[ 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 '10.128.0.68' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 60.196670][ C0] [ 60.199029][ C0] ======================================================== [ 60.206197][ C0] WARNING: possible irq lock inversion dependency detected [ 60.213365][ C0] 5.9.0-rc4-next-20200908-syzkaller #0 Not tainted [ 60.219853][ C0] -------------------------------------------------------- [ 60.227023][ C0] swapper/0/0 just changed the state of lock: [ 60.233076][ C0] ffff888214ce5908 (&group->lock){..-.}-{2:2}, at: _snd_pcm_stream_lock_irqsave+0x9f/0xd0 [ 60.242960][ C0] but this lock took another, SOFTIRQ-READ-unsafe lock in the past: [ 60.250915][ C0] (&card->ctl_files_rwlock){.+.+}-{2:2} [ 60.250928][ C0] [ 60.250928][ C0] [ 60.250928][ C0] and interrupts could create inverse lock ordering between them. [ 60.250928][ C0] [ 60.270814][ C0] [ 60.270814][ C0] other info that might help us debug this: [ 60.278959][ C0] Possible interrupt unsafe locking scenario: [ 60.278959][ C0] [ 60.287255][ C0] CPU0 CPU1 [ 60.292594][ C0] ---- ---- [ 60.297933][ C0] lock(&card->ctl_files_rwlock); [ 60.303020][ C0] local_irq_disable(); [ 60.309746][ C0] lock(&group->lock); [ 60.316394][ C0] lock(&card->ctl_files_rwlock); [ 60.324066][ C0] [ 60.327497][ C0] lock(&group->lock); [ 60.331819][ C0] [ 60.331819][ C0] *** DEADLOCK *** [ 60.331819][ C0] [ 60.339939][ C0] 1 lock held by swapper/0/0: [ 60.344583][ C0] #0: ffffc90000007d68 ((&dpcm->timer)){+.-.}-{0:0}, at: call_timer_fn+0xdb/0x760 [ 60.353855][ C0] [ 60.353855][ C0] the shortest dependencies between 2nd lock and 1st lock: [ 60.363316][ C0] -> (&card->ctl_files_rwlock){.+.+}-{2:2} { [ 60.369374][ C0] HARDIRQ-ON-R at: [ 60.373429][ C0] lock_acquire+0x1f3/0xaf0 [ 60.379735][ C0] _raw_read_lock+0x5b/0x70 [ 60.386036][ C0] snd_ctl_notify.part.0+0x36/0x550 [ 60.393031][ C0] snd_ctl_notify+0x8f/0xb0 [ 60.399330][ C0] __snd_ctl_add_replace+0x638/0x800 [ 60.406408][ C0] snd_ctl_add_replace+0x76/0x130 [ 60.413231][ C0] snd_dummy_probe+0xbbf/0x1050 [ 60.419880][ C0] platform_drv_probe+0x87/0x140 [ 60.426609][ C0] really_probe+0x282/0x9f0 [ 60.432961][ C0] driver_probe_device+0xfe/0x1d0 [ 60.439795][ C0] __device_attach_driver+0x1c2/0x220 [ 60.446972][ C0] bus_for_each_drv+0x15f/0x1e0 [ 60.453614][ C0] __device_attach+0x228/0x470 [ 60.460171][ C0] bus_probe_device+0x1e4/0x290 [ 60.466815][ C0] device_add+0xb17/0x1c40 [ 60.473023][ C0] platform_device_add+0x34f/0x6d0 [ 60.479929][ C0] platform_device_register_full+0x38c/0x4e0 [ 60.487705][ C0] alsa_card_dummy_init+0x1cc/0x2e0 [ 60.494717][ C0] do_one_initcall+0x10a/0x7b0 [ 60.501363][ C0] kernel_init_freeable+0x5e9/0x66d [ 60.508357][ C0] kernel_init+0xd/0x1c0 [ 60.514409][ C0] ret_from_fork+0x1f/0x30 [ 60.520615][ C0] SOFTIRQ-ON-R at: [ 60.524661][ C0] lock_acquire+0x1f3/0xaf0 [ 60.530973][ C0] _raw_read_lock+0x5b/0x70 [ 60.537283][ C0] snd_ctl_notify.part.0+0x36/0x550 [ 60.544323][ C0] snd_ctl_notify+0x8f/0xb0 [ 60.550625][ C0] __snd_ctl_add_replace+0x638/0x800 [ 60.557707][ C0] snd_ctl_add_replace+0x76/0x130 [ 60.564528][ C0] snd_dummy_probe+0xbbf/0x1050 [ 60.571196][ C0] platform_drv_probe+0x87/0x140 [ 60.577928][ C0] really_probe+0x282/0x9f0 [ 60.584240][ C0] driver_probe_device+0xfe/0x1d0 [ 60.591074][ C0] __device_attach_driver+0x1c2/0x220 [ 60.598239][ C0] bus_for_each_drv+0x15f/0x1e0 [ 60.604881][ C0] __device_attach+0x228/0x470 [ 60.611565][ C0] bus_probe_device+0x1e4/0x290 [ 60.618230][ C0] device_add+0xb17/0x1c40 [ 60.624452][ C0] platform_device_add+0x34f/0x6d0 [ 60.631356][ C0] platform_device_register_full+0x38c/0x4e0 [ 60.639132][ C0] alsa_card_dummy_init+0x1cc/0x2e0 [ 60.646126][ C0] do_one_initcall+0x10a/0x7b0 [ 60.652684][ C0] kernel_init_freeable+0x5e9/0x66d [ 60.659678][ C0] kernel_init+0xd/0x1c0 [ 60.665716][ C0] ret_from_fork+0x1f/0x30 [ 60.671923][ C0] (null) at: [ 60.675462][ C0] general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN [ 60.687151][ C0] KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] [ 60.695558][ C0] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.9.0-rc4-next-20200908-syzkaller #0 [ 60.704636][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 60.714695][ C0] RIP: 0010:print_shortest_lock_dependencies.cold+0x110/0x2af [ 60.722131][ C0] Code: 48 8b 04 24 48 c1 e8 03 42 80 3c 20 00 74 09 48 8b 3c 24 e8 dd fb de 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 [ 60.741795][ C0] RSP: 0018:ffffc90000007870 EFLAGS: 00010003 [ 60.747855][ C0] RAX: 0000000000000001 RBX: ffffffff8c8d45f0 RCX: 0000000000000000 [ 60.755810][ C0] RDX: 0000000000000002 RSI: ffffffff815bc817 RDI: 0000000000000015 [ 60.763768][ C0] RBP: ffffc900000079a0 R08: 0000000000000004 R09: ffff8880ae620f8b [ 60.771727][ C0] R10: 0000000000000000 R11: 6c756e2820202020 R12: dffffc0000000000 [ 60.779675][ C0] R13: ffffffff8c6de3f8 R14: 0000000000000009 R15: 0000000000000001 [ 60.787644][ C0] FS: 0000000000000000(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 [ 60.796591][ C0] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 60.803162][ C0] CR2: 0000000020000dc0 CR3: 0000000092ca9000 CR4: 00000000001506f0 [ 60.811107][ C0] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 60.819069][ C0] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 60.827067][ C0] Call Trace: [ 60.830321][ C0] [ 60.833153][ C0] print_irq_inversion_bug.part.0+0x2c6/0x2ee [ 60.839208][ C0] mark_lock.cold+0x38/0x10d [ 60.843774][ C0] ? lock_chain_count+0x20/0x20 [ 60.848595][ C0] ? lock_is_held_type+0xbb/0xf0 [ 60.853502][ C0] ? find_held_lock+0x2d/0x110 [ 60.858239][ C0] ? debug_object_activate+0x287/0x3e0 [ 60.863674][ C0] ? lock_downgrade+0x830/0x830 [ 60.868498][ C0] __lock_acquire+0x117d/0x55d0 [ 60.873335][ C0] ? __round_jiffies_relative+0x62/0xf0 [ 60.878871][ C0] ? lock_downgrade+0x830/0x830 [ 60.883699][ C0] ? lockdep_hardirqs_on_prepare+0x530/0x530 [ 60.889751][ C0] ? mark_lock+0xf7/0x2300 [ 60.894138][ C0] lock_acquire+0x1f3/0xaf0 [ 60.898619][ C0] ? _snd_pcm_stream_lock_irqsave+0x9f/0xd0 [ 60.904483][ C0] ? lock_release+0x8f0/0x8f0 [ 60.909130][ C0] ? find_held_lock+0x2d/0x110 [ 60.913869][ C0] ? loopback_jiffies_timer_function+0x188/0x220 [ 60.920201][ C0] ? _raw_spin_lock_irqsave+0xa9/0xd0 [ 60.925544][ C0] ? lockdep_hardirqs_off+0x96/0xd0 [ 60.930728][ C0] _raw_spin_lock_irqsave+0x94/0xd0 [ 60.935900][ C0] ? _snd_pcm_stream_lock_irqsave+0x9f/0xd0 [ 60.941791][ C0] _snd_pcm_stream_lock_irqsave+0x9f/0xd0 [ 60.947481][ C0] snd_pcm_period_elapsed+0x24/0x250 [ 60.952754][ C0] loopback_jiffies_timer_function+0x1a8/0x220 [ 60.958893][ C0] call_timer_fn+0x1ac/0x760 [ 60.963460][ C0] ? loopback_jiffies_timer_pos_update+0xf60/0xf60 [ 60.969943][ C0] ? msleep_interruptible+0x130/0x130 [ 60.975288][ C0] ? lock_downgrade+0x830/0x830 [ 60.980119][ C0] ? _raw_spin_unlock_irq+0x1f/0x80 [ 60.985287][ C0] ? lockdep_hardirqs_on_prepare+0x19c/0x530 [ 60.991238][ C0] ? _raw_spin_unlock_irq+0x1f/0x80 [ 60.996414][ C0] ? loopback_jiffies_timer_pos_update+0xf60/0xf60 [ 61.002887][ C0] __run_timers.part.0+0x67c/0xaa0 [ 61.007971][ C0] ? call_timer_fn+0x760/0x760 [ 61.012706][ C0] ? clockevents_program_event+0x12b/0x350 [ 61.018485][ C0] ? kvm_sched_clock_read+0x14/0x40 [ 61.023655][ C0] ? sched_clock+0x2a/0x40 [ 61.028043][ C0] ? sched_clock_cpu+0x18/0x1b0 [ 61.032880][ C0] run_timer_softirq+0xae/0x1a0 [ 61.037705][ C0] __do_softirq+0x1f7/0xa91 [ 61.042196][ C0] asm_call_on_stack+0xf/0x20 [ 61.046840][ C0] [ 61.049753][ C0] do_softirq_own_stack+0x9d/0xd0 [ 61.054768][ C0] irq_exit_rcu+0x235/0x280 [ 61.059245][ C0] sysvec_apic_timer_interrupt+0x51/0xf0 [ 61.064906][ C0] asm_sysvec_apic_timer_interrupt+0x12/0x20 [ 61.070866][ C0] RIP: 0010:native_safe_halt+0xe/0x10 [ 61.076232][ C0] Code: ff 4c 89 ef e8 23 c4 b4 f9 e9 8e fe ff ff 48 89 df e8 16 c4 b4 f9 eb 8a cc cc cc cc e9 07 00 00 00 0f 00 2d 94 f6 4a 00 fb f4 90 e9 07 00 00 00 0f 00 2d 84 f6 4a 00 f4 c3 cc cc 55 53 e8 e9 [ 61.095837][ C0] RSP: 0018:ffffffff89a07cd8 EFLAGS: 00000293 [ 61.102143][ C0] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 1ffffffff15796a9 [ 61.110087][ C0] RDX: ffffffff89a99dc0 RSI: ffffffff87fdd050 RDI: 0000000000000000 [ 61.118030][ C0] RBP: ffff88821a8b1064 R08: 0000000000000001 R09: 0000000000000001 [ 61.125975][ C0] R10: 0000000000000000 R11: 0000000000000001 R12: ffff88821a8b1064 [ 61.133919][ C0] R13: 1ffffffff1340fa5 R14: ffff88821a8b1065 R15: 0000000000000001 [ 61.141885][ C0] ? acpi_safe_halt+0x90/0x180 [ 61.146622][ C0] acpi_safe_halt+0x95/0x180 [ 61.151184][ C0] acpi_idle_do_entry+0x15c/0x1b0 [ 61.156193][ C0] acpi_idle_enter+0x403/0xac0 [ 61.160943][ C0] ? acpi_idle_enter_bm+0x2d0/0x2d0 [ 61.166116][ C0] cpuidle_enter_state+0x150/0xa70 [ 61.171200][ C0] ? tick_nohz_idle_stop_tick+0x5af/0xc40 [ 61.176908][ C0] cpuidle_enter+0x4a/0xa0 [ 61.181303][ C0] do_idle+0x48e/0x730 [ 61.185345][ C0] ? arch_cpu_idle_exit+0x70/0x70 [ 61.190342][ C0] ? trace_init_perf_perm_irq_work_exit+0xe/0xe [ 61.196555][ C0] cpu_startup_entry+0x14/0x20 [ 61.201307][ C0] start_kernel+0x490/0x4b1 [ 61.205798][ C0] secondary_startup_64+0xa4/0xb0 [ 61.210790][ C0] Modules linked in: [ 61.214682][ C0] ---[ end trace e523641381143770 ]--- [ 61.220132][ C0] RIP: 0010:print_shortest_lock_dependencies.cold+0x110/0x2af [ 61.227559][ C0] Code: 48 8b 04 24 48 c1 e8 03 42 80 3c 20 00 74 09 48 8b 3c 24 e8 dd fb de 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 [ 61.247144][ C0] RSP: 0018:ffffc90000007870 EFLAGS: 00010003 [ 61.253188][ C0] RAX: 0000000000000001 RBX: ffffffff8c8d45f0 RCX: 0000000000000000 [ 61.261138][ C0] RDX: 0000000000000002 RSI: ffffffff815bc817 RDI: 0000000000000015 [ 61.269102][ C0] RBP: ffffc900000079a0 R08: 0000000000000004 R09: ffff8880ae620f8b [ 61.277050][ C0] R10: 0000000000000000 R11: 6c756e2820202020 R12: dffffc0000000000 [ 61.284995][ C0] R13: ffffffff8c6de3f8 R14: 0000000000000009 R15: 0000000000000001 [ 61.292956][ C0] FS: 0000000000000000(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 [ 61.301858][ C0] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 61.308415][ C0] CR2: 0000000020000dc0 CR3: 0000000092ca9000 CR4: 00000000001506f0 [ 61.316379][ C0] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 61.324338][ C0] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 61.332281][ C0] Kernel panic - not syncing: Fatal exception in interrupt [ 61.340910][ C0] Kernel Offset: disabled [ 61.345242][ C0] Rebooting in 86400 seconds..