[ 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 '10.128.0.254' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 66.357840][ C0] [ 66.360291][ C0] ======================================================== [ 66.367528][ C0] WARNING: possible irq lock inversion dependency detected [ 66.374697][ C0] 5.9.0-rc4-next-20200911-syzkaller #0 Not tainted [ 66.381161][ C0] -------------------------------------------------------- [ 66.388326][ C0] swapper/0/0 just changed the state of lock: [ 66.394362][ C0] ffff888099f7a108 (&group->lock){..-.}-{2:2}, at: _snd_pcm_stream_lock_irqsave+0x9f/0xd0 [ 66.404247][ C0] but this lock took another, SOFTIRQ-READ-unsafe lock in the past: [ 66.412194][ C0] (&card->ctl_files_rwlock){.+.+}-{2:2} [ 66.412211][ C0] [ 66.412211][ C0] [ 66.412211][ C0] and interrupts could create inverse lock ordering between them. [ 66.412211][ C0] [ 66.432101][ C0] [ 66.432101][ C0] other info that might help us debug this: [ 66.440153][ C0] Possible interrupt unsafe locking scenario: [ 66.440153][ C0] [ 66.449398][ C0] CPU0 CPU1 [ 66.454735][ C0] ---- ---- [ 66.460081][ C0] lock(&card->ctl_files_rwlock); [ 66.465174][ C0] local_irq_disable(); [ 66.471907][ C0] lock(&group->lock); [ 66.478567][ C0] lock(&card->ctl_files_rwlock); [ 66.486176][ C0] [ 66.489602][ C0] lock(&group->lock); [ 66.493913][ C0] [ 66.493913][ C0] *** DEADLOCK *** [ 66.493913][ C0] [ 66.502029][ C0] 1 lock held by swapper/0/0: [ 66.506679][ C0] #0: ffffc90000007d80 ((&dpcm->timer)){+.-.}-{0:0}, at: call_timer_fn+0xd5/0x6b0 [ 66.516052][ C0] [ 66.516052][ C0] the shortest dependencies between 2nd lock and 1st lock: [ 66.525405][ C0] -> (&card->ctl_files_rwlock){.+.+}-{2:2} { [ 66.531464][ C0] HARDIRQ-ON-R at: [ 66.535514][ C0] lock_acquire+0x1f2/0xaa0 [ 66.541827][ C0] _raw_read_lock+0x5b/0x70 [ 66.548134][ C0] snd_ctl_notify.part.0+0x36/0x550 [ 66.555131][ C0] snd_ctl_notify+0x8f/0xb0 [ 66.561436][ C0] __snd_ctl_add_replace+0x638/0x800 [ 66.568523][ C0] snd_ctl_add_replace+0x76/0x130 [ 66.575347][ C0] snd_dummy_probe+0xbbf/0x1050 [ 66.581995][ C0] platform_drv_probe+0x87/0x140 [ 66.588744][ C0] really_probe+0x282/0x9f0 [ 66.595058][ C0] driver_probe_device+0xfe/0x1d0 [ 66.601879][ C0] __device_attach_driver+0x1c2/0x220 [ 66.609062][ C0] bus_for_each_drv+0x15f/0x1e0 [ 66.615713][ C0] __device_attach+0x228/0x470 [ 66.622289][ C0] bus_probe_device+0x1e4/0x290 [ 66.628942][ C0] device_add+0xb17/0x1c40 [ 66.635187][ C0] platform_device_add+0x34f/0x6d0 [ 66.642121][ C0] platform_device_register_full+0x38c/0x4e0 [ 66.649921][ C0] alsa_card_dummy_init+0x1cc/0x2e0 [ 66.656927][ C0] do_one_initcall+0x103/0x6f0 [ 66.663497][ C0] kernel_init_freeable+0x5e9/0x66d [ 66.670498][ C0] kernel_init+0xd/0x1c0 [ 66.676539][ C0] ret_from_fork+0x1f/0x30 [ 66.682746][ C0] SOFTIRQ-ON-R at: [ 66.686814][ C0] lock_acquire+0x1f2/0xaa0 [ 66.693131][ C0] _raw_read_lock+0x5b/0x70 [ 66.699452][ C0] snd_ctl_notify.part.0+0x36/0x550 [ 66.706447][ C0] snd_ctl_notify+0x8f/0xb0 [ 66.713636][ C0] __snd_ctl_add_replace+0x638/0x800 [ 66.720724][ C0] snd_ctl_add_replace+0x76/0x130 [ 66.727578][ C0] snd_dummy_probe+0xbbf/0x1050 [ 66.734246][ C0] platform_drv_probe+0x87/0x140 [ 66.740986][ C0] really_probe+0x282/0x9f0 [ 66.747729][ C0] driver_probe_device+0xfe/0x1d0 [ 66.754554][ C0] __device_attach_driver+0x1c2/0x220 [ 66.761736][ C0] bus_for_each_drv+0x15f/0x1e0 [ 66.768399][ C0] __device_attach+0x228/0x470 [ 66.774967][ C0] bus_probe_device+0x1e4/0x290 [ 66.781626][ C0] device_add+0xb17/0x1c40 [ 66.787841][ C0] platform_device_add+0x34f/0x6d0 [ 66.794757][ C0] platform_device_register_full+0x38c/0x4e0 [ 66.802544][ C0] alsa_card_dummy_init+0x1cc/0x2e0 [ 66.809538][ C0] do_one_initcall+0x103/0x6f0 [ 66.816100][ C0] kernel_init_freeable+0x5e9/0x66d [ 66.823110][ C0] kernel_init+0xd/0x1c0 [ 66.829153][ C0] ret_from_fork+0x1f/0x30 [ 66.835375][ C0] (null) at: [ 66.838918][ C0] general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN [ 66.850599][ C0] KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] [ 66.858985][ C0] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.9.0-rc4-next-20200911-syzkaller #0 [ 66.868062][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 66.878142][ C0] RIP: 0010:print_shortest_lock_dependencies.cold+0x110/0x2af [ 66.885591][ 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 [ 66.905185][ C0] RSP: 0018:ffffc90000007898 EFLAGS: 00010003 [ 66.911245][ C0] RAX: 0000000000000001 RBX: ffffffff8cbde770 RCX: 0000000000000000 [ 66.919204][ C0] RDX: 0000000000000002 RSI: ffffffff815c0ec7 RDI: 0000000000000015 [ 66.927161][ C0] RBP: ffffc900000079c8 R08: 0000000000000004 R09: ffff8880ae620f8b [ 66.935117][ C0] R10: 0000000000000000 R11: 6c756e2820202020 R12: dffffc0000000000 [ 66.943067][ C0] R13: ffffffff8c9e74b0 R14: 0000000000000009 R15: 0000000000000001 [ 66.951100][ C0] FS: 0000000000000000(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 [ 66.960121][ C0] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 66.966679][ C0] CR2: 0000000020000000 CR3: 000000009291a000 CR4: 00000000001506f0 [ 66.974647][ C0] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 66.982599][ C0] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 66.990557][ C0] Call Trace: [ 66.993817][ C0] [ 66.996673][ C0] print_irq_inversion_bug.part.0+0x2c6/0x2ee [ 67.002726][ C0] mark_lock.cold+0x38/0x10d [ 67.007293][ C0] ? lock_chain_count+0x20/0x20 [ 67.012117][ C0] ? lock_is_held_type+0xbb/0xf0 [ 67.017039][ C0] ? find_held_lock+0x2d/0x110 [ 67.021787][ C0] ? debug_object_activate+0x287/0x3e0 [ 67.027240][ C0] ? lock_downgrade+0x830/0x830 [ 67.032080][ C0] __lock_acquire+0x117d/0x55d0 [ 67.036907][ C0] ? lock_downgrade+0x830/0x830 [ 67.041731][ C0] ? lockdep_hardirqs_on_prepare+0x530/0x530 [ 67.047685][ C0] ? mark_lock+0xf7/0x2300 [ 67.052079][ C0] lock_acquire+0x1f2/0xaa0 [ 67.056579][ C0] ? _snd_pcm_stream_lock_irqsave+0x9f/0xd0 [ 67.062637][ C0] ? lock_release+0x890/0x890 [ 67.067310][ C0] ? find_held_lock+0x2d/0x110 [ 67.072062][ C0] ? loopback_jiffies_timer_function+0x188/0x220 [ 67.078365][ C0] ? _raw_spin_lock_irqsave+0xa9/0xd0 [ 67.083711][ C0] _raw_spin_lock_irqsave+0x94/0xd0 [ 67.088931][ C0] ? _snd_pcm_stream_lock_irqsave+0x9f/0xd0 [ 67.094809][ C0] _snd_pcm_stream_lock_irqsave+0x9f/0xd0 [ 67.100515][ C0] snd_pcm_period_elapsed+0x24/0x250 [ 67.105800][ C0] loopback_jiffies_timer_function+0x1a8/0x220 [ 67.111930][ C0] ? loopback_jiffies_timer_pos_update+0xf60/0xf60 [ 67.118409][ C0] call_timer_fn+0x1a5/0x6b0 [ 67.123012][ C0] ? add_timer_on+0x450/0x450 [ 67.127666][ C0] ? lock_downgrade+0x830/0x830 [ 67.132491][ C0] ? _raw_spin_unlock_irq+0x1f/0x80 [ 67.137699][ C0] ? loopback_jiffies_timer_pos_update+0xf60/0xf60 [ 67.144184][ C0] __run_timers.part.0+0x67c/0xa50 [ 67.149277][ C0] ? call_timer_fn+0x6b0/0x6b0 [ 67.154016][ C0] ? lapic_next_event+0x4d/0x80 [ 67.158843][ C0] ? clockevents_program_event+0x12b/0x350 [ 67.164624][ C0] ? kvm_sched_clock_read+0x14/0x40 [ 67.169814][ C0] ? sched_clock+0x2a/0x40 [ 67.174220][ C0] ? sched_clock_cpu+0x18/0x1b0 [ 67.179046][ C0] ? hrtimer_interrupt+0x6ea/0x930 [ 67.184140][ C0] run_timer_softirq+0xae/0x1a0 [ 67.188968][ C0] __do_softirq+0x202/0xa42 [ 67.193445][ C0] asm_call_on_stack+0xf/0x20 [ 67.198097][ C0] [ 67.201021][ C0] do_softirq_own_stack+0x9d/0xd0 [ 67.206015][ C0] irq_exit_rcu+0x235/0x280 [ 67.210492][ C0] sysvec_apic_timer_interrupt+0x51/0xf0 [ 67.216109][ C0] asm_sysvec_apic_timer_interrupt+0x12/0x20 [ 67.222075][ C0] RIP: 0010:native_safe_halt+0xe/0x10 [ 67.227432][ 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 [ 67.247015][ C0] RSP: 0018:ffffffff89c07cd8 EFLAGS: 00000293 [ 67.253063][ C0] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 1ffffffff15cacb9 [ 67.261010][ C0] RDX: ffffffff89c9b040 RSI: ffffffff88034020 RDI: 0000000000000000 [ 67.268954][ C0] RBP: ffff8880a624f864 R08: 0000000000000001 R09: 0000000000000001 [ 67.276908][ C0] R10: 0000000000000000 R11: 0000000000000001 R12: ffff8880a624f864 [ 67.284891][ C0] R13: 1ffffffff1380fa5 R14: ffff8880a624f865 R15: 0000000000000001 [ 67.292852][ C0] ? acpi_safe_halt+0x90/0x180 [ 67.297596][ C0] acpi_safe_halt+0x95/0x180 [ 67.302193][ C0] acpi_idle_do_entry+0x15c/0x1b0 [ 67.307198][ C0] acpi_idle_enter+0x403/0xac0 [ 67.311944][ C0] ? acpi_idle_enter_bm+0x2d0/0x2d0 [ 67.317128][ C0] cpuidle_enter_state+0x150/0xa70 [ 67.322322][ C0] ? tick_nohz_idle_stop_tick+0x5af/0xbc0 [ 67.328014][ C0] cpuidle_enter+0x4a/0xa0 [ 67.332415][ C0] do_idle+0x48e/0x730 [ 67.336467][ C0] ? arch_cpu_idle_exit+0x70/0x70 [ 67.341480][ C0] ? trace_init_perf_perm_irq_work_exit+0xe/0xe [ 67.347699][ C0] cpu_startup_entry+0x14/0x20 [ 67.352443][ C0] start_kernel+0x490/0x4b1 [ 67.356937][ C0] secondary_startup_64_no_verify+0xa6/0xab [ 67.362804][ C0] Modules linked in: [ 67.367226][ C0] ---[ end trace 46ad62b3206abb61 ]--- [ 67.372673][ C0] RIP: 0010:print_shortest_lock_dependencies.cold+0x110/0x2af [ 67.380107][ 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 [ 67.399790][ C0] RSP: 0018:ffffc90000007898 EFLAGS: 00010003 [ 67.405845][ C0] RAX: 0000000000000001 RBX: ffffffff8cbde770 RCX: 0000000000000000 [ 67.415012][ C0] RDX: 0000000000000002 RSI: ffffffff815c0ec7 RDI: 0000000000000015 [ 67.422960][ C0] RBP: ffffc900000079c8 R08: 0000000000000004 R09: ffff8880ae620f8b [ 67.430911][ C0] R10: 0000000000000000 R11: 6c756e2820202020 R12: dffffc0000000000 [ 67.438873][ C0] R13: ffffffff8c9e74b0 R14: 0000000000000009 R15: 0000000000000001 [ 67.446820][ C0] FS: 0000000000000000(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 [ 67.455726][ C0] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 67.462302][ C0] CR2: 0000000020000000 CR3: 000000009291a000 CR4: 00000000001506f0 [ 67.470255][ C0] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 67.478200][ C0] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 67.486144][ C0] Kernel panic - not syncing: Fatal exception in interrupt [ 67.494404][ C0] Kernel Offset: disabled [ 67.498721][ C0] Rebooting in 86400 seconds..