[....] 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[ 23.890502] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. [ 24.907879] random: sshd: uninitialized urandom read (32 bytes read) Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 25.162607] random: sshd: uninitialized urandom read (32 bytes read) [ 25.894554] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.10.35' (ECDSA) to the list of known hosts. [ 31.460335] random: sshd: uninitialized urandom read (32 bytes read) 2018/09/05 09:52:56 fuzzer started [ 32.871348] random: cc1: uninitialized urandom read (8 bytes read) 2018/09/05 09:52:59 connecting to host at 10.128.0.26:41141 2018/09/05 09:52:59 checking revisions... 2018/09/05 09:52:59 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 [ 185.185093] INFO: task syz-fuzzer:4898 blocked for more than 140 seconds. [ 185.192326] Not tainted 4.19.0-rc2-next-20180905+ #57 [ 185.198084] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 185.206091] syz-fuzzer D21624 4898 4890 0x00000000 [ 185.211764] Call Trace: [ 185.214557] __schedule+0x87c/0x1df0 [ 185.218287] ? __sched_text_start+0x8/0x8 [ 185.222453] ? ext4_set_page_dirty+0x254/0x340 [ 185.227058] ? graph_lock+0x170/0x170 [ 185.230882] ? print_usage_bug+0xc0/0xc0 [ 185.234965] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 185.240550] ? find_held_lock+0x36/0x1c0 [ 185.244620] schedule+0xfb/0x450 [ 185.247997] ? mark_held_locks+0xc9/0x160 [ 185.252173] ? __schedule+0x1df0/0x1df0 [ 185.256155] ? _raw_spin_unlock_irq+0x27/0x70 [ 185.260676] ? _raw_spin_unlock_irq+0x27/0x70 [ 185.265183] ? lockdep_hardirqs_on+0x421/0x5c0 [ 185.269775] ? trace_hardirqs_on+0xbd/0x2c0 [ 185.274124] ? kasan_check_read+0x11/0x20 [ 185.278298] ? __lock_page+0x585/0x7a0 [ 185.282206] ? trace_hardirqs_off_caller+0x2b0/0x2b0 [ 185.287335] ? kasan_check_write+0x14/0x20 [ 185.291583] io_schedule+0x1c/0x70 [ 185.295137] __lock_page+0x5b7/0x7a0 [ 185.298867] ? __lock_page_killable+0x850/0x850 [ 185.303563] ? __sb_end_write+0xac/0xe0 [ 185.307939] ? ext4_page_mkwrite+0xa95/0x1450 [ 185.312448] ? page_cache_tree_insert+0x560/0x560 [ 185.317309] ? __lock_is_held+0xb5/0x140 [ 185.321412] ? check_same_owner+0x340/0x340 [ 185.325746] ? rcu_note_context_switch+0x680/0x680 [ 185.330695] do_page_mkwrite+0x429/0x520 [ 185.334778] ? print_bad_pte+0x5f0/0x5f0 [ 185.338862] ? pud_val+0x88/0x100 [ 185.342330] ? find_held_lock+0x36/0x1c0 [ 185.346402] __handle_mm_fault+0x2a0a/0x4350 [ 185.350821] ? vmf_insert_mixed_mkwrite+0x40/0x40 [ 185.355693] ? graph_lock+0x170/0x170 [ 185.359512] ? kasan_check_read+0x11/0x20 [ 185.363675] ? lock_downgrade+0x8f0/0x8f0 [ 185.367827] ? handle_mm_fault+0x8c4/0xc80 [ 185.372099] ? handle_mm_fault+0x8c4/0xc80 [ 185.376368] ? kasan_check_read+0x11/0x20 [ 185.380530] ? rcu_is_watching+0x8c/0x150 [ 185.384688] ? __do_page_fault+0x620/0xe50 [ 185.388940] ? rcu_cleanup_dead_rnp+0x200/0x200 [ 185.393648] handle_mm_fault+0x53e/0xc80 [ 185.397732] ? __handle_mm_fault+0x4350/0x4350 [ 185.402338] ? find_vma+0x34/0x190 [ 185.405884] __do_page_fault+0x620/0xe50 [ 185.409966] ? mm_fault_error+0x380/0x380 [ 185.414244] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 185.419649] ? trace_hardirqs_on+0x2c0/0x2c0 [ 185.424077] do_page_fault+0xf6/0x7a4 [ 185.427896] ? vmalloc_sync_all+0x30/0x30 [ 185.432077] ? error_entry+0x70/0xd0 [ 185.435798] ? trace_hardirqs_off_caller+0xbb/0x2b0 [ 185.440826] ? trace_hardirqs_on_caller+0xc0/0x2b0 [ 185.445794] ? syscall_return_slowpath+0x5e0/0x5e0 [ 185.450752] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 185.455607] ? trace_hardirqs_on_caller+0x2b0/0x2b0 [ 185.460630] ? __bpf_trace_preemptirq_template+0x30/0x30 [ 185.466121] ? prepare_exit_to_usermode+0x291/0x3b0 [ 185.471146] ? page_fault+0x8/0x30 [ 185.474726] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 185.479653] ? page_fault+0x8/0x30 [ 185.483222] page_fault+0x1e/0x30 [ 185.486688] RIP: 0033:0x70b581 [ 185.489917] Code: Bad RIP value. [ 185.493290] RSP: 002b:000000c4201533f0 EFLAGS: 00010212 [ 185.498678] RAX: 000000c420153508 RBX: 000000c420153510 RCX: 00007f587d34b000 [ 185.506002] RDX: 0000000000000543 RSI: 000000000072a460 RDI: 000000c420153348 [ 185.513280] RBP: 000000c420153400 R08: 0000000000000000 R09: 0000000000000000 [ 185.520563] R10: 0000000000949c4a R11: 0000000000000004 R12: 0000000000000000 [ 185.527853] R13: 0000000000000020 R14: 0000000000000013 R15: 000000000000000f [ 185.535142] [ 185.535142] Showing all locks held in the system: [ 185.541485] 4 locks held by kworker/u4:2/41: [ 185.545916] #0: 000000006053b3ae ((wq_completion)"writeback"){+.+.}, at: process_one_work+0xb44/0x1aa0 [ 185.555486] #1: 00000000a9cb9dff ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: process_one_work+0xb9b/0x1aa0 [ 185.566093] #2: 000000007ddccf92 (&fc->fs_type->s_umount_key#29){++++}, at: trylock_super+0x22/0x110 [ 185.575514] #3: 00000000d01c70a4 (&sbi->s_journal_flag_rwsem){.+.+}, at: do_writepages+0x9a/0x1a0 [ 185.584642] 1 lock held by khungtaskd/794: [ 185.588885] #0: 000000000810ff93 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 [ 185.597518] 1 lock held by khugepaged/800: [ 185.601751] #0: 00000000c0a7aad7 (&mm->mmap_sem){++++}, at: collapse_huge_page+0x2bf/0x2250 [ 185.610368] 1 lock held by rsyslogd/4780: [ 185.614527] 2 locks held by getty/4871: [ 185.618515] #0: 00000000c029bb26 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 185.626768] #1: 0000000068953dbc (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 185.635629] 2 locks held by getty/4872: [ 185.639710] #0: 000000004202c52f (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 185.647977] #1: 0000000011fca544 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 185.656975] 2 locks held by getty/4873: [ 185.660964] #0: 0000000087b0eb14 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 185.669217] #1: 000000001c2f8034 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 185.678079] 2 locks held by getty/4874: [ 185.682052] #0: 000000006924e689 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 185.690373] #1: 00000000d2440f19 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 185.699251] 2 locks held by getty/4875: [ 185.703234] #0: 0000000056954753 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 185.711527] #1: 00000000c29310ea (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 185.720424] 2 locks held by getty/4876: [ 185.724397] #0: 00000000ed33cc53 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 185.732682] #1: 000000006d83c208 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 185.741543] 2 locks held by getty/4877: [ 185.745529] #0: 00000000a263b18d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 185.753779] #1: 000000000120283f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 185.762642] 1 lock held by syz-fuzzer/4898: [ 185.767083] #0: 00000000c0a7aad7 (&mm->mmap_sem){++++}, at: __do_page_fault+0x389/0xe50 [ 185.775337] [ 185.776995] ============================================= [ 185.776995] [ 185.784017] NMI backtrace for cpu 0 [ 185.787650] CPU: 0 PID: 794 Comm: khungtaskd Not tainted 4.19.0-rc2-next-20180905+ #57 [ 185.795684] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 185.805014] Call Trace: [ 185.807610] dump_stack+0x1c9/0x2b4 [ 185.811219] ? dump_stack_print_info.cold.2+0x52/0x52 [ 185.816393] ? vprintk_default+0x28/0x30 [ 185.820445] ? lapic_can_unplug_cpu.cold.30+0x3f/0x3f [ 185.825616] nmi_cpu_backtrace.cold.4+0x48/0x88 [ 185.830268] ? rcu_cleanup_dead_rnp+0x200/0x200 [ 185.834935] ? lapic_can_unplug_cpu.cold.30+0x3f/0x3f [ 185.840172] nmi_trigger_cpumask_backtrace+0x1b6/0x1cd [ 185.845443] arch_trigger_cpumask_backtrace+0x14/0x20 [ 185.850628] watchdog+0xb39/0x1040 [ 185.854168] ? reset_hung_task_detector+0xd0/0xd0 [ 185.858992] ? _raw_spin_unlock_irqrestore+0x74/0xc0 [ 185.864074] ? _raw_spin_unlock_irqrestore+0x74/0xc0 [ 185.869159] ? lockdep_hardirqs_on+0x421/0x5c0 [ 185.873721] ? trace_hardirqs_on+0xbd/0x2c0 [ 185.878023] ? kasan_check_read+0x11/0x20 [ 185.882152] ? __kthread_parkme+0xd7/0x1b0 [ 185.886366] ? kasan_check_write+0x14/0x20 [ 185.890647] ? do_raw_spin_lock+0xc1/0x200 [ 185.894887] ? __kthread_parkme+0x58/0x1b0 [ 185.899133] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 185.904661] ? __kthread_parkme+0x106/0x1b0 [ 185.908963] kthread+0x35a/0x420 [ 185.912307] ? reset_hung_task_detector+0xd0/0xd0 [ 185.917160] ? kthread_bind+0x40/0x40 [ 185.920940] ret_from_fork+0x3a/0x50 [ 185.924722] Sending NMI from CPU 0 to CPUs 1: [ 185.929540] NMI backtrace for cpu 1 [ 185.929545] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.19.0-rc2-next-20180905+ #57 [ 185.929550] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 185.929553] RIP: 0010:__sanitizer_cov_trace_pc+0x14/0x50 [ 185.929561] Code: 4a 89 74 10 e8 4a 89 54 10 f0 4a 89 4c d8 20 4c 89 08 5d c3 66 90 55 65 48 8b 04 25 40 ee 01 00 65 8b 15 bf 43 86 7e 48 89 e5 <81> e2 00 01 1f 00 48 8b 75 08 75 2b 8b 90 88 12 00 00 83 fa 02 75 [ 185.929564] RSP: 0018:ffff8801d9f1fa90 EFLAGS: 00000083 [ 185.929569] RAX: ffff8801d9f0e380 RBX: 0000000000000800 RCX: ffffffff81690ecd [ 185.929573] RDX: 0000000080000002 RSI: 0000000000000200 RDI: 0000000000000004 [ 185.929576] RBP: ffff8801d9f1fa90 R08: ffff8801d9f0e380 R09: ffffed003b6246e8 [ 185.929579] R10: ffffed003b6246e8 R11: ffff8801db123743 R12: 0000000000000007 [ 185.929583] R13: 00000000000001c0 R14: 0000000000000200 R15: 00000000000001d5 [ 185.929587] FS: 0000000000000000(0000) GS:ffff8801db100000(0000) knlGS:0000000000000000 [ 185.929590] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 185.929593] CR2: ffffffffff600400 CR3: 00000001b7d75000 CR4: 00000000001406e0 [ 185.929595] Call Trace: [ 185.929597] __next_timer_interrupt+0x65/0x1a0 [ 185.929600] get_next_timer_interrupt+0x68/0x320 [ 185.929602] tick_nohz_next_event+0x61a/0x8a0 [ 185.929605] ? __tick_nohz_idle_restart_tick+0x3c0/0x3c0 [ 185.929607] ? rcu_idle_exit+0x345/0x430 [ 185.929610] ? rcu_idle_exit+0x345/0x430 [ 185.929612] ? lockdep_hardirqs_on+0x421/0x5c0 [ 185.929614] ? do_idle+0x2d6/0x580 [ 185.929617] ? __sanitizer_cov_trace_const_cmp2+0x18/0x20 [ 185.929620] tick_nohz_idle_stop_tick+0x633/0xcb0 [ 185.929622] ? tick_nohz_tick_stopped_cpu+0x80/0x80 [ 185.929625] ? tsc_verify_tsc_adjust+0x109/0x380 [ 185.929627] ? trace_hardirqs_off+0xb8/0x2b0 [ 185.929631] ? trace_hardirqs_off_caller+0x2b0/0x2b0 [ 185.929634] ? mark_tsc_async_resets+0x20/0x20 [ 185.929637] ? trace_hardirqs_on+0x2c0/0x2c0 [ 185.929640] ? __tick_nohz_idle_restart_tick+0x28c/0x3c0 [ 185.929642] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 185.929644] do_idle+0x3a0/0x580 [ 185.929647] ? retint_kernel+0x10/0x10 [ 185.929649] ? arch_cpu_idle_exit+0x70/0x70 [ 185.929651] cpu_startup_entry+0x10c/0x120 [ 185.929653] ? cpu_in_idle+0x20/0x20 [ 185.929656] start_secondary+0x433/0x5d0 [ 185.929658] ? set_cpu_sibling_map+0x18b0/0x18b0 [ 185.929661] secondary_startup_64+0xa4/0xb0 [ 185.930234] Kernel panic - not syncing: hung_task: blocked tasks [ 186.163412] CPU: 0 PID: 794 Comm: khungtaskd Not tainted 4.19.0-rc2-next-20180905+ #57 [ 186.171444] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 186.180774] Call Trace: [ 186.183362] dump_stack+0x1c9/0x2b4 [ 186.186975] ? dump_stack_print_info.cold.2+0x52/0x52 [ 186.192165] ? printk_safe_log_store+0x2f0/0x2f0 [ 186.196903] panic+0x238/0x4e7 [ 186.200077] ? add_taint.cold.5+0x16/0x16 [ 186.204208] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 186.209729] ? nmi_trigger_cpumask_backtrace+0x18c/0x1cd [ 186.215158] ? printk_safe_flush+0xd7/0x130 [ 186.219464] watchdog+0xb4a/0x1040 [ 186.222988] ? reset_hung_task_detector+0xd0/0xd0 [ 186.227813] ? _raw_spin_unlock_irqrestore+0x74/0xc0 [ 186.232896] ? _raw_spin_unlock_irqrestore+0x74/0xc0 [ 186.237982] ? lockdep_hardirqs_on+0x421/0x5c0 [ 186.242663] ? trace_hardirqs_on+0xbd/0x2c0 [ 186.246975] ? kasan_check_read+0x11/0x20 [ 186.251106] ? __kthread_parkme+0xd7/0x1b0 [ 186.255321] ? kasan_check_write+0x14/0x20 [ 186.259550] ? do_raw_spin_lock+0xc1/0x200 [ 186.263794] ? __kthread_parkme+0x58/0x1b0 [ 186.268007] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 186.273523] ? __kthread_parkme+0x106/0x1b0 [ 186.277831] kthread+0x35a/0x420 [ 186.281179] ? reset_hung_task_detector+0xd0/0xd0 [ 186.285998] ? kthread_bind+0x40/0x40 [ 186.289789] ret_from_fork+0x3a/0x50 [ 186.293932] Dumping ftrace buffer: [ 186.297479] (ftrace buffer empty) [ 186.301191] Kernel Offset: disabled [ 186.304827] Rebooting in 86400 seconds..