rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (1 GPs behind) idle=9b6/1/0x4000000000000002 softirq=11513/11516 fqs=30 
rcu: 	 (t=10500 jiffies g=13797 q=166)
rcu: rcu_preempt kthread starved for 10439 jiffies! g13797 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1
rcu: RCU grace-period kthread stack dump:
rcu_preempt     I22568    10      2 0x80000000
Call Trace:
 context_switch kernel/sched/core.c:2831 [inline]
 __schedule+0x8cf/0x21d0 kernel/sched/core.c:3472
 schedule+0xfe/0x460 kernel/sched/core.c:3516
 schedule_timeout+0x140/0x260 kernel/time/timer.c:1804
 rcu_gp_fqs_loop+0x762/0xa80 kernel/rcu/tree.c:1934
 rcu_gp_kthread+0x341/0xc70 kernel/rcu/tree.c:2090
 kthread+0x35a/0x440 kernel/kthread.c:246
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
NMI backtrace for cpu 0
CPU: 0 PID: 8938 Comm: syz-executor3 Not tainted 4.20.0-rc6+ #337
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __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
 </IRQ>
RIP: 0010:__read_once_size include/linux/compiler.h:182 [inline]
RIP: 0010:__read_seqcount_begin include/linux/seqlock.h:113 [inline]
RIP: 0010:raw_read_seqcount_begin include/linux/seqlock.h:148 [inline]
RIP: 0010:read_seqcount_begin include/linux/seqlock.h:165 [inline]
RIP: 0010:xfrm_state_find+0x20b6/0x3eb0 net/xfrm/xfrm_state.c:949
Code: 95 41 03 01 e8 8f b6 90 fa e9 4a e4 ff ff e8 71 33 ae fa 0f 0b e8 6a 33 ae fa 0f 0b e8 63 33 ae fa f3 90 48 c7 c0 a0 08 18 8a <c6> 03 04 8b 00 41 89 c4 41 89 87 c0 fd ff ff 89 85 04 fc ff ff 41
RSP: 0018:ffff888192f9e5d0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: ffffffff8a1808a0 RBX: ffffed10325f3cfa RCX: ffffc9000be32000
RDX: 0000000000040000 RSI: ffffffff86d150fd RDI: 0000000000000005
RBP: ffff888192f9ea38 R08: ffff8881cc37c000 R09: 0000000000000002
R10: 0000000000000000 R11: ffff8881cc37c000 R12: 0000000000000001
R13: 0000000000000000 R14: 0000000000000000 R15: ffff888192f9ea10
 xfrm_tmpl_resolve_one net/xfrm/xfrm_policy.c:1413 [inline]
 xfrm_tmpl_resolve+0x3c0/0xe50 net/xfrm/xfrm_policy.c:1458
 xfrm_resolve_and_create_bundle+0x184/0x2800 net/xfrm/xfrm_policy.c:1753
 xfrm_lookup_with_ifid+0x39e/0x2b80 net/xfrm/xfrm_policy.c:2076
 xfrm_lookup net/xfrm/xfrm_policy.c:2200 [inline]
 xfrm_lookup_route+0x3c/0x1f0 net/xfrm/xfrm_policy.c:2211
 ip6_dst_lookup_flow+0x1c6/0x270 net/ipv6/ip6_output.c:1090
 inet6_csk_route_socket+0x8c6/0x1030 net/ipv6/inet6_connection_sock.c:110
 inet6_csk_xmit+0x118/0x630 net/ipv6/inet6_connection_sock.c:125
 l2tp_xmit_core net/l2tp/l2tp_core.c:1030 [inline]
 l2tp_xmit_skb+0x131f/0x1640 net/l2tp/l2tp_core.c:1132
 pppol2tp_sendmsg+0x4b1/0x6c0 net/l2tp/l2tp_ppp.c:329
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:631
 ___sys_sendmsg+0x51d/0x930 net/socket.c:2116
 __sys_sendmmsg+0x246/0x6d0 net/socket.c:2211
 __do_sys_sendmmsg net/socket.c:2240 [inline]
 __se_sys_sendmmsg net/socket.c:2237 [inline]
 __x64_sys_sendmmsg+0x9d/0x100 net/socket.c:2237
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457659
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:00007fa1c0289c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000457659
RDX: 00000000000000a9 RSI: 0000000020005fc0 RDI: 0000000000000005
RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa1c028a6d4
R13: 00000000004c3e14 R14: 00000000004d6c38 R15: 00000000ffffffff