rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (10506 ticks this GP) idle=57e/1/0x4000000000000002 softirq=14528/14529 fqs=7 
	(t=10503 jiffies g=8589 q=15)
rcu: rcu_preempt kthread starved for 10489 jiffies! g8589 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0
rcu: RCU grace-period kthread stack dump:
rcu_preempt     I29240    10      2 0x80004000
Call Trace:
 context_switch kernel/sched/core.c:3380 [inline]
 __schedule+0x934/0x1f90 kernel/sched/core.c:4080
 schedule+0xdc/0x2b0 kernel/sched/core.c:4154
 schedule_timeout+0x486/0xc50 kernel/time/timer.c:1895
 rcu_gp_fqs_loop kernel/rcu/tree.c:1658 [inline]
 rcu_gp_kthread+0xa10/0x1940 kernel/rcu/tree.c:1818
 kthread+0x361/0x430 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
NMI backtrace for cpu 1
CPU: 1 PID: 9638 Comm: syz-executor816 Not tainted 5.6.0-rc1-next-20200212-syzkaller #0
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+0x197/0x210 lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x70/0xb2 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x23b/0x28b 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+0x183/0x1cf kernel/rcu/tree_stall.h:254
 print_cpu_stall kernel/rcu/tree_stall.h:475 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:549 [inline]
 rcu_pending kernel/rcu/tree.c:3030 [inline]
 rcu_sched_clock_irq.cold+0x51a/0xc3d kernel/rcu/tree.c:2276
 update_process_times+0x2d/0x70 kernel/time/timer.c:1726
 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:171
 tick_sched_timer+0x53/0x140 kernel/time/tick-sched.c:1314
 __run_hrtimer kernel/time/hrtimer.c:1517 [inline]
 __hrtimer_run_queues+0x364/0xe40 kernel/time/hrtimer.c:1579
 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1641
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1119 [inline]
 smp_apic_timer_interrupt+0x160/0x610 arch/x86/kernel/apic/apic.c:1144
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
 </IRQ>
RIP: 0010:hash_ip4_expire.isra.0+0x6b8/0x8d0 net/netfilter/ipset/ip_set_hash_gen.h:471
Code: 7d c0 48 89 03 e8 b8 4c d2 fa e8 53 61 e5 fa 48 8b 45 80 83 45 94 01 48 c1 e8 03 42 0f b6 04 38 84 c0 74 06 0f 8e 02 01 00 00 <48> 8b 45 98 bb 01 00 00 00 44 8b 75 94 0f b6 48 08 44 89 f7 d3 e3
RSP: 0018:ffffc900024f6e28 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8690699e
RDX: 0000000000000000 RSI: ffffffff86906c4d RDI: 0000000000000005
RBP: ffffc900024f6ed8 R08: ffff88808dfa24c0 R09: ffffed1011ef3a73
R10: ffffed1011ef3a72 R11: ffff88808f79d397 R12: ffff88808f79d3d0
R13: ffff8880a6dcb700 R14: 0000000000000003 R15: dffffc0000000000
 hash_ip4_add+0x178/0x1b6c net/netfilter/ipset/ip_set_hash_gen.h:709
 hash_ip4_uadt+0x546/0x7a0 net/netfilter/ipset/ip_set_hash_ip.c:151
 call_ad+0x1a0/0x5a0 net/netfilter/ipset/ip_set_core.c:1717
 ip_set_ad.isra.0+0x572/0xb20 net/netfilter/ipset/ip_set_core.c:1805
 ip_set_uadd+0x37/0x50 net/netfilter/ipset/ip_set_core.c:1830
 nfnetlink_rcv_msg+0xcf2/0xfb0 net/netfilter/nfnetlink.c:229
 netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2477
 nfnetlink_rcv+0x1ba/0x460 net/netfilter/nfnetlink.c:563
 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
 netlink_unicast+0x59e/0x7e0 net/netlink/af_netlink.c:1328
 netlink_sendmsg+0x91c/0xea0 net/netlink/af_netlink.c:1917
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg+0xd7/0x130 net/socket.c:672
 ____sys_sendmsg+0x753/0x880 net/socket.c:2343
 ___sys_sendmsg+0x100/0x170 net/socket.c:2397
 __sys_sendmsg+0x105/0x1d0 net/socket.c:2430
 __do_sys_sendmsg net/socket.c:2439 [inline]
 __se_sys_sendmsg net/socket.c:2437 [inline]
 __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2437
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x441579
Code: e8 fc ab 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 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 9b 09 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fff8402f668 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441579
RDX: 0000000000000000 RSI: 0000000020000d00 RDI: 0000000000000004
RBP: 000000000003ccc9 R08: 00000000004002c8 R09: 00000000004002c8
R10: 00000000004002c8 R11: 0000000000000246 R12: 00000000004023a0
R13: 0000000000402430 R14: 0000000000000000 R15: 0000000000000000