syzbot

watchdog: BUG: soft lockup - CPU#1 stuck for 22s! [syz-executor.0:9513]
Modules linked in:
irq event stamp: 8179467
hardirqs last  enabled at (8179466): [<ffffffff817e9190>] slab_alloc_node mm/slab.c:3327 [inline]
hardirqs last  enabled at (8179466): [<ffffffff817e9190>] kmem_cache_alloc_node_trace+0x2f0/0x400 mm/slab.c:3659
hardirqs last disabled at (8179467): [<ffffffff874018ae>] apic_timer_interrupt+0x8e/0xa0 arch/x86/entry/entry_64.S:793
softirqs last  enabled at (2714): [<ffffffff85c64e48>] pneigh_ifdown_and_unlock net/core/neighbour.c:708 [inline]
softirqs last  enabled at (2714): [<ffffffff85c64e48>] neigh_ifdown+0x148/0x350 net/core/neighbour.c:297
softirqs last disabled at (2715): [<ffffffff8740110a>] do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1016
CPU: 1 PID: 9513 Comm: syz-executor.0 Not tainted 4.14.238-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff888097560540 task.stack: ffff88804ec20000
RIP: 0010:__orc_find+0x58/0xf0 arch/x86/kernel/unwind_orc.c:47
RSP: 0018:ffff8880ba506f18 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff10
RAX: 0000000000000000 RBX: ffffffff8a52446c RCX: ffffffff85be4db5
RDX: 0000000000000001 RSI: ffffffff8ac7f444 RDI: ffffffff8a524450
RBP: ffffffff8a524470 R08: ffffffff8ac7f444 R09: ffffffff8ac7f480
R10: 00000000001034f6 R11: 0000000000066071 R12: ffffffff8a524474
R13: ffffffff8a524450 R14: ffffffff8a52446c R15: dffffc0000000000
FS:  00007f8df638d700(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000001f38808 CR3: 00000000ae8e7000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 orc_find arch/x86/kernel/unwind_orc.c:118 [inline]
 unwind_next_frame+0x59a/0x17d0 arch/x86/kernel/unwind_orc.c:348
 __save_stack_trace+0x90/0x160 arch/x86/kernel/stacktrace.c:44
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551
 kmem_cache_alloc_node_trace+0x153/0x400 mm/slab.c:3661
 __do_kmalloc_node mm/slab.c:3681 [inline]
 __kmalloc_node_track_caller+0x38/0x70 mm/slab.c:3696
 __kmalloc_reserve net/core/skbuff.c:137 [inline]
 __alloc_skb+0x96/0x510 net/core/skbuff.c:205
 alloc_skb include/linux/skbuff.h:980 [inline]
 ip_do_fragment+0xab0/0x1fb0 net/ipv4/ip_output.c:743
 ip_fragment.constprop.0+0x146/0x200 net/ipv4/ip_output.c:550
 ip_finish_output+0x89e/0xc50 net/ipv4/ip_output.c:316
 NF_HOOK_COND include/linux/netfilter.h:239 [inline]
 ip_output+0x1cd/0x510 net/ipv4/ip_output.c:406
 dst_output include/net/dst.h:470 [inline]
 ip_local_out+0x93/0x170 net/ipv4/ip_output.c:125
 iptunnel_xmit+0x5cc/0x950 net/ipv4/ip_tunnel_core.c:91
 geneve_xmit_skb drivers/net/geneve.c:867 [inline]
 geneve_xmit+0xea1/0x2c50 drivers/net/geneve.c:948
 __netdev_start_xmit include/linux/netdevice.h:4051 [inline]
 netdev_start_xmit include/linux/netdevice.h:4060 [inline]
 xmit_one net/core/dev.c:3005 [inline]
 dev_hard_start_xmit+0x188/0x890 net/core/dev.c:3021
 __dev_queue_xmit+0x1d7f/0x2480 net/core/dev.c:3521
 neigh_hh_output include/net/neighbour.h:490 [inline]
 neigh_output include/net/neighbour.h:498 [inline]
 ip6_finish_output2+0xc6a/0x1f10 net/ipv6/ip6_output.c:120
 ip6_finish_output+0x5c6/0xd50 net/ipv6/ip6_output.c:192
 NF_HOOK_COND include/linux/netfilter.h:239 [inline]
 ip6_output+0x1c5/0x660 net/ipv6/ip6_output.c:209
 dst_output include/net/dst.h:470 [inline]
 NF_HOOK include/linux/netfilter.h:250 [inline]
 mld_sendpack+0x5fe/0xea0 net/ipv6/mcast.c:1657
 mld_send_initial_cr.part.0+0xf5/0x140 net/ipv6/mcast.c:2074
 mld_send_initial_cr net/ipv6/mcast.c:1170 [inline]
 mld_dad_timer_expire+0x140/0x520 net/ipv6/mcast.c:2093
 call_timer_fn+0x14a/0x650 kernel/time/timer.c:1280
 expire_timers+0x232/0x4d0 kernel/time/timer.c:1319
 __run_timers kernel/time/timer.c:1637 [inline]
 run_timer_softirq+0x1d5/0x5a0 kernel/time/timer.c:1650
 __do_softirq+0x24d/0x9ff kernel/softirq.c:288
 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1016
 </IRQ>
 do_softirq.part.0+0x154/0x1b0 kernel/softirq.c:332
 do_softirq kernel/softirq.c:324 [inline]
 __local_bh_enable_ip+0x12b/0x170 kernel/softirq.c:185
 pneigh_ifdown_and_unlock net/core/neighbour.c:708 [inline]
 neigh_ifdown+0x148/0x350 net/core/neighbour.c:297
 fib_disable_ip net/ipv4/fib_frontend.c:1155 [inline]
 fib_inetaddr_event+0x1cd/0x260 net/ipv4/fib_frontend.c:1180
 notifier_call_chain+0x108/0x1a0 kernel/notifier.c:93
 __blocking_notifier_call_chain kernel/notifier.c:317 [inline]
 __blocking_notifier_call_chain kernel/notifier.c:304 [inline]
 blocking_notifier_call_chain kernel/notifier.c:328 [inline]
 blocking_notifier_call_chain+0x79/0x90 kernel/notifier.c:325
 __inet_del_ifa+0x4c1/0xaf0 net/ipv4/devinet.c:409
 inet_del_ifa net/ipv4/devinet.c:439 [inline]
 inetdev_destroy net/ipv4/devinet.c:304 [inline]
 inetdev_event+0x4ec/0x10a0 net/ipv4/devinet.c:1529
 notifier_call_chain+0x108/0x1a0 kernel/notifier.c:93
 call_netdevice_notifiers_info net/core/dev.c:1667 [inline]
 call_netdevice_notifiers_mtu net/core/dev.c:1706 [inline]
 dev_set_mtu+0x23d/0x3c0 net/core/dev.c:6913
 do_setlink+0x4f3/0x2bf0 net/core/rtnetlink.c:2055
 rtnl_group_changelink net/core/rtnetlink.c:2512 [inline]
 rtnl_newlink+0xccc/0x1860 net/core/rtnetlink.c:2666
 rtnetlink_rcv_msg+0x3be/0xb10 net/core/rtnetlink.c:4320
 netlink_rcv_skb+0x125/0x390 net/netlink/af_netlink.c:2435
 netlink_unicast_kernel net/netlink/af_netlink.c:1289 [inline]
 netlink_unicast+0x437/0x610 net/netlink/af_netlink.c:1315
 netlink_sendmsg+0x62e/0xb80 net/netlink/af_netlink.c:1880
 sock_sendmsg_nosec net/socket.c:646 [inline]
 sock_sendmsg+0xb5/0x100 net/socket.c:656
 ___sys_sendmsg+0x6c8/0x800 net/socket.c:2062
 __sys_sendmsg+0xa3/0x120 net/socket.c:2096
 SYSC_sendmsg net/socket.c:2107 [inline]
 SyS_sendmsg+0x27/0x40 net/socket.c:2103
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x4665d9
RSP: 002b:00007f8df638d188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9
RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000004
RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80
R13: 00007ffd3201779f R14: 00007f8df638d300 R15: 0000000000022000
Code: 00 00 00 fc ff df 49 89 fe 48 89 fd eb 0c 48 8d 6b 04 49 89 de 49 39 ec 72 4d 4c 89 e0 48 29 e8 48 89 c2 48 c1 e8 3f 48 c1 fa 02 <48> 01 d0 48 d1 f8 48 8d 5c 85 00 48 89 d8 48 c1 e8 03 42 0f b6 
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at pc 0xffffffff8722d07e