rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-....: (10500 ticks this GP) idle=ffa/1/0x4000000000000002 softirq=17285/17285 fqs=5250 (t=10502 jiffies g=9577 q=235) NMI backtrace for cpu 1 CPU: 1 PID: 9872 Comm: syz-executor437 Not tainted 5.6.0-rc1-next-20200211-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: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 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:752 [inline] RIP: 0010:lock_is_held_type+0x272/0x320 kernel/locking/lockdep.c:4523 Code: ff df c7 83 9c 08 00 00 00 00 00 00 48 c1 e8 03 80 3c 10 00 0f 85 88 00 00 00 48 83 3d 5e 11 59 08 00 74 31 48 8b 7d c0 57 9d <0f> 1f 44 00 00 48 83 c4 20 44 89 e0 5b 41 5c 41 5d 41 5e 41 5f 5d RSP: 0018:ffffc90001ea6eb8 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff13676b7 RBX: ffff888094af0340 RCX: ffff888094af0be0 RDX: dffffc0000000000 RSI: ffff8880a3e06338 RDI: 0000000000000286 RBP: ffffc90001ea6f00 R08: ffff888094af0340 R09: ffffc90001ea6f28 R10: fffff520003d4de7 R11: ffffc90001ea6f3f R12: 0000000000000001 R13: ffff888094af0c08 R14: ffff8880a3e06338 R15: 0000000000000001 lock_is_held include/linux/lockdep.h:361 [inline] hash_ip4_del+0xa3a/0xce0 net/netfilter/ipset/ip_set_hash_gen.h:847 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_udel+0x3a/0x50 net/netfilter/ipset/ip_set_core.c:1839 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: 0033:0x440509 Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffdb631b258 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440509 RDX: 0000000000000040 RSI: 0000000020000080 RDI: 0000000000000004 RBP: 00000000006ca018 R08: 0000000000000018 R09: 00000000004002c8 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000401d90 R13: 0000000000401e20 R14: 0000000000000000 R15: 0000000000000000