[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 57.239435][ T26] audit: type=1800 audit(1571027337.771:25): pid=8705 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 57.278897][ T26] audit: type=1800 audit(1571027337.771:26): pid=8705 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 57.300802][ T26] audit: type=1800 audit(1571027337.781:27): pid=8705 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 '10.128.1.40' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 646.574763][ T1054] INFO: task kworker/0:2:2913 blocked for more than 143 seconds. [ 646.582667][ T1054] Not tainted 5.4.0-rc1+ #0 [ 646.588446][ T1054] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 646.597515][ T1054] kworker/0:2 D27000 2913 2 0x80004000 [ 646.603958][ T1054] Workqueue: ipv6_addrconf addrconf_verify_work [ 646.616053][ T1054] Call Trace: [ 646.619453][ T1054] __schedule+0x94f/0x1e70 [ 646.623879][ T1054] ? __sched_text_start+0x8/0x8 [ 646.629297][ T1054] ? __kasan_check_read+0x11/0x20 [ 646.634340][ T1054] ? _raw_spin_unlock_irq+0x5e/0x90 [ 646.639964][ T1054] schedule+0xd9/0x260 [ 646.644055][ T1054] schedule_preempt_disabled+0x13/0x20 [ 646.650003][ T1054] __mutex_lock+0x7b0/0x13c0 [ 646.654964][ T1054] ? rtnl_lock+0x17/0x20 [ 646.659221][ T1054] ? mutex_trylock+0x2d0/0x2d0 [ 646.663998][ T1054] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 646.670674][ T1054] ? rcu_lockdep_current_cpu_online+0xe3/0x130 [ 646.677209][ T1054] mutex_lock_nested+0x16/0x20 [ 646.681981][ T1054] ? mutex_lock_nested+0x16/0x20 [ 646.687300][ T1054] rtnl_lock+0x17/0x20 [ 646.691379][ T1054] addrconf_verify_work+0xe/0x20 [ 646.696781][ T1054] process_one_work+0x9af/0x1740 [ 646.701745][ T1054] ? pwq_dec_nr_in_flight+0x320/0x320 [ 646.707499][ T1054] ? lock_acquire+0x190/0x410 [ 646.712201][ T1054] worker_thread+0x98/0xe40 [ 646.717070][ T1054] ? trace_hardirqs_on+0x67/0x240 [ 646.722121][ T1054] kthread+0x361/0x430 [ 646.726566][ T1054] ? process_one_work+0x1740/0x1740 [ 646.731781][ T1054] ? kthread_cancel_delayed_work_sync+0x20/0x20 [ 646.738797][ T1054] ret_from_fork+0x24/0x30 [ 646.743280][ T1054] [ 646.743280][ T1054] Showing all locks held in the system: [ 646.751509][ T1054] 1 lock held by khungtaskd/1054: [ 646.756862][ T1054] #0: ffffffff88faae40 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e [ 646.767404][ T1054] 3 locks held by kworker/0:2/2913: [ 646.772602][ T1054] #0: ffff888216019428 ((wq_completion)ipv6_addrconf){+.+.}, at: process_one_work+0x88b/0x1740 [ 646.783456][ T1054] #1: ffff8880a05b7dc0 ((addr_chk_work).work){+.+.}, at: process_one_work+0x8c1/0x1740 [ 646.793602][ T1054] #2: ffffffff89993b20 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 [ 646.802000][ T1054] 1 lock held by rsyslogd/8744: [ 646.807165][ T1054] #0: ffff8880899fa120 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 [ 646.816227][ T1054] 2 locks held by getty/8833: [ 646.820905][ T1054] #0: ffff888090baedd0 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 646.831225][ T1054] #1: ffffc90005f292e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 [ 646.841186][ T1054] 2 locks held by getty/8834: [ 646.846190][ T1054] #0: ffff88808d0f6dd0 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 646.855483][ T1054] #1: ffffc90005f392e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 [ 646.865407][ T1054] 2 locks held by getty/8835: [ 646.870081][ T1054] #0: ffff888090148e10 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 646.879498][ T1054] #1: ffffc90005f252e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 [ 646.889436][ T1054] 2 locks held by getty/8836: [ 646.894114][ T1054] #0: ffff8880a7ab3750 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 646.903552][ T1054] #1: ffffc90005f412e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 [ 646.913508][ T1054] 2 locks held by getty/8837: [ 646.918502][ T1054] #0: ffff8880a7accf10 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 646.927787][ T1054] #1: ffffc90005f3d2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 [ 646.937783][ T1054] 2 locks held by getty/8838: [ 646.942454][ T1054] #0: ffff88808d0f7650 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 646.951807][ T1054] #1: ffffc90005f352e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 [ 646.961829][ T1054] 2 locks held by getty/8839: [ 646.966808][ T1054] #0: ffff88808d162bd0 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 646.976096][ T1054] #1: ffffc90005f112e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 [ 646.986011][ T1054] 1 lock held by syz-executor910/8859: [ 646.991525][ T1054] [ 646.993856][ T1054] ============================================= [ 646.993856][ T1054] [ 647.003639][ T1054] NMI backtrace for cpu 0 [ 647.008379][ T1054] CPU: 0 PID: 1054 Comm: khungtaskd Not tainted 5.4.0-rc1+ #0 [ 647.015831][ T1054] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 647.025883][ T1054] Call Trace: [ 647.029242][ T1054] dump_stack+0x172/0x1f0 [ 647.033581][ T1054] nmi_cpu_backtrace.cold+0x70/0xb2 [ 647.038784][ T1054] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 647.045026][ T1054] ? lapic_can_unplug_cpu.cold+0x3a/0x3a [ 647.050669][ T1054] nmi_trigger_cpumask_backtrace+0x23b/0x28b [ 647.056653][ T1054] arch_trigger_cpumask_backtrace+0x14/0x20 [ 647.062545][ T1054] watchdog+0x9d0/0xef0 [ 647.066706][ T1054] kthread+0x361/0x430 [ 647.070778][ T1054] ? reset_hung_task_detector+0x30/0x30 [ 647.076320][ T1054] ? kthread_cancel_delayed_work_sync+0x20/0x20 [ 647.082570][ T1054] ret_from_fork+0x24/0x30 [ 647.087061][ T1054] Sending NMI from CPU 0 to CPUs 1: [ 647.093230][ C1] NMI backtrace for cpu 1 [ 647.093235][ C1] CPU: 1 PID: 8859 Comm: syz-executor910 Not tainted 5.4.0-rc1+ #0 [ 647.093241][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 647.093245][ C1] RIP: 0010:lockdep_hardirqs_off+0x1df/0x2e0 [ 647.093255][ C1] Code: 5c 08 00 00 5b 41 5c 41 5d 5d c3 48 c7 c0 58 1d f3 88 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 0f 85 d3 00 00 00 <48> 83 3d 21 9e 99 07 00 0f 84 b9 00 00 00 9c 58 0f 1f 44 00 00 f6 [ 647.093258][ C1] RSP: 0018:ffff8880a6f3f1b8 EFLAGS: 00000046 [ 647.093265][ C1] RAX: 1ffffffff11e63ab RBX: ffff88808c9c6080 RCX: 0000000000000000 [ 647.093269][ C1] RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffff88808c9c6914 [ 647.093273][ C1] RBP: ffff8880a6f3f1d0 R08: ffff88808c9c6080 R09: fffffbfff16be5d1 [ 647.093277][ C1] R10: fffffbfff16be5d0 R11: 0000000000000003 R12: ffffffff8746591f [ 647.093281][ C1] R13: ffff88808c9c6080 R14: ffffffff8746591f R15: 0000000000000003 [ 647.093286][ C1] FS: 00000000011e4880(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 [ 647.093290][ C1] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 647.093294][ C1] CR2: ffffffffff600400 CR3: 00000000a8920000 CR4: 00000000001406e0 [ 647.093298][ C1] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 647.093302][ C1] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 647.093304][ C1] Call Trace: [ 647.093308][ C1] ? __wake_up_common_lock+0xc8/0x150 [ 647.093310][ C1] trace_hardirqs_off+0x62/0x240 [ 647.093313][ C1] _raw_spin_lock_irqsave+0x6f/0xcd [ 647.093316][ C1] __wake_up_common_lock+0xc8/0x150 [ 647.093319][ C1] ? __wake_up_common+0x610/0x610 [ 647.093322][ C1] ? trace_hardirqs_on+0x67/0x240 [ 647.093325][ C1] ? kmem_cache_free+0x26b/0x320 [ 647.093328][ C1] ? kfree_skbmem+0xca/0x150 [ 647.093330][ C1] __wake_up+0xe/0x10 [ 647.093334][ C1] netlink_broadcast_filtered+0x705/0xb80 [ 647.093337][ C1] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 647.093340][ C1] ? refcount_inc_not_zero_checked+0x144/0x200 [ 647.093344][ C1] ? refcount_dec_and_mutex_lock+0x90/0x90 [ 647.093347][ C1] netlink_broadcast+0x3a/0x50 [ 647.093350][ C1] rtnetlink_send+0xdd/0x110 [ 647.093353][ C1] tcf_action_add+0x243/0x370 [ 647.093356][ C1] ? tca_action_gd+0x1730/0x1730 [ 647.093359][ C1] ? mark_held_locks+0xa4/0xf0 [ 647.093362][ C1] ? trace_hardirqs_on_thunk+0x1a/0x20 [ 647.093365][ C1] tc_ctl_action+0x3b5/0x4bc [ 647.093368][ C1] ? tcf_action_add+0x370/0x370 [ 647.093371][ C1] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 647.093374][ C1] ? tcf_action_add+0x370/0x370 [ 647.093377][ C1] rtnetlink_rcv_msg+0x463/0xb00 [ 647.093380][ C1] ? rtnl_bridge_getlink+0x910/0x910 [ 647.093383][ C1] ? lock_downgrade+0x920/0x920 [ 647.093386][ C1] ? netlink_deliver_tap+0x22d/0xbf0 [ 647.093388][ C1] ? find_held_lock+0x35/0x130 [ 647.093391][ C1] netlink_rcv_skb+0x177/0x450 [ 647.093394][ C1] ? rtnl_bridge_getlink+0x910/0x910 [ 647.093397][ C1] ? netlink_ack+0xb50/0xb50 [ 647.093400][ C1] ? __kasan_check_read+0x11/0x20 [ 647.093403][ C1] ? netlink_deliver_tap+0x254/0xbf0 [ 647.093406][ C1] rtnetlink_rcv+0x1d/0x30 [ 647.093409][ C1] netlink_unicast+0x531/0x710 [ 647.093412][ C1] ? netlink_attachskb+0x7c0/0x7c0 [ 647.093415][ C1] ? _copy_from_iter_full+0x25d/0x8c0 [ 647.093418][ C1] ? __sanitizer_cov_trace_cmp8+0x18/0x20 [ 647.093421][ C1] ? __check_object_size+0x3d/0x437 [ 647.093424][ C1] netlink_sendmsg+0x8a5/0xd60 [ 647.093427][ C1] ? netlink_unicast+0x710/0x710 [ 647.093430][ C1] ? aa_sock_msg_perm.isra.0+0xba/0x170 [ 647.093433][ C1] ? apparmor_socket_sendmsg+0x2a/0x30 [ 647.093436][ C1] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 647.093439][ C1] ? security_socket_sendmsg+0x8d/0xc0 [ 647.093442][ C1] ? netlink_unicast+0x710/0x710 [ 647.093445][ C1] sock_sendmsg+0xd7/0x130 [ 647.093448][ C1] ___sys_sendmsg+0x803/0x920 [ 647.093451][ C1] ? copy_msghdr_from_user+0x440/0x440 [ 647.093454][ C1] ? lockdep_hardirqs_on+0x421/0x5e0 [ 647.093457][ C1] ? release_sock+0x156/0x1c0 [ 647.093460][ C1] ? trace_hardirqs_on+0x67/0x240 [ 647.093463][ C1] ? release_sock+0x156/0x1c0 [ 647.093466][ C1] ? __local_bh_enable_ip+0x15a/0x270 [ 647.093469][ C1] ? _raw_spin_unlock_bh+0x31/0x40 [ 647.093472][ C1] ? release_sock+0x156/0x1c0 [ 647.093475][ C1] ? sock_setsockopt+0x191/0x2290 [ 647.093478][ C1] ? sock_enable_timestamp+0x120/0x120 [ 647.093481][ C1] ? aa_sk_perm+0x288/0x880 [ 647.093484][ C1] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 647.093487][ C1] ? __fget_light+0x1a9/0x230 [ 647.093490][ C1] ? __fdget+0x1b/0x20 [ 647.093493][ C1] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 647.093496][ C1] __sys_sendmsg+0x105/0x1d0 [ 647.093499][ C1] ? __sys_sendmsg_sock+0xd0/0xd0 [ 647.093502][ C1] ? down_read_non_owner+0x490/0x490 [ 647.093505][ C1] ? trace_hardirqs_on_thunk+0x1a/0x20 [ 647.093508][ C1] ? do_syscall_64+0x26/0x760 [ 647.093511][ C1] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 647.093514][ C1] ? do_syscall_64+0x26/0x760 [ 647.093517][ C1] __x64_sys_sendmsg+0x78/0xb0 [ 647.093519][ C1] do_syscall_64+0xfa/0x760 [ 647.093523][ C1] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 647.093525][ C1] RIP: 0033:0x440939 [ 647.093534][ C1] 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 [ 647.093538][ C1] RSP: 002b:00007ffeea8a8d98 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 647.093545][ C1] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440939 [ 647.093549][ C1] RDX: 0000000020000010 RSI: 0000000020001480 RDI: 0000000000000003 [ 647.093553][ C1] RBP: 00000000006cb018 R08: 0000000000000002 R09: 00000000004002c8 [ 647.093558][ C1] R10: 0000000000000008 R11: 0000000000000246 R12: 00000000004021c0 [ 647.093562][ C1] R13: 0000000000402250 R14: 0000000000000000 R15: 0000000000000000 [ 647.102474][ T1054] Kernel panic - not syncing: hung_task: blocked tasks [ 647.681646][ T1054] CPU: 0 PID: 1054 Comm: khungtaskd Not tainted 5.4.0-rc1+ #0 [ 647.689098][ T1054] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 647.699155][ T1054] Call Trace: [ 647.702451][ T1054] dump_stack+0x172/0x1f0 [ 647.706785][ T1054] panic+0x2dc/0x755 [ 647.710679][ T1054] ? add_taint.cold+0x16/0x16 [ 647.715350][ T1054] ? lapic_can_unplug_cpu.cold+0x3a/0x3a [ 647.720983][ T1054] ? ___preempt_schedule+0x16/0x20 [ 647.726098][ T1054] ? nmi_trigger_cpumask_backtrace+0x21b/0x28b [ 647.732251][ T1054] ? nmi_trigger_cpumask_backtrace+0x24c/0x28b [ 647.738407][ T1054] ? nmi_trigger_cpumask_backtrace+0x256/0x28b [ 647.744557][ T1054] ? nmi_trigger_cpumask_backtrace+0x21b/0x28b [ 647.750712][ T1054] watchdog+0x9e1/0xef0 [ 647.754873][ T1054] kthread+0x361/0x430 [ 647.759030][ T1054] ? reset_hung_task_detector+0x30/0x30 [ 647.764575][ T1054] ? kthread_cancel_delayed_work_sync+0x20/0x20 [ 647.770814][ T1054] ret_from_fork+0x24/0x30 [ 647.776677][ T1054] Kernel Offset: disabled [ 647.781008][ T1054] Rebooting in 86400 seconds..