[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 19.170787] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 22.859392] random: sshd: uninitialized urandom read (32 bytes read) [ 23.169183] random: sshd: uninitialized urandom read (32 bytes read) [ 24.001155] random: sshd: uninitialized urandom read (32 bytes read) [ 228.322896] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.38' (ECDSA) to the list of known hosts. [ 233.839425] random: sshd: uninitialized urandom read (32 bytes read) executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 400.526580] watchdog: BUG: soft lockup - CPU#1 stuck for 135s! [kworker/u4:4:656] [ 400.534246] Modules linked in: [ 400.537430] irq event stamp: 951694 [ 400.541061] hardirqs last enabled at (951693): [] restore_regs_and_return_to_kernel+0x0/0x2b [ 400.551280] hardirqs last disabled at (951694): [] interrupt_entry+0xb5/0xf0 [ 400.560023] softirqs last enabled at (725832): [] __do_softirq+0x780/0xb17 [ 400.568679] softirqs last disabled at (725765): [] irq_exit+0x1d1/0x200 [ 400.577623] CPU: 1 PID: 656 Comm: kworker/u4:4 Not tainted 4.18.0-rc1+ #109 [ 400.584711] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 400.594104] Workqueue: events_unbound flush_to_ldisc [ 400.599208] RIP: 0010:write_comp_data+0x6d/0x70 [ 400.603858] Code: 00 4e 8d 14 dd 28 00 00 00 4d 39 d0 72 1b 49 83 c1 01 4a 89 7c 10 e0 4a 89 74 10 e8 4a 89 54 10 f0 4a 89 4c d8 20 4c 89 08 5d 66 90 55 65 48 8b 04 25 40 ee 01 00 65 8b 15 1f 43 86 7e 48 89 [ 400.623200] RSP: 0018:ffff8801d801f230 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13 [ 400.630905] RAX: 0000000000000000 RBX: 0000000267eb5e47 RCX: ffffffff83a40d07 [ 400.638164] RDX: fffffffd9814b7b2 RSI: 0000000000000edf RDI: 0000000000000007 [ 400.645423] RBP: ffff8801d801f238 R08: ffff8801d80101c0 R09: 0000000000000006 [ 400.652685] R10: ffff8801d80101c0 R11: 0000000000000000 R12: ffffc90001e68000 [ 400.659949] R13: 00000000000015f9 R14: fffffffd9814b7b2 R15: 00000000000000ff [ 400.667216] FS: 0000000000000000(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000 [ 400.675431] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 400.681304] CR2: 00007f54f2c5de78 CR3: 00000001ae0aa000 CR4: 00000000001406e0 [ 400.688571] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 400.695830] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 400.703089] Call Trace: [ 400.705671] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 400.711200] __process_echoes+0x277/0x8d0 [ 400.715348] commit_echoes+0x163/0x1d0 [ 400.719251] n_tty_receive_buf_common+0x205b/0x2c60 [ 400.724265] ? save_stack+0x43/0xd0 [ 400.727887] ? __kasan_slab_free+0x11a/0x170 [ 400.732301] ? n_tty_receive_char_lnext+0x710/0x710 [ 400.737313] ? lock_release+0xa30/0xa30 [ 400.741286] ? trace_hardirqs_off+0xd/0x10 [ 400.745514] ? _raw_spin_unlock_irqrestore+0x63/0xc0 [ 400.750610] ? debug_check_no_obj_freed+0x30b/0x595 [ 400.755623] ? active_load_balance_cpu_stop+0x1030/0x1030 [ 400.761156] n_tty_receive_buf2+0x33/0x40 [ 400.765302] tty_ldisc_receive_buf+0xb0/0x190 [ 400.769790] ? n_tty_receive_buf_common+0x2c60/0x2c60 [ 400.774981] tty_port_default_receive_buf+0x115/0x180 [ 400.780165] ? tty_port_lower_dtr_rts+0x90/0x90 [ 400.784825] ? trace_hardirqs_on+0xd/0x10 [ 400.788976] flush_to_ldisc+0x3fd/0x570 [ 400.792956] ? tty_buffer_free+0x160/0x160 [ 400.797194] ? __lock_is_held+0xb5/0x140 [ 400.801261] process_one_work+0xc73/0x1ba0 [ 400.805490] ? debug_check_no_locks_freed+0x310/0x310 [ 400.810680] ? pwq_dec_nr_in_flight+0x4a0/0x4a0 [ 400.815342] ? lock_repin_lock+0x430/0x430 [ 400.819588] ? __sched_text_start+0x8/0x8 [ 400.823728] ? lock_downgrade+0x8f0/0x8f0 [ 400.827873] ? graph_lock+0x170/0x170 [ 400.831665] ? find_held_lock+0x36/0x1c0 [ 400.835756] ? lock_acquire+0x1e4/0x540 [ 400.839722] ? worker_thread+0x3dc/0x13c0 [ 400.843866] ? lock_downgrade+0x8f0/0x8f0 [ 400.848010] ? lock_release+0xa30/0xa30 [ 400.851980] ? kasan_check_read+0x11/0x20 [ 400.856120] ? do_raw_spin_unlock+0xa7/0x2f0 [ 400.860521] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 400.865099] ? kasan_check_write+0x14/0x20 [ 400.869329] ? do_raw_spin_lock+0xc1/0x200 [ 400.873560] worker_thread+0x189/0x13c0 [ 400.877542] ? process_one_work+0x1ba0/0x1ba0 [ 400.882037] ? graph_lock+0x170/0x170 [ 400.885842] ? find_held_lock+0x36/0x1c0 [ 400.889908] ? __schedule+0x1ed0/0x1ed0 [ 400.893881] ? do_raw_spin_unlock+0xa7/0x2f0 [ 400.898287] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 400.902865] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 400.908395] ? __kthread_parkme+0x111/0x1d0 [ 400.912720] ? parse_args.cold.15+0x1b3/0x1b3 [ 400.917212] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 400.922225] ? trace_hardirqs_on+0xd/0x10 [ 400.926378] kthread+0x345/0x410 [ 400.929736] ? process_one_work+0x1ba0/0x1ba0 [ 400.934222] ? kthread_bind+0x40/0x40 [ 400.938024] ret_from_fork+0x3a/0x50 [ 400.941738] Sending NMI from CPU 1 to CPUs 0: [ 400.946228] NMI backtrace for cpu 0 [ 400.946238] CPU: 0 PID: 4536 Comm: kworker/u4:11 Not tainted 4.18.0-rc1+ #109 [ 400.946242] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 400.946256] Workqueue: events_unbound flush_to_ldisc [ 400.946268] RIP: 0010:__sanitizer_cov_trace_const_cmp1+0x11/0x20 [ 400.946269] Code: bf 06 00 00 00 48 89 e5 48 8b 4d 08 e8 c8 fe ff ff 5d c3 66 0f 1f 44 00 00 55 40 0f b6 d6 40 0f b6 f7 bf 01 00 00 00 48 89 e5 <48> 8b 4d 08 e8 a6 fe ff ff 5d c3 0f 1f 40 00 55 0f b7 d6 0f b7 f7 [ 400.946390] RSP: 0018:ffff8801c8747238 EFLAGS: 00000246 [ 400.946397] RAX: 0000000000000000 RBX: 000000026d68de61 RCX: dffffc0000000000 [ 400.946402] RDX: 0000000000000000 RSI: 0000000000000082 RDI: 0000000000000001 [ 400.946407] RBP: ffff8801c8747238 R08: ffff8801ae296140 R09: 0000000000000006 [ 400.946412] R10: ffff8801ae296140 R11: 0000000000000000 R12: ffffc90001e50000 [ 400.946420] R13: 00000000000019f9 R14: 0000000000000000 R15: 00000000000000ff [ 400.946428] FS: 0000000000000000(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000 [ 400.946433] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 400.946438] CR2: 00007f54f2d02e78 CR3: 00000001ae0aa000 CR4: 00000000001406f0 [ 400.946445] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 400.946450] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 400.946452] Call Trace: [ 400.946461] __process_echoes+0x249/0x8d0 [ 400.946471] commit_echoes+0x163/0x1d0 [ 400.946481] n_tty_receive_buf_common+0x205b/0x2c60 [ 400.946489] ? save_stack+0x43/0xd0 [ 400.946498] ? __kasan_slab_free+0x11a/0x170 [ 400.946510] ? n_tty_receive_char_lnext+0x710/0x710 [ 400.946519] ? lock_release+0xa30/0xa30 [ 400.946529] ? trace_hardirqs_off+0xd/0x10 [ 400.946538] ? _raw_spin_unlock_irqrestore+0x63/0xc0 [ 400.946546] ? debug_check_no_obj_freed+0x30b/0x595 [ 400.946555] ? active_load_balance_cpu_stop+0x1030/0x1030 [ 400.946564] n_tty_receive_buf2+0x33/0x40 [ 400.946574] tty_ldisc_receive_buf+0xb0/0x190 [ 400.946583] ? n_tty_receive_buf_common+0x2c60/0x2c60 [ 400.946594] tty_port_default_receive_buf+0x115/0x180 [ 400.946603] ? tty_port_lower_dtr_rts+0x90/0x90 [ 400.946612] ? trace_hardirqs_on+0xd/0x10 [ 400.946622] flush_to_ldisc+0x3fd/0x570 [ 400.946633] ? tty_buffer_free+0x160/0x160 [ 400.946643] ? __lock_is_held+0xb5/0x140 [ 400.946653] process_one_work+0xc73/0x1ba0 [ 400.946663] ? debug_check_no_locks_freed+0x310/0x310 [ 400.946674] ? pwq_dec_nr_in_flight+0x4a0/0x4a0 [ 400.946682] ? lock_repin_lock+0x430/0x430 [ 400.946694] ? __sched_text_start+0x8/0x8 [ 400.946702] ? lock_downgrade+0x8f0/0x8f0 [ 400.946711] ? graph_lock+0x170/0x170 [ 400.946720] ? graph_lock+0x170/0x170 [ 400.946733] ? lock_acquire+0x1e4/0x540 [ 400.946741] ? worker_thread+0x3dc/0x13c0 [ 400.946750] ? lock_downgrade+0x8f0/0x8f0 [ 400.946760] ? lock_release+0xa30/0xa30 [ 400.946768] ? kasan_check_read+0x11/0x20 [ 400.946776] ? do_raw_spin_unlock+0xa7/0x2f0 [ 400.946784] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 400.946793] ? kasan_check_write+0x14/0x20 [ 400.946801] ? do_raw_spin_lock+0xc1/0x200 [ 400.946810] worker_thread+0x189/0x13c0 [ 400.946821] ? process_one_work+0x1ba0/0x1ba0 [ 400.946831] ? graph_lock+0x170/0x170 [ 400.946839] ? find_held_lock+0x36/0x1c0 [ 400.946850] ? find_held_lock+0x36/0x1c0 [ 400.946859] ? retint_kernel+0x10/0x10 [ 400.946868] ? schedule+0xfb/0x450 [ 400.946876] ? __schedule+0x1ed0/0x1ed0 [ 400.946885] ? retint_kernel+0x10/0x10 [ 400.946894] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 400.946901] ? __kthread_parkme+0x111/0x1d0 [ 400.946909] ? parse_args.cold.15+0x1b3/0x1b3 [ 400.946918] kthread+0x345/0x410 [ 400.946927] ? process_one_work+0x1ba0/0x1ba0 [ 400.946934] ? kthread_bind+0x40/0x40 [ 400.946942] ret_from_fork+0x3a/0x50 [ 400.947238] Kernel panic - not syncing: softlockup: hung tasks [ 401.309714] CPU: 1 PID: 656 Comm: kworker/u4:4 Tainted: G L 4.18.0-rc1+ #109 [ 401.318191] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 401.328364] Workqueue: events_unbound flush_to_ldisc [ 401.333464] Call Trace: [ 401.336034] [ 401.338183] dump_stack+0x1c9/0x2b4 [ 401.341807] ? dump_stack_print_info.cold.2+0x52/0x52 [ 401.346992] ? printk_safe_log_store+0x2f0/0x2f0 [ 401.351745] panic+0x238/0x4e7 [ 401.354930] ? add_taint.cold.5+0x16/0x16 [ 401.359073] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 401.364608] ? watchdog_timer_fn.cold.5+0xe2/0x126 [ 401.369531] ? watchdog_timer_fn.cold.5+0xd9/0x126 [ 401.374487] watchdog_timer_fn.cold.5+0xf3/0x126 [ 401.379334] __hrtimer_run_queues+0x3eb/0x10c0 [ 401.383970] ? watchdog+0x30/0x30 [ 401.387423] ? hrtimer_start_range_ns+0xd20/0xd20 [ 401.392265] ? pvclock_read_flags+0x160/0x160 [ 401.396764] ? kvm_clock_read+0x25/0x30 [ 401.400735] ? kvm_clock_read+0x25/0x30 [ 401.404702] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 401.409714] ? ktime_get_update_offsets_now+0x3db/0x5d0 [ 401.415076] ? do_timer+0x50/0x50 [ 401.418522] ? rcu_nmi_exit+0xe0/0x2d0 [ 401.422408] ? do_raw_spin_lock+0xc1/0x200 [ 401.426639] hrtimer_interrupt+0x2f3/0x750 [ 401.430898] smp_apic_timer_interrupt+0x165/0x730 [ 401.435734] ? smp_call_function_single_interrupt+0x660/0x660 [ 401.441618] ? _raw_spin_unlock+0x22/0x30 [ 401.445759] ? handle_edge_irq+0x330/0x870 [ 401.449987] ? task_prio+0x50/0x50 [ 401.453526] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 401.458365] apic_timer_interrupt+0xf/0x20 [ 401.462583] [ 401.464812] RIP: 0010:write_comp_data+0x6d/0x70 [ 401.469467] Code: 00 4e 8d 14 dd 28 00 00 00 4d 39 d0 72 1b 49 83 c1 01 4a 89 7c 10 e0 4a 89 74 10 e8 4a 89 54 10 f0 4a 89 4c d8 20 4c 89 08 5d 66 90 55 65 48 8b 04 25 40 ee 01 00 65 8b 15 1f 43 86 7e 48 89 [ 401.488801] RSP: 0018:ffff8801d801f230 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13 [ 401.496508] RAX: 0000000000000000 RBX: 0000000267eb5e47 RCX: ffffffff83a40d07 [ 401.503768] RDX: fffffffd9814b7b2 RSI: 0000000000000edf RDI: 0000000000000007 [ 401.511032] RBP: ffff8801d801f238 R08: ffff8801d80101c0 R09: 0000000000000006 [ 401.518291] R10: ffff8801d80101c0 R11: 0000000000000000 R12: ffffc90001e68000 [ 401.525552] R13: 00000000000015f9 R14: fffffffd9814b7b2 R15: 00000000000000ff [ 401.532831] ? __process_echoes+0x277/0x8d0 [ 401.537153] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 401.542681] __process_echoes+0x277/0x8d0 [ 401.546826] commit_echoes+0x163/0x1d0 [ 401.550710] n_tty_receive_buf_common+0x205b/0x2c60 [ 401.555720] ? save_stack+0x43/0xd0 [ 401.559337] ? __kasan_slab_free+0x11a/0x170 [ 401.563765] ? n_tty_receive_char_lnext+0x710/0x710 [ 401.568773] ? lock_release+0xa30/0xa30 [ 401.572742] ? trace_hardirqs_off+0xd/0x10 [ 401.576976] ? _raw_spin_unlock_irqrestore+0x63/0xc0 [ 401.582072] ? debug_check_no_obj_freed+0x30b/0x595 [ 401.587082] ? active_load_balance_cpu_stop+0x1030/0x1030 [ 401.592627] n_tty_receive_buf2+0x33/0x40 [ 401.596775] tty_ldisc_receive_buf+0xb0/0x190 [ 401.601262] ? n_tty_receive_buf_common+0x2c60/0x2c60 [ 401.606448] tty_port_default_receive_buf+0x115/0x180 [ 401.611645] ? tty_port_lower_dtr_rts+0x90/0x90 [ 401.616306] ? trace_hardirqs_on+0xd/0x10 [ 401.620455] flush_to_ldisc+0x3fd/0x570 [ 401.624428] ? tty_buffer_free+0x160/0x160 [ 401.628663] ? __lock_is_held+0xb5/0x140 [ 401.632727] process_one_work+0xc73/0x1ba0 [ 401.636954] ? debug_check_no_locks_freed+0x310/0x310 [ 401.642143] ? pwq_dec_nr_in_flight+0x4a0/0x4a0 [ 401.646804] ? lock_repin_lock+0x430/0x430 [ 401.651049] ? __sched_text_start+0x8/0x8 [ 401.655193] ? lock_downgrade+0x8f0/0x8f0 [ 401.659339] ? graph_lock+0x170/0x170 [ 401.663133] ? find_held_lock+0x36/0x1c0 [ 401.667207] ? lock_acquire+0x1e4/0x540 [ 401.671173] ? worker_thread+0x3dc/0x13c0 [ 401.675313] ? lock_downgrade+0x8f0/0x8f0 [ 401.679468] ? lock_release+0xa30/0xa30 [ 401.683438] ? kasan_check_read+0x11/0x20 [ 401.687578] ? do_raw_spin_unlock+0xa7/0x2f0 [ 401.691980] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 401.696556] ? kasan_check_write+0x14/0x20 [ 401.700784] ? do_raw_spin_lock+0xc1/0x200 [ 401.705016] worker_thread+0x189/0x13c0 [ 401.708998] ? process_one_work+0x1ba0/0x1ba0 [ 401.713492] ? graph_lock+0x170/0x170 [ 401.717309] ? find_held_lock+0x36/0x1c0 [ 401.721377] ? __schedule+0x1ed0/0x1ed0 [ 401.725343] ? do_raw_spin_unlock+0xa7/0x2f0 [ 401.729744] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 401.734321] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 401.739848] ? __kthread_parkme+0x111/0x1d0 [ 401.744164] ? parse_args.cold.15+0x1b3/0x1b3 [ 401.748652] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 401.753662] ? trace_hardirqs_on+0xd/0x10 [ 401.757804] kthread+0x345/0x410 [ 401.761165] ? process_one_work+0x1ba0/0x1ba0 [ 401.765649] ? kthread_bind+0x40/0x40 [ 401.769444] ret_from_fork+0x3a/0x50 [ 401.773781] Dumping ftrace buffer: [ 401.777410] (ftrace buffer empty) [ 401.781096] Kernel Offset: disabled [ 401.784702] Rebooting in 86400 seconds..