[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 15.666706] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 19.228455] random: sshd: uninitialized urandom read (32 bytes read) [ 19.593285] random: sshd: uninitialized urandom read (32 bytes read) [ 20.322476] random: sshd: uninitialized urandom read (32 bytes read) [ 654.860281] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.12' (ECDSA) to the list of known hosts. [ 660.286360] random: sshd: uninitialized urandom read (32 bytes read) executing program [ 861.151220] INFO: task syz-executor027:4468 blocked for more than 140 seconds. [ 861.158680] Not tainted 4.18.0-rc5-next-20180720+ #12 [ 861.164409] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 861.172398] syz-executor027 D25504 4468 4464 0x00000004 [ 861.178061] Call Trace: [ 861.180674] __schedule+0x87c/0x1ea0 [ 861.184418] ? __sched_text_start+0x8/0x8 [ 861.188591] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 861.193222] ? kasan_check_write+0x14/0x20 [ 861.197513] ? do_raw_spin_lock+0xc1/0x200 [ 861.201777] ? trace_hardirqs_on+0xd/0x10 [ 861.205951] ? prepare_to_wait_event+0x396/0xc70 [ 861.210741] ? prepare_to_wait_exclusive+0x550/0x550 [ 861.215865] ? send_sigio+0x340/0x340 [ 861.219695] ? do_raw_spin_unlock+0xa7/0x2f0 [ 861.224121] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 861.228751] schedule+0xfb/0x450 [ 861.232159] ? lock_downgrade+0x8f0/0x8f0 [ 861.236383] ? __schedule+0x1ea0/0x1ea0 [ 861.240410] ? check_same_owner+0x340/0x340 [ 861.244807] ? do_raw_spin_unlock+0xa7/0x2f0 [ 861.249262] ? replenish_dl_entity.cold.54+0x37/0x37 [ 861.254429] request_wait_answer+0x4c8/0x920 [ 861.258860] ? fuse_read_forget.isra.22+0xdc0/0xdc0 [ 861.263929] ? finish_wait+0x430/0x430 [ 861.267858] ? send_sigio+0x340/0x340 [ 861.271697] ? lock_acquire+0x1e4/0x540 [ 861.275699] ? finish_wait+0x430/0x430 [ 861.279629] ? refcount_inc_not_zero_checked+0x1e5/0x2f0 [ 861.285107] ? finish_wait+0x430/0x430 [ 861.289030] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 861.293642] ? fuse_dev_ioctl+0x430/0x430 [ 861.297913] ? kasan_check_write+0x14/0x20 [ 861.302186] ? do_raw_spin_lock+0xc1/0x200 [ 861.306453] __fuse_request_send+0x12a/0x1d0 [ 861.310886] fuse_request_send+0x62/0xa0 [ 861.314990] fuse_simple_request+0x33d/0x730 [ 861.319449] fuse_lookup_name+0x3ee/0x830 [ 861.323630] ? fuse_valid_type+0xb0/0xb0 [ 861.327723] ? mutex_lock_nested+0x16/0x20 [ 861.331985] fuse_lookup+0xff/0x4c0 [ 861.335633] ? fuse_lookup_name+0x830/0x830 [ 861.339984] ? lock_acquire+0x1e4/0x540 [ 861.343981] ? __lockdep_init_map+0x105/0x590 [ 861.348532] __lookup_slow+0x2b5/0x540 [ 861.352460] ? vfs_unlink+0x510/0x510 [ 861.356436] ? down_read+0xb5/0x1d0 [ 861.360109] ? lookup_slow+0x49/0x80 [ 861.363891] ? __down_interruptible+0x700/0x700 [ 861.368606] ? lookup_fast+0x470/0x12a0 [ 861.372649] ? __follow_mount_rcu.isra.35.part.36+0x890/0x890 [ 861.378570] lookup_slow+0x57/0x80 [ 861.382132] walk_component+0x94a/0x2630 [ 861.386219] ? inode_permission+0xb2/0x560 [ 861.390492] ? path_init+0x1fc0/0x1fc0 [ 861.394400] ? walk_component+0x2630/0x2630 [ 861.398744] ? save_stack+0xa9/0xd0 [ 861.402393] ? save_stack+0x43/0xd0 [ 861.406053] ? kmem_cache_alloc+0x12e/0x760 [ 861.410401] ? getname_flags+0xd0/0x5a0 [ 861.414398] ? user_path_at_empty+0x2d/0x50 [ 861.418734] ? ksys_chroot+0xc0/0x2f0 [ 861.422563] path_lookupat.isra.45+0x212/0xc00 [ 861.427166] ? path_parentat.isra.43+0x160/0x160 [ 861.431956] ? __sanitizer_cov_trace_switch+0x53/0x90 [ 861.437168] ? __sanitizer_cov_trace_cmp8+0x18/0x20 [ 861.442218] ? __check_object_size+0xa3/0x5d7 [ 861.446750] ? usercopy_warn+0x120/0x120 [ 861.450839] ? kasan_check_read+0x11/0x20 [ 861.455035] ? do_raw_spin_unlock+0xa7/0x2f0 [ 861.459507] filename_lookup+0x264/0x510 [ 861.463603] ? filename_parentat.isra.58+0x570/0x570 [ 861.468728] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 861.474292] ? mpi_free.cold.1+0x19/0x19 [ 861.478377] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 861.483928] ? getname_flags+0x26e/0x5a0 [ 861.488013] user_path_at_empty+0x40/0x50 [ 861.492192] ksys_chroot+0xc0/0x2f0 [ 861.495830] ? __ia32_sys_fchdir+0x1f0/0x1f0 [ 861.500267] ? do_raw_spin_trylock+0x1c0/0x1c0 [ 861.504895] ? compat_start_thread+0x80/0x80 [ 861.509335] __x64_sys_chroot+0x31/0x40 [ 861.513358] do_syscall_64+0x1b9/0x820 [ 861.517281] ? syscall_return_slowpath+0x5e0/0x5e0 [ 861.522257] ? syscall_return_slowpath+0x31d/0x5e0 [ 861.527234] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 861.532306] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 861.537300] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 861.542550] RIP: 0033:0x4457e9 [ 861.545749] Code: Bad RIP value. [ 861.549156] RSP: 002b:00007efed0d37da8 EFLAGS: 00000297 ORIG_RAX: 00000000000000a1 [ 861.556907] RAX: ffffffffffffffda RBX: 00000000006dac3c RCX: 00000000004457e9 [ 861.564201] RDX: 0000000000402534 RSI: 5d3eb8ca47b1110e RDI: 0000000020000040 [ 861.571518] RBP: 00000000006dac38 R08: 00007efed0d38700 R09: 0000000000000000 [ 861.578811] R10: 00007efed0d38700 R11: 0000000000000297 R12: 0030656c69662f2e [ 861.586104] R13: 65646f6d746f6f72 R14: 2f30656c69662f2e R15: 0000000000000001 [ 861.593427] INFO: lockdep is turned off. [ 861.597500] NMI backtrace for cpu 1 [ 861.601144] CPU: 1 PID: 900 Comm: khungtaskd Not tainted 4.18.0-rc5-next-20180720+ #12 [ 861.609195] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 861.618546] Call Trace: [ 861.621125] dump_stack+0x1c9/0x2b4 [ 861.624734] ? dump_stack_print_info.cold.2+0x52/0x52 [ 861.629907] ? vprintk_default+0x28/0x30 [ 861.633953] ? lapic_can_unplug_cpu.cold.28+0x3f/0x3f [ 861.639121] nmi_cpu_backtrace.cold.3+0x48/0x88 [ 861.643772] ? lapic_can_unplug_cpu.cold.28+0x3f/0x3f [ 861.648963] nmi_trigger_cpumask_backtrace+0x151/0x192 [ 861.654224] arch_trigger_cpumask_backtrace+0x14/0x20 [ 861.659396] watchdog+0xb39/0x10b0 [ 861.662921] ? reset_hung_task_detector+0xd0/0xd0 [ 861.667767] ? kasan_check_read+0x11/0x20 [ 861.671897] ? do_raw_spin_unlock+0xa7/0x2f0 [ 861.676289] ? _raw_spin_unlock_irqrestore+0x74/0xc0 [ 861.681371] ? __kthread_parkme+0x58/0x1b0 [ 861.685594] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 861.690589] ? trace_hardirqs_on+0xd/0x10 [ 861.694721] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 861.700236] ? __kthread_parkme+0x106/0x1b0 [ 861.704536] kthread+0x345/0x410 [ 861.707885] ? reset_hung_task_detector+0xd0/0xd0 [ 861.712710] ? kthread_bind+0x40/0x40 [ 861.716491] ret_from_fork+0x3a/0x50 [ 861.720258] Sending NMI from CPU 1 to CPUs 0: [ 861.724822] NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0x6/0x10 [ 861.725777] Kernel panic - not syncing: hung_task: blocked tasks [ 861.738559] CPU: 1 PID: 900 Comm: khungtaskd Not tainted 4.18.0-rc5-next-20180720+ #12 [ 861.746594] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 861.755930] Call Trace: [ 861.758515] dump_stack+0x1c9/0x2b4 [ 861.762122] ? dump_stack_print_info.cold.2+0x52/0x52 [ 861.767331] ? printk_safe_log_store+0x2f0/0x2f0 [ 861.772076] panic+0x238/0x4e7 [ 861.775249] ? add_taint.cold.5+0x16/0x16 [ 861.779395] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 861.784931] ? nmi_trigger_cpumask_backtrace+0x13a/0x192 [ 861.790366] ? printk_safe_flush+0xd7/0x130 [ 861.794690] watchdog+0xb4a/0x10b0 [ 861.798230] ? reset_hung_task_detector+0xd0/0xd0 [ 861.803076] ? kasan_check_read+0x11/0x20 [ 861.807206] ? do_raw_spin_unlock+0xa7/0x2f0 [ 861.811599] ? _raw_spin_unlock_irqrestore+0x74/0xc0 [ 861.816690] ? __kthread_parkme+0x58/0x1b0 [ 861.820907] ? trace_hardirqs_on_caller+0x421/0x5c0 [ 861.825909] ? trace_hardirqs_on+0xd/0x10 [ 861.830040] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 861.835555] ? __kthread_parkme+0x106/0x1b0 [ 861.840376] kthread+0x345/0x410 [ 861.843726] ? reset_hung_task_detector+0xd0/0xd0 [ 861.848560] ? kthread_bind+0x40/0x40 [ 861.852363] ret_from_fork+0x3a/0x50 [ 861.856497] Dumping ftrace buffer: [ 861.860035] (ftrace buffer empty) [ 861.863746] Kernel Offset: disabled [ 861.867379] Rebooting in 86400 seconds..