[....] 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[?25l[?1c7[ ok 8[?25h[?0c. [ 28.245613] kauditd_printk_skb: 7 callbacks suppressed [ 28.245623] audit: type=1800 audit(1545177748.235:29): pid=5832 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="rc.local" dev="sda1" ino=2432 res=0 [ 28.272869] audit: type=1800 audit(1545177748.235:30): pid=5832 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="rmnologin" dev="sda1" ino=2423 res=0 Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.23' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 728.685271] rcu: INFO: rcu_preempt self-detected stall on CPU [ 728.691584] rcu: 1-....: (10500 ticks this GP) idle=37e/1/0x4000000000000002 softirq=6309/6309 fqs=5250 [ 728.701441] rcu: (t=10502 jiffies g=4321 q=29) [ 728.706195] NMI backtrace for cpu 1 [ 728.709808] CPU: 1 PID: 5987 Comm: syz-executor800 Not tainted 4.20.0-rc7+ #377 [ 728.717239] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 728.726632] Call Trace: [ 728.729229] [ 728.731438] dump_stack+0x244/0x39d [ 728.735059] ? dump_stack_print_info.cold.1+0x20/0x20 [ 728.740305] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 728.745839] ? do_raw_spin_lock+0x14f/0x350 [ 728.750171] nmi_cpu_backtrace.cold.2+0x5c/0xa1 [ 728.754861] ? lapic_can_unplug_cpu.cold.27+0x3f/0x3f [ 728.760044] nmi_trigger_cpumask_backtrace+0x1e8/0x22a [ 728.765329] arch_trigger_cpumask_backtrace+0x14/0x20 [ 728.770538] rcu_dump_cpu_stacks+0x16f/0x1bc [ 728.774952] print_cpu_stall.cold.67+0x1f3/0x3c7 [ 728.779741] ? trace_hardirqs_on+0x310/0x310 [ 728.784144] ? print_other_cpu_stall+0x160/0x160 [ 728.788907] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 728.794446] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 728.799997] ? do_trace_rcu_torture_read+0x10/0x10 [ 728.804934] ? rcu_preempt_need_deferred_qs+0x74/0x1f0 [ 728.810221] ? __lock_is_held+0xb5/0x140 [ 728.814271] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 728.819801] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 728.825367] ? check_preemption_disabled+0x48/0x280 [ 728.830375] rcu_check_callbacks+0xf3b/0x13f0 [ 728.834872] ? __lock_acquire+0x62f/0x4c20 [ 728.839097] ? rcutree_dead_cpu+0x10/0x10 [ 728.843237] ? mark_held_locks+0x130/0x130 [ 728.847465] ? zap_class+0x640/0x640 [ 728.851187] ? mark_held_locks+0x130/0x130 [ 728.855418] ? __lock_acquire+0x62f/0x4c20 [ 728.859656] ? debug_smp_processor_id+0x1c/0x20 [ 728.864338] ? nohz_balance_exit_idle+0x65/0x3e0 [ 728.869087] ? print_usage_bug+0xc0/0xc0 [ 728.873139] ? zap_class+0x640/0x640 [ 728.876851] ? find_held_lock+0x36/0x1c0 [ 728.880921] ? cpuacct_account_field+0x219/0x3d0 [ 728.885682] ? zap_class+0x640/0x640 [ 728.889430] ? kasan_check_read+0x11/0x20 [ 728.893570] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 728.899099] ? check_preemption_disabled+0x48/0x280 [ 728.904109] ? trace_hardirqs_off+0xb8/0x310 [ 728.908509] ? __lock_is_held+0xb5/0x140 [ 728.912559] ? trace_hardirqs_on+0x310/0x310 [ 728.916963] ? check_preemption_disabled+0x48/0x280 [ 728.922005] ? raise_softirq+0x199/0x420 [ 728.926060] ? raise_softirq_irqoff+0x2e0/0x2e0 [ 728.930734] ? account_system_index_time+0x333/0x5d0 [ 728.935831] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 728.941358] ? check_preemption_disabled+0x48/0x280 [ 728.946366] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 728.951922] ? hrtimer_run_queues+0x9a/0x400 [ 728.956339] ? run_local_timers+0x19b/0x230 [ 728.960650] ? timer_clear_idle+0x90/0x90 [ 728.964791] ? irqtime_account_process_tick.isra.6+0x35b/0x490 [ 728.970759] ? account_process_tick+0x282/0x350 [ 728.975419] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 728.980951] update_process_times+0x2d/0x70 [ 728.985287] tick_sched_handle+0x9f/0x180 [ 728.989426] tick_sched_timer+0x45/0x130 [ 728.993480] __hrtimer_run_queues+0x41c/0x10d0 [ 728.998069] ? tick_sched_do_timer+0x1a0/0x1a0 [ 729.002645] ? hrtimer_start_range_ns+0xe00/0xe00 [ 729.007503] ? pvclock_read_flags+0x160/0x160 [ 729.012002] ? trace_hardirqs_on+0x310/0x310 [ 729.016405] ? kvm_clock_read+0x18/0x30 [ 729.020368] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 729.025376] ? ktime_get_update_offsets_now+0x3b3/0x540 [ 729.031206] ? do_timer+0x50/0x50 [ 729.035096] ? rwlock_bug.part.2+0x90/0x90 [ 729.039336] ? trace_hardirqs_on+0x310/0x310 [ 729.043734] ? rcu_softirq_qs+0x20/0x20 [ 729.047720] hrtimer_interrupt+0x313/0x780 [ 729.051979] smp_apic_timer_interrupt+0x1a1/0x760 [ 729.056814] ? smp_reschedule_interrupt+0x109/0x650 [ 729.061821] ? smp_call_function_single_interrupt+0x650/0x650 [ 729.067703] ? interrupt_entry+0xb5/0xc0 [ 729.071754] ? trace_hardirqs_off_caller+0xbb/0x310 [ 729.076757] ? trace_hardirqs_off_caller+0xbb/0x310 [ 729.081776] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 729.086611] ? trace_hardirqs_on_caller+0x310/0x310 [ 729.091627] ? trace_hardirqs_on_caller+0x310/0x310 [ 729.096633] ? task_prio+0x50/0x50 [ 729.100174] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 729.105711] ? check_preemption_disabled+0x48/0x280 [ 729.110721] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 729.115558] apic_timer_interrupt+0xf/0x20 [ 729.119777] [ 729.122006] RIP: 0010:__sanitizer_cov_trace_pc+0x4b/0x50 [ 729.127564] Code: 90 d8 12 00 00 83 fa 02 75 20 48 8b 88 e0 12 00 00 8b 80 dc 12 00 00 48 8b 11 48 83 c2 01 48 39 d0 76 07 48 89 34 d1 48 89 11 <5d> c3 0f 1f 00 55 40 0f b6 d6 40 0f b6 f7 31 ff 48 89 e5 48 8b 4d [ 729.146451] RSP: 0018:ffff8881c1e17988 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13 [ 729.154167] RAX: ffff8881c2860200 RBX: 0000000000000004 RCX: ffffffff81ced656 [ 729.161438] RDX: 0000000000000000 RSI: ffffffff8344bfe8 RDI: ffff8881b4364cc0 [ 729.168699] RBP: ffff8881c1e17988 R08: ffff8881c2860200 R09: 0000000000000007 [ 729.175960] R10: 0000000000000000 R11: ffff8881c2860200 R12: ffff8881b4364cc0 [ 729.183219] R13: 0000000001237d36 R14: ffff8881b4364cc0 R15: 0000000000000004 [ 729.190529] ? rw_verify_area+0xf6/0x360 [ 729.194625] ? security_file_permission+0x18/0x220 [ 729.199549] security_file_permission+0x18/0x220 [ 729.204294] rw_verify_area+0x111/0x360 [ 729.208279] do_splice_to+0x8b/0x190 [ 729.212003] ? direct_splice_actor+0x128/0x190 [ 729.216581] splice_direct_to_actor+0x31c/0x9d0 [ 729.221245] ? pipe_to_sendpage+0x400/0x400 [ 729.225562] ? do_splice_to+0x190/0x190 [ 729.229524] ? security_file_permission+0x1c2/0x220 [ 729.234533] ? rw_verify_area+0x118/0x360 [ 729.238674] do_splice_direct+0x2d4/0x420 [ 729.242819] ? splice_direct_to_actor+0x9d0/0x9d0 [ 729.247656] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 729.253200] ? __sb_start_write+0x1b2/0x370 [ 729.257515] do_sendfile+0x62a/0xe20 [ 729.261228] ? do_compat_pwritev64+0x1c0/0x1c0 [ 729.265806] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 729.271447] ? _copy_from_user+0xdf/0x150 [ 729.275590] __x64_sys_sendfile64+0x15d/0x250 [ 729.280087] ? __ia32_sys_sendfile+0x2a0/0x2a0 [ 729.284670] do_syscall_64+0x1b9/0x820 [ 729.288550] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 729.293906] ? syscall_return_slowpath+0x5e0/0x5e0 [ 729.298825] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 729.303657] ? trace_hardirqs_on_caller+0x310/0x310 [ 729.308673] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 729.313688] ? prepare_exit_to_usermode+0x291/0x3b0 [ 729.318701] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 729.323538] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 729.328718] RIP: 0033:0x4400d9 [ 729.331913] Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 729.350815] RSP: 002b:00007ffdd3e00e58 EFLAGS: 00000203 ORIG_RAX: 0000000000000028 [ 729.358517] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004400d9 [ 729.365787] RDX: 0000000020000000 RSI: 0000000000000003 RDI: 0000000000000003 [ 729.373044] RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8 [ 729.380314] R10: 00008080fffffffe R11: 0000000000000203 R12: 0000000000401960 [ 729.387583] R13: 00000000004019f0 R14: 0000000000000000 R15: 0000000000000000