======================================
| [ 1168.940208][T22128] 1 lock held by ip/22128:
| [ 1168.940383][T22128]  #0: ffffffffbe0a1d28 (rtnl_mutex){+.+.}-{4:4}, at: rtm_new_nexthop (net/ipv4/nexthop.c:3216 net/ipv4/nexthop.c:3271)
| [ 1168.940656][T22128]
| [ 1168.940656][T22128] stack backtrace:
[ 1168.940861][T22128] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 1168.940863][T22128] Call Trace:
[ 1168.940865][T22128]  <TASK>
[ 1168.940867][T22128]  dump_stack_lvl (lib/dump_stack.c:122)
[ 1168.940873][T22128]  lockdep_rcu_suspicious.cold (kernel/locking/lockdep.c:6877)
[ 1168.940879][T22128]  fib6_update_sernum (net/ipv6/ip6_fib.c:111 (discriminator 10))
[ 1168.940883][T22128]  nh_rt_cache_flush (net/ipv4/nexthop.c:2204 (discriminator 4))
[ 1168.940887][T22128]  replace_nexthop (net/ipv4/nexthop.c:2570)
[ 1168.940892][T22128]  insert_nexthop (net/ipv4/nexthop.c:2605)
[ 1168.940894][T22128]  ? nexthop_create (net/ipv4/nexthop.c:2924)
[ 1168.940897][T22128]  rtm_new_nexthop (net/ipv4/nexthop.c:2971 net/ipv4/nexthop.c:3275)
[ 1168.940900][T22128]  ? insert_nexthop (net/ipv4/nexthop.c:3246)
[ 1168.940902][T22128]  ? lock_acquire.part.0 (kernel/locking/lockdep.c:470 kernel/locking/lockdep.c:5870)
[ 1168.940905][T22128]  ? find_held_lock (kernel/locking/lockdep.c:5350 (discriminator 1))
[ 1168.940912][T22128]  ? lock_acquire.part.0 (kernel/locking/lockdep.c:470 kernel/locking/lockdep.c:5870)
[ 1168.940913][T22128]  ? find_held_lock (kernel/locking/lockdep.c:5350 (discriminator 1))
[ 1168.940918][T22128]  ? find_held_lock (kernel/locking/lockdep.c:5350 (discriminator 1))
[ 1168.940920][T22128]  ? insert_nexthop (net/ipv4/nexthop.c:3246)
[ 1168.940922][T22128]  ? __lock_release.isra.0 (kernel/locking/lockdep.c:5536)
[ 1168.940926][T22128]  ? insert_nexthop (net/ipv4/nexthop.c:3246)
[ 1168.940928][T22128]  rtnetlink_rcv_msg (net/core/rtnetlink.c:6958)
[ 1168.940933][T22128]  ? rtnl_fdb_dump (net/core/rtnetlink.c:6861)
[ 1168.940935][T22128]  ? __lock_acquire (kernel/locking/lockdep.c:5237 (discriminator 1))
[ 1168.940938][T22128]  ? lock_acquire.part.0 (kernel/locking/lockdep.c:470 kernel/locking/lockdep.c:5870)
[ 1168.940939][T22128]  ? find_held_lock (kernel/locking/lockdep.c:5350 (discriminator 1))
[ 1168.940943][T22128]  netlink_rcv_skb (net/netlink/af_netlink.c:2550)
[ 1168.940945][T22128]  ? rtnl_fdb_dump (net/core/rtnetlink.c:6861)
[ 1168.940948][T22128]  ? netlink_ack (net/netlink/af_netlink.c:2527)
[ 1168.940953][T22128]  ? netlink_deliver_tap (./include/linux/rcupdate.h:322 (discriminator 1) ./include/linux/rcupdate.h:881 (discriminator 1) ./include/net/netns/generic.h:48 (discriminator 1) net/netlink/af_netlink.c:333 (discriminator 1))
[ 1168.940956][T22128]  ? netlink_deliver_tap (./include/linux/rcupdate.h:322 (discriminator 1) ./include/linux/rcupdate.h:881 (discriminator 1) net/netlink/af_netlink.c:340 (discriminator 1))
[ 1168.940960][T22128]  netlink_unicast (net/netlink/af_netlink.c:1319 net/netlink/af_netlink.c:1344)
[ 1168.940963][T22128]  ? netlink_attachskb (net/netlink/af_netlink.c:1329)
[ 1168.940964][T22128]  ? __alloc_skb (./include/linux/bottom_half.h:20 (discriminator 1) net/core/skbuff.c:695 (discriminator 1))
[ 1168.940967][T22128]  ? napi_skb_cache_get (net/core/skbuff.c:674)
[ 1168.940968][T22128]  ? lock_acquire.part.0 (kernel/locking/lockdep.c:470 kernel/locking/lockdep.c:5870)
[ 1168.940970][T22128]  ? __lock_acquire (kernel/locking/lockdep.c:5237 (discriminator 1))
[ 1168.940973][T22128]  netlink_sendmsg (net/netlink/af_netlink.c:1894)
[ 1168.940977][T22128]  ? netlink_unicast (net/netlink/af_netlink.c:1813)
[ 1168.940980][T22128]  ? __might_fault (mm/memory.c:7217 (discriminator 4))
[ 1168.940985][T22128]  ____sys_sendmsg (net/socket.c:727 (discriminator 4) net/socket.c:742 (discriminator 4) net/socket.c:2592 (discriminator 4))
[ 1168.940987][T22128]  ? copy_msghdr_from_user (net/socket.c:2532)
[ 1168.940989][T22128]  ? get_timestamp.constprop.0 (net/socket.c:2538)
[ 1168.940990][T22128]  ? move_addr_to_kernel (net/socket.c:2518)
[ 1168.940993][T22128]  ? stack_depot_save_flags (lib/stackdepot.c:609 (discriminator 4) lib/stackdepot.c:676 (discriminator 4))
[ 1168.940997][T22128]  ? rcu_read_lock_any_held (kernel/rcu/update.c:386 (discriminator 1) kernel/rcu/update.c:380 (discriminator 1))
[ 1168.941002][T22128]  ___sys_sendmsg (net/socket.c:2648)
[ 1168.941004][T22128]  ? __call_rcu_common.constprop.0 (./arch/x86/include/asm/irqflags.h:26 ./arch/x86/include/asm/irqflags.h:109 ./arch/x86/include/asm/irqflags.h:127 kernel/rcu/tree.c:3133)
[ 1168.941007][T22128]  ? copy_msghdr_from_user (net/socket.c:2635)
[ 1168.941021][T22128]  __sys_sendmsg (net/socket.c:2678 (discriminator 1))
[ 1168.941023][T22128]  ? __sys_sendmsg_sock (net/socket.c:2663)
[ 1168.941025][T22128]  ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4473)
[ 1168.941029][T22128]  ? __call_rcu_common.constprop.0 (./arch/x86/include/asm/irqflags.h:26 ./arch/x86/include/asm/irqflags.h:109 ./arch/x86/include/asm/irqflags.h:151 kernel/rcu/tree.c:3156)
[ 1168.941035][T22128]  ? do_raw_spin_unlock (./arch/x86/include/asm/atomic.h:23 ./include/linux/atomic/atomic-arch-fallback.h:457 ./include/linux/atomic/atomic-instrumented.h:33 ./include/asm-generic/qspinlock.h:57 kernel/locking/spinlock_debug.c:101 kernel/locking/spinlock_debug.c:141)
[ 1168.941037][T22128]  ? rcu_is_watching (./include/linux/context_tracking.h:128 (discriminator 1) kernel/rcu/tree.c:752 (discriminator 1))
[ 1168.941040][T22128]  do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1))
[ 1168.941042][T22128]  ? exc_page_fault (arch/x86/mm/fault.c:1480 (discriminator 3) arch/x86/mm/fault.c:1527 (discriminator 3))
[ 1168.941044][T22128]  entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[ 1168.941046][T22128] RIP: 0033:0x7f297c23cc5e
[ 1168.941050][T22128] Code: 4d 89 d8 e8 34 bd 00 00 4c 8b 5d f8 41 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 11 c9 c3 0f 1f 80 00 00 00 00 48 8b 45 10 0f 05 <c9> c3 83 e2 39 83 fa 08 75 e7 e8 13 ff ff ff 0f 1f 00 f3 0f 1e fa
All code
========
   0:	4d 89 d8             	mov    %r11,%r8
   3:	e8 34 bd 00 00       	call   0xbd3c
   8:	4c 8b 5d f8          	mov    -0x8(%rbp),%r11
   c:	41 8b 93 08 03 00 00 	mov    0x308(%r11),%edx
  13:	59                   	pop    %rcx
  14:	5e                   	pop    %rsi
  15:	48 83 f8 fc          	cmp    $0xfffffffffffffffc,%rax
  19:	74 11                	je     0x2c
  1b:	c9                   	leave
  1c:	c3                   	ret
  1d:	0f 1f 80 00 00 00 00 	nopl   0x0(%rax)
  24:	48 8b 45 10          	mov    0x10(%rbp),%rax
  28:	0f 05                	syscall
  2a:*	c9                   	leave		<-- trapping instruction
  2b:	c3                   	ret
  2c:	83 e2 39             	and    $0x39,%edx
  2f:	83 fa 08             	cmp    $0x8,%edx
  32:	75 e7                	jne    0x1b
  34:	e8 13 ff ff ff       	call   0xffffffffffffff4c
  39:	0f 1f 00             	nopl   (%rax)
  3c:	f3 0f 1e fa          	endbr64

Code starting with the faulting instruction
===========================================
   0:	c9                   	leave
   1:	c3                   	ret
   2:	83 e2 39             	and    $0x39,%edx
   5:	83 fa 08             	cmp    $0x8,%edx
   8:	75 e7                	jne    0xfffffffffffffff1
   a:	e8 13 ff ff ff       	call   0xffffffffffffff22
   f:	0f 1f 00             	nopl   (%rax)
  12:	f3 0f 1e fa          	endbr64
[ 1168.941052][T22128] RSP: 002b:00007ffe4e3998f0 EFLAGS: 00000202 ORIG_RAX: 000000000000002e
[ 1168.941055][T22128] RAX: ffffffffffffffda RBX: 000000000048a910 RCX: 00007f297c23cc5e
[ 1168.941056][T22128] RDX: 0000000000000000 RSI: 00007ffe4e3999b0 RDI: 0000000000000005
[ 1168.941057][T22128] RBP: 00007ffe4e399900 R08: 0000000000000000 R09: 0000000000000000
[ 1168.941058][T22128] R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffe4e39b726


Finger prints:
fib6_update_sernum:nh_rt_cache_flush:replace_nexthop:insert_nexthop:rtm_new_nexthop