TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. INFO: rcu_preempt self-detected stall on CPU 0-...: (1 GPs behind) idle=c36/140000000000001/0 softirq=200853/200857 fqs=5226 (t=10500 jiffies g=58785 c=58784 q=1659) NMI backtrace for cpu 0 CPU: 0 PID: 7 Comm: ksoftirqd/0 Not tainted 4.14.142 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x138/0x197 lib/dump_stack.c:53 nmi_cpu_backtrace.cold+0x57/0x94 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x141/0x189 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_single_cpu_backtrace include/linux/nmi.h:158 [inline] rcu_dump_cpu_stacks+0x186/0x1d2 kernel/rcu/tree.c:1396 print_cpu_stall kernel/rcu/tree.c:1542 [inline] check_cpu_stall kernel/rcu/tree.c:1610 [inline] __rcu_pending kernel/rcu/tree.c:3390 [inline] rcu_pending kernel/rcu/tree.c:3452 [inline] rcu_check_callbacks.cold+0x43d/0xd0a kernel/rcu/tree.c:2792 update_process_times+0x31/0x70 kernel/time/timer.c:1588 tick_sched_handle+0x85/0x160 kernel/time/tick-sched.c:161 tick_sched_timer+0x43/0x130 kernel/time/tick-sched.c:1219 __run_hrtimer kernel/time/hrtimer.c:1220 [inline] __hrtimer_run_queues+0x270/0xbc0 kernel/time/hrtimer.c:1284 hrtimer_interrupt+0x1d8/0x5d0 kernel/time/hrtimer.c:1318 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1075 [inline] smp_apic_timer_interrupt+0x11c/0x5e0 arch/x86/kernel/apic/apic.c:1100 apic_timer_interrupt+0x96/0xa0 arch/x86/entry/entry_64.S:792 RIP: 0010:__list_add_valid+0x70/0xa0 lib/list_debug.c:35 RSP: 0018:ffff8880a9ceebe8 EFLAGS: 00000283 ORIG_RAX: ffffffffffffff10 RAX: dffffc0000000000 RBX: ffff888093e5c6b8 RCX: 0000000000000000 RDX: ffff888093e5c750 RSI: ffff888093e5c750 RDI: ffff888093e5c758 RBP: ffff8880a9ceec00 R08: 0000000000000000 R09: ffff8880a9ce2b50 R10: ffff8880a9ce2b30 R11: ffff8880a9ce21c0 R12: ffff888093e5c750 R13: ffff888093e5c6b8 R14: ffff888093e5c750 R15: ffff888093e5c740 __list_add include/linux/list.h:60 [inline] list_add_tail include/linux/list.h:93 [inline] list_move_tail include/linux/list.h:183 [inline] hhf_dequeue+0x61b/0xa60 net/sched/sch_hhf.c:438 dequeue_skb net/sched/sch_generic.c:148 [inline] qdisc_restart net/sched/sch_generic.c:241 [inline] __qdisc_run+0x2b8/0xe00 net/sched/sch_generic.c:257 __dev_xmit_skb net/core/dev.c:3235 [inline] __dev_queue_xmit+0x1571/0x25e0 net/core/dev.c:3493 dev_queue_xmit+0x18/0x20 net/core/dev.c:3558 br_dev_queue_push_xmit+0x367/0x530 net/bridge/br_forward.c:55 br_nf_dev_queue_xmit+0x307/0x1440 net/bridge/br_netfilter_hooks.c:776 NF_HOOK include/linux/netfilter.h:250 [inline] NF_HOOK include/linux/netfilter.h:244 [inline] br_nf_post_routing+0xb80/0xf00 net/bridge/br_netfilter_hooks.c:822 nf_hook_entry_hookfn include/linux/netfilter.h:108 [inline] nf_hook_slow+0xaf/0x1b0 net/netfilter/core.c:467 nf_hook include/linux/netfilter.h:205 [inline] NF_HOOK include/linux/netfilter.h:248 [inline] br_forward_finish+0x1b7/0x320 net/bridge/br_forward.c:67 br_nf_hook_thresh+0x25b/0x2e0 net/bridge/br_netfilter_hooks.c:1005 br_nf_forward_finish+0x264/0x640 net/bridge/br_netfilter_hooks.c:550 NF_HOOK include/linux/netfilter.h:250 [inline] NF_HOOK include/linux/netfilter.h:244 [inline] br_nf_forward_ip net/bridge/br_netfilter_hooks.c:617 [inline] br_nf_forward_ip+0x5fc/0x11d0 net/bridge/br_netfilter_hooks.c:561 nf_hook_entry_hookfn include/linux/netfilter.h:108 [inline] nf_hook_slow+0xaf/0x1b0 net/netfilter/core.c:467 nf_hook include/linux/netfilter.h:205 [inline] NF_HOOK include/linux/netfilter.h:248 [inline] __br_forward+0x312/0x9c0 net/bridge/br_forward.c:111 deliver_clone+0x61/0xc0 net/bridge/br_forward.c:127 br_flood+0x43c/0x530 net/bridge/br_forward.c:222 br_handle_frame_finish+0xaf0/0x1830 net/bridge/br_input.c:210 br_nf_hook_thresh+0x25b/0x2e0 net/bridge/br_netfilter_hooks.c:1005 br_nf_pre_routing_finish_ipv6+0x621/0xc50 net/bridge/br_netfilter_ipv6.c:210 NF_HOOK include/linux/netfilter.h:250 [inline] br_nf_pre_routing_ipv6+0x417/0x790 net/bridge/br_netfilter_ipv6.c:240 br_nf_pre_routing+0xdce/0x12c7 net/bridge/br_netfilter_hooks.c:491 nf_hook_entry_hookfn include/linux/netfilter.h:108 [inline] nf_hook_slow+0xaf/0x1b0 net/netfilter/core.c:467 nf_hook include/linux/netfilter.h:205 [inline] NF_HOOK include/linux/netfilter.h:248 [inline] br_handle_frame+0x80c/0x1110 net/bridge/br_input.c:348 __netif_receive_skb_core+0x789/0x2ca0 net/core/dev.c:4431 __netif_receive_skb+0x2c/0x1b0 net/core/dev.c:4515 process_backlog+0x21f/0x730 net/core/dev.c:5197 napi_poll net/core/dev.c:5598 [inline] net_rx_action+0x490/0xf80 net/core/dev.c:5664 __do_softirq+0x244/0x9a0 kernel/softirq.c:288 run_ksoftirqd kernel/softirq.c:670 [inline] run_ksoftirqd+0x8c/0x1b0 kernel/softirq.c:662 smpboot_thread_fn+0x5f4/0x960 kernel/smpboot.c:164 kthread+0x319/0x430 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 INFO: rcu_sched detected stalls on CPUs/tasks: 0-...: (1 GPs behind) idle=c36/140000000000000/0 softirq=200771/200857 fqs=5210 (detected by 1, t=10529 jiffies, g=40490, c=40489, q=43) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 7 Comm: ksoftirqd/0 Not tainted 4.14.142 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8880a9ce21c0 task.stack: ffff8880a9ce8000 RIP: 0010:__list_add_valid+0x0/0xa0 lib/list_debug.c:23 RSP: 0018:ffff8880a9ceec08 EFLAGS: 00000246 RAX: 1ffff110127cb8eb RBX: ffff888093e5c6b8 RCX: 0000000000000000 RDX: ffff888093e5c750 RSI: ffff888093e5c750 RDI: ffff888093e5c6b8 RBP: ffff8880a9ceec60 R08: 0000000000000000 R09: ffff8880a9ce2b50 R10: ffff8880a9ce2b30 R11: ffff8880a9ce21c0 R12: dffffc0000000000 R13: ffff888093e5c4c0 R14: ffff888093e5c750 R15: ffff888093e5c740 FS: 0000000000000000(0000) GS:ffff8880aee00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b31f33000 CR3: 000000000766a000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: dequeue_skb net/sched/sch_generic.c:148 [inline] qdisc_restart net/sched/sch_generic.c:241 [inline] __qdisc_run+0x2b8/0xe00 net/sched/sch_generic.c:257 __dev_xmit_skb net/core/dev.c:3235 [inline] __dev_queue_xmit+0x1571/0x25e0 net/core/dev.c:3493 dev_queue_xmit+0x18/0x20 net/core/dev.c:3558 br_dev_queue_push_xmit+0x367/0x530 net/bridge/br_forward.c:55 br_nf_dev_queue_xmit+0x307/0x1440 net/bridge/br_netfilter_hooks.c:776 NF_HOOK include/linux/netfilter.h:250 [inline] NF_HOOK include/linux/netfilter.h:244 [inline] br_nf_post_routing+0xb80/0xf00 net/bridge/br_netfilter_hooks.c:822 nf_hook_entry_hookfn include/linux/netfilter.h:108 [inline] nf_hook_slow+0xaf/0x1b0 net/netfilter/core.c:467 nf_hook include/linux/netfilter.h:205 [inline] NF_HOOK include/linux/netfilter.h:248 [inline] br_forward_finish+0x1b7/0x320 net/bridge/br_forward.c:67 br_nf_hook_thresh+0x25b/0x2e0 net/bridge/br_netfilter_hooks.c:1005 br_nf_forward_finish+0x264/0x640 net/bridge/br_netfilter_hooks.c:550 NF_HOOK include/linux/netfilter.h:250 [inline] NF_HOOK include/linux/netfilter.h:244 [inline] br_nf_forward_ip net/bridge/br_netfilter_hooks.c:617 [inline] br_nf_forward_ip+0x5fc/0x11d0 net/bridge/br_netfilter_hooks.c:561 nf_hook_entry_hookfn include/linux/netfilter.h:108 [inline] nf_hook_slow+0xaf/0x1b0 net/netfilter/core.c:467 nf_hook include/linux/netfilter.h:205 [inline] NF_HOOK include/linux/netfilter.h:248 [inline] __br_forward+0x312/0x9c0 net/bridge/br_forward.c:111 deliver_clone+0x61/0xc0 net/bridge/br_forward.c:127 br_flood+0x43c/0x530 net/bridge/br_forward.c:222 br_handle_frame_finish+0xaf0/0x1830 net/bridge/br_input.c:210 br_nf_hook_thresh+0x25b/0x2e0 net/bridge/br_netfilter_hooks.c:1005 br_nf_pre_routing_finish_ipv6+0x621/0xc50 net/bridge/br_netfilter_ipv6.c:210 NF_HOOK include/linux/netfilter.h:250 [inline] br_nf_pre_routing_ipv6+0x417/0x790 net/bridge/br_netfilter_ipv6.c:240 br_nf_pre_routing+0xdce/0x12c7 net/bridge/br_netfilter_hooks.c:491 nf_hook_entry_hookfn include/linux/netfilter.h:108 [inline] nf_hook_slow+0xaf/0x1b0 net/netfilter/core.c:467 nf_hook include/linux/netfilter.h:205 [inline] NF_HOOK include/linux/netfilter.h:248 [inline] br_handle_frame+0x80c/0x1110 net/bridge/br_input.c:348 __netif_receive_skb_core+0x789/0x2ca0 net/core/dev.c:4431 __netif_receive_skb+0x2c/0x1b0 net/core/dev.c:4515 process_backlog+0x21f/0x730 net/core/dev.c:5197 napi_poll net/core/dev.c:5598 [inline] net_rx_action+0x490/0xf80 net/core/dev.c:5664 __do_softirq+0x244/0x9a0 kernel/softirq.c:288 run_ksoftirqd kernel/softirq.c:670 [inline] run_ksoftirqd+0x8c/0x1b0 kernel/softirq.c:662 smpboot_thread_fn+0x5f4/0x960 kernel/smpboot.c:164 kthread+0x319/0x430 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Code: 54 49 89 fc e8 52 76 84 fe 4c 89 e6 48 c7 c7 c0 2e 9d 86 e8 73 fd ff ff 41 5c 5d c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <48> b8 00 00 00 00 00 fc ff df 55 48 89 e5 41 55 49 89 fd 48 8d INFO: rcu_bh detected stalls on CPUs/tasks: 0-...: (1 GPs behind) idle=c36/140000000000000/0 softirq=198030/200857 fqs=5226 (detected by 1, t=10620 jiffies, g=161, c=160, q=40) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 7 Comm: ksoftirqd/0 Not tainted 4.14.142 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8880a9ce21c0 task.stack: ffff8880a9ce8000 RIP: 0010:hhf_dequeue+0x51a/0xa60 net/sched/sch_hhf.c:435 RSP: 0018:ffff8880a9ceec10 EFLAGS: 00000a07 RAX: 0000000000000000 RBX: ffff888093e5c6b8 RCX: 0000000000000000 RDX: 1ffff110127cb8ed RSI: ffff888093e5c750 RDI: ffff888093e5c76c RBP: ffff8880a9ceec60 R08: 0000000000000000 R09: ffff8880a9ce2b50 R10: ffff8880a9ce2b30 R11: ffff8880a9ce21c0 R12: dffffc0000000000 R13: ffff888093e5c4c0 R14: 0000000000000001 R15: ffff888093e5c740 FS: 0000000000000000(0000) GS:ffff8880aee00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b31f33000 CR3: 000000000766a000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: dequeue_skb net/sched/sch_generic.c:148 [inline] qdisc_restart net/sched/sch_generic.c:241 [inline] __qdisc_run+0x2b8/0xe00 net/sched/sch_generic.c:257 __dev_xmit_skb net/core/dev.c:3235 [inline] __dev_queue_xmit+0x1571/0x25e0 net/core/dev.c:3493 dev_queue_xmit+0x18/0x20 net/core/dev.c:3558 br_dev_queue_push_xmit+0x367/0x530 net/bridge/br_forward.c:55 br_nf_dev_queue_xmit+0x307/0x1440 net/bridge/br_netfilter_hooks.c:776 NF_HOOK include/linux/netfilter.h:250 [inline] NF_HOOK include/linux/netfilter.h:244 [inline] br_nf_post_routing+0xb80/0xf00 net/bridge/br_netfilter_hooks.c:822 nf_hook_entry_hookfn include/linux/netfilter.h:108 [inline] nf_hook_slow+0xaf/0x1b0 net/netfilter/core.c:467 nf_hook include/linux/netfilter.h:205 [inline] NF_HOOK include/linux/netfilter.h:248 [inline] br_forward_finish+0x1b7/0x320 net/bridge/br_forward.c:67 br_nf_hook_thresh+0x25b/0x2e0 net/bridge/br_netfilter_hooks.c:1005 br_nf_forward_finish+0x264/0x640 net/bridge/br_netfilter_hooks.c:550 NF_HOOK include/linux/netfilter.h:250 [inline] NF_HOOK include/linux/netfilter.h:244 [inline] br_nf_forward_ip net/bridge/br_netfilter_hooks.c:617 [inline] br_nf_forward_ip+0x5fc/0x11d0 net/bridge/br_netfilter_hooks.c:561 nf_hook_entry_hookfn include/linux/netfilter.h:108 [inline] nf_hook_slow+0xaf/0x1b0 net/netfilter/core.c:467 nf_hook include/linux/netfilter.h:205 [inline] NF_HOOK include/linux/netfilter.h:248 [inline] __br_forward+0x312/0x9c0 net/bridge/br_forward.c:111 deliver_clone+0x61/0xc0 net/bridge/br_forward.c:127 br_flood+0x43c/0x530 net/bridge/br_forward.c:222 br_handle_frame_finish+0xaf0/0x1830 net/bridge/br_input.c:210 br_nf_hook_thresh+0x25b/0x2e0 net/bridge/br_netfilter_hooks.c:1005 br_nf_pre_routing_finish_ipv6+0x621/0xc50 net/bridge/br_netfilter_ipv6.c:210 NF_HOOK include/linux/netfilter.h:250 [inline] br_nf_pre_routing_ipv6+0x417/0x790 net/bridge/br_netfilter_ipv6.c:240 br_nf_pre_routing+0xdce/0x12c7 net/bridge/br_netfilter_hooks.c:491 nf_hook_entry_hookfn include/linux/netfilter.h:108 [inline] nf_hook_slow+0xaf/0x1b0 net/netfilter/core.c:467 nf_hook include/linux/netfilter.h:205 [inline] NF_HOOK include/linux/netfilter.h:248 [inline] br_handle_frame+0x80c/0x1110 net/bridge/br_input.c:348 __netif_receive_skb_core+0x789/0x2ca0 net/core/dev.c:4431 __netif_receive_skb+0x2c/0x1b0 net/core/dev.c:4515 process_backlog+0x21f/0x730 net/core/dev.c:5197 napi_poll net/core/dev.c:5598 [inline] net_rx_action+0x490/0xf80 net/core/dev.c:5664 __do_softirq+0x244/0x9a0 kernel/softirq.c:288 run_ksoftirqd kernel/softirq.c:670 [inline] run_ksoftirqd+0x8c/0x1b0 kernel/softirq.c:662 smpboot_thread_fn+0x5f4/0x960 kernel/smpboot.c:164 kthread+0x319/0x430 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Code: c0 01 00 00 8b 45 b8 48 8d 53 f0 48 39 d1 74 37 e8 3c 51 6d fc 49 8d bd ac 02 00 00 8b 45 b8 48 89 fa 48 c1 ea 03 42 0f b6 0c 22 <48> 89 fa 83 e2 07 83 c2 03 38 ca 7c 08 84 c9 0f 85 d1 03 00 00