[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 20.988598] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. [ 21.315905] random: sshd: uninitialized urandom read (32 bytes read) [ 21.610197] random: sshd: uninitialized urandom read (32 bytes read) Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 22.555723] random: sshd: uninitialized urandom read (32 bytes read) [ 481.743222] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.18' (ECDSA) to the list of known hosts. [ 487.268589] random: sshd: uninitialized urandom read (32 bytes read) executing program executing program executing program [ 717.792269] INFO: task syz-executor168:4571 blocked for more than 140 seconds. [ 717.800071] Not tainted 4.18.0-rc5+ #18 [ 717.804651] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 717.812708] syz-executor168 D22680 4571 4569 0x00000000 [ 717.818654] Call Trace: [ 717.822296] __schedule+0x87c/0x1ed0 [ 717.826474] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 717.831199] ? __sched_text_start+0x8/0x8 [ 717.835654] ? _raw_spin_unlock+0x22/0x30 [ 717.839978] ? __queue_work+0x68d/0x1410 [ 717.844173] ? graph_lock+0x170/0x170 [ 717.848080] ? graph_lock+0x170/0x170 [ 717.851976] ? flush_rcu_work+0x90/0x90 [ 717.857079] ? kasan_check_write+0x14/0x20 [ 717.861440] ? do_raw_spin_lock+0xc1/0x200 [ 717.865783] ? print_usage_bug+0xc0/0xc0 [ 717.869915] ? print_usage_bug+0xc0/0xc0 [ 717.874198] ? graph_lock+0x170/0x170 [ 717.878100] schedule+0xfb/0x450 [ 717.881826] ? __schedule+0x1ed0/0x1ed0 [ 717.885895] ? print_usage_bug+0xc0/0xc0 [ 717.890337] schedule_timeout+0x1cc/0x260 [ 717.894570] ? usleep_range+0x1a0/0x1a0 [ 717.898623] ? mark_held_locks+0xc9/0x160 [ 717.902853] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 717.907573] ? _raw_spin_unlock_irq+0x27/0x70 [ 717.912169] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 717.917319] wait_for_completion+0x430/0x8d0 [ 717.921872] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 717.927107] ? wait_for_completion_interruptible+0x950/0x950 [ 717.933232] ? wake_up_q+0x100/0x100 [ 717.937213] ? pcrypt_aead_enc+0x190/0x190 [ 717.941594] ? sock_kmalloc+0x182/0x1f0 [ 717.945860] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 717.951462] ? pcrypt_aead_decrypt+0x370/0x460 [ 717.956182] aead_recvmsg+0x1544/0x1bb0 [ 717.960347] ? aead_release+0x50/0x50 [ 717.964247] ? aead_release+0x50/0x50 [ 717.968230] sock_recvmsg_nosec+0x8c/0xb0 [ 717.972865] ? __sock_tx_timestamp+0xd0/0xd0 [ 717.977527] ___sys_recvmsg+0x2b6/0x680 [ 717.981742] ? ___sys_sendmsg+0x930/0x930 [ 717.986219] ? alloc_pages_current+0x114/0x210 [ 717.991637] ? find_held_lock+0x36/0x1c0 [ 717.995795] ? lock_downgrade+0x8f0/0x8f0 [ 718.000062] ? af_alg_sendpage+0xb50/0xb50 [ 718.004659] ? rcu_note_context_switch+0x730/0x730 [ 718.010538] ? check_same_owner+0x340/0x340 [ 718.014940] __sys_recvmmsg+0x301/0xba0 [ 718.019152] ? __ia32_sys_recvmsg+0xb0/0xb0 [ 718.023566] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 718.029393] ? __vfs_write+0x11f/0x9f0 [ 718.033421] ? fsnotify+0xbb4/0x14e0 [ 718.037223] ? fsnotify_first_mark+0x350/0x350 [ 718.041856] ? __fsnotify_parent+0xcc/0x420 [ 718.046256] ? __sys_accept4+0x5ad/0x8a0 [ 718.050407] ? fsnotify+0x14e0/0x14e0 [ 718.054336] ? vfs_write+0x2a8/0x560 [ 718.058130] do_sys_recvmmsg+0x181/0x1a0 [ 718.062319] ? __sys_recvmmsg+0xba0/0xba0 [ 718.066644] ? __ia32_sys_read+0xb0/0xb0 [ 718.070966] ? __ia32_sys_fallocate+0xf0/0xf0 [ 718.075567] __x64_sys_recvmmsg+0xbe/0x150 [ 718.079991] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 718.085210] do_syscall_64+0x1b9/0x820 [ 718.089197] ? syscall_slow_exit_work+0x500/0x500 [ 718.094247] ? syscall_return_slowpath+0x5e0/0x5e0 [ 718.099622] ? syscall_return_slowpath+0x31d/0x5e0 [ 718.104654] ? entry_SYSCALL_64_after_hwframe+0x59/0xbe [ 718.110166] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 718.115125] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 718.120419] RIP: 0033:0x440379 [ 718.123693] Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 718.144031] RSP: 002b:00007fff4f0b41d8 EFLAGS: 00000207 ORIG_RAX: 000000000000012b [ 718.151867] RAX: ffffffffffffffda RBX: 0000000020000000 RCX: 0000000000440379 [ 718.159237] RDX: 0000000000000002 RSI: 0000000020003340 RDI: 000000000000000a [ 718.166593] RBP: 00000000006ca018 R08: 0000000000000000 R09: 00000000004002c8 [ 718.174057] R10: 0000000000000000 R11: 0000000000000207 R12: 0000000000401c00 [ 718.181393] R13: 0000000000401c90 R14: 0000000000000000 R15: 0000000000000000 [ 718.188936] [ 718.188936] Showing all locks held in the system: [ 718.195437] 1 lock held by khungtaskd/903: [ 718.199806] #0: (____ptrval____) (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 [ 718.208614] 1 lock held by rsyslogd/4453: [ 718.212815] #0: (____ptrval____) (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 [ 718.220931] 2 locks held by getty/4543: [ 718.224982] #0: (____ptrval____) (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 718.233389] #1: (____ptrval____) (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 718.242467] 2 locks held by getty/4544: [ 718.246502] #0: (____ptrval____) (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 718.254889] #1: (____ptrval____) (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 718.263882] 2 locks held by getty/4545: [ 718.267896] #0: (____ptrval____) (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 718.276226] #1: (____ptrval____) (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 718.285179] 2 locks held by getty/4546: [ 718.289212] #0: (____ptrval____) (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 718.297563] #1: (____ptrval____) (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 718.306521] 2 locks held by getty/4547: [ 718.310619] #0: (____ptrval____) (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 718.318945] #1: (____ptrval____) (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 718.327920] 2 locks held by getty/4548: [ 718.332045] #0: (____ptrval____) (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 718.340401] #1: (____ptrval____) (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 718.349516] 2 locks held by getty/4549: [ 718.353554] #0: (____ptrval____) (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 718.361921] #1: (____ptrval____) (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 718.370895] 1 lock held by syz-executor168/4571: [ 718.375787] #0: (____ptrval____) (sk_lock-AF_ALG){+.+.}, at: aead_recvmsg+0xbb/0x1bb0 [ 718.383998] [ 718.385663] ============================================= [ 718.385663] [ 718.392761] NMI backtrace for cpu 1 [ 718.396446] CPU: 1 PID: 903 Comm: khungtaskd Not tainted 4.18.0-rc5+ #18 [ 718.403292] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 718.412647] Call Trace: [ 718.415322] dump_stack+0x1c9/0x2b4 [ 718.418953] ? dump_stack_print_info.cold.2+0x52/0x52 [ 718.424140] ? vprintk_default+0x28/0x30 [ 718.428232] nmi_cpu_backtrace.cold.4+0x19/0xce [ 718.432889] ? rcu_report_qs_rnp+0x7a0/0x7a0 [ 718.437334] ? lapic_can_unplug_cpu.cold.27+0x3f/0x3f [ 718.442541] nmi_trigger_cpumask_backtrace+0x151/0x192 [ 718.447830] arch_trigger_cpumask_backtrace+0x14/0x20 [ 718.453029] watchdog+0x9c4/0xf80 [ 718.456488] ? reset_hung_task_detector+0xd0/0xd0 [ 718.461340] ? kasan_check_read+0x11/0x20 [ 718.465483] ? do_raw_spin_unlock+0xa7/0x2f0 [ 718.469904] ? _raw_spin_unlock_irqrestore+0x74/0xc0 [ 718.475073] ? __kthread_parkme+0x58/0x1b0 [ 718.479305] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 718.484323] ? trace_hardirqs_on+0xd/0x10 [ 718.488477] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 718.494045] ? __kthread_parkme+0x106/0x1b0 [ 718.498375] kthread+0x345/0x410 [ 718.501752] ? reset_hung_task_detector+0xd0/0xd0 [ 718.506616] ? kthread_bind+0x40/0x40 [ 718.510425] ret_from_fork+0x3a/0x50 [ 718.514249] Sending NMI from CPU 1 to CPUs 0: [ 718.518853] NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0x6/0x10 [ 718.519825] Kernel panic - not syncing: hung_task: blocked tasks [ 718.532630] CPU: 1 PID: 903 Comm: khungtaskd Not tainted 4.18.0-rc5+ #18 [ 718.539464] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 718.548815] Call Trace: [ 718.551414] dump_stack+0x1c9/0x2b4 [ 718.555040] ? dump_stack_print_info.cold.2+0x52/0x52 [ 718.560239] ? printk_safe_log_store+0x2f0/0x2f0 [ 718.565103] panic+0x238/0x4e7 [ 718.568319] ? add_taint.cold.5+0x16/0x16 [ 718.572474] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 718.578039] ? nmi_trigger_cpumask_backtrace+0x13a/0x192 [ 718.583522] ? printk_safe_flush+0xd7/0x130 [ 718.587849] watchdog+0x9d5/0xf80 [ 718.591326] ? reset_hung_task_detector+0xd0/0xd0 [ 718.596181] ? kasan_check_read+0x11/0x20 [ 718.600323] ? do_raw_spin_unlock+0xa7/0x2f0 [ 718.604753] ? _raw_spin_unlock_irqrestore+0x74/0xc0 [ 718.609893] ? __kthread_parkme+0x58/0x1b0 [ 718.614135] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 718.619152] ? trace_hardirqs_on+0xd/0x10 [ 718.623287] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 718.628810] ? __kthread_parkme+0x106/0x1b0 [ 718.633131] kthread+0x345/0x410 [ 718.636531] ? reset_hung_task_detector+0xd0/0xd0 [ 718.641424] ? kthread_bind+0x40/0x40 [ 718.645241] ret_from_fork+0x3a/0x50 [ 718.649800] Dumping ftrace buffer: [ 718.653486] (ftrace buffer empty) [ 718.657211] Kernel Offset: disabled [ 718.660900] Rebooting in 86400 seconds..