[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 60.457409][ T26] audit: type=1800 audit(1575887163.118:25): pid=8777 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 60.477925][ T26] audit: type=1800 audit(1575887163.138:26): pid=8777 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 60.498454][ T26] audit: type=1800 audit(1575887163.138:27): pid=8777 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 '10.128.0.211' (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 syzkaller login: [ 793.256219][ T1114] INFO: task login:8910 blocked for more than 143 seconds. [ 793.263684][ T1114] Not tainted 5.5.0-rc1-syzkaller #0 [ 793.269921][ T1114] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 793.278752][ T1114] login D23240 8910 1 0x80000002 [ 793.285087][ T1114] Call Trace: [ 793.288567][ T1114] __schedule+0x934/0x1f90 [ 793.292996][ T1114] ? __sched_text_start+0x8/0x8 [ 793.298017][ T1114] ? __lock_acquire+0x29c9/0x4a00 [ 793.303047][ T1114] schedule+0xdc/0x2b0 [ 793.307255][ T1114] schedule_timeout+0x717/0xc50 [ 793.312163][ T1114] ? __kasan_check_read+0x11/0x20 [ 793.317348][ T1114] ? usleep_range+0x170/0x170 [ 793.322027][ T1114] ? mark_held_locks+0xa4/0xf0 [ 793.326969][ T1114] ? _raw_spin_unlock_irq+0x23/0x80 [ 793.332314][ T1114] ? __ldsem_down_write_nested+0x3aa/0x8f0 [ 793.338462][ T1114] ? _raw_spin_unlock_irq+0x23/0x80 [ 793.343659][ T1114] ? lockdep_hardirqs_on+0x421/0x5e0 [ 793.350027][ T1114] ? trace_hardirqs_on+0x67/0x240 [ 793.355062][ T1114] __ldsem_down_write_nested+0x3b2/0x8f0 [ 793.360854][ T1114] ? ldsem_wake+0x40/0x40 [ 793.365239][ T1114] ? ___might_sleep+0x163/0x2c0 [ 793.370269][ T1114] ? put_tty_driver+0x20/0x20 [ 793.374964][ T1114] ldsem_down_write+0x33/0x40 [ 793.380297][ T1114] ? ldsem_down_write+0x33/0x40 [ 793.385168][ T1114] tty_ldisc_lock+0x66/0xb0 [ 793.389867][ T1114] tty_ldisc_hangup+0x1c6/0x640 [ 793.394775][ T1114] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 793.401204][ T1114] ? put_tty_driver+0x20/0x20 [ 793.405881][ T1114] __tty_hangup.part.0+0x2fb/0x750 [ 793.411141][ T1114] tty_vhangup_session+0x25/0x30 [ 793.416227][ T1114] disassociate_ctty.part.0+0xb4/0x740 [ 793.421686][ T1114] disassociate_ctty+0x81/0xa0 [ 793.426656][ T1114] do_exit+0x1b42/0x2ef0 [ 793.430925][ T1114] ? __vfs_write+0x92/0x110 [ 793.435445][ T1114] ? mm_update_next_owner+0x7c0/0x7c0 [ 793.441059][ T1114] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 793.447526][ T1114] ? ksys_write+0x1cf/0x290 [ 793.452072][ T1114] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 793.457767][ T1114] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 793.463236][ T1114] do_group_exit+0x135/0x360 [ 793.467981][ T1114] __x64_sys_exit_group+0x44/0x50 [ 793.473005][ T1114] do_syscall_64+0xfa/0x790 [ 793.478576][ T1114] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 793.484474][ T1114] RIP: 0033:0x7ff0d726c1e8 [ 793.489077][ T1114] Code: Bad RIP value. [ 793.493139][ T1114] RSP: 002b:00007ffe1995faa8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 793.501727][ T1114] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ff0d726c1e8 [ 793.509835][ T1114] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 793.517957][ T1114] RBP: 00007ff0d7541840 R08: 00000000000000e7 R09: ffffffffffffffa8 [ 793.525933][ T1114] R10: 00007ff0d7547740 R11: 0000000000000246 R12: 00007ff0d7541840 [ 793.534052][ T1114] R13: 0000000000000001 R14: 0000000000000001 R15: 000000000060b798 [ 793.542206][ T1114] [ 793.542206][ T1114] Showing all locks held in the system: [ 793.550219][ T1114] 1 lock held by khungtaskd/1114: [ 793.555575][ T1114] #0: ffffffff899a56c0 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x279 [ 793.565085][ T1114] 3 locks held by rs:main Q:Reg/8813: [ 793.570582][ T1114] 1 lock held by rsyslogd/8815: [ 793.575418][ T1114] #0: ffff88809f97e360 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 [ 793.584457][ T1114] 2 locks held by getty/8907: [ 793.589273][ T1114] #0: ffff8880974b3090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 793.598391][ T1114] #1: ffffc9000176b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 [ 793.608987][ T1114] 2 locks held by getty/8908: [ 793.614090][ T1114] #0: ffff8880a4572090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 793.623229][ T1114] #1: ffffc900017db2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 [ 793.635637][ T1114] 2 locks held by getty/8909: [ 793.640468][ T1114] #0: ffff888097dfb090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 793.649644][ T1114] #1: ffffc900017cb2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 [ 793.659474][ T1114] 2 locks held by login/8910: [ 793.664143][ T1114] #0: ffff888094924198 (&tty->legacy_mutex){+.+.}, at: tty_lock+0xc7/0x130 [ 793.672998][ T1114] #1: ffff888094924090 (&tty->ldisc_sem){++++}, at: ldsem_down_write+0x33/0x40 [ 793.682185][ T1114] 2 locks held by getty/8911: [ 793.686976][ T1114] #0: ffff8880a6684090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 793.695924][ T1114] #1: ffffc900017eb2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 [ 793.705645][ T1114] 2 locks held by getty/8912: [ 793.710436][ T1114] #0: ffff8880a2e34090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 793.719523][ T1114] #1: ffffc9000179b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 [ 793.729207][ T1114] 2 locks held by getty/8913: [ 793.733871][ T1114] #0: ffff888094b2c090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 793.743893][ T1114] #1: ffffc900017232e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 [ 793.753590][ T1114] 2 locks held by syz-executor577/9070: [ 793.759433][ T1114] [ 793.761757][ T1114] ============================================= [ 793.761757][ T1114] [ 793.770287][ T1114] NMI backtrace for cpu 1 [ 793.774619][ T1114] CPU: 1 PID: 1114 Comm: khungtaskd Not tainted 5.5.0-rc1-syzkaller #0 [ 793.782848][ T1114] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 793.792892][ T1114] Call Trace: [ 793.796258][ T1114] dump_stack+0x197/0x210 [ 793.800593][ T1114] nmi_cpu_backtrace.cold+0x70/0xb2 [ 793.805833][ T1114] ? vprintk_func+0x86/0x189 [ 793.810447][ T1114] ? lapic_can_unplug_cpu.cold+0x3a/0x3a [ 793.816074][ T1114] nmi_trigger_cpumask_backtrace+0x23b/0x28b [ 793.822052][ T1114] arch_trigger_cpumask_backtrace+0x14/0x20 [ 793.827941][ T1114] watchdog+0xb11/0x10c0 [ 793.832217][ T1114] kthread+0x361/0x430 [ 793.836280][ T1114] ? reset_hung_task_detector+0x30/0x30 [ 793.841816][ T1114] ? kthread_mod_delayed_work+0x1f0/0x1f0 [ 793.847533][ T1114] ret_from_fork+0x24/0x30 [ 793.852063][ T1114] Sending NMI from CPU 1 to CPUs 0: [ 793.858013][ C0] NMI backtrace for cpu 0 [ 793.858019][ C0] CPU: 0 PID: 9070 Comm: syz-executor577 Not tainted 5.5.0-rc1-syzkaller #0 [ 793.858025][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 793.858029][ C0] RIP: 0010:match_held_lock+0x10/0x510 [ 793.858039][ C0] Code: 85 c0 78 02 c9 c3 89 c7 89 45 fc e8 8a e6 ff ff 8b 45 fc c9 c3 0f 1f 44 00 00 48 b8 00 00 00 00 00 fc ff df 55 48 89 e5 41 57 <41> 56 41 55 41 54 53 48 89 fb 48 83 c7 10 48 89 fa 48 83 ec 08 48 [ 793.858043][ C0] RSP: 0018:ffffc90002497708 EFLAGS: 00000097 [ 793.858050][ C0] RAX: dffffc0000000000 RBX: ffff88809ecbe440 RCX: ffff88809ecbecd8 [ 793.858054][ C0] RDX: 0000000000000000 RSI: ffff8880ae837358 RDI: ffff88809ecbed28 [ 793.858059][ C0] RBP: ffffc90002497710 R08: ffff88809ecbe440 R09: fffff52000492ee5 [ 793.858064][ C0] R10: fffff52000492ee4 R11: 0000000000000003 R12: ffffed1013d97d9a [ 793.858068][ C0] R13: ffff88809ecbed28 R14: ffff8880ae837358 R15: 0000000000000002 [ 793.858073][ C0] FS: 0000000001464880(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 [ 793.858077][ C0] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 793.858082][ C0] CR2: 00000000006cc080 CR3: 00000000926df000 CR4: 00000000001406f0 [ 793.858086][ C0] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 793.858096][ C0] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 793.858099][ C0] Call Trace: [ 793.858102][ C0] lock_is_held_type+0x1b8/0x320 [ 793.858105][ C0] ? prandom_u32+0x7d/0xb0 [ 793.858108][ C0] update_rq_clock+0x2a7/0x430 [ 793.858111][ C0] __schedule+0x27d/0x1f90 [ 793.858114][ C0] ? __sched_text_start+0x8/0x8 [ 793.858117][ C0] schedule+0xdc/0x2b0 [ 793.858120][ C0] paste_selection+0x2f5/0x460 [ 793.858123][ C0] ? vcs_remove_sysfs+0x60/0x60 [ 793.858127][ C0] ? lock_downgrade+0x920/0x920 [ 793.858129][ C0] ? wake_up_q+0x140/0x140 [ 793.858132][ C0] tioclinux+0x133/0x480 [ 793.858135][ C0] vt_ioctl+0x1a41/0x26d0 [ 793.858139][ C0] ? complete_change_console+0x3a0/0x3a0 [ 793.858142][ C0] ? lock_downgrade+0x920/0x920 [ 793.858145][ C0] ? rwlock_bug.part.0+0x90/0x90 [ 793.858149][ C0] ? tomoyo_path_number_perm+0x214/0x520 [ 793.858152][ C0] ? find_held_lock+0x35/0x130 [ 793.858155][ C0] ? tomoyo_path_number_perm+0x214/0x520 [ 793.858159][ C0] ? __sanitizer_cov_trace_switch+0x49/0x80 [ 793.858162][ C0] ? tty_jobctrl_ioctl+0x50/0xd40 [ 793.858166][ C0] ? complete_change_console+0x3a0/0x3a0 [ 793.858168][ C0] tty_ioctl+0xa37/0x14f0 [ 793.858171][ C0] ? tty_vhangup+0x30/0x30 [ 793.858175][ C0] ? tomoyo_path_number_perm+0x454/0x520 [ 793.858179][ C0] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 793.858182][ C0] ? tomoyo_path_number_perm+0x25e/0x520 [ 793.858186][ C0] ? tomoyo_execute_permission+0x4a0/0x4a0 [ 793.858189][ C0] ? __do_page_fault+0x56a/0xd80 [ 793.858192][ C0] ? tty_vhangup+0x30/0x30 [ 793.858195][ C0] do_vfs_ioctl+0x977/0x14e0 [ 793.858199][ C0] ? compat_ioctl_preallocate+0x220/0x220 [ 793.858202][ C0] ? __kasan_check_write+0x14/0x20 [ 793.858205][ C0] ? up_read+0x1cd/0x810 [ 793.858208][ C0] ? tomoyo_file_ioctl+0x23/0x30 [ 793.858213][ C0] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 793.858216][ C0] ? security_file_ioctl+0x8d/0xc0 [ 793.858219][ C0] ksys_ioctl+0xab/0xd0 [ 793.858222][ C0] __x64_sys_ioctl+0x73/0xb0 [ 793.858225][ C0] do_syscall_64+0xfa/0x790 [ 793.858229][ C0] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 793.858232][ C0] RIP: 0033:0x441239 [ 793.858242][ 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 [ 793.858245][ C0] RSP: 002b:00007fff7d59ceb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 793.858253][ C0] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441239 [ 793.858258][ C0] RDX: 0000000020000080 RSI: 000000000000541c RDI: 0000000000000003 [ 793.858262][ C0] RBP: 000000000008ff63 R08: 000000000000000d R09: 00000000004002c8 [ 793.858267][ C0] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402060 [ 793.858272][ C0] R13: 00000000004020f0 R14: 0000000000000000 R15: 0000000000000000 [ 793.859371][ T1114] Kernel panic - not syncing: hung_task: blocked tasks [ 794.274141][ T1114] CPU: 1 PID: 1114 Comm: khungtaskd Not tainted 5.5.0-rc1-syzkaller #0 [ 794.282376][ T1114] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 794.292418][ T1114] Call Trace: [ 794.295721][ T1114] dump_stack+0x197/0x210 [ 794.300049][ T1114] panic+0x2e3/0x75c [ 794.303935][ T1114] ? add_taint.cold+0x16/0x16 [ 794.308621][ T1114] ? lapic_can_unplug_cpu.cold+0x3a/0x3a [ 794.314252][ T1114] ? ___preempt_schedule+0x16/0x18 [ 794.319365][ T1114] ? nmi_trigger_cpumask_backtrace+0x21b/0x28b [ 794.325511][ T1114] ? nmi_trigger_cpumask_backtrace+0x24c/0x28b [ 794.331656][ T1114] ? nmi_trigger_cpumask_backtrace+0x256/0x28b [ 794.337802][ T1114] ? nmi_trigger_cpumask_backtrace+0x21b/0x28b [ 794.343951][ T1114] watchdog+0xb22/0x10c0 [ 794.348200][ T1114] kthread+0x361/0x430 [ 794.352262][ T1114] ? reset_hung_task_detector+0x30/0x30 [ 794.357812][ T1114] ? kthread_mod_delayed_work+0x1f0/0x1f0 [ 794.363526][ T1114] ret_from_fork+0x24/0x30 [ 794.369379][ T1114] Kernel Offset: disabled [ 794.373711][ T1114] Rebooting in 86400 seconds..