======================================
| [1494.614800][T18720] #1: ffff888006227430 (&tb->tb6_lock){+.-.}-{3:3}, at: ip6_route_add (net/ipv6/route.c:1317 net/ipv6/route.c:3883) 
| [1494.615047][T18720] #2: ffff88800a438180 (&nh->lock){+...}-{3:3}, at: fib6_add (net/ipv6/ip6_fib.c:1508) 
| [ 1494.615270][T18720]
| [ 1494.615270][T18720] stack backtrace:
[ 1494.615447][T18720] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 1494.615450][T18720] Call Trace:
[ 1494.615452][T18720]  <TASK>
[1494.615454][T18720] dump_stack_lvl (lib/dump_stack.c:123) 
[1494.615462][T18720] print_deadlock_bug (kernel/locking/lockdep.c:3042) 
[1494.615470][T18720] validate_chain (kernel/locking/lockdep.c:3896) 
[1494.615476][T18720] ? __pfx_validate_chain (kernel/locking/lockdep.c:3862) 
[1494.615480][T18720] ? hlock_class (./arch/x86/include/asm/bitops.h:227 ./arch/x86/include/asm/bitops.h:239 ./include/asm-generic/bitops/instrumented-non-atomic.h:142 kernel/locking/lockdep.c:230) 
[1494.615483][T18720] ? mark_lock (kernel/locking/lockdep.c:4729 (discriminator 3)) 
[1494.615488][T18720] __lock_acquire (kernel/locking/lockdep.c:5228) 
[1494.615494][T18720] lock_acquire.part.0 (kernel/locking/lockdep.c:469 kernel/locking/lockdep.c:5853) 
[1494.615498][T18720] ? fib6_purge_rt (./include/linux/list.h:373 net/ipv6/ip6_fib.c:1053) 
[1494.615502][T18720] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5816) 
[1494.615506][T18720] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 21)) 
[1494.615509][T18720] ? lock_acquire (kernel/locking/lockdep.c:5824) 
[1494.615512][T18720] ? fib6_purge_rt (./include/linux/list.h:373 net/ipv6/ip6_fib.c:1053) 
[1494.615516][T18720] _raw_spin_lock (./include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) 
[1494.615520][T18720] ? fib6_purge_rt (./include/linux/list.h:373 net/ipv6/ip6_fib.c:1053) 
[1494.615523][T18720] fib6_purge_rt (./include/linux/list.h:373 net/ipv6/ip6_fib.c:1053) 
[1494.615527][T18720] ? __pfx_fib6_purge_rt (net/ipv6/ip6_fib.c:1044) 
[1494.615531][T18720] ? nlmsg_notify (net/netlink/af_netlink.c:2578) 
[1494.615538][T18720] fib6_add_rt2node (net/ipv6/ip6_fib.c:1316) 
[1494.615544][T18720] ? __pfx_fib6_add_rt2node (net/ipv6/ip6_fib.c:1092) 
[1494.615547][T18720] ? do_raw_spin_lock (./arch/x86/include/asm/atomic.h:107 ./include/linux/atomic/atomic-arch-fallback.h:2170 ./include/linux/atomic/atomic-instrumented.h:1302 ./include/asm-generic/qspinlock.h:111 kernel/locking/spinlock_debug.c:116) 
[1494.615551][T18720] ? lock_acquire (kernel/locking/lockdep.c:5824) 
[1494.615554][T18720] ? fib6_add (net/ipv6/ip6_fib.c:1508) 
[1494.615558][T18720] fib6_add (net/ipv6/ip6_fib.c:1514) 
[1494.615562][T18720] ip6_route_add (./include/linux/spinlock.h:396 net/ipv6/route.c:1318 net/ipv6/route.c:3883) 
[1494.615565][T18720] ? __pfx_inet6_rtm_newroute (net/ipv6/route.c:5669) 
[1494.615568][T18720] inet6_rtm_newroute (net/ipv6/route.c:5683) 
[1494.615570][T18720] ? __pfx_inet6_rtm_newroute (net/ipv6/route.c:5669) 
[1494.615578][T18720] ? rtnetlink_rcv_msg (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/core/rtnetlink.c:6952) 
[1494.615583][T18720] rtnetlink_rcv_msg (net/core/rtnetlink.c:6954) 
[1494.615587][T18720] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6857) 
[1494.615589][T18720] ? hlock_class (./arch/x86/include/asm/bitops.h:227 ./arch/x86/include/asm/bitops.h:239 ./include/asm-generic/bitops/instrumented-non-atomic.h:142 kernel/locking/lockdep.c:230) 
[1494.615591][T18720] ? mark_lock (kernel/locking/lockdep.c:4729 (discriminator 3)) 
[1494.615596][T18720] ? __lock_acquire (kernel/locking/lockdep.c:5228) 
[1494.615600][T18720] netlink_rcv_skb (net/netlink/af_netlink.c:2534) 
[1494.615603][T18720] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6857) 
[1494.615606][T18720] ? __pfx_netlink_rcv_skb (net/netlink/af_netlink.c:2511) 
[1494.615613][T18720] ? netlink_deliver_tap (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/netlink/af_netlink.c:340) 
[1494.615616][T18720] ? netlink_deliver_tap (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 ./include/net/netns/generic.h:48 net/netlink/af_netlink.c:333) 
[1494.615620][T18720] netlink_unicast (net/netlink/af_netlink.c:1313 net/netlink/af_netlink.c:1339) 
[1494.615623][T18720] ? __pfx_netlink_unicast (net/netlink/af_netlink.c:1324) 
[1494.615627][T18720] ? find_held_lock (kernel/locking/lockdep.c:5341) 
[1494.615631][T18720] netlink_sendmsg (net/netlink/af_netlink.c:1883) 
[1494.615635][T18720] ? __pfx_netlink_sendmsg (net/netlink/af_netlink.c:1802) 
[1494.615641][T18720] ____sys_sendmsg (net/socket.c:712 net/socket.c:727 net/socket.c:2566) 
[1494.615649][T18720] ? __pfx_____sys_sendmsg (net/socket.c:2512) 
[1494.615652][T18720] ? __pfx_copy_msghdr_from_user (net/socket.c:2492) 
[1494.615658][T18720] ___sys_sendmsg (net/socket.c:2622) 
[1494.615662][T18720] ? __pfx____sys_sendmsg (net/socket.c:2609) 
[1494.615666][T18720] ? ___sys_recvmsg (net/socket.c:2818) 
[1494.615669][T18720] ? __pfx____sys_recvmsg (net/socket.c:2818) 
[1494.615673][T18720] ? do_user_addr_fault (./include/linux/rcupdate.h:337 ./include/linux/rcupdate.h:849 ./include/linux/mm.h:740 arch/x86/mm/fault.c:1339) 
[1494.615677][T18720] ? do_user_addr_fault (./include/linux/rcupdate.h:337 ./include/linux/rcupdate.h:849 ./include/linux/mm.h:740 arch/x86/mm/fault.c:1339) 
[1494.615681][T18720] ? find_held_lock (kernel/locking/lockdep.c:5341) 
[1494.615684][T18720] ? __lock_release (kernel/locking/lockdep.c:5527) 
[1494.615689][T18720] __sys_sendmsg (net/socket.c:2652) 
[1494.615691][T18720] ? __pfx___sys_sendmsg (net/socket.c:2637) 
[1494.615696][T18720] ? do_user_addr_fault (./include/linux/rcupdate.h:882 ./include/linux/mm.h:742 arch/x86/mm/fault.c:1339) 
[1494.615701][T18720] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) 
[1494.615705][T18720] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) 
[ 1494.615710][T18720] RIP: 0033:0x7fb23daf99a7
[ 1494.615715][T18720] Code: 0a 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b9 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 89 54 24 1c 48 89 74 24 10
All code
========
   0:	0a 00                	or     (%rax),%al
   2:	f7 d8                	neg    %eax
   4:	64 89 02             	mov    %eax,%fs:(%rdx)
   7:	48 c7 c0 ff ff ff ff 	mov    $0xffffffffffffffff,%rax
   e:	eb b9                	jmp    0xffffffffffffffc9
  10:	0f 1f 00             	nopl   (%rax)
  13:	f3 0f 1e fa          	endbr64
  17:	64 8b 04 25 18 00 00 	mov    %fs:0x18,%eax
  1e:	00 
  1f:	85 c0                	test   %eax,%eax
  21:	75 10                	jne    0x33
  23:	b8 2e 00 00 00       	mov    $0x2e,%eax
  28:	0f 05                	syscall
  2a:*	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax		<-- trapping instruction
  30:	77 51                	ja     0x83
  32:	c3                   	ret
  33:	48 83 ec 28          	sub    $0x28,%rsp
  37:	89 54 24 1c          	mov    %edx,0x1c(%rsp)
  3b:	48 89 74 24 10       	mov    %rsi,0x10(%rsp)

Code starting with the faulting instruction
===========================================
   0:	48 3d 00 f0 ff ff    	cmp    $0xfffffffffffff000,%rax
   6:	77 51                	ja     0x59
   8:	c3                   	ret
   9:	48 83 ec 28          	sub    $0x28,%rsp
   d:	89 54 24 1c          	mov    %edx,0x1c(%rsp)
  11:	48 89 74 24 10       	mov    %rsi,0x10(%rsp)
[ 1494.615717][T18720] RSP: 002b:00007fff19aa9ea8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[ 1494.615721][T18720] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fb23daf99a7
[ 1494.615723][T18720] RDX: 0000000000000000 RSI: 00007fff19aa9f10 RDI: 0000000000000005
[ 1494.615725][T18720] RBP: 00007fff19aac448 R08: 0000000000000004 R09: 0000000000000000
[ 1494.615727][T18720] R10: 00007fb23db48ac0 R11: 0000000000000246 R12: 00007fff19aab220


Finger prints:
print_deadlock_bug:validate_chain:__lock_acquire:_raw_spin_lock:fib6_purge_rt