[....] 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[ 23.642763] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 25.955154] random: sshd: uninitialized urandom read (32 bytes read) [ 26.233534] random: sshd: uninitialized urandom read (32 bytes read) [ 26.927919] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.54' (ECDSA) to the list of known hosts. [ 32.725492] random: sshd: uninitialized urandom read (32 bytes read) 2018/09/05 11:06:56 fuzzer started [ 34.200167] random: cc1: uninitialized urandom read (8 bytes read) 2018/09/05 11:06:59 connecting to host at 10.128.0.26:38023 2018/09/05 11:06:59 checking revisions... 2018/09/05 11:06:59 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 [ 185.211850] INFO: task syz-fuzzer:4937 blocked for more than 140 seconds. [ 185.219154] Not tainted 4.19.0-rc2-next-20180905+ #58 [ 185.225236] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 185.233250] syz-fuzzer D18312 4937 4929 0x00000000 [ 185.238958] Call Trace: [ 185.241695] __schedule+0x87c/0x1df0 [ 185.245478] ? graph_lock+0x170/0x170 [ 185.249348] ? __sched_text_start+0x8/0x8 [ 185.253665] ? graph_lock+0x170/0x170 [ 185.257523] ? print_usage_bug+0xc0/0xc0 [ 185.261674] ? mark_held_locks+0xc9/0x160 [ 185.266109] ? find_held_lock+0x36/0x1c0 [ 185.270245] schedule+0xfb/0x450 [ 185.273682] ? mark_held_locks+0xc9/0x160 [ 185.277894] ? __schedule+0x1df0/0x1df0 [ 185.281921] ? _raw_spin_unlock_irq+0x27/0x70 [ 185.286496] ? _raw_spin_unlock_irq+0x27/0x70 [ 185.291059] ? lockdep_hardirqs_on+0x421/0x5c0 [ 185.296057] ? trace_hardirqs_on+0xbd/0x2c0 [ 185.300436] ? kasan_check_read+0x11/0x20 [ 185.304665] ? __lock_page+0x585/0x7a0 [ 185.308633] ? trace_hardirqs_off_caller+0x2b0/0x2b0 [ 185.314087] ? kasan_check_write+0x14/0x20 [ 185.318347] io_schedule+0x1c/0x70 [ 185.321911] __lock_page+0x5b7/0x7a0 [ 185.325667] ? __lock_page_killable+0x850/0x850 [ 185.330364] ? __sched_text_start+0x8/0x8 [ 185.334533] ? page_cache_tree_insert+0x560/0x560 [ 185.339427] ? __lock_is_held+0xb5/0x140 [ 185.343546] ? check_same_owner+0x340/0x340 [ 185.347888] do_page_mkwrite+0x429/0x520 [ 185.351993] ? print_bad_pte+0x5f0/0x5f0 [ 185.356069] ? pud_val+0x88/0x100 [ 185.359648] ? find_held_lock+0x36/0x1c0 [ 185.363739] __handle_mm_fault+0x2a0a/0x4350 [ 185.368292] ? vmf_insert_mixed_mkwrite+0x40/0x40 [ 185.373141] ? graph_lock+0x170/0x170 [ 185.376964] ? kasan_check_read+0x11/0x20 [ 185.381223] ? lock_downgrade+0x8f0/0x8f0 [ 185.385401] ? handle_mm_fault+0x8c4/0xc80 [ 185.389728] ? handle_mm_fault+0x8c4/0xc80 [ 185.394007] ? kasan_check_read+0x11/0x20 [ 185.398252] ? rcu_is_watching+0x8c/0x150 [ 185.402501] ? __do_page_fault+0x620/0xe50 [ 185.406762] ? rcu_cleanup_dead_rnp+0x200/0x200 [ 185.411544] handle_mm_fault+0x53e/0xc80 [ 185.415646] ? __handle_mm_fault+0x4350/0x4350 [ 185.420251] ? find_vma+0x34/0x190 [ 185.423822] __do_page_fault+0x620/0xe50 [ 185.427912] ? mm_fault_error+0x380/0x380 [ 185.432092] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 185.437483] ? trace_hardirqs_on+0x2c0/0x2c0 [ 185.441913] do_page_fault+0xf6/0x7a4 [ 185.445786] ? vmalloc_sync_all+0x30/0x30 [ 185.449956] ? error_entry+0x70/0xd0 [ 185.453740] ? trace_hardirqs_off_caller+0xbb/0x2b0 [ 185.458777] ? trace_hardirqs_on_caller+0xc0/0x2b0 [ 185.463750] ? syscall_return_slowpath+0x5e0/0x5e0 [ 185.468712] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 185.473576] ? trace_hardirqs_on_caller+0x2b0/0x2b0 [ 185.478643] ? __bpf_trace_preemptirq_template+0x30/0x30 [ 185.484106] ? prepare_exit_to_usermode+0x291/0x3b0 [ 185.489161] ? page_fault+0x8/0x30 [ 185.492736] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 185.497611] ? page_fault+0x8/0x30 [ 185.501183] page_fault+0x1e/0x30 [ 185.504767] RIP: 0033:0x70b581 [ 185.507996] 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 [ 185.526942] RSP: 002b:000000c4200313f0 EFLAGS: 00010212 [ 185.532322] RAX: 000000c420031508 RBX: 000000c420031510 RCX: 00007f866e7b6000 [ 185.539641] RDX: 0000000000000543 RSI: 000000000072a460 RDI: 000000c420031348 [ 185.546977] RBP: 000000c420031400 R08: 0000000000000000 R09: 0000000000000000 [ 185.554317] R10: 0000000000949c4a R11: 0000000000000004 R12: 0000000000000000 [ 185.561629] R13: 0000000000000020 R14: 0000000000000013 R15: 000000000000000f [ 185.568951] [ 185.568951] Showing all locks held in the system: [ 185.575301] 4 locks held by kworker/u4:1/22: [ 185.579770] #0: 0000000052957d4b ((wq_completion)"writeback"){+.+.}, at: process_one_work+0xb44/0x1aa0 [ 185.589408] #1: 00000000b546704d ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: process_one_work+0xb9b/0x1aa0 [ 185.600073] #2: 00000000d237a6e1 (&fc->fs_type->s_umount_key#29){++++}, at: trylock_super+0x22/0x110 [ 185.609480] #3: 000000003d143c1c (&sbi->s_journal_flag_rwsem){.+.+}, at: do_writepages+0x9a/0x1a0 [ 185.618665] 1 lock held by khungtaskd/794: [ 185.623042] #0: 00000000adfb5ebc (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 [ 185.631687] 1 lock held by khugepaged/800: [ 185.635927] #0: 0000000055b7fb5a (&mm->mmap_sem){++++}, at: collapse_huge_page+0x2bf/0x2250 [ 185.644576] 1 lock held by rsyslogd/4818: [ 185.648725] #0: 0000000076dc56aa (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 [ 185.656740] 2 locks held by getty/4909: [ 185.660719] #0: 00000000a5d9adc5 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 185.668981] #1: 00000000acfa0b08 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 185.677866] 2 locks held by getty/4910: [ 185.681976] #0: 000000009928efe1 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 185.690299] #1: 00000000d2e6327d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 185.699291] 2 locks held by getty/4911: [ 185.703342] #0: 00000000632cdfd9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 185.711669] #1: 000000005a56df0e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 185.720863] 2 locks held by getty/4912: [ 185.724839] #0: 000000005e2c5f48 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 185.733210] #1: 000000007f7851b6 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 185.742179] 2 locks held by getty/4913: [ 185.746180] #0: 000000003a290c29 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 185.754462] #1: 00000000f0122597 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 185.763342] 2 locks held by getty/4914: [ 185.767334] #0: 0000000024fe72c9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 185.775710] #1: 000000008744e137 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 185.784592] 2 locks held by getty/4915: [ 185.788585] #0: 00000000ff9e67b2 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 185.796910] #1: 000000009c200ab5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 185.805804] 1 lock held by syz-fuzzer/4937: [ 185.810133] #0: 0000000055b7fb5a (&mm->mmap_sem){++++}, at: __do_page_fault+0x389/0xe50 [ 185.818471] [ 185.820133] ============================================= [ 185.820133] [ 185.827179] NMI backtrace for cpu 1 [ 185.830826] CPU: 1 PID: 794 Comm: khungtaskd Not tainted 4.19.0-rc2-next-20180905+ #58 [ 185.838865] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 185.848201] Call Trace: [ 185.850773] dump_stack+0x1c9/0x2b4 [ 185.854392] ? dump_stack_print_info.cold.2+0x52/0x52 [ 185.859630] ? vprintk_default+0x28/0x30 [ 185.863686] ? lapic_can_unplug_cpu.cold.30+0x3f/0x3f [ 185.868903] nmi_cpu_backtrace.cold.4+0x48/0x88 [ 185.873556] ? rcu_cleanup_dead_rnp+0x200/0x200 [ 185.878213] ? lapic_can_unplug_cpu.cold.30+0x3f/0x3f [ 185.883401] nmi_trigger_cpumask_backtrace+0x1b6/0x1cd [ 185.888677] arch_trigger_cpumask_backtrace+0x14/0x20 [ 185.894036] watchdog+0xb39/0x1040 [ 185.897572] ? reset_hung_task_detector+0xd0/0xd0 [ 185.902458] ? _raw_spin_unlock_irqrestore+0x74/0xc0 [ 185.907550] ? _raw_spin_unlock_irqrestore+0x74/0xc0 [ 185.912680] ? lockdep_hardirqs_on+0x421/0x5c0 [ 185.917261] ? trace_hardirqs_on+0xbd/0x2c0 [ 185.921566] ? kasan_check_read+0x11/0x20 [ 185.925704] ? __kthread_parkme+0xd7/0x1b0 [ 185.929941] ? kasan_check_write+0x14/0x20 [ 185.934210] ? do_raw_spin_lock+0xc1/0x200 [ 185.938482] ? __kthread_parkme+0x58/0x1b0 [ 185.942709] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 185.948379] ? __kthread_parkme+0x106/0x1b0 [ 185.952696] kthread+0x35a/0x420 [ 185.956060] ? reset_hung_task_detector+0xd0/0xd0 [ 185.960882] ? kthread_bind+0x40/0x40 [ 185.964671] ret_from_fork+0x3a/0x50 [ 185.968448] Sending NMI from CPU 1 to CPUs 0: [ 185.973286] NMI backtrace for cpu 0 [ 185.973291] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.19.0-rc2-next-20180905+ #58 [ 185.973296] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 185.973298] RIP: 0010:lockdep_sys_exit_thunk+0x20/0x2e [ 185.973307] Code: 8b 7d 08 e8 60 36 81 00 eb 18 55 48 89 e5 57 56 52 51 50 41 50 41 51 41 52 41 53 e8 48 31 5e 00 eb 00 41 5b 41 5a 41 59 41 58 <58> 59 5a 5e 5f 5d c3 90 90 90 90 90 90 90 55 48 89 e5 41 57 41 56 [ 185.973310] RSP: 0018:ffff8801db007fc0 EFLAGS: 00000082 [ 185.973315] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 [ 185.973319] RDX: 1ffffffff100ecc9 RSI: 0000000000000000 RDI: ffffffff88076648 [ 185.973322] RBP: ffff8801db007fe8 R08: ffffed003b6046df R09: ffffed003b6046de [ 185.973326] R10: ffffed003b6046de R11: ffff8801db0236f3 R12: 0000000000000000 [ 185.973329] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 185.973333] FS: 0000000000000000(0000) GS:ffff8801db000000(0000) knlGS:0000000000000000 [ 185.973336] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 185.973340] CR2: ffffffffff600400 CR3: 00000001d9831000 CR4: 00000000001406f0 [ 185.973341] Call Trace: [ 185.973343] [ 185.973346] ? rcu_dynticks_eqs_enter+0x22/0x30 [ 185.973348] ret_from_intr+0xb/0x1e [ 185.973349] [ 185.973352] RIP: 0010:native_safe_halt+0x6/0x10 [ 185.973360] Code: c7 48 89 45 d8 e8 ca 7a e5 fa 48 8b 45 d8 e9 d2 fe ff ff 48 89 df e8 b9 7a e5 fa eb 8a 90 90 90 90 90 90 90 55 48 89 e5 fb f4 <5d> c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 f4 5d c3 90 90 90 90 90 [ 185.973363] RSP: 0018:ffffffff88007bb8 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff02 [ 185.973369] RAX: dffffc0000000000 RBX: 1ffffffff1000f7b RCX: 0000000000000000 [ 185.973372] RDX: 1ffffffff10237d8 RSI: 0000000000000001 RDI: ffffffff8811bec0 [ 185.973376] RBP: ffffffff88007bb8 R08: ffffffff88075e40 R09: 0000000000000000 [ 185.973379] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 185.973383] R13: ffffffff88007c78 R14: 0000000000000000 R15: 0000000000000000 [ 185.973385] default_idle+0xc2/0x410 [ 185.973387] ? kasan_check_write+0x14/0x20 [ 185.973390] ? __sched_text_end+0x1/0x1 [ 185.973392] ? rcu_idle_enter+0x30a/0x480 [ 185.973394] ? rcu_eqs_special_set+0x1b0/0x1b0 [ 185.973397] ? tsc_verify_tsc_adjust+0x109/0x380 [ 185.973400] ? trace_hardirqs_off_caller+0x2b0/0x2b0 [ 185.973402] ? mark_tsc_async_resets+0x20/0x20 [ 185.973405] ? trace_hardirqs_on+0x2c0/0x2c0 [ 185.973408] ? __tick_nohz_idle_restart_tick+0x28c/0x3c0 [ 185.973410] arch_cpu_idle+0x10/0x20 [ 185.973412] default_idle_call+0x6d/0x90 [ 185.973414] do_idle+0x3aa/0x580 [ 185.973428] ? arch_cpu_idle_exit+0x70/0x70 [ 185.973430] cpu_startup_entry+0x10c/0x120 [ 185.973433] ? cpu_in_idle+0x20/0x20 [ 185.973435] rest_init+0xe1/0xe4 [ 185.973437] start_kernel+0x8f9/0x934 [ 185.973439] ? mem_encrypt_init+0xb/0xb [ 185.973442] ? early_idt_handler_common+0x3b/0x60 [ 185.973445] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 185.973447] ? x86_family+0x3e/0x50 [ 185.973450] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 185.973453] x86_64_start_reservations+0x29/0x2b [ 185.973455] x86_64_start_kernel+0x76/0x79 [ 185.973457] secondary_startup_64+0xa4/0xb0 [ 185.973967] Kernel panic - not syncing: hung_task: blocked tasks [ 186.283473] CPU: 1 PID: 794 Comm: khungtaskd Not tainted 4.19.0-rc2-next-20180905+ #58 [ 186.291527] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 186.300903] Call Trace: [ 186.303492] dump_stack+0x1c9/0x2b4 [ 186.307235] ? dump_stack_print_info.cold.2+0x52/0x52 [ 186.312421] ? printk_safe_log_store+0x2f0/0x2f0 [ 186.317168] panic+0x238/0x4e7 [ 186.320346] ? add_taint.cold.5+0x16/0x16 [ 186.324483] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 186.330173] ? nmi_trigger_cpumask_backtrace+0x18c/0x1cd [ 186.335634] ? printk_safe_flush+0xd7/0x130 [ 186.339977] watchdog+0xb4a/0x1040 [ 186.343632] ? reset_hung_task_detector+0xd0/0xd0 [ 186.348472] ? _raw_spin_unlock_irqrestore+0x74/0xc0 [ 186.353572] ? _raw_spin_unlock_irqrestore+0x74/0xc0 [ 186.358724] ? lockdep_hardirqs_on+0x421/0x5c0 [ 186.363411] ? trace_hardirqs_on+0xbd/0x2c0 [ 186.367742] ? kasan_check_read+0x11/0x20 [ 186.371891] ? __kthread_parkme+0xd7/0x1b0 [ 186.376145] ? kasan_check_write+0x14/0x20 [ 186.380377] ? do_raw_spin_lock+0xc1/0x200 [ 186.384612] ? __kthread_parkme+0x58/0x1b0 [ 186.388838] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 186.394369] ? __kthread_parkme+0x106/0x1b0 [ 186.398675] kthread+0x35a/0x420 [ 186.402027] ? reset_hung_task_detector+0xd0/0xd0 [ 186.406857] ? kthread_bind+0x40/0x40 [ 186.410644] ret_from_fork+0x3a/0x50 [ 186.414741] Dumping ftrace buffer: [ 186.418298] (ftrace buffer empty) [ 186.422006] Kernel Offset: disabled [ 186.425618] Rebooting in 86400 seconds..