[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 45.865711][ T25] audit: type=1800 audit(1575174292.284:25): pid=8070 uid=0 auid=4294967295 ses=4294967295 subj=_ op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 45.885472][ T25] audit: type=1800 audit(1575174292.284:26): pid=8070 uid=0 auid=4294967295 ses=4294967295 subj=_ op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 45.928580][ T25] audit: type=1800 audit(1575174292.284:27): pid=8070 uid=0 auid=4294967295 ses=4294967295 subj=_ op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2436 res=0 [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.15.199' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 594.695305][ T1099] INFO: task syz-executor013:8221 blocked for more than 143 seconds. [ 594.703743][ T1099] Not tainted 5.4.0-syzkaller #0 [ 594.709871][ T1099] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 594.718669][ T1099] syz-executor013 D27496 8221 8219 0x00004000 [ 594.725309][ T1099] Call Trace: [ 594.729041][ T1099] __schedule+0x837/0xc50 [ 594.733462][ T1099] schedule+0x181/0x210 [ 594.737810][ T1099] __lock_sock+0x164/0x2b0 [ 594.742277][ T1099] ? init_wait_entry+0xe0/0xe0 [ 594.747084][ T1099] lock_sock_nested+0x7c/0x120 [ 594.751870][ T1099] virtio_transport_release+0x5e/0xd40 [ 594.757373][ T1099] vsock_assign_transport+0x19e/0x3b0 [ 594.762741][ T1099] vsock_stream_connect+0x46d/0xb50 [ 594.767988][ T1099] ? init_wait_entry+0xe0/0xe0 [ 594.772834][ T1099] ? security_socket_connect+0xa0/0xd0 [ 594.778336][ T1099] ? __vsock_bind+0xcb0/0xcb0 [ 594.783020][ T1099] __sys_connect_file+0x279/0x2f0 [ 594.788156][ T1099] ? prepare_exit_to_usermode+0x221/0x5b0 [ 594.793944][ T1099] ? check_preemption_disabled+0xb4/0x260 [ 594.799701][ T1099] ? debug_smp_processor_id+0x9/0x20 [ 594.805020][ T1099] ? __kasan_check_read+0x11/0x20 [ 594.810077][ T1099] __x64_sys_connect+0xa2/0xf0 [ 594.814852][ T1099] do_syscall_64+0xf7/0x1c0 [ 594.819422][ T1099] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 594.825358][ T1099] RIP: 0033:0x4401b9 [ 594.829306][ T1099] Code: Bad RIP value. [ 594.833348][ T1099] RSP: 002b:00007fff1f12a168 EFLAGS: 00000246 ORIG_RAX: 000000000000002a [ 594.841896][ T1099] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004401b9 [ 594.850053][ T1099] RDX: 0000000000000010 RSI: 00000000200000c0 RDI: 0000000000000003 [ 594.859630][ T1099] RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8 [ 594.867837][ T1099] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401a40 [ 594.875837][ T1099] R13: 0000000000401ad0 R14: 0000000000000000 R15: 0000000000000000 [ 594.884119][ T1099] [ 594.884119][ T1099] Showing all locks held in the system: [ 594.891911][ T1099] 1 lock held by khungtaskd/1099: [ 594.897310][ T1099] #0: ffffffff890d4bc0 (rcu_read_lock){....}, at: rcu_lock_acquire+0x4/0x30 [ 594.906290][ T1099] 2 locks held by rsyslogd/8108: [ 594.911228][ T1099] #0: ffff88809bbf6120 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x243/0x2e0 [ 594.920262][ T1099] #1: ffff8880aeb36f98 (&rq->lock){-.-.}, at: __fs_reclaim_acquire+0x4/0x30 [ 594.929204][ T1099] 2 locks held by getty/8198: [ 594.933945][ T1099] #0: ffff888095e65090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 [ 594.943310][ T1099] #1: ffffc90005f3d2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 [ 594.952935][ T1099] 2 locks held by getty/8199: [ 594.957629][ T1099] #0: ffff8880a7aaa090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 [ 594.966964][ T1099] #1: ffffc90005f552e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 [ 594.976544][ T1099] 2 locks held by getty/8200: [ 594.981200][ T1099] #0: ffff8880946a5090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 [ 594.990432][ T1099] #1: ffffc90005f412e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 [ 595.000013][ T1099] 2 locks held by getty/8201: [ 595.004663][ T1099] #0: ffff8880964bb090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 [ 595.013900][ T1099] #1: ffffc90005f452e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 [ 595.023493][ T1099] 2 locks held by getty/8202: [ 595.028190][ T1099] #0: ffff8880912b0090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 [ 595.037412][ T1099] #1: ffffc90005f512e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 [ 595.047035][ T1099] 2 locks held by getty/8203: [ 595.051698][ T1099] #0: ffff8880963fc090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 [ 595.060930][ T1099] #1: ffffc90005f312e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 [ 595.070507][ T1099] 2 locks held by getty/8204: [ 595.075233][ T1099] #0: ffff8880a0b58090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 [ 595.084436][ T1099] #1: ffffc90005f252e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 [ 595.094033][ T1099] 1 lock held by syz-executor013/8221: [ 595.099526][ T1099] #0: ffff8880a38668d0 (sk_lock-AF_VSOCK){+.+.}, at: vsock_stream_connect+0x110/0xb50 [ 595.109202][ T1099] [ 595.111519][ T1099] ============================================= [ 595.111519][ T1099] [ 595.120419][ T1099] NMI backtrace for cpu 0 [ 595.124739][ T1099] CPU: 0 PID: 1099 Comm: khungtaskd Not tainted 5.4.0-syzkaller #0 [ 595.132609][ T1099] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 595.142778][ T1099] Call Trace: [ 595.146053][ T1099] dump_stack+0x1fb/0x318 [ 595.150358][ T1099] nmi_cpu_backtrace+0xaf/0x1a0 [ 595.155295][ T1099] ? nmi_trigger_cpumask_backtrace+0x16d/0x290 [ 595.161558][ T1099] ? arch_trigger_cpumask_backtrace+0x20/0x20 [ 595.167666][ T1099] nmi_trigger_cpumask_backtrace+0x174/0x290 [ 595.173749][ T1099] arch_trigger_cpumask_backtrace+0x10/0x20 [ 595.180682][ T1099] trigger_all_cpu_backtrace+0x17/0x20 [ 595.187241][ T1099] watchdog+0xd49/0xd60 [ 595.191594][ T1099] kthread+0x332/0x350 [ 595.195644][ T1099] ? hungtask_pm_notify+0x50/0x50 [ 595.200644][ T1099] ? kthread_blkcg+0xe0/0xe0 [ 595.205603][ T1099] ret_from_fork+0x24/0x30 [ 595.210163][ T1099] Sending NMI from CPU 0 to CPUs 1: [ 595.215752][ C1] NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0xe/0x10 [ 595.216699][ T1099] Kernel panic - not syncing: hung_task: blocked tasks [ 595.231289][ T1099] CPU: 0 PID: 1099 Comm: khungtaskd Not tainted 5.4.0-syzkaller #0 [ 595.239150][ T1099] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 595.249450][ T1099] Call Trace: [ 595.252963][ T1099] dump_stack+0x1fb/0x318 [ 595.257444][ T1099] panic+0x264/0x7a9 [ 595.261334][ T1099] ? nmi_trigger_cpumask_backtrace+0x21a/0x290 [ 595.267481][ T1099] watchdog+0xd5c/0xd60 [ 595.271883][ T1099] kthread+0x332/0x350 [ 595.275933][ T1099] ? hungtask_pm_notify+0x50/0x50 [ 595.280945][ T1099] ? kthread_blkcg+0xe0/0xe0 [ 595.285514][ T1099] ret_from_fork+0x24/0x30 [ 595.292077][ T1099] Kernel Offset: disabled [ 595.296406][ T1099] Rebooting in 86400 seconds..