[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 65.356753][ T26] audit: type=1800 audit(1575957588.851:25): pid=8854 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 65.385119][ T26] audit: type=1800 audit(1575957588.851:26): pid=8854 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 65.444883][ T26] audit: type=1800 audit(1575957588.861:27): pid=8854 uid=0 auid=4294967295 ses=4294967295 subj==unconfined 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 '10.128.0.216' (ECDSA) to the list of known hosts. 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 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 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 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 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 syzkaller login: [ 777.775041][ T1117] INFO: task login:8982 blocked for more than 143 seconds. [ 777.782515][ T1117] Not tainted 5.5.0-rc1-syzkaller #0 [ 777.791011][ T1117] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 777.800078][ T1117] login D23224 8982 1 0x80000002 [ 777.812623][ T1117] Call Trace: [ 777.816494][ T1117] __schedule+0x934/0x1f90 [ 777.820940][ T1117] ? __sched_text_start+0x8/0x8 [ 777.826297][ T1117] ? __lock_acquire+0x29c9/0x4a00 [ 777.831339][ T1117] schedule+0xdc/0x2b0 [ 777.836177][ T1117] schedule_timeout+0x717/0xc50 [ 777.841121][ T1117] ? __kasan_check_read+0x11/0x20 [ 777.846530][ T1117] ? usleep_range+0x170/0x170 [ 777.851259][ T1117] ? mark_held_locks+0xa4/0xf0 [ 777.856569][ T1117] ? _raw_spin_unlock_irq+0x23/0x80 [ 777.861858][ T1117] ? __ldsem_down_write_nested+0x3aa/0x8f0 [ 777.868255][ T1117] ? _raw_spin_unlock_irq+0x23/0x80 [ 777.873540][ T1117] ? lockdep_hardirqs_on+0x421/0x5e0 [ 777.879516][ T1117] ? trace_hardirqs_on+0x67/0x240 [ 777.884708][ T1117] __ldsem_down_write_nested+0x3b2/0x8f0 [ 777.890933][ T1117] ? ldsem_wake+0x40/0x40 [ 777.895977][ T1117] ? ___might_sleep+0x163/0x2c0 [ 777.900951][ T1117] ? put_tty_driver+0x20/0x20 [ 777.906110][ T1117] ldsem_down_write+0x33/0x40 [ 777.910831][ T1117] ? ldsem_down_write+0x33/0x40 [ 777.917165][ T1117] tty_ldisc_lock+0x66/0xb0 [ 777.921838][ T1117] tty_ldisc_hangup+0x1c6/0x640 [ 777.927237][ T1117] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 777.933618][ T1117] ? put_tty_driver+0x20/0x20 [ 777.938841][ T1117] __tty_hangup.part.0+0x2fb/0x750 [ 777.943981][ T1117] tty_vhangup_session+0x25/0x30 [ 777.949387][ T1117] disassociate_ctty.part.0+0xb4/0x740 [ 777.955200][ T1117] disassociate_ctty+0x81/0xa0 [ 777.960090][ T1117] do_exit+0x1b42/0x2ef0 [ 777.964422][ T1117] ? __vfs_write+0x92/0x110 [ 777.969475][ T1117] ? mm_update_next_owner+0x7c0/0x7c0 [ 777.975320][ T1117] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 777.981662][ T1117] ? ksys_write+0x1cf/0x290 [ 777.986732][ T1117] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 777.992238][ T1117] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 777.998234][ T1117] do_group_exit+0x135/0x360 [ 778.002857][ T1117] __x64_sys_exit_group+0x44/0x50 [ 778.008378][ T1117] do_syscall_64+0xfa/0x790 [ 778.013078][ T1117] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 778.019548][ T1117] RIP: 0033:0x7f489a9441e8 [ 778.024080][ T1117] Code: Bad RIP value. [ 778.028612][ T1117] RSP: 002b:00007ffc539294a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 778.037815][ T1117] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f489a9441e8 [ 778.047315][ T1117] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 778.056264][ T1117] RBP: 00007f489ac19840 R08: 00000000000000e7 R09: ffffffffffffffa8 [ 778.064377][ T1117] R10: 00007f489ac1f740 R11: 0000000000000246 R12: 00007f489ac19840 [ 778.072962][ T1117] R13: 0000000000000001 R14: 0000000000000001 R15: 000000000060b798 [ 778.081657][ T1117] [ 778.081657][ T1117] Showing all locks held in the system: [ 778.089878][ T1117] 1 lock held by khungtaskd/1117: [ 778.095548][ T1117] #0: ffffffff899a56c0 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x279 [ 778.105738][ T1117] 1 lock held by rsyslogd/8892: [ 778.110691][ T1117] #0: ffff8880942438a0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 [ 778.120102][ T1117] 2 locks held by login/8982: [ 778.125436][ T1117] #0: ffff88808afac198 (&tty->legacy_mutex){+.+.}, at: tty_lock+0xc7/0x130 [ 778.134180][ T1117] #1: ffff88808afac090 (&tty->ldisc_sem){++++}, at: ldsem_down_write+0x33/0x40 [ 778.143841][ T1117] 2 locks held by getty/8983: [ 778.148970][ T1117] #0: ffff888092c63090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 778.158527][ T1117] #1: ffffc900017fb2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 [ 778.168646][ T1117] 2 locks held by getty/8984: [ 778.173332][ T1117] #0: ffff88809426d090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 778.184101][ T1117] #1: ffffc900017eb2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 [ 778.194237][ T1117] 2 locks held by getty/8985: [ 778.199287][ T1117] #0: ffff8880a8de4090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 778.208974][ T1117] #1: ffffc9000182b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 [ 778.219058][ T1117] 2 locks held by getty/8986: [ 778.223784][ T1117] #0: ffff8880a85d4090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 778.233329][ T1117] #1: ffffc9000181b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 [ 778.243406][ T1117] 2 locks held by getty/8987: [ 778.248560][ T1117] #0: ffff88808c78e090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 778.258006][ T1117] #1: ffffc9000180b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 [ 778.268203][ T1117] 2 locks held by getty/8988: [ 778.272882][ T1117] #0: ffff88809a017090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 778.282206][ T1117] #1: ffffc9000176b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 [ 778.292547][ T1117] 3 locks held by syz-executor520/9189: [ 778.298587][ T1117] #0: ffff88808afac090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 778.308934][ T1117] #1: ffff8880aa5bc0a8 (&buf->lock){+.+.}, at: tty_buffer_lock_exclusive+0x30/0x40 [ 778.318801][ T1117] #2: ffff8880ae837358 (&rq->lock){-.-.}, at: __schedule+0x232/0x1f90 [ 778.327637][ T1117] [ 778.329992][ T1117] ============================================= [ 778.329992][ T1117] [ 778.338872][ T1117] NMI backtrace for cpu 1 [ 778.343323][ T1117] CPU: 1 PID: 1117 Comm: khungtaskd Not tainted 5.5.0-rc1-syzkaller #0 [ 778.351563][ T1117] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 778.362484][ T1117] Call Trace: [ 778.365897][ T1117] dump_stack+0x197/0x210 [ 778.370232][ T1117] nmi_cpu_backtrace.cold+0x70/0xb2 [ 778.375565][ T1117] ? vprintk_func+0x86/0x189 [ 778.380213][ T1117] ? lapic_can_unplug_cpu.cold+0x3a/0x3a [ 778.386095][ T1117] nmi_trigger_cpumask_backtrace+0x23b/0x28b [ 778.392099][ T1117] arch_trigger_cpumask_backtrace+0x14/0x20 [ 778.398085][ T1117] watchdog+0xb11/0x10c0 [ 778.402395][ T1117] kthread+0x361/0x430 [ 778.406464][ T1117] ? reset_hung_task_detector+0x30/0x30 [ 778.412032][ T1117] ? kthread_mod_delayed_work+0x1f0/0x1f0 [ 778.417907][ T1117] ret_from_fork+0x24/0x30 [ 778.422448][ T1117] Sending NMI from CPU 1 to CPUs 0: [ 778.428778][ C0] NMI backtrace for cpu 0 [ 778.428785][ C0] CPU: 0 PID: 9189 Comm: syz-executor520 Not tainted 5.5.0-rc1-syzkaller #0 [ 778.428791][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 778.428796][ C0] RIP: 0010:rcu_dynticks_curr_cpu_in_eqs+0x32/0xb0 [ 778.428806][ C0] Code: c7 c3 00 81 03 00 48 83 ec 08 e8 79 34 30 02 48 ba 00 00 00 00 00 fc ff df 89 c0 48 8d 3c c5 60 81 55 89 48 89 f9 48 c1 e9 03 <80> 3c 11 00 75 63 48 03 1c c5 60 81 55 89 be 04 00 00 00 4c 8d a3 [ 778.428810][ C0] RSP: 0018:ffffc900028676c8 EFLAGS: 00000802 [ 778.428817][ C0] RAX: 0000000000000000 RBX: 0000000000038100 RCX: 1ffffffff12ab02c [ 778.428822][ C0] RDX: dffffc0000000000 RSI: ffffffff8392e053 RDI: ffffffff89558160 [ 778.428826][ C0] RBP: ffffc900028676e0 R08: ffff88808a37c3c0 R09: ffffed1015d0703d [ 778.428831][ C0] R10: ffffed1015d0703c R11: ffff8880ae8381e3 R12: ffff8880ae8373c0 [ 778.428836][ C0] R13: ffffffff899c5cf0 R14: ffff88808a37c3c0 R15: 0000000000000d74 [ 778.428841][ C0] FS: 0000000001371880(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 [ 778.428845][ C0] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 778.428849][ C0] CR2: ffffffffff600400 CR3: 00000000a7952000 CR4: 00000000001406f0 [ 778.428854][ C0] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 778.428858][ C0] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 778.428861][ C0] Call Trace: [ 778.428864][ C0] rcu_is_watching+0x10/0x30 [ 778.428867][ C0] update_curr+0x5f8/0x8d0 [ 778.428869][ C0] ? sched_clock+0x2e/0x50 [ 778.428873][ C0] pick_next_task_fair+0x221/0xc70 [ 778.428876][ C0] __schedule+0x375/0x1f90 [ 778.428879][ C0] ? __sched_text_start+0x8/0x8 [ 778.428882][ C0] schedule+0xdc/0x2b0 [ 778.428885][ C0] paste_selection+0x2f5/0x460 [ 778.428888][ C0] ? vcs_remove_sysfs+0x60/0x60 [ 778.428891][ C0] ? lock_downgrade+0x920/0x920 [ 778.428894][ C0] ? wake_up_q+0x140/0x140 [ 778.428897][ C0] tioclinux+0x133/0x480 [ 778.428900][ C0] vt_ioctl+0x1a41/0x26d0 [ 778.428903][ C0] ? complete_change_console+0x3a0/0x3a0 [ 778.428907][ C0] ? lock_downgrade+0x920/0x920 [ 778.428910][ C0] ? rwlock_bug.part.0+0x90/0x90 [ 778.428913][ C0] ? tomoyo_path_number_perm+0x214/0x520 [ 778.428916][ C0] ? find_held_lock+0x35/0x130 [ 778.428920][ C0] ? tomoyo_path_number_perm+0x214/0x520 [ 778.428923][ C0] ? __sanitizer_cov_trace_switch+0x49/0x80 [ 778.428927][ C0] ? tty_jobctrl_ioctl+0x50/0xd40 [ 778.428930][ C0] ? complete_change_console+0x3a0/0x3a0 [ 778.428933][ C0] tty_ioctl+0xa37/0x14f0 [ 778.428936][ C0] ? tty_vhangup+0x30/0x30 [ 778.428940][ C0] ? tomoyo_path_number_perm+0x454/0x520 [ 778.428944][ C0] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 778.428948][ C0] ? tomoyo_path_number_perm+0x25e/0x520 [ 778.428951][ C0] ? tomoyo_execute_permission+0x4a0/0x4a0 [ 778.428955][ C0] ? tty_vhangup+0x30/0x30 [ 778.428958][ C0] do_vfs_ioctl+0x977/0x14e0 [ 778.428961][ C0] ? compat_ioctl_preallocate+0x220/0x220 [ 778.428964][ C0] ? kmem_cache_free+0x26b/0x320 [ 778.428967][ C0] ? putname+0xf4/0x130 [ 778.428969][ C0] ? do_sys_open+0x31d/0x5d0 [ 778.428972][ C0] ? tomoyo_file_ioctl+0x23/0x30 [ 778.428975][ C0] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 778.428978][ C0] ? security_file_ioctl+0x8d/0xc0 [ 778.428981][ C0] ksys_ioctl+0xab/0xd0 [ 778.428983][ C0] __x64_sys_ioctl+0x73/0xb0 [ 778.428986][ C0] do_syscall_64+0xfa/0x790 [ 778.428989][ C0] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 778.428992][ C0] RIP: 0033:0x441219 [ 778.429001][ C0] Code: e8 3c ad 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 9b 09 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 778.429004][ C0] RSP: 002b:00007ffe618000b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 778.429011][ C0] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441219 [ 778.429016][ C0] RDX: 0000000020000080 RSI: 000000000000541c RDI: 0000000000000004 [ 778.429020][ C0] RBP: 000000000008b001 R08: 000000000000000d R09: 00000000004002c8 [ 778.429024][ C0] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402040 [ 778.429029][ C0] R13: 00000000004020d0 R14: 0000000000000000 R15: 0000000000000000 [ 778.431444][ T1117] Kernel panic - not syncing: hung_task: blocked tasks [ 778.853330][ T1117] CPU: 1 PID: 1117 Comm: khungtaskd Not tainted 5.5.0-rc1-syzkaller #0 [ 778.863944][ T1117] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 778.874017][ T1117] Call Trace: [ 778.877325][ T1117] dump_stack+0x197/0x210 [ 778.881702][ T1117] panic+0x2e3/0x75c [ 778.885635][ T1117] ? add_taint.cold+0x16/0x16 [ 778.890346][ T1117] ? lapic_can_unplug_cpu.cold+0x3a/0x3a [ 778.896002][ T1117] ? ___preempt_schedule+0x16/0x18 [ 778.901136][ T1117] ? nmi_trigger_cpumask_backtrace+0x21b/0x28b [ 778.907294][ T1117] ? nmi_trigger_cpumask_backtrace+0x24c/0x28b [ 778.913449][ T1117] ? nmi_trigger_cpumask_backtrace+0x256/0x28b [ 778.919804][ T1117] ? nmi_trigger_cpumask_backtrace+0x21b/0x28b [ 778.925996][ T1117] watchdog+0xb22/0x10c0 [ 778.930288][ T1117] kthread+0x361/0x430 [ 778.935684][ T1117] ? reset_hung_task_detector+0x30/0x30 [ 778.941250][ T1117] ? kthread_mod_delayed_work+0x1f0/0x1f0 [ 778.947084][ T1117] ret_from_fork+0x24/0x30 [ 778.953262][ T1117] Kernel Offset: disabled [ 778.957618][ T1117] Rebooting in 86400 seconds..