rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-....: (1 GPs behind) idle=5de/1/0x4000000000000002 softirq=375631/375632 fqs=5243 rcu: (t=10500 jiffies g=550969 q=1216) NMI backtrace for cpu 0 CPU: 0 PID: 17818 Comm: syz-executor5 Not tainted 4.20.0-rc7+ #357 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x244/0x39d lib/dump_stack.c:113 nmi_cpu_backtrace.cold.2+0x5c/0xa1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1e8/0x22a 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:164 [inline] rcu_dump_cpu_stacks+0x16f/0x1bc kernel/rcu/tree.c:1195 print_cpu_stall.cold.67+0x1f3/0x3c7 kernel/rcu/tree.c:1334 check_cpu_stall kernel/rcu/tree.c:1408 [inline] rcu_pending kernel/rcu/tree.c:2961 [inline] rcu_check_callbacks+0xf3b/0x13f0 kernel/rcu/tree.c:2506 update_process_times+0x2d/0x70 kernel/time/timer.c:1636 tick_sched_handle+0x9f/0x180 kernel/time/tick-sched.c:164 tick_sched_timer+0x45/0x130 kernel/time/tick-sched.c:1274 __run_hrtimer kernel/time/hrtimer.c:1398 [inline] __hrtimer_run_queues+0x41c/0x10d0 kernel/time/hrtimer.c:1460 hrtimer_interrupt+0x313/0x780 kernel/time/hrtimer.c:1518 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1034 [inline] smp_apic_timer_interrupt+0x1a1/0x760 arch/x86/kernel/apic/apic.c:1059 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:23 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:67 [inline] RIP: 0010:write_comp_data+0xd/0x70 kernel/kcov.c:122 Code: e8 78 ee 43 00 e9 6f fc ff ff e8 ce 63 c9 ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 48 89 e5 65 4c 8b 04 25 40 ee 01 00 <65> 8b 05 bc 68 82 7e a9 00 01 1f 00 75 51 41 8b 80 d8 12 00 00 83 RSP: 0018:ffff8881dac06768 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000007 RBX: ffff8881d8135bc8 RCX: ffffffff86d05a55 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: ffff8881dac06768 R08: ffff8881cd9f46c0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8881dac06de8 R13: 0000000000000000 R14: 0000000000000011 R15: 0000000000000000 __sanitizer_cov_trace_const_cmp2+0x18/0x20 kernel/kcov.c:181 __xfrm6_selector_match net/xfrm/xfrm_policy.c:208 [inline] xfrm_selector_match+0x4d5/0xf90 net/xfrm/xfrm_policy.c:221 xfrm_policy_match+0x1ef/0x2d0 net/xfrm/xfrm_policy.c:1894 __xfrm_policy_eval_candidates net/xfrm/xfrm_policy.c:2022 [inline] xfrm_policy_eval_candidates net/xfrm/xfrm_policy.c:2053 [inline] xfrm_policy_lookup_bytype+0xa13/0xe80 net/xfrm/xfrm_policy.c:2113 xfrm_policy_lookup+0x7e/0x80 net/xfrm/xfrm_policy.c:2145 __xfrm_policy_check+0x14f0/0x2c40 net/xfrm/xfrm_policy.c:3354 __xfrm_policy_check2 include/net/xfrm.h:1166 [inline] xfrm_policy_check include/net/xfrm.h:1175 [inline] xfrm6_policy_check include/net/xfrm.h:1185 [inline] udpv6_queue_rcv_one_skb+0x517/0x16b0 net/ipv6/udp.c:615 udpv6_queue_rcv_skb+0x594/0x8f0 net/ipv6/udp.c:699 __udp6_lib_mcast_deliver net/ipv6/udp.c:812 [inline] __udp6_lib_rcv+0x1ecf/0x3190 net/ipv6/udp.c:916 udpv6_rcv+0x21/0x30 net/ipv6/udp.c:1026 ip6_protocol_deliver_rcu+0x372/0x1940 net/ipv6/ip6_input.c:394 ip6_input_finish+0x84/0x170 net/ipv6/ip6_input.c:434 NF_HOOK include/linux/netfilter.h:289 [inline] ip6_input+0xe9/0x600 net/ipv6/ip6_input.c:443 ip6_mc_input+0x514/0x11c0 net/ipv6/ip6_input.c:537 dst_input include/net/dst.h:450 [inline] ip6_rcv_finish+0x17a/0x330 net/ipv6/ip6_input.c:76 NF_HOOK include/linux/netfilter.h:289 [inline] ipv6_rcv+0x115/0x640 net/ipv6/ip6_input.c:272 __netif_receive_skb_one_core+0x14d/0x200 net/core/dev.c:4973 __netif_receive_skb+0x2c/0x1e0 net/core/dev.c:5083 process_backlog+0x24e/0x7a0 net/core/dev.c:5923 napi_poll net/core/dev.c:6346 [inline] net_rx_action+0x7fa/0x19b0 net/core/dev.c:6412 __do_softirq+0x308/0xb7e kernel/softirq.c:292 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1027 do_softirq.part.14+0x126/0x160 kernel/softirq.c:337 do_softirq+0x19/0x20 kernel/softirq.c:340 netif_rx_ni+0x521/0x860 net/core/dev.c:4569 dev_loopback_xmit+0x287/0x8c0 net/core/dev.c:3576 NF_HOOK include/linux/netfilter.h:289 [inline] ip6_finish_output2+0x193a/0x2930 net/ipv6/ip6_output.c:84 ip6_finish_output+0x583/0xc50 net/ipv6/ip6_output.c:154 NF_HOOK_COND include/linux/netfilter.h:278 [inline] ip6_output+0x232/0x9d0 net/ipv6/ip6_output.c:171 dst_output include/net/dst.h:444 [inline] ip6_local_out+0xc5/0x1b0 net/ipv6/output_core.c:176 ip6_send_skb+0xbc/0x340 net/ipv6/ip6_output.c:1727 udp_v6_send_skb.isra.32+0x831/0x14a0 net/ipv6/udp.c:1169 udpv6_sendmsg+0x2d86/0x36a0 net/ipv6/udp.c:1466 inet_sendmsg+0x1a1/0x690 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:631 __sys_sendto+0x3d7/0x670 net/socket.c:1788 __do_sys_sendto net/socket.c:1800 [inline] __se_sys_sendto net/socket.c:1796 [inline] __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1796 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457669 Code: fd b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f120932cc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000000457669 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 000000000072bf00 R08: 0000000020000300 R09: 000000000000001c R10: 0000000000000000 R11: 0000000000000246 R12: 00007f120932d6d4 R13: 00000000004c4539 R14: 00000000004d75a8 R15: 00000000ffffffff rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 0-... } 10644 jiffies s: 50309 root: 0x1/. rcu: blocking rcu_node structures: Task dump for CPU 0: syz-executor5 R running task 25208 17818 6237 0x80000008 Call Trace: