[....] Starting OpenBSD Secure Shell server: sshd[ 18.907445] random: sshd: uninitialized urandom read (32 bytes read, 31 bits of entropy available) [?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 20.760262] random: sshd: uninitialized urandom read (32 bytes read, 34 bits of entropy available) [ 21.255763] random: sshd: uninitialized urandom read (32 bytes read, 34 bits of entropy available) [ 22.120144] random: sshd: uninitialized urandom read (32 bytes read, 110 bits of entropy available) [ 51.372761] random: sshd: uninitialized urandom read (32 bytes read, 126 bits of entropy available) [ 54.162097] random: nonblocking pool is initialized Warning: Permanently added '10.128.15.200' (ECDSA) to the list of known hosts. executing program INIT: Id "4" respawning too fast: disabled for 5 minutes INIT: Id "1" respawning too fast: disabled for 5 minutes INIT: Id "3" respawning too fast: disabled for 5 minutes INIT: Id "6" respawning too fast: disabled for 5 minutes INIT: Id "5" respawning too fast: disabled for 5 minutes INIT: Id "2" respawning too fast: disabled for 5 minutes [ 242.224720] INFO: task syzkaller454913:3769 blocked for more than 120 seconds. [ 242.232109] Not tainted 4.4.115-gaa856bd #6 [ 242.236958] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 242.244919] syzkaller454913 D ffff8801d8a27648 27976 3769 3767 0x00000002 [ 242.252337] ffff8801d8a27648 0000000000000000 0000000000000000 0000000000000000 [ 242.260350] 0000000000000001 ffff8801d8a27600 ffff8801db21fdb8 ffff8801db21fde0 [ 242.268355] ffff8801db21f4d8 ffffffff84217840 ffff8801d8891800 0000000000000000 [ 242.276353] Call Trace: [ 242.278918] [] schedule+0x7a/0x1b0 [ 242.284080] [] schedule_preempt_disabled+0x13/0x20 [ 242.290662] [] mutex_lock_nested+0x306/0x850 [ 242.296733] [] ? snd_seq_do_ioctl+0x15d/0x1b0 [ 242.302852] [] ? __ww_mutex_lock+0x14f0/0x14f0 [ 242.309085] [] ? do_exit+0x82a/0x2a10 [ 242.314514] [] ? debug_check_no_obj_freed+0x2d2/0x9b0 [ 242.321370] [] snd_seq_do_ioctl+0x15d/0x1b0 [ 242.327338] [] snd_seq_kernel_client_ctl+0xd7/0x150 [ 242.333985] [] snd_seq_oss_writeq_clear+0xe0/0x140 [ 242.340564] [] ? snd_seq_oss_writeq_wakeup+0xc0/0xc0 [ 242.347316] [] ? kasan_slab_free+0x88/0xc0 [ 242.353176] [] ? kfree+0xfc/0x300 [ 242.358290] [] ? create_port+0x230/0x230 [ 242.363978] [] snd_seq_oss_writeq_delete+0x1f/0x30 [ 242.370560] [] free_devinfo+0x61/0xb0 [ 242.376013] [] port_delete+0xd5/0x110 [ 242.381444] [] snd_seq_delete_port+0x1c3/0x200 [ 242.387679] [] snd_seq_ioctl_delete_port+0xf2/0x1d0 [ 242.394322] [] ? snd_seq_ioctl_set_port_info+0x190/0x190 [ 242.401430] [] snd_seq_do_ioctl+0x182/0x1b0 [ 242.407403] [] snd_seq_kernel_client_ctl+0xd7/0x150 [ 242.414043] [] ? snd_midi_event_new+0x200/0x200 [ 242.420371] [] snd_seq_event_port_detach+0xaf/0x100 [ 242.427055] [] ? snd_seq_event_port_attach+0x190/0x190 [ 242.433965] [] delete_port+0x73/0xb0 [ 242.439346] [] snd_seq_oss_release+0xe4/0x130 [ 242.445503] [] odev_release+0x52/0x70 [ 242.450944] [] __fput+0x233/0x6d0 [ 242.456054] [] ____fput+0x15/0x20 [ 242.461135] [] task_work_run+0x104/0x180 [ 242.466859] [] do_exit+0x82a/0x2a10 [ 242.472114] [] ? __fsnotify_parent+0xbc/0x340 [ 242.478279] [] ? avc_policy_seqno+0x9/0x20 [ 242.484139] [] ? fsnotify+0x5ad/0xee0 [ 242.489597] [] ? fsnotify+0xee0/0xee0 [ 242.495049] [] ? release_task+0x1240/0x1240 [ 242.500994] [] ? rw_verify_area+0x100/0x2f0 [ 242.506970] [] ? vfs_write+0x227/0x530 [ 242.512482] [] ? SyS_write+0x13d/0x1b0 [ 242.518031] [] do_group_exit+0x108/0x320 [ 242.523732] [] ? lockdep_sys_exit_thunk+0x12/0x14 [ 242.530328] [] SyS_exit_group+0x1d/0x20 [ 242.535959] [] entry_SYSCALL_64_fastpath+0x1c/0x98 [ 242.542577] INFO: lockdep is turned off. [ 242.546669] Sending NMI to all CPUs: [ 242.550497] NMI backtrace for cpu 0 [ 242.554095] CPU: 0 PID: 486 Comm: khungtaskd Not tainted 4.4.115-gaa856bd #6 [ 242.561291] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 242.570640] task: ffff8800bad81800 task.stack: ffff8800bad08000 [ 242.576869] RIP: 0010:[] [] flat_send_IPI_mask+0xf7/0x1a0 [ 242.585822] RSP: 0018:ffff8800bad0fcb8 EFLAGS: 00000046 [ 242.591244] RAX: 0000000003000000 RBX: 0000000000000c00 RCX: ffffffff8126a292 [ 242.598521] RDX: 0000000000000c00 RSI: 0000000000000002 RDI: ffffffffff5fb300 [ 242.605804] RBP: ffff8800bad0fce0 R08: 0000000000000001 R09: 0000000000000000 [ 242.613052] R10: 0000000000000000 R11: fffffbfff0ad7e2c R12: 0000000000000246 [ 242.620342] R13: 0000000000000003 R14: ffffffff8426f3a0 R15: 0000000000000002 [ 242.627621] FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 [ 242.635854] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 242.641716] CR2: 00007f9ed182f9ce CR3: 00000001d21c2000 CR4: 0000000000160670 [ 242.649008] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 242.656283] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 242.663543] Stack: [ 242.665699] ffffffff8426f3a0 ffffffff847ef7c0 fffffbfff08fd9ac dffffc0000000000 [ 242.673204] ffff8801db31bca0 ffff8800bad0fd00 ffffffff810b99fb ffffffff839f61c0 [ 242.680740] 0000000000000003 ffff8800bad0fd60 ffffffff81d0ed14 ffffffff839fe320 [ 242.688266] Call Trace: [ 242.690822] [] nmi_raise_cpu_backtrace+0x5b/0x70 [ 242.697231] [] nmi_trigger_all_cpu_backtrace+0x4a4/0x550 [ 242.704308] [] ? irq_force_complete_move+0x3b0/0x3b0 [ 242.711080] [] arch_trigger_all_cpu_backtrace+0x14/0x20 [ 242.718095] [] watchdog+0x6fa/0xae0 [ 242.723346] [] ? watchdog+0xc3/0xae0 [ 242.728715] [] kthread+0x268/0x300 [ 242.733877] [] ? reset_hung_task_detector+0x20/0x20 [ 242.740570] [] ? kthread_create_on_node+0x400/0x400 [ 242.747243] [] ? kthread_create_on_node+0x400/0x400 [ 242.753890] [] ret_from_fork+0x55/0x80 [ 242.759433] [] ? kthread_create_on_node+0x400/0x400 [ 242.766097] Code: b3 5f ff f6 c4 10 75 e1 44 89 e8 c1 e0 18 89 04 25 10 b3 5f ff 44 89 fa 09 da 80 cf 04 41 83 ff 02 0f 44 d3 89 14 25 00 b3 5f ff <41> f7 c4 00 02 00 00 74 1a e8 0b 2f 17 00 4c 89 e7 57 9d 0f 1f [ 242.785121] NMI backtrace for cpu 1 [ 242.788724] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.4.115-gaa856bd #6 [ 242.795659] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 242.805026] task: ffff8801d9b49800 task.stack: ffff8801d9b58000 [ 242.811069] RIP: 0010:[] [] native_safe_halt+0x6/0x10 [ 242.820087] RSP: 0018:ffff8801d9b5fd98 EFLAGS: 00000246 [ 242.825533] RAX: 0000000000000003 RBX: ffffffff847dd8c8 RCX: ffffffff81d63b5b [ 242.832778] RDX: 0000000000000004 RSI: ffffffff839fe320 RDI: ffffffff84418180 [ 242.840054] RBP: ffff8801d9b5fd98 R08: 0000000000000000 R09: 0000000000000000 [ 242.847333] R10: 0000000000000000 R11: 1ffff1003b36bf82 R12: 0000000000000001 [ 242.854580] R13: fffffbfff070887c R14: ffffffff847ebc38 R15: 0000000000000000 [ 242.861878] FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 [ 242.870118] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 242.876020] CR2: 00007f0628c669b8 CR3: 00000001d21c2000 CR4: 0000000000160670 [ 242.883269] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 242.890561] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 242.897846] Stack: [ 242.899979] ffff8801d9b5fdd0 ffffffff81027ed5 ffff8801d9b60000 ffffffff847dd8c8 [ 242.907524] fffffbfff070887c ffffffff847ebc38 0000000000000000 ffff8801d9b5fde0 [ 242.915054] ffffffff8102945a ffff8801d9b5fdf8 ffffffff81221468 dffffc0000000000 [ 242.922569] Call Trace: [ 242.925163] [] default_idle+0x55/0x3c0 [ 242.930672] [] arch_cpu_idle+0xa/0x10 [ 242.936146] [] default_idle_call+0x48/0x70 [ 242.942008] [] cpu_startup_entry+0x5fd/0x8f0 [ 242.948075] [] ? call_cpuidle+0xe0/0xe0 [ 242.953676] [] ? clockevents_register_device+0x122/0x230 [ 242.960785] [] start_secondary+0x304/0x3e0 [ 242.966666] [] ? set_cpu_sibling_map+0x1080/0x1080 [ 242.973227] Code: 00 00 00 00 00 55 48 89 e5 fa 5d c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 fb 5d c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 fb f4 <5d> c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 f4 5d c3 66 0f 1f 84 [ 242.992367] Kernel panic - not syncing: hung_task: blocked tasks [ 242.998500] CPU: 0 PID: 486 Comm: khungtaskd Not tainted 4.4.115-gaa856bd #6 [ 243.005659] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 243.015072] 0000000000000000 74de0ffa2c7e1a86 ffff8800bad0fca8 ffffffff81d03dad [ 243.023065] ffffffff83882f20 ffff8800bad0fd80 dffffc0000000000 7fffffffffffffff [ 243.031054] ffff8801d8891c48 ffff8800bad0fd70 ffffffff8141acca 0000000041b58ab3 [ 243.039027] Call Trace: [ 243.041590] [] dump_stack+0xc1/0x124 [ 243.046931] [] panic+0x1aa/0x388 [ 243.051922] [] ? percpu_up_read.constprop.45+0xe1/0xe1 [ 243.058820] [] ? nmi_trigger_all_cpu_backtrace+0x3f8/0x550 [ 243.066073] [] ? nmi_trigger_all_cpu_backtrace+0x3f8/0x550 [ 243.073329] [] watchdog+0x70b/0xae0 [ 243.078585] [] ? watchdog+0xc3/0xae0 [ 243.083924] [] kthread+0x268/0x300 [ 243.089088] [] ? reset_hung_task_detector+0x20/0x20 [ 243.095726] [] ? kthread_create_on_node+0x400/0x400 [ 243.102378] [] ? kthread_create_on_node+0x400/0x400 [ 243.109016] [] ret_from_fork+0x55/0x80 [ 243.114535] [] ? kthread_create_on_node+0x400/0x400 [ 243.121577] Dumping ftrace buffer: [ 243.125097] (ftrace buffer empty) [ 243.128778] Kernel Offset: disabled [ 243.132375] Rebooting in 86400 seconds..