rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-....: (1 GPs behind) idle=932/1/0x4000000000000002 softirq=17178/17179 fqs=5250 (t=10502 jiffies g=9617 q=36) NMI backtrace for cpu 1 CPU: 1 PID: 9663 Comm: syz-executor787 Not tainted 5.5.0-rc6-syzkaller #0 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+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:455 [inline] check_cpu_stall kernel/rcu/tree_stall.h:529 [inline] rcu_pending kernel/rcu/tree.c:2827 [inline] rcu_sched_clock_irq.cold+0x509/0xc0d kernel/rcu/tree.c:2271 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:1110 [inline] smp_apic_timer_interrupt+0x160/0x610 arch/x86/kernel/apic/apic.c:1135 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 RIP: 0010:hash_ip4_del+0x1dd/0xce0 net/netfilter/ipset/ip_set_hash_gen.h:849 Code: 21 d3 e8 06 68 e5 fa 89 d8 49 8d 7c c7 10 48 89 85 68 ff ff ff 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 <0f> 85 fd 09 00 00 48 8b 45 98 48 8b 8d 68 ff ff ff 48 8b 44 c8 10 RSP: 0018:ffffc90002076f10 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: dffffc0000000000 RBX: 00000000000000ac RCX: 1ffffffff14f9ac6 RDX: 1ffff110139f60ae RSI: ffffffff867bcfd9 RDI: ffff88809cfb0570 RBP: ffffc90002076fb0 R08: ffff8880a2fc01c0 R09: ffffc90002076f28 R10: fffff5200040ede7 R11: ffffc90002076f3f R12: 0000000000000001 R13: 00000000ffffffff R14: ffffc90002077030 R15: ffff88809cfb0000 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:1716 ip_set_ad.isra.0+0x572/0xb20 net/netfilter/ipset/ip_set_core.c:1804 ip_set_udel+0x3a/0x50 net/netfilter/ipset/ip_set_core.c:1838 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: 0033:0x445b79 Code: e8 bc b7 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 2b 12 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007efe4b0bddb8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00000000006dac28 RCX: 0000000000445b79 RDX: 0000000000000040 RSI: 0000000020000080 RDI: 0000000000000004 RBP: 00000000006dac20 R08: 0000000000000018 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000246 R12: 00000000006dac2c R13: 00007ffe3e94402f R14: 00007efe4b0be9c0 R15: 20c49ba5e353f7cf