[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 19.938480] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. [ 20.455406] random: sshd: uninitialized urandom read (32 bytes read) [ 20.819283] random: sshd: uninitialized urandom read (32 bytes read) Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 21.718296] random: sshd: uninitialized urandom read (32 bytes read) [ 537.858548] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.43' (ECDSA) to the list of known hosts. [ 543.325322] random: sshd: uninitialized urandom read (32 bytes read) executing program executing program executing program [ 717.791174] INFO: task syz-executor633:4560 blocked for more than 140 seconds. [ 717.799232] Not tainted 4.18.0-rc5+ #157 [ 717.803975] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 717.811992] syz-executor633 D24000 4560 4558 0x00000000 [ 717.817764] Call Trace: [ 717.820456] __schedule+0x87c/0x1ed0 [ 717.824223] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 717.828847] ? __sched_text_start+0x8/0x8 [ 717.833035] ? _raw_spin_unlock+0x22/0x30 [ 717.837230] ? __queue_work+0x68d/0x1410 [ 717.841323] ? graph_lock+0x170/0x170 [ 717.845155] ? graph_lock+0x170/0x170 [ 717.848978] ? flush_rcu_work+0x90/0x90 [ 717.853007] ? kasan_check_write+0x14/0x20 [ 717.857312] ? do_raw_spin_lock+0xc1/0x200 [ 717.861689] ? print_usage_bug+0xc0/0xc0 [ 717.865775] ? print_usage_bug+0xc0/0xc0 [ 717.869875] ? graph_lock+0x170/0x170 [ 717.873720] schedule+0xfb/0x450 [ 717.877119] ? __schedule+0x1ed0/0x1ed0 [ 717.881128] ? print_usage_bug+0xc0/0xc0 [ 717.885229] schedule_timeout+0x1cc/0x260 [ 717.889403] ? usleep_range+0x1a0/0x1a0 [ 717.893440] ? mark_held_locks+0xc9/0x160 [ 717.897618] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 717.902253] ? _raw_spin_unlock_irq+0x27/0x70 [ 717.906792] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 717.911889] wait_for_completion+0x430/0x8d0 [ 717.916336] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 717.921404] ? wait_for_completion_interruptible+0x950/0x950 [ 717.927407] ? wake_up_q+0x100/0x100 [ 717.931155] ? pcrypt_aead_enc+0x190/0x190 [ 717.935497] ? sock_kmalloc+0x182/0x1f0 [ 717.939518] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 717.945182] ? pcrypt_aead_decrypt+0x370/0x460 [ 717.949821] aead_recvmsg+0x1544/0x1bb0 [ 717.953850] ? aead_release+0x50/0x50 [ 717.957696] ? aead_release+0x50/0x50 [ 717.961608] sock_recvmsg_nosec+0x8c/0xb0 [ 717.965815] ? __sock_tx_timestamp+0xd0/0xd0 [ 717.970277] ___sys_recvmsg+0x2b6/0x680 [ 717.974292] ? ___sys_sendmsg+0x930/0x930 [ 717.978566] ? alloc_pages_current+0x114/0x210 [ 717.983196] ? find_held_lock+0x36/0x1c0 [ 717.987294] ? lock_downgrade+0x8f0/0x8f0 [ 717.991571] ? af_alg_sendpage+0xb50/0xb50 [ 717.995841] ? rcu_note_context_switch+0x730/0x730 [ 718.000824] ? check_same_owner+0x340/0x340 [ 718.005187] __sys_recvmmsg+0x301/0xba0 [ 718.009195] ? __ia32_sys_recvmsg+0xb0/0xb0 [ 718.014597] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 718.020182] ? __vfs_write+0x11f/0x9f0 [ 718.024119] ? fsnotify+0xbb4/0x14e0 [ 718.027883] ? fsnotify_first_mark+0x350/0x350 [ 718.032499] ? __fsnotify_parent+0xcc/0x420 [ 718.036878] ? __sys_accept4+0x5ad/0x8a0 [ 718.040982] ? fsnotify+0x14e0/0x14e0 [ 718.044841] ? vfs_write+0x2a8/0x560 [ 718.048624] do_sys_recvmmsg+0x181/0x1a0 [ 718.052741] ? __sys_recvmmsg+0xba0/0xba0 [ 718.056939] ? __ia32_sys_read+0xb0/0xb0 [ 718.061074] ? __ia32_sys_fallocate+0xf0/0xf0 [ 718.065642] __x64_sys_recvmmsg+0xbe/0x150 [ 718.069929] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 718.074977] do_syscall_64+0x1b9/0x820 [ 718.079250] ? syscall_return_slowpath+0x5e0/0x5e0 [ 718.084204] ? syscall_return_slowpath+0x31d/0x5e0 [ 718.089180] ? entry_SYSCALL_64_after_hwframe+0x59/0xbe [ 718.094601] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 718.099526] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 718.105185] RIP: 0033:0x440379 [ 718.108419] 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 [ 718.127682] RSP: 002b:00007ffedddb43b8 EFLAGS: 00000207 ORIG_RAX: 000000000000012b [ 718.135612] RAX: ffffffffffffffda RBX: 0000000020000000 RCX: 0000000000440379 [ 718.142915] RDX: 0000000000000002 RSI: 0000000020003340 RDI: 000000000000000a [ 718.150213] RBP: 00000000006ca018 R08: 0000000000000000 R09: 00000000004002c8 [ 718.157516] R10: 0000000000000000 R11: 0000000000000207 R12: 0000000000401c00 [ 718.164819] R13: 0000000000401c90 R14: 0000000000000000 R15: 0000000000000000 [ 718.172141] [ 718.172141] Showing all locks held in the system: [ 718.178497] 1 lock held by khungtaskd/901: [ 718.182770] #0: (____ptrval____) (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 [ 718.191422] 1 lock held by rsyslogd/4443: [ 718.195684] 2 locks held by getty/4533: [ 718.199684] #0: (____ptrval____) (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 718.207978] #1: (____ptrval____) (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 718.216901] 2 locks held by getty/4534: [ 718.220911] #0: (____ptrval____) (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 718.229189] #1: (____ptrval____) (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 718.238079] 2 locks held by getty/4535: [ 718.242067] #0: (____ptrval____) (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 718.250360] #1: (____ptrval____) (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 718.259260] 2 locks held by getty/4536: [ 718.263278] #0: (____ptrval____) (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 718.271574] #1: (____ptrval____) (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 718.280472] 2 locks held by getty/4537: [ 718.284464] #0: (____ptrval____) (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 718.293157] #1: (____ptrval____) (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 718.302092] 2 locks held by getty/4538: [ 718.306181] #0: (____ptrval____) (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 718.314474] #1: (____ptrval____) (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 718.323377] 2 locks held by getty/4539: [ 718.327374] #0: (____ptrval____) (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 718.335672] #1: (____ptrval____) (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 718.344581] 1 lock held by syz-executor633/4560: [ 718.349383] #0: (____ptrval____) (sk_lock-AF_ALG){+.+.}, at: aead_recvmsg+0xbb/0x1bb0 [ 718.358024] [ 718.359680] ============================================= [ 718.359680] [ 718.366744] NMI backtrace for cpu 0 [ 718.370409] CPU: 0 PID: 901 Comm: khungtaskd Not tainted 4.18.0-rc5+ #157 [ 718.377325] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 718.386659] Call Trace: [ 718.389295] dump_stack+0x1c9/0x2b4 [ 718.393023] ? dump_stack_print_info.cold.2+0x52/0x52 [ 718.398194] ? vprintk_default+0x28/0x30 [ 718.402287] nmi_cpu_backtrace.cold.4+0x19/0xce [ 718.406944] ? rcu_report_qs_rnp+0x7a0/0x7a0 [ 718.411507] ? lapic_can_unplug_cpu.cold.27+0x3f/0x3f [ 718.416704] nmi_trigger_cpumask_backtrace+0x151/0x192 [ 718.421970] arch_trigger_cpumask_backtrace+0x14/0x20 [ 718.427148] watchdog+0x9c4/0xf80 [ 718.430634] ? reset_hung_task_detector+0xd0/0xd0 [ 718.435474] ? kasan_check_read+0x11/0x20 [ 718.439601] ? do_raw_spin_unlock+0xa7/0x2f0 [ 718.443992] ? _raw_spin_unlock_irqrestore+0x74/0xc0 [ 718.449072] ? __kthread_parkme+0x58/0x1b0 [ 718.453294] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 718.458288] ? trace_hardirqs_on+0xd/0x10 [ 718.462416] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 718.468196] ? __kthread_parkme+0x106/0x1b0 [ 718.472497] kthread+0x345/0x410 [ 718.475842] ? reset_hung_task_detector+0xd0/0xd0 [ 718.480686] ? kthread_bind+0x40/0x40 [ 718.484467] ret_from_fork+0x3a/0x50 [ 718.488259] Sending NMI from CPU 0 to CPUs 1: [ 718.492807] NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0x6/0x10 [ 718.493793] Kernel panic - not syncing: hung_task: blocked tasks [ 718.506542] CPU: 0 PID: 901 Comm: khungtaskd Not tainted 4.18.0-rc5+ #157 [ 718.513634] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 718.522973] Call Trace: [ 718.525555] dump_stack+0x1c9/0x2b4 [ 718.529162] ? dump_stack_print_info.cold.2+0x52/0x52 [ 718.534345] ? printk_safe_log_store+0x2f0/0x2f0 [ 718.539088] panic+0x238/0x4e7 [ 718.542271] ? add_taint.cold.5+0x16/0x16 [ 718.546486] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 718.552004] ? nmi_trigger_cpumask_backtrace+0x13a/0x192 [ 718.557430] ? printk_safe_flush+0xd7/0x130 [ 718.561736] watchdog+0x9d5/0xf80 [ 718.565172] ? reset_hung_task_detector+0xd0/0xd0 [ 718.569999] ? kasan_check_read+0x11/0x20 [ 718.574126] ? do_raw_spin_unlock+0xa7/0x2f0 [ 718.578519] ? _raw_spin_unlock_irqrestore+0x74/0xc0 [ 718.583610] ? __kthread_parkme+0x58/0x1b0 [ 718.587826] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 718.592822] ? trace_hardirqs_on+0xd/0x10 [ 718.597384] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 718.602910] ? __kthread_parkme+0x106/0x1b0 [ 718.607215] kthread+0x345/0x410 [ 718.610560] ? reset_hung_task_detector+0xd0/0xd0 [ 718.615385] ? kthread_bind+0x40/0x40 [ 718.619164] ret_from_fork+0x3a/0x50 [ 718.623416] Dumping ftrace buffer: [ 718.627044] (ftrace buffer empty) [ 718.630748] Kernel Offset: disabled [ 718.634368] Rebooting in 86400 seconds..