[ OK ] Started Getty on tty1. [ OK ] Started Getty on tty2. [ OK ] Started Getty on tty5. [ OK ] Started Getty on tty4. [ OK ] Started Getty on tty3. [ 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 '10.128.0.116' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 65.079421][ C1] [ 65.081866][ C1] ======================================================== [ 65.089043][ C1] WARNING: possible irq lock inversion dependency detected [ 65.096214][ C1] 5.9.0-rc4-next-20200911-syzkaller #0 Not tainted [ 65.102714][ C1] -------------------------------------------------------- [ 65.109888][ C1] swapper/1/0 just changed the state of lock: [ 65.115933][ C1] ffff8882153c3108 (&group->lock){..-.}-{2:2}, at: _snd_pcm_stream_lock_irqsave+0x9f/0xd0 [ 65.125809][ C1] but this lock took another, SOFTIRQ-READ-unsafe lock in the past: [ 65.134715][ C1] (&card->ctl_files_rwlock){.+.+}-{2:2} [ 65.134727][ C1] [ 65.134727][ C1] [ 65.134727][ C1] and interrupts could create inverse lock ordering between them. [ 65.134727][ C1] [ 65.155209][ C1] [ 65.155209][ C1] other info that might help us debug this: [ 65.163246][ C1] Possible interrupt unsafe locking scenario: [ 65.163246][ C1] [ 65.171535][ C1] CPU0 CPU1 [ 65.176872][ C1] ---- ---- [ 65.182208][ C1] lock(&card->ctl_files_rwlock); [ 65.187312][ C1] local_irq_disable(); [ 65.194324][ C1] lock(&group->lock); [ 65.200966][ C1] lock(&card->ctl_files_rwlock); [ 65.208563][ C1] [ 65.211987][ C1] lock(&group->lock); [ 65.216312][ C1] [ 65.216312][ C1] *** DEADLOCK *** [ 65.216312][ C1] [ 65.224437][ C1] 1 lock held by swapper/1/0: [ 65.229088][ C1] #0: ffffc90000da8d80 ((&dpcm->timer)){+.-.}-{0:0}, at: call_timer_fn+0xd5/0x6b0 [ 65.238353][ C1] [ 65.238353][ C1] the shortest dependencies between 2nd lock and 1st lock: [ 65.247697][ C1] -> (&card->ctl_files_rwlock){.+.+}-{2:2} { [ 65.253748][ C1] HARDIRQ-ON-R at: [ 65.257792][ C1] lock_acquire+0x1f2/0xaa0 [ 65.264099][ C1] _raw_read_lock+0x5b/0x70 [ 65.271002][ C1] snd_ctl_notify.part.0+0x36/0x550 [ 65.278002][ C1] snd_ctl_notify+0x8f/0xb0 [ 65.284317][ C1] __snd_ctl_add_replace+0x638/0x800 [ 65.291393][ C1] snd_ctl_add_replace+0x76/0x130 [ 65.298212][ C1] snd_dummy_probe+0xbbf/0x1050 [ 65.304869][ C1] platform_drv_probe+0x87/0x140 [ 65.311596][ C1] really_probe+0x282/0x9f0 [ 65.317912][ C1] driver_probe_device+0xfe/0x1d0 [ 65.324739][ C1] __device_attach_driver+0x1c2/0x220 [ 65.331901][ C1] bus_for_each_drv+0x15f/0x1e0 [ 65.338543][ C1] __device_attach+0x228/0x470 [ 65.345098][ C1] bus_probe_device+0x1e4/0x290 [ 65.351738][ C1] device_add+0xb17/0x1c40 [ 65.357946][ C1] platform_device_add+0x34f/0x6d0 [ 65.364853][ C1] platform_device_register_full+0x38c/0x4e0 [ 65.372635][ C1] alsa_card_dummy_init+0x1cc/0x2e0 [ 65.379628][ C1] do_one_initcall+0x103/0x6f0 [ 65.386187][ C1] kernel_init_freeable+0x5e9/0x66d [ 65.393175][ C1] kernel_init+0xd/0x1c0 [ 65.399211][ C1] ret_from_fork+0x1f/0x30 [ 65.405414][ C1] SOFTIRQ-ON-R at: [ 65.409462][ C1] lock_acquire+0x1f2/0xaa0 [ 65.415760][ C1] _raw_read_lock+0x5b/0x70 [ 65.422063][ C1] snd_ctl_notify.part.0+0x36/0x550 [ 65.429054][ C1] snd_ctl_notify+0x8f/0xb0 [ 65.435372][ C1] __snd_ctl_add_replace+0x638/0x800 [ 65.442460][ C1] snd_ctl_add_replace+0x76/0x130 [ 65.449279][ C1] snd_dummy_probe+0xbbf/0x1050 [ 65.455925][ C1] platform_drv_probe+0x87/0x140 [ 65.462664][ C1] really_probe+0x282/0x9f0 [ 65.468961][ C1] driver_probe_device+0xfe/0x1d0 [ 65.475779][ C1] __device_attach_driver+0x1c2/0x220 [ 65.482954][ C1] bus_for_each_drv+0x15f/0x1e0 [ 65.489624][ C1] __device_attach+0x228/0x470 [ 65.496211][ C1] bus_probe_device+0x1e4/0x290 [ 65.502865][ C1] device_add+0xb17/0x1c40 [ 65.509088][ C1] platform_device_add+0x34f/0x6d0 [ 65.515992][ C1] platform_device_register_full+0x38c/0x4e0 [ 65.523765][ C1] alsa_card_dummy_init+0x1cc/0x2e0 [ 65.530758][ C1] do_one_initcall+0x103/0x6f0 [ 65.537401][ C1] kernel_init_freeable+0x5e9/0x66d [ 65.544418][ C1] kernel_init+0xd/0x1c0 [ 65.550464][ C1] ret_from_fork+0x1f/0x30 [ 65.556668][ C1] (null) at: [ 65.561176][ C1] general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN [ 65.572854][ C1] KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] [ 65.581233][ C1] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.9.0-rc4-next-20200911-syzkaller #0 [ 65.590305][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 65.600340][ C1] RIP: 0010:print_shortest_lock_dependencies.cold+0x110/0x2af [ 65.607765][ 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 [ 65.627347][ C1] RSP: 0018:ffffc90000da8898 EFLAGS: 00010003 [ 65.633384][ C1] RAX: 0000000000000001 RBX: ffffffff8cbdd970 RCX: 0000000000000000 [ 65.641360][ C1] RDX: 0000000000000002 RSI: ffffffff815c0ec7 RDI: 0000000000000015 [ 65.649326][ C1] RBP: ffffc90000da89c8 R08: 0000000000000004 R09: ffff8880ae720f8b [ 65.657285][ C1] R10: 0000000000000000 R11: 6c756e2820202020 R12: dffffc0000000000 [ 65.665239][ C1] R13: ffffffff8c9e74b0 R14: 0000000000000009 R15: 0000000000000001 [ 65.673193][ C1] FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 [ 65.682090][ C1] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 65.688662][ C1] CR2: 0000000020000dc0 CR3: 0000000009c8e000 CR4: 00000000001506e0 [ 65.696627][ C1] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 65.704583][ C1] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 65.712524][ C1] Call Trace: [ 65.715780][ C1] [ 65.718612][ C1] print_irq_inversion_bug.part.0+0x2c6/0x2ee [ 65.725520][ C1] mark_lock.cold+0x38/0x10d [ 65.730094][ C1] ? lock_chain_count+0x20/0x20 [ 65.734934][ C1] ? lock_is_held_type+0xbb/0xf0 [ 65.739841][ C1] ? find_held_lock+0x2d/0x110 [ 65.744577][ C1] ? debug_object_activate+0x287/0x3e0 [ 65.750026][ C1] ? lock_downgrade+0x830/0x830 [ 65.754858][ C1] __lock_acquire+0x117d/0x55d0 [ 65.759682][ C1] ? lock_downgrade+0x830/0x830 [ 65.764512][ C1] ? lockdep_hardirqs_on_prepare+0x530/0x530 [ 65.770466][ C1] ? mark_lock+0xf7/0x2300 [ 65.774854][ C1] lock_acquire+0x1f2/0xaa0 [ 65.779328][ C1] ? _snd_pcm_stream_lock_irqsave+0x9f/0xd0 [ 65.785191][ C1] ? lock_release+0x890/0x890 [ 65.789837][ C1] ? find_held_lock+0x2d/0x110 [ 65.794940][ C1] ? loopback_jiffies_timer_function+0x188/0x220 [ 65.801307][ C1] ? _raw_spin_lock_irqsave+0xa9/0xd0 [ 65.806681][ C1] _raw_spin_lock_irqsave+0x94/0xd0 [ 65.811869][ C1] ? _snd_pcm_stream_lock_irqsave+0x9f/0xd0 [ 65.817751][ C1] _snd_pcm_stream_lock_irqsave+0x9f/0xd0 [ 65.823458][ C1] snd_pcm_period_elapsed+0x24/0x250 [ 65.828726][ C1] loopback_jiffies_timer_function+0x1a8/0x220 [ 65.834886][ C1] ? loopback_jiffies_timer_pos_update+0xf60/0xf60 [ 65.841368][ C1] call_timer_fn+0x1a5/0x6b0 [ 65.845935][ C1] ? add_timer_on+0x450/0x450 [ 65.850586][ C1] ? lock_downgrade+0x830/0x830 [ 65.855431][ C1] ? _raw_spin_unlock_irq+0x1f/0x80 [ 65.860622][ C1] ? loopback_jiffies_timer_pos_update+0xf60/0xf60 [ 65.867103][ C1] __run_timers.part.0+0x67c/0xa50 [ 65.872210][ C1] ? call_timer_fn+0x6b0/0x6b0 [ 65.876961][ C1] ? lapic_next_event+0x4d/0x80 [ 65.881802][ C1] ? clockevents_program_event+0x12b/0x350 [ 65.887586][ C1] ? kvm_sched_clock_read+0x14/0x40 [ 65.892758][ C1] ? sched_clock+0x2a/0x40 [ 65.897147][ C1] ? sched_clock_cpu+0x18/0x1b0 [ 65.901981][ C1] ? hrtimer_interrupt+0x6ea/0x930 [ 65.907074][ C1] run_timer_softirq+0xae/0x1a0 [ 65.911900][ C1] __do_softirq+0x202/0xa42 [ 65.916394][ C1] asm_call_on_stack+0xf/0x20 [ 65.921043][ C1] [ 65.923958][ C1] do_softirq_own_stack+0x9d/0xd0 [ 65.928965][ C1] irq_exit_rcu+0x235/0x280 [ 65.933458][ C1] sysvec_apic_timer_interrupt+0x51/0xf0 [ 65.939080][ C1] asm_sysvec_apic_timer_interrupt+0x12/0x20 [ 65.945038][ C1] RIP: 0010:native_safe_halt+0xe/0x10 [ 65.950388][ 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 [ 65.969978][ C1] RSP: 0018:ffffc90000d3fd10 EFLAGS: 00000293 [ 65.976082][ C1] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 1ffffffff15cacb9 [ 65.984051][ C1] RDX: ffff8880a9630340 RSI: ffffffff88034020 RDI: 0000000000000000 [ 65.992015][ C1] RBP: ffff8880a66d6064 R08: 0000000000000001 R09: 0000000000000001 [ 65.999960][ C1] R10: 0000000000000000 R11: 0000000000000001 R12: ffff8880a66d6064 [ 66.007907][ C1] R13: 1ffff920001a7fac R14: ffff8880a66d6065 R15: 0000000000000001 [ 66.015873][ C1] ? acpi_safe_halt+0x90/0x180 [ 66.020620][ C1] acpi_safe_halt+0x95/0x180 [ 66.025182][ C1] acpi_idle_do_entry+0x15c/0x1b0 [ 66.030191][ C1] acpi_idle_enter+0x403/0xac0 [ 66.034938][ C1] ? acpi_idle_enter_bm+0x2d0/0x2d0 [ 66.040133][ C1] cpuidle_enter_state+0x150/0xa70 [ 66.045218][ C1] ? tick_nohz_idle_stop_tick+0x504/0xbc0 [ 66.051041][ C1] cpuidle_enter+0x4a/0xa0 [ 66.055456][ C1] do_idle+0x48e/0x730 [ 66.059610][ C1] ? arch_cpu_idle_exit+0x70/0x70 [ 66.064615][ C1] ? _raw_write_unlock_irqrestore+0x71/0x90 [ 66.070484][ C1] ? lockdep_hardirqs_on+0x53/0x100 [ 66.075667][ C1] cpu_startup_entry+0x14/0x20 [ 66.080408][ C1] secondary_startup_64_no_verify+0xa6/0xab [ 66.086270][ C1] Modules linked in: [ 66.090168][ C1] ---[ end trace c6202f54691f9401 ]--- [ 66.095611][ C1] RIP: 0010:print_shortest_lock_dependencies.cold+0x110/0x2af [ 66.103036][ 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 [ 66.122622][ C1] RSP: 0018:ffffc90000da8898 EFLAGS: 00010003 [ 66.128658][ C1] RAX: 0000000000000001 RBX: ffffffff8cbdd970 RCX: 0000000000000000 [ 66.136610][ C1] RDX: 0000000000000002 RSI: ffffffff815c0ec7 RDI: 0000000000000015 [ 66.144563][ C1] RBP: ffffc90000da89c8 R08: 0000000000000004 R09: ffff8880ae720f8b [ 66.152592][ C1] R10: 0000000000000000 R11: 6c756e2820202020 R12: dffffc0000000000 [ 66.160536][ C1] R13: ffffffff8c9e74b0 R14: 0000000000000009 R15: 0000000000000001 [ 66.168480][ C1] FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 [ 66.177378][ C1] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 66.183931][ C1] CR2: 0000000020000dc0 CR3: 0000000009c8e000 CR4: 00000000001506e0 [ 66.191876][ C1] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 66.200427][ C1] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 66.208369][ C1] Kernel panic - not syncing: Fatal exception in interrupt [ 66.216750][ C1] Kernel Offset: disabled [ 66.221084][ C1] Rebooting in 86400 seconds..