[ 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 '10.128.0.44' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program syzkaller login: [ 527.338905][ C1] [ 527.341308][ C1] ======================================================== [ 527.348480][ C1] WARNING: possible irq lock inversion dependency detected [ 527.355709][ C1] 5.9.0-rc4-next-20200911-syzkaller #0 Not tainted [ 527.362236][ C1] -------------------------------------------------------- [ 527.369407][ C1] swapper/1/0 just changed the state of lock: [ 527.375449][ C1] ffff888099e7f908 (&group->lock){..-.}-{2:2}, at: _snd_pcm_stream_lock_irqsave+0x9f/0xd0 [ 527.385431][ C1] but this lock took another, SOFTIRQ-READ-unsafe lock in the past: [ 527.393374][ C1] (&card->ctl_files_rwlock){.+.+}-{2:2} [ 527.393385][ C1] [ 527.393385][ C1] [ 527.393385][ C1] and interrupts could create inverse lock ordering between them. [ 527.393385][ C1] [ 527.413261][ C1] [ 527.413261][ C1] other info that might help us debug this: [ 527.421293][ C1] Possible interrupt unsafe locking scenario: [ 527.421293][ C1] [ 527.429640][ C1] CPU0 CPU1 [ 527.434979][ C1] ---- ---- [ 527.440334][ C1] lock(&card->ctl_files_rwlock); [ 527.445423][ C1] local_irq_disable(); [ 527.452181][ C1] lock(&group->lock); [ 527.458844][ C1] lock(&card->ctl_files_rwlock); [ 527.466445][ C1] [ 527.469870][ C1] lock(&group->lock); [ 527.474172][ C1] [ 527.474172][ C1] *** DEADLOCK *** [ 527.474172][ C1] [ 527.482292][ C1] 1 lock held by swapper/1/0: [ 527.486936][ C1] #0: ffffc90000da8d80 ((&dpcm->timer)){+.-.}-{0:0}, at: call_timer_fn+0xd5/0x6b0 [ 527.496225][ C1] [ 527.496225][ C1] the shortest dependencies between 2nd lock and 1st lock: [ 527.505582][ C1] -> (&card->ctl_files_rwlock){.+.+}-{2:2} { [ 527.511627][ C1] HARDIRQ-ON-R at: [ 527.515678][ C1] lock_acquire+0x1f2/0xaa0 [ 527.522030][ C1] _raw_read_lock+0x5b/0x70 [ 527.528369][ C1] snd_ctl_notify.part.0+0x36/0x550 [ 527.535376][ C1] snd_ctl_notify+0x8f/0xb0 [ 527.541679][ C1] __snd_ctl_add_replace+0x638/0x800 [ 527.548764][ C1] snd_ctl_add_replace+0x76/0x130 [ 527.555650][ C1] snd_dummy_probe+0xbbf/0x1050 [ 527.562360][ C1] platform_drv_probe+0x87/0x140 [ 527.569111][ C1] really_probe+0x282/0x9f0 [ 527.575423][ C1] driver_probe_device+0xfe/0x1d0 [ 527.582244][ C1] __device_attach_driver+0x1c2/0x220 [ 527.589413][ C1] bus_for_each_drv+0x15f/0x1e0 [ 527.596059][ C1] __device_attach+0x228/0x470 [ 527.602619][ C1] bus_probe_device+0x1e4/0x290 [ 527.609266][ C1] device_add+0xb17/0x1c40 [ 527.615489][ C1] platform_device_add+0x34f/0x6d0 [ 527.622405][ C1] platform_device_register_full+0x38c/0x4e0 [ 527.630198][ C1] alsa_card_dummy_init+0x1cc/0x2e0 [ 527.637216][ C1] do_one_initcall+0x103/0x6f0 [ 527.643777][ C1] kernel_init_freeable+0x5e9/0x66d [ 527.650801][ C1] kernel_init+0xd/0x1c0 [ 527.656964][ C1] ret_from_fork+0x1f/0x30 [ 527.663173][ C1] SOFTIRQ-ON-R at: [ 527.667233][ C1] lock_acquire+0x1f2/0xaa0 [ 527.673570][ C1] _raw_read_lock+0x5b/0x70 [ 527.679872][ C1] snd_ctl_notify.part.0+0x36/0x550 [ 527.686877][ C1] snd_ctl_notify+0x8f/0xb0 [ 527.693182][ C1] __snd_ctl_add_replace+0x638/0x800 [ 527.700268][ C1] snd_ctl_add_replace+0x76/0x130 [ 527.707116][ C1] snd_dummy_probe+0xbbf/0x1050 [ 527.713785][ C1] platform_drv_probe+0x87/0x140 [ 527.720523][ C1] really_probe+0x282/0x9f0 [ 527.726823][ C1] driver_probe_device+0xfe/0x1d0 [ 527.733644][ C1] __device_attach_driver+0x1c2/0x220 [ 527.740813][ C1] bus_for_each_drv+0x15f/0x1e0 [ 527.747505][ C1] __device_attach+0x228/0x470 [ 527.754064][ C1] bus_probe_device+0x1e4/0x290 [ 527.760763][ C1] device_add+0xb17/0x1c40 [ 527.766977][ C1] platform_device_add+0x34f/0x6d0 [ 527.773886][ C1] platform_device_register_full+0x38c/0x4e0 [ 527.781663][ C1] alsa_card_dummy_init+0x1cc/0x2e0 [ 527.788668][ C1] do_one_initcall+0x103/0x6f0 [ 527.795248][ C1] kernel_init_freeable+0x5e9/0x66d [ 527.802298][ C1] kernel_init+0xd/0x1c0 [ 527.808342][ C1] ret_from_fork+0x1f/0x30 [ 527.814555][ C1] (null) at: [ 527.818102][ C1] general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN [ 527.829801][ C1] KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] [ 527.838190][ C1] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.9.0-rc4-next-20200911-syzkaller #0 [ 527.847314][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 527.857419][ C1] RIP: 0010:print_shortest_lock_dependencies.cold+0x110/0x2af [ 527.864849][ 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 [ 527.884426][ C1] RSP: 0018:ffffc90000da8898 EFLAGS: 00010003 [ 527.890467][ C1] RAX: 0000000000000001 RBX: ffffffff8cbdf810 RCX: 0000000000000000 [ 527.898416][ C1] RDX: 0000000000000002 RSI: ffffffff815c0ec7 RDI: 0000000000000015 [ 527.906367][ C1] RBP: ffffc90000da89c8 R08: 0000000000000004 R09: ffff8880ae720f8b [ 527.914321][ C1] R10: 0000000000000000 R11: 6c756e2820202020 R12: dffffc0000000000 [ 527.922303][ C1] R13: ffffffff8c9e73f8 R14: 0000000000000009 R15: 0000000000000001 [ 527.930251][ C1] FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 [ 527.939150][ C1] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 527.945706][ C1] CR2: 00000000004cca70 CR3: 000000008eb61000 CR4: 00000000001506e0 [ 527.953663][ C1] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 527.961618][ C1] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 527.969562][ C1] Call Trace: [ 527.972821][ C1] [ 527.975672][ C1] print_irq_inversion_bug.part.0+0x2c6/0x2ee [ 527.981720][ C1] mark_lock.cold+0x38/0x10d [ 527.986296][ C1] ? lock_chain_count+0x20/0x20 [ 527.991122][ C1] ? lock_is_held_type+0xbb/0xf0 [ 527.996034][ C1] ? find_held_lock+0x2d/0x110 [ 528.000783][ C1] ? debug_object_activate+0x287/0x3e0 [ 528.006234][ C1] ? lock_downgrade+0x830/0x830 [ 528.011068][ C1] __lock_acquire+0x117d/0x55d0 [ 528.015895][ C1] ? lock_downgrade+0x830/0x830 [ 528.020721][ C1] ? lockdep_hardirqs_on_prepare+0x530/0x530 [ 528.026672][ C1] ? mark_lock+0xf7/0x2300 [ 528.031083][ C1] lock_acquire+0x1f2/0xaa0 [ 528.035563][ C1] ? _snd_pcm_stream_lock_irqsave+0x9f/0xd0 [ 528.041432][ C1] ? lock_release+0x890/0x890 [ 528.046100][ C1] ? find_held_lock+0x2d/0x110 [ 528.050840][ C1] ? loopback_jiffies_timer_function+0x188/0x220 [ 528.057141][ C1] ? _raw_spin_lock_irqsave+0xa9/0xd0 [ 528.062506][ C1] _raw_spin_lock_irqsave+0x94/0xd0 [ 528.067690][ C1] ? _snd_pcm_stream_lock_irqsave+0x9f/0xd0 [ 528.073566][ C1] _snd_pcm_stream_lock_irqsave+0x9f/0xd0 [ 528.079281][ C1] snd_pcm_period_elapsed+0x24/0x250 [ 528.084564][ C1] loopback_jiffies_timer_function+0x1a8/0x220 [ 528.090692][ C1] ? loopback_jiffies_timer_pos_update+0xf60/0xf60 [ 528.097186][ C1] call_timer_fn+0x1a5/0x6b0 [ 528.101754][ C1] ? add_timer_on+0x450/0x450 [ 528.106412][ C1] ? lock_downgrade+0x830/0x830 [ 528.111238][ C1] ? rwlock_bug.part.0+0x90/0x90 [ 528.116160][ C1] ? _raw_spin_unlock_irq+0x1f/0x80 [ 528.121358][ C1] ? loopback_jiffies_timer_pos_update+0xf60/0xf60 [ 528.127835][ C1] __run_timers.part.0+0x67c/0xa50 [ 528.132936][ C1] ? call_timer_fn+0x6b0/0x6b0 [ 528.137672][ C1] ? lapic_next_event+0x4d/0x80 [ 528.142498][ C1] ? clockevents_program_event+0x12b/0x350 [ 528.148279][ C1] ? kvm_sched_clock_read+0x14/0x40 [ 528.153454][ C1] ? sched_clock+0x2a/0x40 [ 528.157846][ C1] ? sched_clock_cpu+0x18/0x1b0 [ 528.162669][ C1] ? hrtimer_interrupt+0x6ea/0x930 [ 528.167752][ C1] run_timer_softirq+0xae/0x1a0 [ 528.172579][ C1] __do_softirq+0x202/0xa42 [ 528.177073][ C1] asm_call_on_stack+0xf/0x20 [ 528.181721][ C1] [ 528.184641][ C1] do_softirq_own_stack+0x9d/0xd0 [ 528.189656][ C1] irq_exit_rcu+0x235/0x280 [ 528.194134][ C1] sysvec_apic_timer_interrupt+0x51/0xf0 [ 528.199743][ C1] asm_sysvec_apic_timer_interrupt+0x12/0x20 [ 528.205711][ C1] RIP: 0010:native_safe_halt+0xe/0x10 [ 528.211058][ 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 [ 528.230634][ C1] RSP: 0018:ffffc90000d3fd10 EFLAGS: 00000293 [ 528.236673][ C1] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 1ffffffff15cacb9 [ 528.244632][ C1] RDX: ffff8880a9630340 RSI: ffffffff88034020 RDI: 0000000000000000 [ 528.252588][ C1] RBP: ffff8880a673e864 R08: 0000000000000001 R09: 0000000000000001 [ 528.260534][ C1] R10: 0000000000000000 R11: 0000000000000001 R12: ffff8880a673e864 [ 528.268495][ C1] R13: 1ffff920001a7fac R14: ffff8880a673e865 R15: 0000000000000001 [ 528.276458][ C1] ? acpi_safe_halt+0x90/0x180 [ 528.281198][ C1] acpi_safe_halt+0x95/0x180 [ 528.285763][ C1] acpi_idle_do_entry+0x15c/0x1b0 [ 528.290764][ C1] acpi_idle_enter+0x403/0xac0 [ 528.295503][ C1] ? acpi_idle_enter_bm+0x2d0/0x2d0 [ 528.300747][ C1] cpuidle_enter_state+0x150/0xa70 [ 528.305840][ C1] cpuidle_enter+0x4a/0xa0 [ 528.310232][ C1] do_idle+0x48e/0x730 [ 528.314277][ C1] ? arch_cpu_idle_exit+0x70/0x70 [ 528.319288][ C1] cpu_startup_entry+0x14/0x20 [ 528.324030][ C1] secondary_startup_64_no_verify+0xa6/0xab [ 528.329894][ C1] Modules linked in: [ 528.333785][ C1] ---[ end trace 193bab0eab0d8447 ]--- [ 528.339219][ C1] RIP: 0010:print_shortest_lock_dependencies.cold+0x110/0x2af [ 528.346661][ 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 [ 528.366262][ C1] RSP: 0018:ffffc90000da8898 EFLAGS: 00010003 [ 528.372307][ C1] RAX: 0000000000000001 RBX: ffffffff8cbdf810 RCX: 0000000000000000 [ 528.380252][ C1] RDX: 0000000000000002 RSI: ffffffff815c0ec7 RDI: 0000000000000015 [ 528.388197][ C1] RBP: ffffc90000da89c8 R08: 0000000000000004 R09: ffff8880ae720f8b [ 528.396142][ C1] R10: 0000000000000000 R11: 6c756e2820202020 R12: dffffc0000000000 [ 528.404094][ C1] R13: ffffffff8c9e73f8 R14: 0000000000000009 R15: 0000000000000001 [ 528.412049][ C1] FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 [ 528.420958][ C1] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 528.427548][ C1] CR2: 00000000004cca70 CR3: 000000008eb61000 CR4: 00000000001506e0 [ 528.435510][ C1] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 528.443468][ C1] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 528.451415][ C1] Kernel panic - not syncing: Fatal exception in interrupt [ 528.459736][ C1] Kernel Offset: disabled [ 528.464064][ C1] Rebooting in 86400 seconds..