[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [ 65.139002][ T9628] sshd (9628) used greatest stack depth: 23336 bytes left [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [ 65.416807][ T26] kauditd_printk_skb: 7 callbacks suppressed [ 65.416817][ T26] audit: type=1800 audit(1564437151.790:29): pid=9562 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 [ 65.451147][ T26] audit: type=1800 audit(1564437151.790:30): pid=9562 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 '10.128.1.12' (ECDSA) to the list of known hosts. syzkaller login: [ 191.102709][ T9714] IPVS: ftp: loaded support on port[0] = 21 [ 191.147763][ T9714] chnl_net:caif_netlink_parms(): no params data found [ 191.170616][ T9714] bridge0: port 1(bridge_slave_0) entered blocking state [ 191.178177][ T9714] bridge0: port 1(bridge_slave_0) entered disabled state [ 191.185968][ T9714] device bridge_slave_0 entered promiscuous mode [ 191.193285][ T9714] bridge0: port 2(bridge_slave_1) entered blocking state [ 191.201138][ T9714] bridge0: port 2(bridge_slave_1) entered disabled state [ 191.209059][ T9714] device bridge_slave_1 entered promiscuous mode [ 191.222985][ T9714] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link [ 191.233673][ T9714] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link [ 191.250707][ T9714] team0: Port device team_slave_0 added [ 191.257962][ T9714] team0: Port device team_slave_1 added [ 191.337283][ T9714] device hsr_slave_0 entered promiscuous mode [ 191.385820][ T9714] device hsr_slave_1 entered promiscuous mode [ 191.430882][ T9714] bridge0: port 2(bridge_slave_1) entered blocking state [ 191.438638][ T9714] bridge0: port 2(bridge_slave_1) entered forwarding state [ 191.446093][ T9714] bridge0: port 1(bridge_slave_0) entered blocking state [ 191.454662][ T9714] bridge0: port 1(bridge_slave_0) entered forwarding state [ 191.479830][ T9714] 8021q: adding VLAN 0 to HW filter on device bond0 [ 191.491294][ T5] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready [ 191.509974][ T5] bridge0: port 1(bridge_slave_0) entered disabled state [ 191.517752][ T5] bridge0: port 2(bridge_slave_1) entered disabled state [ 191.526040][ T5] IPv6: ADDRCONF(NETDEV_CHANGE): bond0: link becomes ready [ 191.536892][ T9714] 8021q: adding VLAN 0 to HW filter on device team0 [ 191.546198][ T22] IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_0: link becomes ready [ 191.554587][ T22] bridge0: port 1(bridge_slave_0) entered blocking state [ 191.561857][ T22] bridge0: port 1(bridge_slave_0) entered forwarding state [ 191.572003][ T5] IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_1: link becomes ready [ 191.580463][ T5] bridge0: port 2(bridge_slave_1) entered blocking state [ 191.587638][ T5] bridge0: port 2(bridge_slave_1) entered forwarding state [ 191.601802][ T22] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_0: link becomes ready [ 191.610618][ T22] IPv6: ADDRCONF(NETDEV_CHANGE): team0: link becomes ready [ 191.621299][ T5] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_1: link becomes ready executing program [ 191.632423][ T22] IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_0: link becomes ready [ 191.645325][ T5] IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_1: link becomes ready [ 191.655051][ T9714] IPv6: ADDRCONF(NETDEV_CHANGE): hsr0: link becomes ready [ 191.670601][ T9714] 8021q: adding VLAN 0 to HW filter on device batadv0 [ 191.702455][ C1] TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. [ 296.865405][ C1] rcu: INFO: rcu_preempt self-detected stall on CPU [ 296.873289][ C1] rcu: 1-...!: (10500 ticks this GP) idle=59a/1/0x4000000000000002 softirq=9848/9848 fqs=0 [ 296.883681][ C1] (t=10500 jiffies g=9465 q=47) [ 296.888599][ C1] rcu: rcu_preempt kthread starved for 10500 jiffies! g9465 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1 [ 296.899908][ C1] rcu: RCU grace-period kthread stack dump: [ 296.905860][ C1] rcu_preempt I29392 10 2 0x80004000 [ 296.912170][ C1] Call Trace: [ 296.915520][ C1] __schedule+0x755/0x15b0 [ 296.919934][ C1] ? __sched_text_start+0x8/0x8 [ 296.924761][ C1] schedule+0xa8/0x270 [ 296.928972][ C1] schedule_timeout+0x486/0xc50 [ 296.933908][ C1] ? rwlock_bug.part.0+0x90/0x90 [ 296.938823][ C1] ? usleep_range+0x170/0x170 [ 296.943477][ C1] ? trace_hardirqs_on+0x67/0x240 [ 296.948491][ C1] ? __kasan_check_read+0x11/0x20 [ 296.955358][ C1] ? __next_timer_interrupt+0x1a0/0x1a0 [ 296.960895][ C1] ? swake_up_one+0x60/0x60 [ 296.965377][ C1] ? trace_hardirqs_on+0x67/0x240 [ 296.970380][ C1] rcu_gp_kthread+0x9b2/0x18c0 [ 296.975131][ C1] ? rcu_barrier+0x310/0x310 [ 296.979878][ C1] ? trace_hardirqs_on+0x67/0x240 [ 296.984891][ C1] ? __kasan_check_read+0x11/0x20 [ 296.989903][ C1] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 296.996118][ C1] ? __kthread_parkme+0x108/0x1c0 [ 297.001417][ C1] ? __kasan_check_read+0x11/0x20 [ 297.006422][ C1] kthread+0x361/0x430 [ 297.010487][ C1] ? rcu_barrier+0x310/0x310 [ 297.015068][ C1] ? kthread_cancel_delayed_work_sync+0x20/0x20 [ 297.021379][ C1] ret_from_fork+0x24/0x30 [ 297.025808][ C1] NMI backtrace for cpu 1 [ 297.030122][ C1] CPU: 1 PID: 9714 Comm: syz-executor209 Not tainted 5.3.0-rc2-next-20190729 #54 [ 297.039200][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 297.049495][ C1] Call Trace: [ 297.052757][ C1] [ 297.055663][ C1] dump_stack+0x172/0x1f0 [ 297.059971][ C1] nmi_cpu_backtrace.cold+0x70/0xb2 [ 297.065154][ C1] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 297.071391][ C1] ? lapic_can_unplug_cpu.cold+0x45/0x45 [ 297.077004][ C1] nmi_trigger_cpumask_backtrace+0x23b/0x28b [ 297.082966][ C1] arch_trigger_cpumask_backtrace+0x14/0x20 [ 297.088933][ C1] rcu_dump_cpu_stacks+0x183/0x1cf [ 297.094027][ C1] rcu_sched_clock_irq.cold+0x4dd/0xc13 [ 297.100073][ C1] ? raise_softirq+0x138/0x340 [ 297.104820][ C1] update_process_times+0x32/0x80 [ 297.109841][ C1] tick_sched_handle+0xa2/0x190 [ 297.114669][ C1] tick_sched_timer+0x53/0x140 [ 297.119423][ C1] __hrtimer_run_queues+0x364/0xe40 [ 297.124601][ C1] ? tick_sched_do_timer+0x1b0/0x1b0 [ 297.129955][ C1] ? hrtimer_start_range_ns+0xcb0/0xcb0 [ 297.135479][ C1] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 297.141179][ C1] ? ktime_get_update_offsets_now+0x2d3/0x440 [ 297.147225][ C1] hrtimer_interrupt+0x314/0x770 [ 297.152197][ C1] smp_apic_timer_interrupt+0x160/0x610 [ 297.157722][ C1] apic_timer_interrupt+0xf/0x20 [ 297.162642][ C1] RIP: 0010:native_queued_spin_lock_slowpath+0x132/0x9f0 [ 297.169643][ C1] Code: 00 00 00 48 8b 45 d0 65 48 33 04 25 28 00 00 00 0f 85 37 07 00 00 48 81 c4 98 00 00 00 5b 41 5c 41 5d 41 5e 41 5f 5d c3 f3 90 73 ff ff ff 8b 45 98 4c 8d 65 d8 3d 00 01 00 00 0f 84 e5 00 00 [ 297.189316][ C1] RSP: 0018:ffff8880ae909210 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff13 [ 297.197882][ C1] RAX: 0000000000000000 RBX: ffff8880934ccd48 RCX: ffffffff8158f117 [ 297.205831][ C1] RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8880934ccd48 [ 297.213779][ C1] RBP: ffff8880ae9092d0 R08: 1ffff110126999a9 R09: ffffed10126999aa [ 297.221758][ C1] R10: ffffed10126999a9 R11: ffff8880934ccd4b R12: 0000000000000001 [ 297.229804][ C1] R13: 0000000000000003 R14: ffffed10126999a9 R15: 0000000000000001 [ 297.237768][ C1] ? apic_timer_interrupt+0xa/0x20 [ 297.242866][ C1] ? native_queued_spin_lock_slowpath+0xb7/0x9f0 [ 297.249183][ C1] ? __pv_queued_spin_lock_slowpath+0xd10/0xd10 [ 297.255767][ C1] ? mark_held_locks+0xf0/0xf0 [ 297.260513][ C1] do_raw_spin_lock+0x20e/0x2e0 [ 297.265341][ C1] ? rwlock_bug.part.0+0x90/0x90 [ 297.270272][ C1] ? lock_acquire+0x190/0x410 [ 297.274981][ C1] ? release_sock+0x20/0x1c0 [ 297.279560][ C1] ? __kasan_check_read+0x11/0x20 [ 297.284565][ C1] _raw_spin_lock_bh+0x3b/0x50 [ 297.289302][ C1] ? release_sock+0x20/0x1c0 [ 297.293867][ C1] release_sock+0x20/0x1c0 [ 297.298296][ C1] wait_on_pending_writer+0x20f/0x420 [ 297.303678][ C1] ? ip6_rcv_finish+0x1de/0x2f0 [ 297.308510][ C1] ? tls_init+0x560/0x560 [ 297.312832][ C1] ? process_backlog+0x206/0x750 [ 297.317749][ C1] ? net_rx_action+0x508/0x10c0 [ 297.322578][ C1] ? __do_softirq+0x262/0x98c [ 297.327234][ C1] ? prepare_to_wait_exclusive+0x320/0x320 [ 297.333051][ C1] ? inet_release+0xed/0x200 [ 297.337631][ C1] ? inet6_release+0x53/0x80 [ 297.342318][ C1] ? __sock_release+0xce/0x280 [ 297.347071][ C1] ? sock_close+0x1e/0x30 [ 297.351986][ C1] ? __fput+0x2ff/0x890 [ 297.356482][ C1] ? ____fput+0x16/0x20 [ 297.360876][ C1] ? task_work_run+0x145/0x1c0 [ 297.365627][ C1] ? exit_to_usermode_loop+0x316/0x380 [ 297.371066][ C1] tls_sk_proto_cleanup+0x2c5/0x3e0 [ 297.376245][ C1] ? wait_on_pending_writer+0x420/0x420 [ 297.381781][ C1] tls_sk_proto_unhash+0x90/0x3f0 [ 297.386826][ C1] tcp_set_state+0x5b9/0x7d0 [ 297.391402][ C1] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 297.397641][ C1] ? __sk_mem_reduce_allocated+0x1b0/0x560 [ 297.403428][ C1] ? tcp_alloc_md5sig_pool+0x4a0/0x4a0 [ 297.408880][ C1] ? __sk_mem_reclaim+0x55/0x70 [ 297.413715][ C1] ? tcp_write_queue_purge+0x5d8/0x1310 [ 297.419283][ C1] ? inet6_sk_rx_dst_set+0x244/0x6f0 [ 297.424550][ C1] tcp_done+0xe2/0x320 [ 297.428701][ C1] tcp_reset+0x132/0x500 [ 297.432923][ C1] tcp_validate_incoming+0xa2d/0x1660 [ 297.438281][ C1] tcp_rcv_established+0x6b5/0x1e70 [ 297.444072][ C1] ? mark_held_locks+0xf0/0xf0 [ 297.448860][ C1] ? sk_filter_trim_cap+0x45f/0xb30 [ 297.454057][ C1] ? tcp_data_queue+0x4860/0x4860 [ 297.459061][ C1] ? do_raw_spin_lock+0x12a/0x2e0 [ 297.464063][ C1] ? rwlock_bug.part.0+0x90/0x90 [ 297.469512][ C1] ? lock_acquire+0x190/0x410 [ 297.474260][ C1] tcp_v6_do_rcv+0x41e/0x12c0 [ 297.478926][ C1] tcp_v6_rcv+0x31f1/0x3500 [ 297.483419][ C1] ? tcp_v6_syn_recv_sock+0x2290/0x2290 [ 297.488992][ C1] ? nf_confirm+0x360/0x4d0 [ 297.493581][ C1] ? mark_held_locks+0xf0/0xf0 [ 297.498333][ C1] ip6_protocol_deliver_rcu+0x2fe/0x1660 [ 297.503956][ C1] ip6_input_finish+0x84/0x170 [ 297.508703][ C1] ip6_input+0xe4/0x3f0 [ 297.513030][ C1] ? ip6_input_finish+0x170/0x170 [ 297.518044][ C1] ? __kasan_check_read+0x11/0x20 [ 297.523053][ C1] ? ip6_protocol_deliver_rcu+0x1660/0x1660 [ 297.528946][ C1] ? lock_downgrade+0x920/0x920 [ 297.533782][ C1] ? __sanitizer_cov_trace_const_cmp2+0x18/0x20 [ 297.540022][ C1] ip6_rcv_finish+0x1de/0x2f0 [ 297.544687][ C1] ipv6_rcv+0x10e/0x420 [ 297.548825][ C1] ? ip6_rcv_core.isra.0+0x1bb0/0x1bb0 [ 297.554276][ C1] ? lock_downgrade+0x920/0x920 [ 297.559195][ C1] ? lock_downgrade+0x920/0x920 [ 297.564053][ C1] ? ip6_rcv_finish_core.isra.0+0x560/0x560 [ 297.569949][ C1] ? trace_hardirqs_off+0x62/0x240 [ 297.575129][ C1] ? ip6_rcv_core.isra.0+0x1bb0/0x1bb0 [ 297.580571][ C1] __netif_receive_skb_one_core+0x113/0x1a0 [ 297.586443][ C1] ? __netif_receive_skb_core+0x3060/0x3060 [ 297.592334][ C1] ? lock_acquire+0x190/0x410 [ 297.597004][ C1] ? process_backlog+0x195/0x750 [ 297.601941][ C1] __netif_receive_skb+0x2c/0x1d0 [ 297.606962][ C1] process_backlog+0x206/0x750 [ 297.611808][ C1] ? lock_acquire+0x190/0x410 [ 297.616465][ C1] ? clockevents_program_event+0x15a/0x370 [ 297.622259][ C1] net_rx_action+0x508/0x10c0 [ 297.626917][ C1] ? napi_complete_done+0x4b0/0x4b0 [ 297.632096][ C1] ? sched_clock+0x2e/0x50 [ 297.636495][ C1] ? kvm_clock_read+0x18/0x30 [ 297.641157][ C1] ? inet_csk_listen_stop+0x1bc/0x850 [ 297.646512][ C1] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 297.652738][ C1] __do_softirq+0x262/0x98c [ 297.657278][ C1] ? inet_csk_listen_stop+0x1bc/0x850 [ 297.662630][ C1] do_softirq_own_stack+0x2a/0x40 [ 297.667652][ C1] [ 297.670582][ C1] do_softirq.part.0+0x11a/0x170 [ 297.675498][ C1] __local_bh_enable_ip+0x211/0x270 [ 297.680686][ C1] inet_csk_listen_stop+0x1e0/0x850 [ 297.685889][ C1] tcp_close+0xd5b/0x10e0 [ 297.690290][ C1] ? ip_mc_drop_socket+0x211/0x270 [ 297.695387][ C1] ? down_write+0xdf/0x150 [ 297.699788][ C1] inet_release+0xed/0x200 [ 297.704185][ C1] inet6_release+0x53/0x80 [ 297.708590][ C1] __sock_release+0xce/0x280 [ 297.713621][ C1] sock_close+0x1e/0x30 [ 297.717759][ C1] __fput+0x2ff/0x890 [ 297.721726][ C1] ? __sock_release+0x280/0x280 [ 297.726559][ C1] ____fput+0x16/0x20 [ 297.730617][ C1] task_work_run+0x145/0x1c0 [ 297.735191][ C1] exit_to_usermode_loop+0x316/0x380 [ 297.740474][ C1] do_syscall_64+0x65f/0x760 [ 297.745058][ C1] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 297.754246][ C1] RIP: 0033:0x406581 [ 297.758139][ C1] Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 24 1a 00 00 c3 48 83 ec 08 e8 6a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 b3 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01 [ 297.778301][ C1] RSP: 002b:00007fffb1505230 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 [ 297.786721][ C1] RAX: 0000000000000000 RBX: 0000000000000005 RCX: 0000000000406581 [ 297.794677][ C1] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004 [ 297.804106][ C1] RBP: 00000000006dcc20 R08: 0000000000000140 R09: 0000000000000140 [ 297.812059][ C1] R10: 00007fffb1505260 R11: 0000000000000293 R12: 00007fffb1505290 [ 297.820007][ C1] R13: 00000000006dcc2c R14: 000000000000002d R15: 0000000000000007 [ 301.535582][ T9716] rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 1-... } 10939 jiffies s: 105 root: 0x2/. [ 301.547486][ T9716] rcu: blocking rcu_node structures: [ 301.552841][ T9716] Task dump for CPU 1: [ 301.557233][ T9716] syz-executor209 R running task 24264 9714 9713 0x8000000a [ 301.565123][ T9716] Call Trace: [ 301.568961][ T9716] ? __kasan_check_read+0x11/0x20 [ 301.573984][ T9716] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 301.580702][ T9716] ? lock_downgrade+0x920/0x920 [ 301.586051][ T9716] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 301.593088][ T9716] ? __this_cpu_preempt_check+0x3a/0x210 [ 301.599059][ T9716] ? inet_csk_listen_stop+0x1bc/0x850 [ 301.604538][ T9716] ? ksoftirqd_running+0x16/0x70 [ 301.609943][ T9716] ? inet_csk_listen_stop+0x1bc/0x850 [ 301.615321][ T9716] ? do_softirq.part.0+0x11a/0x170 [ 301.620611][ T9716] ? __local_bh_enable_ip+0x211/0x270 [ 301.626773][ T9716] ? inet_csk_listen_stop+0x1e0/0x850 [ 301.632138][ T9716] ? tcp_close+0xd5b/0x10e0 [ 301.636790][ T9716] ? ip_mc_drop_socket+0x211/0x270 [ 301.641890][ T9716] ? down_write+0xdf/0x150 [ 301.646780][ T9716] ? inet_release+0xed/0x200 [ 301.651360][ T9716] ? inet6_release+0x53/0x80 [ 301.656089][ T9716] ? __sock_release+0xce/0x280 [ 301.660943][ T9716] ? sock_close+0x1e/0x30 [ 301.665282][ T9716] ? __fput+0x2ff/0x890 [ 301.669931][ T9716] ? __sock_release+0x280/0x280 [ 301.674854][ T9716] ? ____fput+0x16/0x20 [ 301.679170][ T9716] ? task_work_run+0x145/0x1c0 [ 301.683929][ T9716] ? exit_to_usermode_loop+0x316/0x380 [ 301.690027][ T9716] ? do_syscall_64+0x65f/0x760 [ 301.694779][ T9716] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe