9 af f9 eb 8a cc cc cc cc e9 07 00 00 00 0f 00 2d 84 87 65 00 fb f4 90 e9 07 00 00 00 0f 00 2d 74 87 65 00 f4 c3 cc cc 55 53 e8 69 [ 69.756954][ C1] RSP: 0018:ffffc90000d3fd10 EFLAGS: 00000293 [ 69.763010][ C1] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 1ffffffff15cacb9 [ 69.770987][ C1] RDX: ffff8880a9630340 RSI: ffffffff88034020 RDI: 0000000000000000 [ 69.778950][ C1] RBP: ffff8880a619b064 R08: 0000000000000001 R09: 0000000000000001 [ 69.786931][ C1] R10: 0000000000000000 R11: 0000000000000001 R12: ffff8880a619b064 [ 69.794896][ C1] R13: 1ffff920001a7fac R14: ffff8880a619b065 R15: 0000000000000001 [ 69.802889][ C1] ? acpi_safe_halt+0x90/0x180 [ 69.807660][ C1] acpi_safe_halt+0x95/0x180 [ 69.812242][ C1] acpi_idle_do_entry+0x15c/0x1b0 [ 69.817278][ C1] acpi_idle_enter+0x403/0xac0 [ 69.822039][ C1] ? acpi_idle_enter_bm+0x2d0/0x2d0 [ 69.827245][ C1] cpuidle_enter_state+0x150/0xa70 [ 69.833064][ C1] cpuidle_enter+0x4a/0xa0 [ 69.837484][ C1] do_idle+0x48e/0x730 [ 69.841564][ C1] ? arch_cpu_idle_exit+0x70/0x70 [ 69.846585][ C1] ? _raw_write_unlock_irqrestore+0x70/0x90 [ 69.852493][ C1] ? lockdep_hardirqs_on+0x53/0x100 [ 69.857710][ C1] cpu_startup_entry+0x14/0x20 [ 69.862489][ C1] secondary_startup_64_no_verify+0xa6/0xab [ 69.868375][ C1] Modules linked in: [ 69.872283][ C1] ---[ end trace acbc3456f59a16f4 ]--- [ 69.877753][ C1] RIP: 0010:print_shortest_lock_dependencies.cold+0x110/0x2af [ 69.885217][ C1] Code: 48 8b 04 24 48 c1 e8 03 42 80 3c 20 00 74 09 48 8b 3c 24 e8 5b 11 da 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 [ 69.905442][ C1] RSP: 0018:ffffc90000da8898 EFLAGS: 00010003 [ 69.911514][ C1] RAX: 0000000000000001 RBX: ffffffff8cbde5b0 RCX: 0000000000000000 [ 69.919495][ C1] RDX: 0000000000000002 RSI: ffffffff815c0ec7 RDI: 0000000000000015 [ 69.927468][ C1] RBP: ffffc90000da89c8 R08: 0000000000000004 R09: ffff8880ae720f8b [ 69.935450][ C1] R10: 0000000000000000 R11: 6c756e2820202020 R12: dffffc0000000000 [ 69.943440][ C1] R13: ffffffff8c9e73f8 R14: 0000000000000009 R15: 0000000000000001 [ 69.951401][ C1] FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 [ 69.960318][ C1] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 69.966896][ C1] CR2: 0000000000000040 CR3: 0000000009c8e000 CR4: 00000000001506e0 [ 69.974880][ C1] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 69.982840][ C1] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 69.990809][ C1] Kernel panic - not syncing: Fatal exception in interrupt [ 69.999231][ C1] Kernel Offset: disabled [ 70.003571][ C1] Rebooting in 86400 seconds..