[ 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... Starting Load/Save RF Kill Switch Status... [ OK ] Started Update UTMP about System Runlevel Changes. [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.184' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 65.899810][ C0] [ 65.902338][ C0] ======================================================== [ 65.909537][ C0] WARNING: possible irq lock inversion dependency detected [ 65.916836][ C0] 5.9.0-rc4-next-20200911-syzkaller #0 Not tainted [ 65.924089][ C0] -------------------------------------------------------- [ 65.931263][ C0] swapper/0/0 just changed the state of lock: [ 65.937308][ C0] ffff88809a0f8908 (&group->lock){..-.}-{2:2}, at: _snd_pcm_stream_lock_irqsave+0x9f/0xd0 [ 65.947328][ C0] but this lock took another, SOFTIRQ-READ-unsafe lock in the past: [ 65.955296][ C0] (&card->ctl_files_rwlock){.+.+}-{2:2} [ 65.955309][ C0] [ 65.955309][ C0] [ 65.955309][ C0] and interrupts could create inverse lock ordering between them. [ 65.955309][ C0] [ 65.975207][ C0] [ 65.975207][ C0] other info that might help us debug this: [ 65.983262][ C0] Possible interrupt unsafe locking scenario: [ 65.983262][ C0] [ 65.991663][ C0] CPU0 CPU1 [ 65.997019][ C0] ---- ---- [ 66.002358][ C0] lock(&card->ctl_files_rwlock); [ 66.008154][ C0] local_irq_disable(); [ 66.014913][ C0] lock(&group->lock); [ 66.021575][ C0] lock(&card->ctl_files_rwlock); [ 66.029182][ C0] [ 66.032631][ C0] lock(&group->lock); [ 66.036938][ C0] [ 66.036938][ C0] *** DEADLOCK *** [ 66.036938][ C0] [ 66.045078][ C0] 1 lock held by swapper/0/0: [ 66.049724][ C0] #0: ffffc90000007d80 ((&dpcm->timer)){+.-.}-{0:0}, at: call_timer_fn+0xd5/0x6b0 [ 66.059014][ C0] [ 66.059014][ C0] the shortest dependencies between 2nd lock and 1st lock: [ 66.068379][ C0] -> (&card->ctl_files_rwlock){.+.+}-{2:2} { [ 66.074451][ C0] HARDIRQ-ON-R at: [ 66.078513][ C0] lock_acquire+0x1f2/0xaa0 [ 66.084837][ C0] _raw_read_lock+0x5b/0x70 [ 66.091190][ C0] snd_ctl_notify.part.0+0x36/0x550 [ 66.098325][ C0] snd_ctl_notify+0x8f/0xb0 [ 66.104728][ C0] __snd_ctl_add_replace+0x638/0x800 [ 66.111823][ C0] snd_ctl_add_replace+0x76/0x130 [ 66.118659][ C0] snd_dummy_probe+0xbbf/0x1050 [ 66.125327][ C0] platform_drv_probe+0x87/0x140 [ 66.132079][ C0] really_probe+0x282/0x9f0 [ 66.138394][ C0] driver_probe_device+0xfe/0x1d0 [ 66.145334][ C0] __device_attach_driver+0x1c2/0x220 [ 66.152513][ C0] bus_for_each_drv+0x15f/0x1e0 [ 66.159173][ C0] __device_attach+0x228/0x470 [ 66.165747][ C0] bus_probe_device+0x1e4/0x290 [ 66.172395][ C0] device_add+0xb17/0x1c40 [ 66.178612][ C0] platform_device_add+0x34f/0x6d0 [ 66.185531][ C0] platform_device_register_full+0x38c/0x4e0 [ 66.193321][ C0] alsa_card_dummy_init+0x1cc/0x2e0 [ 66.200321][ C0] do_one_initcall+0x103/0x6f0 [ 66.207005][ C0] kernel_init_freeable+0x5e9/0x66d [ 66.214015][ C0] kernel_init+0xd/0x1c0 [ 66.220061][ C0] ret_from_fork+0x1f/0x30 [ 66.226287][ C0] SOFTIRQ-ON-R at: [ 66.230335][ C0] lock_acquire+0x1f2/0xaa0 [ 66.236636][ C0] _raw_read_lock+0x5b/0x70 [ 66.242936][ C0] snd_ctl_notify.part.0+0x36/0x550 [ 66.250017][ C0] snd_ctl_notify+0x8f/0xb0 [ 66.257533][ C0] __snd_ctl_add_replace+0x638/0x800 [ 66.264613][ C0] snd_ctl_add_replace+0x76/0x130 [ 66.271436][ C0] snd_dummy_probe+0xbbf/0x1050 [ 66.278085][ C0] platform_drv_probe+0x87/0x140 [ 66.284884][ C0] really_probe+0x282/0x9f0 [ 66.291194][ C0] driver_probe_device+0xfe/0x1d0 [ 66.298109][ C0] __device_attach_driver+0x1c2/0x220 [ 66.305385][ C0] bus_for_each_drv+0x15f/0x1e0 [ 66.312039][ C0] __device_attach+0x228/0x470 [ 66.318609][ C0] bus_probe_device+0x1e4/0x290 [ 66.325272][ C0] device_add+0xb17/0x1c40 [ 66.331850][ C0] platform_device_add+0x34f/0x6d0 [ 66.338890][ C0] platform_device_register_full+0x38c/0x4e0 [ 66.346696][ C0] alsa_card_dummy_init+0x1cc/0x2e0 [ 66.353708][ C0] do_one_initcall+0x103/0x6f0 [ 66.360373][ C0] kernel_init_freeable+0x5e9/0x66d [ 66.367369][ C0] kernel_init+0xd/0x1c0 [ 66.373423][ C0] ret_from_fork+0x1f/0x30 [ 66.380009][ C0] (null) at: [ 66.383765][ C0] general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN [ 66.395453][ C0] KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] [ 66.403841][ C0] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.9.0-rc4-next-20200911-syzkaller #0 [ 66.412915][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 66.422976][ C0] RIP: 0010:print_shortest_lock_dependencies.cold+0x110/0x2af [ 66.430696][ C0] 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 [ 66.450369][ C0] RSP: 0018:ffffc90000007898 EFLAGS: 00010003 [ 66.456415][ C0] RAX: 0000000000000001 RBX: ffffffff8cbdd4a0 RCX: 0000000000000000 [ 66.464378][ C0] RDX: 0000000000000002 RSI: ffffffff815c0ec7 RDI: 0000000000000015 [ 66.472348][ C0] RBP: ffffc900000079c8 R08: 0000000000000004 R09: ffff8880ae620f8b [ 66.480391][ C0] R10: 0000000000000000 R11: 6c756e2820202020 R12: dffffc0000000000 [ 66.488346][ C0] R13: ffffffff8c9e7340 R14: 0000000000000009 R15: 0000000000000001 [ 66.496321][ C0] FS: 0000000000000000(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 [ 66.505236][ C0] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 66.511801][ C0] CR2: 000000000043e740 CR3: 0000000092f76000 CR4: 00000000001506f0 [ 66.519755][ C0] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 66.527703][ C0] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 66.535693][ C0] Call Trace: [ 66.538967][ C0] [ 66.541810][ C0] print_irq_inversion_bug.part.0+0x2c6/0x2ee [ 66.547861][ C0] mark_lock.cold+0x38/0x10d [ 66.552449][ C0] ? lock_chain_count+0x20/0x20 [ 66.557278][ C0] ? lock_is_held_type+0xbb/0xf0 [ 66.562209][ C0] ? find_held_lock+0x2d/0x110 [ 66.567223][ C0] ? debug_object_activate+0x287/0x3e0 [ 66.572661][ C0] ? lock_downgrade+0x830/0x830 [ 66.577504][ C0] __lock_acquire+0x117d/0x55d0 [ 66.582330][ C0] ? lock_downgrade+0x830/0x830 [ 66.587166][ C0] ? lockdep_hardirqs_on_prepare+0x530/0x530 [ 66.593129][ C0] ? mark_lock+0xf7/0x2300 [ 66.597536][ C0] lock_acquire+0x1f2/0xaa0 [ 66.602038][ C0] ? _snd_pcm_stream_lock_irqsave+0x9f/0xd0 [ 66.608087][ C0] ? lock_release+0x890/0x890 [ 66.613546][ C0] ? find_held_lock+0x2d/0x110 [ 66.618286][ C0] ? loopback_jiffies_timer_function+0x188/0x220 [ 66.624632][ C0] ? _raw_spin_lock_irqsave+0xa9/0xd0 [ 66.629978][ C0] _raw_spin_lock_irqsave+0x94/0xd0 [ 66.635169][ C0] ? _snd_pcm_stream_lock_irqsave+0x9f/0xd0 [ 66.641035][ C0] _snd_pcm_stream_lock_irqsave+0x9f/0xd0 [ 66.646728][ C0] snd_pcm_period_elapsed+0x24/0x250 [ 66.651989][ C0] loopback_jiffies_timer_function+0x1a8/0x220 [ 66.658309][ C0] ? loopback_jiffies_timer_pos_update+0xf60/0xf60 [ 66.664795][ C0] call_timer_fn+0x1a5/0x6b0 [ 66.669379][ C0] ? add_timer_on+0x450/0x450 [ 66.674041][ C0] ? lock_downgrade+0x830/0x830 [ 66.678889][ C0] ? rwlock_bug.part.0+0x90/0x90 [ 66.683801][ C0] ? _raw_spin_unlock_irq+0x1f/0x80 [ 66.689058][ C0] ? loopback_jiffies_timer_pos_update+0xf60/0xf60 [ 66.695536][ C0] __run_timers.part.0+0x67c/0xa50 [ 66.700634][ C0] ? call_timer_fn+0x6b0/0x6b0 [ 66.705382][ C0] ? lapic_next_event+0x4d/0x80 [ 66.710206][ C0] ? clockevents_program_event+0x12b/0x350 [ 66.715992][ C0] ? kvm_sched_clock_read+0x14/0x40 [ 66.721161][ C0] ? sched_clock+0x2a/0x40 [ 66.725550][ C0] ? sched_clock_cpu+0x18/0x1b0 [ 66.730374][ C0] ? hrtimer_interrupt+0x6ea/0x930 [ 66.735459][ C0] run_timer_softirq+0xae/0x1a0 [ 66.740301][ C0] __do_softirq+0x202/0xa42 [ 66.744779][ C0] asm_call_on_stack+0xf/0x20 [ 66.749424][ C0] [ 66.752337][ C0] do_softirq_own_stack+0x9d/0xd0 [ 66.757349][ C0] irq_exit_rcu+0x235/0x280 [ 66.761828][ C0] sysvec_apic_timer_interrupt+0x51/0xf0 [ 66.767434][ C0] asm_sysvec_apic_timer_interrupt+0x12/0x20 [ 66.774097][ C0] RIP: 0010:native_safe_halt+0xe/0x10 [ 66.783174][ C0] 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 [ 66.802750][ C0] RSP: 0018:ffffffff89c07cd8 EFLAGS: 00000293 [ 66.808806][ C0] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 1ffffffff15cacb9 [ 66.816788][ C0] RDX: ffffffff89c9b040 RSI: ffffffff88034020 RDI: 0000000000000000 [ 66.824733][ C0] RBP: ffff8880a66cd864 R08: 0000000000000001 R09: 0000000000000001 [ 66.832714][ C0] R10: 0000000000000000 R11: 0000000000000001 R12: ffff8880a66cd864 [ 66.840762][ C0] R13: 1ffffffff1380fa5 R14: ffff8880a66cd865 R15: 0000000000000001 [ 66.848728][ C0] ? acpi_safe_halt+0x90/0x180 [ 66.853486][ C0] acpi_safe_halt+0x95/0x180 [ 66.858061][ C0] acpi_idle_do_entry+0x15c/0x1b0 [ 66.863074][ C0] acpi_idle_enter+0x403/0xac0 [ 66.867827][ C0] ? acpi_idle_enter_bm+0x2d0/0x2d0 [ 66.872999][ C0] cpuidle_enter_state+0x150/0xa70 [ 66.878113][ C0] ? tick_nohz_idle_stop_tick+0x5af/0xbc0 [ 66.883803][ C0] cpuidle_enter+0x4a/0xa0 [ 66.888205][ C0] do_idle+0x48e/0x730 [ 66.892248][ C0] ? arch_cpu_idle_exit+0x70/0x70 [ 66.897247][ C0] ? trace_init_perf_perm_irq_work_exit+0xe/0xe [ 66.903472][ C0] cpu_startup_entry+0x14/0x20 [ 66.908210][ C0] start_kernel+0x490/0x4b1 [ 66.912719][ C0] secondary_startup_64_no_verify+0xa6/0xab [ 66.918580][ C0] Modules linked in: [ 66.922472][ C0] ---[ end trace 90459c86a7435b5b ]--- [ 66.927908][ C0] RIP: 0010:print_shortest_lock_dependencies.cold+0x110/0x2af [ 66.935335][ C0] 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 [ 66.954909][ C0] RSP: 0018:ffffc90000007898 EFLAGS: 00010003 [ 66.960965][ C0] RAX: 0000000000000001 RBX: ffffffff8cbdd4a0 RCX: 0000000000000000 [ 66.968925][ C0] RDX: 0000000000000002 RSI: ffffffff815c0ec7 RDI: 0000000000000015 [ 66.976882][ C0] RBP: ffffc900000079c8 R08: 0000000000000004 R09: ffff8880ae620f8b [ 66.984827][ C0] R10: 0000000000000000 R11: 6c756e2820202020 R12: dffffc0000000000 [ 66.992772][ C0] R13: ffffffff8c9e7340 R14: 0000000000000009 R15: 0000000000000001 [ 67.000721][ C0] FS: 0000000000000000(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 [ 67.009624][ C0] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 67.016180][ C0] CR2: 000000000043e740 CR3: 0000000092f76000 CR4: 00000000001506f0 [ 67.024406][ C0] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 67.032368][ C0] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 67.040327][ C0] Kernel panic - not syncing: Fatal exception in interrupt [ 67.049116][ C0] Kernel Offset: disabled [ 67.053434][ C0] Rebooting in 86400 seconds..