[....] 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[ 23.452939] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 28.508083] random: sshd: uninitialized urandom read (32 bytes read) [ 28.773636] random: sshd: uninitialized urandom read (32 bytes read) [ 29.508938] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.55' (ECDSA) to the list of known hosts. [ 35.243439] random: sshd: uninitialized urandom read (32 bytes read) 2018/09/05 23:10:25 fuzzer started [ 36.247084] random: cc1: uninitialized urandom read (8 bytes read) 2018/09/05 23:10:26 connecting to host at 10.128.0.26:39751 2018/09/05 23:10:26 checking revisions... 2018/09/05 23:10:26 testing simple 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 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 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 185.231744] INFO: task syz-fuzzer:4912 blocked for more than 140 seconds. [ 185.238857] Not tainted 4.19.0-rc2-next-20180905+ #59 [ 185.244636] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 185.252663] syz-fuzzer D22208 4912 4896 0x00000000 [ 185.258389] Call Trace: [ 185.261038] __schedule+0x87c/0x1df0 [ 185.264839] ? __sched_text_start+0x8/0x8 [ 185.269042] ? ext4_set_page_dirty+0x254/0x340 [ 185.273703] ? graph_lock+0x170/0x170 [ 185.277591] ? print_usage_bug+0xc0/0xc0 [ 185.281738] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 185.287324] ? find_held_lock+0x36/0x1c0 [ 185.291448] schedule+0xfb/0x450 [ 185.294867] ? mark_held_locks+0xc9/0x160 [ 185.299113] ? __schedule+0x1df0/0x1df0 [ 185.303140] ? _raw_spin_unlock_irq+0x27/0x70 [ 185.307696] ? _raw_spin_unlock_irq+0x27/0x70 [ 185.312248] ? lockdep_hardirqs_on+0x421/0x5c0 [ 185.316908] ? trace_hardirqs_on+0xbd/0x2c0 [ 185.321284] ? kasan_check_read+0x11/0x20 [ 185.325520] ? __lock_page+0x585/0x7a0 [ 185.329532] ? trace_hardirqs_off_caller+0x2b0/0x2b0 [ 185.334775] ? kasan_check_write+0x14/0x20 [ 185.339089] io_schedule+0x1c/0x70 [ 185.342679] __lock_page+0x5b7/0x7a0 [ 185.346450] ? __lock_page_killable+0x850/0x850 [ 185.351195] ? __sb_end_write+0xac/0xe0 [ 185.355232] ? ext4_page_mkwrite+0xa95/0x1450 [ 185.359788] ? page_cache_tree_insert+0x560/0x560 [ 185.364695] ? __lock_is_held+0xb5/0x140 [ 185.368812] ? check_same_owner+0x340/0x340 [ 185.373253] ? rcu_note_context_switch+0x680/0x680 [ 185.378247] do_page_mkwrite+0x429/0x520 [ 185.382388] ? print_bad_pte+0x5f0/0x5f0 [ 185.386499] ? pud_val+0x88/0x100 [ 185.390031] ? find_held_lock+0x36/0x1c0 [ 185.394160] __handle_mm_fault+0x2a0a/0x4350 [ 185.398644] ? vmf_insert_mixed_mkwrite+0x40/0x40 [ 185.403581] ? graph_lock+0x170/0x170 [ 185.407457] ? kasan_check_read+0x11/0x20 [ 185.411671] ? lock_downgrade+0x8f0/0x8f0 [ 185.415888] ? handle_mm_fault+0x8c4/0xc80 [ 185.420173] ? handle_mm_fault+0x8c4/0xc80 [ 185.424465] ? kasan_check_read+0x11/0x20 [ 185.428704] ? rcu_is_watching+0x8c/0x150 [ 185.432908] ? __do_page_fault+0x620/0xe50 [ 185.437193] ? rcu_cleanup_dead_rnp+0x200/0x200 [ 185.441934] handle_mm_fault+0x53e/0xc80 [ 185.446054] ? __handle_mm_fault+0x4350/0x4350 [ 185.450720] ? find_vma+0x34/0x190 [ 185.454314] __do_page_fault+0x620/0xe50 [ 185.458461] ? mm_fault_error+0x380/0x380 [ 185.462674] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 185.468105] ? trace_hardirqs_on+0x2c0/0x2c0 [ 185.472587] do_page_fault+0xf6/0x7a4 [ 185.476471] ? vmalloc_sync_all+0x30/0x30 [ 185.480663] ? error_entry+0x70/0xd0 [ 185.484435] ? trace_hardirqs_off_caller+0xbb/0x2b0 [ 185.489583] ? trace_hardirqs_on_caller+0xc0/0x2b0 [ 185.494593] ? syscall_return_slowpath+0x5e0/0x5e0 [ 185.499587] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 185.504504] ? trace_hardirqs_on_caller+0x2b0/0x2b0 [ 185.509593] ? __bpf_trace_preemptirq_template+0x30/0x30 [ 185.515121] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 185.520196] ? recalc_sigpending_tsk+0x180/0x180 [ 185.525013] ? kasan_check_write+0x14/0x20 [ 185.529308] ? page_fault+0x8/0x30 [ 185.532911] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 185.537842] ? page_fault+0x8/0x30 [ 185.541448] page_fault+0x1e/0x30 [ 185.544945] RIP: 0033:0x70b581 [ 185.548200] Code: 48 89 6c 24 10 48 8d 6c 24 10 48 8b 44 24 20 48 8b 48 08 48 8b 50 10 48 8d 58 08 48 83 fa 08 0f 8c 1e 01 00 00 48 8b 54 24 28 <88> 11 48 8b 48 08 48 8b 70 10 48 83 fe 01 0f 86 44 01 00 00 48 89 [ 185.567189] RSP: 002b:000000c4201713f0 EFLAGS: 00010212 [ 185.572631] RAX: 000000c420171508 RBX: 000000c420171510 RCX: 00007f36a5aa3000 [ 185.579969] RDX: 0000000000000543 RSI: 000000000072a460 RDI: 000000c420171348 [ 185.587292] RBP: 000000c420171400 R08: 0000000000000000 R09: 0000000000000000 [ 185.594611] R10: 0000000000949c4a R11: 0000000000000004 R12: 0000000000000000 [ 185.601940] R13: 0000000000000020 R14: 0000000000000013 R15: 000000000000000f [ 185.609272] [ 185.609272] Showing all locks held in the system: [ 185.615662] 4 locks held by kworker/u4:1/22: [ 185.620122] #0: 00000000187f58b2 ((wq_completion)"writeback"){+.+.}, at: process_one_work+0xb44/0x1aa0 [ 185.629803] #1: 00000000a3167db3 ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: process_one_work+0xb9b/0x1aa0 [ 185.640445] #2: 0000000004b36728 (&fc->fs_type->s_umount_key#29){++++}, at: trylock_super+0x22/0x110 [ 185.649916] #3: 000000003d7da111 (&sbi->s_journal_flag_rwsem){.+.+}, at: do_writepages+0x9a/0x1a0 [ 185.659128] 1 lock held by khungtaskd/794: [ 185.663415] #0: 00000000b3f8c3fe (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 [ 185.672096] 1 lock held by khugepaged/800: [ 185.676381] #0: 00000000b0e1d5e1 (&mm->mmap_sem){++++}, at: collapse_huge_page+0x2bf/0x2250 [ 185.685092] 1 lock held by rsyslogd/4783: [ 185.689303] 2 locks held by getty/4874: [ 185.693312] #0: 00000000e014e5bc (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 185.701629] #1: 00000000d0c99809 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 185.710580] 2 locks held by getty/4875: [ 185.714624] #0: 0000000024bf42f4 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 185.722943] #1: 000000008b9a6a77 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 185.731906] 2 locks held by getty/4876: [ 185.735930] #0: 00000000970542ca (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 185.744247] #1: 00000000d860daa5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 185.753185] 2 locks held by getty/4877: [ 185.757218] #0: 000000001a50831b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 185.765580] #1: 000000001c283d47 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 185.774514] 2 locks held by getty/4878: [ 185.778569] #0: 00000000051d30a8 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 185.786872] #1: 000000001cd74c97 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 185.795792] 2 locks held by getty/4879: [ 185.799805] #0: 0000000085a19c98 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 185.808111] #1: 000000002a576dae (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 185.817035] 2 locks held by getty/4880: [ 185.821047] #0: 00000000e06e7cde (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 185.829370] #1: 00000000d9b2f732 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 185.838298] 1 lock held by syz-fuzzer/4912: [ 185.842702] #0: 00000000b0e1d5e1 (&mm->mmap_sem){++++}, at: __do_page_fault+0x389/0xe50 [ 185.851041] [ 185.852728] ============================================= [ 185.852728] [ 185.859791] NMI backtrace for cpu 0 [ 185.863474] CPU: 0 PID: 794 Comm: khungtaskd Not tainted 4.19.0-rc2-next-20180905+ #59 [ 185.871548] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 185.880902] Call Trace: [ 185.883502] dump_stack+0x1c9/0x2b4 [ 185.887137] ? dump_stack_print_info.cold.2+0x52/0x52 [ 185.892330] ? vprintk_default+0x28/0x30 [ 185.896402] ? lapic_can_unplug_cpu.cold.30+0x3f/0x3f [ 185.901596] nmi_cpu_backtrace.cold.4+0x48/0x88 [ 185.906272] ? rcu_cleanup_dead_rnp+0x200/0x200 [ 185.910952] ? lapic_can_unplug_cpu.cold.30+0x3f/0x3f [ 185.916149] nmi_trigger_cpumask_backtrace+0x1b6/0x1cd [ 185.921434] arch_trigger_cpumask_backtrace+0x14/0x20 [ 185.926629] watchdog+0xb39/0x1040 [ 185.930205] ? reset_hung_task_detector+0xd0/0xd0 [ 185.935084] ? _raw_spin_unlock_irqrestore+0x74/0xc0 [ 185.940202] ? _raw_spin_unlock_irqrestore+0x74/0xc0 [ 185.945313] ? lockdep_hardirqs_on+0x421/0x5c0 [ 185.949917] ? trace_hardirqs_on+0xbd/0x2c0 [ 185.954249] ? kasan_check_read+0x11/0x20 [ 185.958408] ? __kthread_parkme+0xd7/0x1b0 [ 185.962650] ? kasan_check_write+0x14/0x20 [ 185.966904] ? do_raw_spin_lock+0xc1/0x200 [ 185.971150] ? __kthread_parkme+0x58/0x1b0 [ 185.975391] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 185.980926] ? __kthread_parkme+0x106/0x1b0 [ 185.985270] kthread+0x35a/0x420 [ 185.988651] ? reset_hung_task_detector+0xd0/0xd0 [ 185.993497] ? kthread_bind+0x40/0x40 [ 185.997306] ret_from_fork+0x3a/0x50 [ 186.001098] Sending NMI from CPU 0 to CPUs 1: [ 186.006183] NMI backtrace for cpu 1 [ 186.006190] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.19.0-rc2-next-20180905+ #59 [ 186.006196] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 186.006200] RIP: 0010:lock_release+0x6b9/0x9f0 [ 186.006211] Code: 87 e8 1b de e7 ff 0f 0b 48 b8 00 00 00 00 00 fc ff df 4d 89 f8 49 c1 e8 03 41 c6 04 00 f8 e9 aa fd ff ff 65 ff 05 77 6c a3 7e <48> ba 00 00 00 00 00 fc ff df 49 8d 44 24 c0 48 c1 e8 03 48 01 d0 [ 186.006216] RSP: 0018:ffff8801d9f1f998 EFLAGS: 00000087 [ 186.006224] RAX: 0000000000000001 RBX: 1ffff1003b3e3f38 RCX: ffffffff8169bc28 [ 186.006229] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8801d9f0ebbc [ 186.006234] RBP: ffff8801d9f1fac8 R08: 0000000000000000 R09: ffffed003b6246e8 [ 186.006240] R10: ffffed003b6246e8 R11: ffff8801db123743 R12: ffff8801d9f1faa0 [ 186.006245] R13: ffff8801db123758 R14: 0000002c6f2d4510 R15: ffff8801d9f0e380 [ 186.006251] FS: 0000000000000000(0000) GS:ffff8801db100000(0000) knlGS:0000000000000000 [ 186.006255] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 186.006260] CR2: 00007fa02aa75000 CR3: 00000001b5e96000 CR4: 00000000001406e0 [ 186.006263] Call Trace: [ 186.006267] ? lock_acquire+0x1e4/0x4f0 [ 186.006271] ? get_next_timer_interrupt+0x13c/0x320 [ 186.006275] ? lock_downgrade+0x8f0/0x8f0 [ 186.006278] ? lock_release+0x9f0/0x9f0 [ 186.006282] ? lock_downgrade+0x8f0/0x8f0 [ 186.006286] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 186.006291] ? __sanitizer_cov_trace_cmp8+0x18/0x20 [ 186.006294] ? find_next_bit+0x104/0x130 [ 186.006299] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 186.006302] _raw_spin_unlock+0x1a/0x30 [ 186.006306] get_next_timer_interrupt+0x13c/0x320 [ 186.006310] tick_nohz_next_event+0x61a/0x8a0 [ 186.006315] ? __tick_nohz_idle_restart_tick+0x3c0/0x3c0 [ 186.006318] ? rcu_idle_exit+0x345/0x430 [ 186.006322] ? rcu_idle_exit+0x345/0x430 [ 186.006326] ? lockdep_hardirqs_on+0x421/0x5c0 [ 186.006329] ? do_idle+0x2d6/0x580 [ 186.006333] ? __sanitizer_cov_trace_const_cmp2+0x18/0x20 [ 186.006338] tick_nohz_idle_stop_tick+0x633/0xcb0 [ 186.006342] ? tick_nohz_tick_stopped_cpu+0x80/0x80 [ 186.006346] ? tsc_verify_tsc_adjust+0x109/0x380 [ 186.006349] ? trace_hardirqs_off+0xb8/0x2b0 [ 186.006354] ? trace_hardirqs_off_caller+0x2b0/0x2b0 [ 186.006358] ? mark_tsc_async_resets+0x20/0x20 [ 186.006361] ? trace_hardirqs_on+0x2c0/0x2c0 [ 186.006366] ? __tick_nohz_idle_restart_tick+0x28c/0x3c0 [ 186.006370] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 186.006373] do_idle+0x3a0/0x580 [ 186.006377] ? retint_kernel+0x10/0x10 [ 186.006381] ? arch_cpu_idle_exit+0x70/0x70 [ 186.006385] cpu_startup_entry+0x10c/0x120 [ 186.006388] ? cpu_in_idle+0x20/0x20 [ 186.006392] start_secondary+0x433/0x5d0 [ 186.006396] ? set_cpu_sibling_map+0x18b0/0x18b0 [ 186.006400] secondary_startup_64+0xa4/0xb0 [ 186.006641] Kernel panic - not syncing: hung_task: blocked tasks [ 186.281097] CPU: 0 PID: 794 Comm: khungtaskd Not tainted 4.19.0-rc2-next-20180905+ #59 [ 186.289150] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 186.298534] Call Trace: [ 186.301146] dump_stack+0x1c9/0x2b4 [ 186.304817] ? dump_stack_print_info.cold.2+0x52/0x52 [ 186.310028] ? printk_safe_log_store+0x2f0/0x2f0 [ 186.314805] panic+0x238/0x4e7 [ 186.318007] ? add_taint.cold.5+0x16/0x16 [ 186.322173] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 186.327722] ? nmi_trigger_cpumask_backtrace+0x18c/0x1cd [ 186.333177] ? printk_safe_flush+0xd7/0x130 [ 186.337508] watchdog+0xb4a/0x1040 [ 186.341078] ? reset_hung_task_detector+0xd0/0xd0 [ 186.345933] ? _raw_spin_unlock_irqrestore+0x74/0xc0 [ 186.351051] ? _raw_spin_unlock_irqrestore+0x74/0xc0 [ 186.356161] ? lockdep_hardirqs_on+0x421/0x5c0 [ 186.360756] ? trace_hardirqs_on+0xbd/0x2c0 [ 186.365088] ? kasan_check_read+0x11/0x20 [ 186.369249] ? __kthread_parkme+0xd7/0x1b0 [ 186.373545] ? kasan_check_write+0x14/0x20 [ 186.377809] ? do_raw_spin_lock+0xc1/0x200 [ 186.382065] ? __kthread_parkme+0x58/0x1b0 [ 186.386313] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 186.391858] ? __kthread_parkme+0x106/0x1b0 [ 186.396193] kthread+0x35a/0x420 [ 186.399572] ? reset_hung_task_detector+0xd0/0xd0 [ 186.404424] ? kthread_bind+0x40/0x40 [ 186.408241] ret_from_fork+0x3a/0x50 [ 186.412490] Dumping ftrace buffer: [ 186.416064] (ftrace buffer empty) [ 186.419762] Kernel Offset: disabled [ 186.423379] Rebooting in 86400 seconds..