[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 18.837641] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 21.942270] random: sshd: uninitialized urandom read (32 bytes read) [ 22.274966] random: sshd: uninitialized urandom read (32 bytes read) [ 23.111255] random: sshd: uninitialized urandom read (32 bytes read) [ 585.072846] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.6' (ECDSA) to the list of known hosts. [ 590.544487] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 861.152209] INFO: task syz-executor255:4549 blocked for more than 140 seconds. [ 861.159827] Not tainted 4.18.0-rc5+ #149 [ 861.164444] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 861.172424] syz-executor255 D22856 4549 4545 0x00000004 [ 861.178164] Call Trace: [ 861.180897] __schedule+0x87c/0x1ed0 [ 861.184709] ? __sched_text_start+0x8/0x8 [ 861.188871] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 861.193600] ? _raw_spin_unlock_irqrestore+0x74/0xc0 [ 861.198718] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 861.203755] ? trace_hardirqs_on+0xd/0x10 [ 861.207909] ? prepare_to_wait_event+0x396/0xc70 [ 861.212686] ? prepare_to_wait_exclusive+0x550/0x550 [ 861.217820] schedule+0xfb/0x450 [ 861.221213] ? __schedule+0x1ed0/0x1ed0 [ 861.225202] ? check_same_owner+0x340/0x340 [ 861.229545] ? do_raw_spin_unlock+0xa7/0x2f0 [ 861.233965] ? replenish_dl_entity.cold.53+0x37/0x37 [ 861.239100] request_wait_answer+0x4c8/0x920 [ 861.243520] ? fuse_read_forget.isra.22+0xdc0/0xdc0 [ 861.248557] ? finish_wait+0x430/0x430 [ 861.252474] ? finish_wait+0x430/0x430 [ 861.256384] ? finish_wait+0x430/0x430 [ 861.260284] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 861.264885] ? fuse_dev_ioctl+0x430/0x430 [ 861.269048] ? kasan_check_write+0x14/0x20 [ 861.273312] ? do_raw_spin_lock+0xc1/0x200 [ 861.277559] __fuse_request_send+0x12a/0x1d0 [ 861.282030] fuse_request_send+0x62/0xa0 [ 861.286125] fuse_simple_request+0x33d/0x730 [ 861.290562] fuse_lookup_name+0x3ee/0x830 [ 861.294720] ? fuse_valid_type+0xb0/0xb0 [ 861.298809] ? __d_lookup_rcu+0xaa0/0xaa0 [ 861.302986] ? mutex_lock_nested+0x16/0x20 [ 861.307256] fuse_lookup+0xf9/0x4c0 [ 861.310894] ? fuse_lookup_name+0x830/0x830 [ 861.315251] ? d_lookup+0x221/0x340 [ 861.318900] fuse_atomic_open+0x214/0x350 [ 861.323082] ? fuse_lookup+0x4c0/0x4c0 [ 861.327013] lookup_open+0xdb1/0x1b40 [ 861.330864] ? complete_walk+0x260/0x260 [ 861.334965] ? down_read+0xb5/0x1d0 [ 861.338614] ? path_openat+0x204c/0x4e10 [ 861.342723] ? __down_interruptible+0x700/0x700 [ 861.347426] ? print_usage_bug+0xc0/0xc0 [ 861.351517] ? kasan_check_read+0x11/0x20 [ 861.355688] path_openat+0x207d/0x4e10 [ 861.359605] ? lock_acquire+0x1e4/0x540 [ 861.363614] ? path_lookupat.isra.45+0xbf0/0xbf0 [ 861.368405] ? __save_stack_trace+0x8d/0xf0 [ 861.372744] ? trace_hardirqs_on+0x10/0x10 [ 861.377038] ? save_stack+0xa9/0xd0 [ 861.380674] ? save_stack+0x43/0xd0 [ 861.384332] ? kasan_kmalloc+0xc4/0xe0 [ 861.388227] ? kasan_slab_alloc+0x12/0x20 [ 861.392401] ? kmem_cache_alloc+0x12e/0x760 [ 861.396744] ? prepare_creds+0x80/0x3f0 [ 861.400760] ? prepare_exec_creds+0x11/0xf0 [ 861.405111] ? prepare_bprm_creds+0x70/0x120 [ 861.409555] ? __do_execve_file.isra.35+0x475/0x2730 [ 861.414674] ? __x64_sys_execve+0x8f/0xc0 [ 861.418870] ? do_syscall_64+0x1b9/0x820 [ 861.422959] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 861.428364] ? find_held_lock+0x36/0x1c0 [ 861.432440] ? print_usage_bug+0xc0/0xc0 [ 861.436547] ? __lock_is_held+0xb5/0x140 [ 861.440625] ? graph_lock+0x170/0x170 [ 861.444452] do_filp_open+0x255/0x380 [ 861.448268] ? may_open_dev+0x100/0x100 [ 861.452278] ? lock_downgrade+0x8f0/0x8f0 [ 861.456438] do_open_execat+0x1fe/0x670 [ 861.460432] ? unregister_binfmt+0x2a0/0x2a0 [ 861.464854] ? do_raw_spin_lock+0xc1/0x200 [ 861.469199] __do_execve_file.isra.35+0x1827/0x2730 [ 861.474256] ? prepare_bprm_creds+0x120/0x120 [ 861.478783] ? __sanitizer_cov_trace_switch+0x53/0x90 [ 861.484031] ? __sanitizer_cov_trace_cmp8+0x18/0x20 [ 861.489097] ? __check_object_size+0x9d/0x5f2 [ 861.493624] ? usercopy_warn+0x120/0x120 [ 861.497717] ? kasan_check_read+0x11/0x20 [ 861.501888] ? do_raw_spin_unlock+0xa7/0x2f0 [ 861.506344] ? kasan_check_read+0x11/0x20 [ 861.510915] ? rcu_is_watching+0x8c/0x150 [ 861.515101] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 861.520665] ? strncpy_from_user+0x3be/0x510 [ 861.525104] ? mpi_free.cold.1+0x19/0x19 [ 861.529196] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 861.534774] ? getname_flags+0x26e/0x5a0 [ 861.538870] __x64_sys_execve+0x8f/0xc0 [ 861.542884] do_syscall_64+0x1b9/0x820 [ 861.546791] ? syscall_return_slowpath+0x5e0/0x5e0 [ 861.551759] ? syscall_return_slowpath+0x31d/0x5e0 [ 861.556713] ? entry_SYSCALL_64_after_hwframe+0x59/0xbe [ 861.562112] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 861.566984] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 861.572207] RIP: 0033:0x445869 [ 861.575403] Code: e8 7c b7 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 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 2b 12 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 861.594638] RSP: 002b:00007f0856ef5da8 EFLAGS: 00000246 ORIG_RAX: 000000000000003b [ 861.602368] RAX: ffffffffffffffda RBX: 00000000006dac3c RCX: 0000000000445869 [ 861.609669] RDX: 00000000200003c0 RSI: 0000000020000340 RDI: 0000000020000000 [ 861.616984] RBP: 00000000006dac38 R08: 0000000000000000 R09: 0000000000000000 [ 861.624289] R10: 0000000000000000 R11: 0000000000000246 R12: 64695f70756f7267 [ 861.631581] R13: 7375662f7665642f R14: 2f30656c69662f2e R15: 0000000000000001 [ 861.638901] [ 861.638901] Showing all locks held in the system: [ 861.645267] 1 lock held by khungtaskd/901: [ 861.649524] #0: (____ptrval____) (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 [ 861.658171] 1 lock held by rsyslogd/4429: [ 861.662350] 2 locks held by getty/4519: [ 861.666334] #0: (____ptrval____) (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 861.674642] #1: (____ptrval____) (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 861.683531] 2 locks held by getty/4520: [ 861.687520] #0: (____ptrval____) (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 861.695779] #1: (____ptrval____) (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 861.704937] 2 locks held by getty/4521: [ 861.708912] #0: (____ptrval____) (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 861.717188] #1: (____ptrval____) (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 861.726063] 2 locks held by getty/4522: [ 861.730071] #0: (____ptrval____) (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 861.738339] #1: (____ptrval____) (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 861.747231] 2 locks held by getty/4523: [ 861.751209] #0: (____ptrval____) (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 861.759485] #1: (____ptrval____) (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 861.768356] 2 locks held by getty/4524: [ 861.772335] #0: (____ptrval____) (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 861.780580] #1: (____ptrval____) (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 861.789446] 2 locks held by getty/4525: [ 861.793418] #0: (____ptrval____) (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 [ 861.801681] #1: (____ptrval____) (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 [ 861.810553] 3 locks held by syz-executor255/4549: [ 861.815408] #0: (____ptrval____) (&sig->cred_guard_mutex){+.+.}, at: prepare_bprm_creds+0x53/0x120 [ 861.824636] #1: (____ptrval____) (&type->i_mutex_dir_key#3){.+.+}, at: path_openat+0x204c/0x4e10 [ 861.833688] #2: (____ptrval____) (&fi->mutex){+.+.}, at: fuse_lock_inode+0xaf/0xe0 [ 861.841509] [ 861.843152] ============================================= [ 861.843152] [ 861.850171] NMI backtrace for cpu 1 [ 861.853807] CPU: 1 PID: 901 Comm: khungtaskd Not tainted 4.18.0-rc5+ #149 [ 861.860710] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 861.870041] Call Trace: [ 861.872704] dump_stack+0x1c9/0x2b4 [ 861.876316] ? dump_stack_print_info.cold.2+0x52/0x52 [ 861.881487] ? vprintk_default+0x28/0x30 [ 861.885533] nmi_cpu_backtrace.cold.4+0x19/0xce [ 861.890180] ? rcu_report_qs_rnp+0x7a0/0x7a0 [ 861.894567] ? lapic_can_unplug_cpu.cold.27+0x3f/0x3f [ 861.899742] nmi_trigger_cpumask_backtrace+0x151/0x192 [ 861.904998] arch_trigger_cpumask_backtrace+0x14/0x20 [ 861.910166] watchdog+0x9c4/0xf80 [ 861.913602] ? reset_hung_task_detector+0xd0/0xd0 [ 861.918425] ? kasan_check_read+0x11/0x20 [ 861.922566] ? do_raw_spin_unlock+0xa7/0x2f0 [ 861.926956] ? _raw_spin_unlock_irqrestore+0x74/0xc0 [ 861.932046] ? __kthread_parkme+0x58/0x1b0 [ 861.936262] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 861.941256] ? trace_hardirqs_on+0xd/0x10 [ 861.945383] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 861.950898] ? __kthread_parkme+0x106/0x1b0 [ 861.955206] kthread+0x345/0x410 [ 861.958552] ? reset_hung_task_detector+0xd0/0xd0 [ 861.963370] ? kthread_bind+0x40/0x40 [ 861.967148] ret_from_fork+0x3a/0x50 [ 861.970923] Sending NMI from CPU 1 to CPUs 0: [ 861.975435] NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0x6/0x10 [ 861.976424] Kernel panic - not syncing: hung_task: blocked tasks [ 861.989152] CPU: 1 PID: 901 Comm: khungtaskd Not tainted 4.18.0-rc5+ #149 [ 861.996064] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 862.005402] Call Trace: [ 862.007984] dump_stack+0x1c9/0x2b4 [ 862.011591] ? dump_stack_print_info.cold.2+0x52/0x52 [ 862.016761] ? printk_safe_log_store+0x2f0/0x2f0 [ 862.021498] panic+0x238/0x4e7 [ 862.024671] ? add_taint.cold.5+0x16/0x16 [ 862.028801] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 862.034317] ? nmi_trigger_cpumask_backtrace+0x13a/0x192 [ 862.039745] ? printk_safe_flush+0xd7/0x130 [ 862.044046] watchdog+0x9d5/0xf80 [ 862.047480] ? reset_hung_task_detector+0xd0/0xd0 [ 862.052304] ? kasan_check_read+0x11/0x20 [ 862.056441] ? do_raw_spin_unlock+0xa7/0x2f0 [ 862.060842] ? _raw_spin_unlock_irqrestore+0x74/0xc0 [ 862.065921] ? __kthread_parkme+0x58/0x1b0 [ 862.070134] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 862.075127] ? trace_hardirqs_on+0xd/0x10 [ 862.079255] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 862.084768] ? __kthread_parkme+0x106/0x1b0 [ 862.089076] kthread+0x345/0x410 [ 862.092423] ? reset_hung_task_detector+0xd0/0xd0 [ 862.097240] ? kthread_bind+0x40/0x40 [ 862.101019] ret_from_fork+0x3a/0x50 [ 862.105201] Dumping ftrace buffer: [ 862.108757] (ftrace buffer empty) [ 862.112445] Kernel Offset: disabled [ 862.116052] Rebooting in 86400 seconds..