INIT: Entering runlevel: 2 [info] Using makefile-style concurrent boot in runlevel 2. [....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.46' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 464.308033] INFO: rcu_sched self-detected stall on CPU [ 464.313491] 0-....: (124999 ticks this GP) idle=1f2/1/4611686018427387906 softirq=10492/10492 fqs=31246 [ 464.323253] (t=125000 jiffies g=4909 c=4908 q=3) [ 464.328163] NMI backtrace for cpu 0 [ 464.331770] CPU: 0 PID: 4481 Comm: syzkaller419220 Not tainted 4.16.0+ #14 [ 464.338753] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 464.348121] Call Trace: [ 464.350678] [ 464.352929] dump_stack+0x1b9/0x294 [ 464.356556] ? dump_stack_print_info.cold.2+0x52/0x52 [ 464.361796] ? lock_release+0xa10/0xa10 [ 464.365754] nmi_cpu_backtrace.cold.4+0x19/0xce [ 464.370423] ? lapic_can_unplug_cpu.cold.26+0x3f/0x3f [ 464.375591] nmi_trigger_cpumask_backtrace+0x151/0x192 [ 464.380847] arch_trigger_cpumask_backtrace+0x14/0x20 [ 464.386050] rcu_dump_cpu_stacks+0x175/0x1c2 [ 464.390460] ? __sanitizer_cov_trace_cmp8+0x18/0x20 [ 464.395462] check_cpu_stall.isra.61.cold.80+0x36c/0x59a [ 464.400891] ? print_other_cpu_stall+0x4a0/0x4a0 [ 464.405630] ? debug_check_no_locks_freed+0x310/0x310 [ 464.410797] ? find_held_lock+0x36/0x1c0 [ 464.414836] ? lock_downgrade+0x8e0/0x8e0 [ 464.418957] ? debug_check_no_locks_freed+0x310/0x310 [ 464.424122] ? lock_release+0xa10/0xa10 [ 464.428076] ? graph_lock+0x170/0x170 [ 464.431854] ? graph_lock+0x170/0x170 [ 464.435632] ? graph_lock+0x170/0x170 [ 464.439408] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 464.444922] ? graph_lock+0x170/0x170 [ 464.448701] ? graph_lock+0x170/0x170 [ 464.452493] ? __lock_is_held+0xb5/0x140 [ 464.456536] rcu_check_callbacks+0x21b/0xad0 [ 464.460930] ? rcu_cpu_stall_reset+0x210/0x210 [ 464.465492] ? trace_hardirqs_off+0xd/0x10 [ 464.469737] ? raise_softirq+0x1b2/0x450 [ 464.473777] ? raise_softirq_irqoff+0x310/0x310 [ 464.478439] ? read_boot_clock64+0x70/0x70 [ 464.482667] ? account_guest_time+0x3d0/0x3d0 [ 464.487139] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 464.492651] ? hrtimer_run_queues+0x70/0x300 [ 464.497041] ? run_local_timers+0x168/0x1d0 [ 464.501338] ? timer_clear_idle+0x50/0x50 [ 464.505470] ? account_system_time+0x7f/0xb0 [ 464.509857] ? account_process_tick+0x76/0x240 [ 464.514415] update_process_times+0x2d/0x70 [ 464.518739] tick_sched_handle+0xa0/0x180 [ 464.522864] tick_sched_timer+0x42/0x130 [ 464.526901] __hrtimer_run_queues+0x3e3/0x10a0 [ 464.531464] ? tick_sched_do_timer+0x100/0x100 [ 464.536033] ? hrtimer_start_range_ns+0xd10/0xd10 [ 464.540891] ? pvclock_read_flags+0x160/0x160 [ 464.545370] ? kvm_clock_read+0x25/0x30 [ 464.549323] ? kvm_clock_read+0x25/0x30 [ 464.553273] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 464.558265] ? ktime_get_update_offsets_now+0x3a6/0x570 [ 464.563605] ? do_timer+0x50/0x50 [ 464.567037] ? rcu_nmi_exit+0xd7/0x2b0 [ 464.570929] ? do_raw_spin_lock+0xc1/0x200 [ 464.575144] hrtimer_interrupt+0x286/0x650 [ 464.579395] smp_apic_timer_interrupt+0x15d/0x710 [ 464.584217] ? smp_call_function_single_interrupt+0x650/0x650 [ 464.590103] ? _raw_spin_lock+0x32/0x40 [ 464.594056] ? _raw_spin_unlock+0x22/0x30 [ 464.598208] ? handle_edge_irq+0x330/0x870 [ 464.602456] ? task_prio+0x50/0x50 [ 464.605995] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 464.610822] apic_timer_interrupt+0xf/0x20 [ 464.615031] [ 464.617301] RIP: 0010:snd_pcm_stream_unlock_irq+0xb7/0xf0 [ 464.622812] RSP: 0018:ffff8801ac8a6b60 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13 [ 464.630495] RAX: ffff8801a89e2700 RBX: 0000000000000000 RCX: 1ffff1003513c5f3 [ 464.637742] RDX: 0000000000000000 RSI: ffffffff85a14e10 RDI: ffffffff88b17bf8 [ 464.644985] RBP: ffff8801ac8a6b68 R08: ffff8801a89e2f78 R09: 0000000000000006 [ 464.652233] R10: ffff8801a89e2700 R11: 0000000000000000 R12: 0000000000000004 [ 464.659477] R13: 00000000ffffffe0 R14: ffff8801d9a6ac00 R15: ffff8801ceb2f200 [ 464.666733] ? snd_pcm_stream_unlock_irq+0xb0/0xf0 [ 464.671684] __snd_pcm_lib_xfer+0x739/0x1d10 [ 464.676068] ? print_usage_bug+0xc0/0xc0 [ 464.680104] ? print_usage_bug+0xc0/0xc0 [ 464.684147] ? lock_release+0xa10/0xa10 [ 464.688096] ? snd_pcm_hw_rule_noresample_func+0x110/0x110 [ 464.693732] ? dummy_proc_read+0x6e0/0x6e0 [ 464.697947] ? pcm_lib_apply_appl_ptr+0x5a0/0x5a0 [ 464.702772] ? mark_held_locks+0xc9/0x160 [ 464.706900] ? retint_kernel+0x10/0x10 [ 464.710770] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 464.715763] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 464.720498] ? retint_kernel+0x10/0x10 [ 464.724365] ? snd_pcm_oss_prepare+0x7d/0x1b0 [ 464.728838] ? write_comp_data+0x70/0x70 [ 464.732874] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 464.738385] ? snd_pcm_oss_prepare+0x87/0x1b0 [ 464.742860] snd_pcm_oss_write3+0xe9/0x220 [ 464.747077] snd_pcm_oss_write2+0x34c/0x460 [ 464.751375] ? snd_pcm_oss_write3+0x220/0x220 [ 464.755848] ? find_held_lock+0x36/0x1c0 [ 464.759885] snd_pcm_oss_sync1+0x332/0x5a0 [ 464.764097] ? snd_pcm_oss_write2+0x460/0x460 [ 464.768624] ? kasan_check_read+0x11/0x20 [ 464.772748] ? rcu_is_watching+0x85/0x140 [ 464.776872] ? rcu_bh_force_quiescent_state+0x20/0x20 [ 464.782041] ? wake_up_q+0x100/0x100 [ 464.785732] ? snd_pcm_format_set_silence+0x203/0x540 [ 464.790898] snd_pcm_oss_sync.isra.29+0x790/0x980 [ 464.795718] ? snd_pcm_oss_sync1+0x5a0/0x5a0 [ 464.800143] ? fsnotify_first_mark+0x330/0x330 [ 464.804702] ? kobject_put+0x8e/0x280 [ 464.808479] snd_pcm_oss_release+0x214/0x290 [ 464.812862] ? snd_pcm_oss_sync.isra.29+0x980/0x980 [ 464.817874] __fput+0x34d/0x890 [ 464.821131] ? fput+0x1a0/0x1a0 [ 464.824388] ? check_same_owner+0x320/0x320 [ 464.828687] ? _raw_spin_unlock_irq+0x27/0x70 [ 464.833160] ____fput+0x15/0x20 [ 464.836443] task_work_run+0x1e4/0x290 [ 464.840307] ? task_work_cancel+0x240/0x240 [ 464.844608] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 464.850124] ? switch_task_namespaces+0xa2/0xd0 [ 464.854769] do_exit+0x1aee/0x2730 [ 464.858285] ? plist_add+0x770/0x770 [ 464.861980] ? mm_update_next_owner+0x980/0x980 [ 464.866624] ? print_usage_bug+0xc0/0xc0 [ 464.870669] ? graph_lock+0x170/0x170 [ 464.874461] ? do_raw_spin_unlock+0x9e/0x2e0 [ 464.878849] ? rcu_note_context_switch+0x710/0x710 [ 464.883928] ? lock_acquire+0x1dc/0x520 [ 464.887887] ? __might_sleep+0x95/0x190 [ 464.891839] ? __lock_acquire+0x7f5/0x5130 [ 464.896055] ? debug_check_no_locks_freed+0x310/0x310 [ 464.901221] ? do_raw_spin_unlock+0x9e/0x2e0 [ 464.905609] ? do_raw_spin_trylock+0x1b0/0x1b0 [ 464.910171] ? kasan_check_write+0x14/0x20 [ 464.914385] ? __sanitizer_cov_trace_switch+0x53/0x90 [ 464.919559] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 464.925072] ? drop_futex_key_refs.isra.13+0x6d/0xe0 [ 464.930153] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 464.935670] ? futex_wait+0x5c1/0x9f0 [ 464.939450] ? futex_wait_setup+0x400/0x400 [ 464.943748] ? __sanitizer_cov_trace_switch+0x53/0x90 [ 464.948914] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 464.954428] ? drop_futex_key_refs.isra.13+0x6d/0xe0 [ 464.959506] ? futex_wake+0x2f6/0x750 [ 464.963282] ? graph_lock+0x170/0x170 [ 464.967064] ? memset+0x31/0x40 [ 464.970323] ? find_held_lock+0x36/0x1c0 [ 464.974367] ? lock_downgrade+0x8e0/0x8e0 [ 464.978498] do_group_exit+0x16f/0x430 [ 464.982363] ? do_raw_spin_trylock+0x1b0/0x1b0 [ 464.986921] ? SyS_exit+0x30/0x30 [ 464.990354] ? _raw_spin_unlock_irq+0x27/0x70 [ 464.994825] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 464.999865] get_signal+0x886/0x1960 [ 465.003560] ? ptrace_notify+0x130/0x130 [ 465.007599] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 465.013112] ? snd_pcm_oss_write+0x6d4/0xa20 [ 465.017507] ? expand_files.part.8+0x9a0/0x9a0 [ 465.022070] ? snd_pcm_oss_ioctl_compat+0x30/0x30 [ 465.026941] ? ipcget+0x168/0x1230 [ 465.030460] ? do_raw_spin_unlock+0x9e/0x2e0 [ 465.034855] ? do_raw_spin_trylock+0x1b0/0x1b0 [ 465.039452] do_signal+0x98/0x2040 [ 465.042969] ? __vfs_write+0x113/0x880 [ 465.046832] ? __fget_light+0x2ef/0x430 [ 465.050782] ? snd_pcm_oss_ioctl_compat+0x30/0x30 [ 465.055600] ? kernel_read+0x120/0x120 [ 465.059466] ? ipc_obtain_object_check+0x120/0x120 [ 465.064372] ? setup_sigcontext+0x7d0/0x7d0 [ 465.068671] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 465.074188] ? fsnotify+0x415/0x1100 [ 465.077887] ? fsnotify_first_mark+0x330/0x330 [ 465.082460] ? exit_to_usermode_loop+0x87/0x310 [ 465.087108] exit_to_usermode_loop+0x28a/0x310 [ 465.091670] ? syscall_slow_exit_work+0x4f0/0x4f0 [ 465.096489] ? do_syscall_64+0xb7/0x9d0 [ 465.100446] do_syscall_64+0x792/0x9d0 [ 465.104311] ? kasan_check_write+0x14/0x20 [ 465.108525] ? syscall_return_slowpath+0x5c0/0x5c0 [ 465.113433] ? syscall_return_slowpath+0x30f/0x5c0 [ 465.118347] ? entry_SYSCALL_64_after_hwframe+0x52/0xb7 [ 465.123689] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 465.128513] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 465.133678] RIP: 0033:0x449eb9 [ 465.136843] RSP: 002b:00007f302d286da8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca [ 465.144530] RAX: fffffffffffffe00 RBX: 00000000006dcc5c RCX: 0000000000449eb9 [ 465.151776] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000006dcc5c [ 465.159028] RBP: 00000000006dcc58 R08: 0000000000000000 R09: 0000000000000000 [ 465.166279] R10: 0000000000000000 R11: 0000000000000246 R12: 0100000000000000 [ 465.173525] R13: 7073642f7665642f R14: 646e732f7665642f R15: 0000000000000009