======================================
| [ 2122.102213][ T8943] 1 lock held by ping6/8943:
| [ 2122.102385][ T8943] #0: ffff888011a49418 (sk_lock-AF_INET6){+.+.}-{0:0}, at: udpv6_connect (net/ipv6/udp.c:1310)
| [ 2122.102686][ T8943]
| [ 2122.102686][ T8943] stack backtrace:
[ 2122.103136][ T8943] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 2122.103337][ T8943] Call Trace:
[ 2122.103462][ T8943]  <TASK>
[ 2122.103560][ T8943] dump_stack_lvl (lib/dump_stack.c:123)
[ 2122.103756][ T8943] lockdep_rcu_suspicious (kernel/locking/lockdep.c:6846)
[ 2122.103928][ T8943] dev_get_by_index_rcu (net/core/dev.c:876 (discriminator 7))
[ 2122.104097][ T8943] ip6_create_rt_oif_rcu (net/ipv6/route.c:1223)
[ 2122.104264][ T8943] ? ip6_route_output_flags (net/ipv6/route.c:2695)
[ 2122.104438][ T8943] ip6_dst_lookup_tail.constprop.0 (net/ipv6/ip6_output.c:1160)
[ 2122.104642][ T8943] ? ip6_datagram_dst_update (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/ipv6/datagram.c:94)
[ 2122.104812][ T8943] ip6_dst_lookup_flow (net/ipv6/ip6_output.c:1265)
[ 2122.104982][ T8943] ? __pfx_ip6_dst_lookup_flow (net/ipv6/ip6_output.c:1260)
[ 2122.105147][ T8943] ? ip6_datagram_dst_update (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 net/ipv6/datagram.c:94)
[ 2122.105312][ T8943] ip6_datagram_dst_update (net/ipv6/datagram.c:96)
[ 2122.105474][ T8943] ? __pfx_ip6_datagram_dst_update (net/ipv6/datagram.c:73)
[ 2122.105696][ T8943] ? __ip6_datagram_connect (net/ipv6/datagram.c:256)
[ 2122.105872][ T8943] __ip6_datagram_connect (net/ipv6/datagram.c:256)
[ 2122.106035][ T8943] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 2122.106209][ T8943] ? __pfx___ip6_datagram_connect (net/ipv6/datagram.c:143)
[ 2122.106417][ T8943] ? mark_held_locks (kernel/locking/lockdep.c:4321)
[ 2122.106596][ T8943] ? __pfx_inet_dgram_connect (net/ipv4/af_inet.c:570)
[ 2122.106765][ T8943] ? udpv6_connect (net/ipv6/udp.c:1310)
[ 2122.106931][ T8943] udpv6_connect (net/ipv6/udp.c:1310)
[ 2122.107094][ T8943] ? inet_dgram_connect (net/ipv4/af_inet.c:590 (discriminator 1))
[ 2122.107258][ T8943] __sys_connect (net/socket.c:2066 net/socket.c:2085)
[ 2122.107425][ T8943] ? __pfx___sys_connect (net/socket.c:2073)
[ 2122.107595][ T8943] ? __pfx_slab_free_after_rcu_debug (mm/slub.c:4643)
[ 2122.107801][ T8943] ? trace_rcu_segcb_stats (./arch/x86/include/asm/bitops.h:227 ./arch/x86/include/asm/bitops.h:239 ./include/asm-generic/bitops/instrumented-non-atomic.h:142 ./include/linux/cpumask.h:570 ./include/linux/cpumask.h:1117 ./include/trace/events/rcu.h:537)
[ 2122.107977][ T8943] ? __sys_setsockopt (net/socket.c:2349)
[ 2122.108155][ T8943] __x64_sys_connect (net/socket.c:2088)
[ 2122.108323][ T8943] do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)
[ 2122.108488][ T8943] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[ 2122.108688][ T8943] RIP: 0033:0x7f8e3db965c7
[ 2122.108856][ T8943] Code: 0a 00 f7 d8 64 89 02 b8 ff ff ff ff eb bc 0f 1f 44 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2a 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 18 89 54 24 0c 48 89 34 24 89
All code
========
   0:	0a 00                	or     (%rax),%al
   2:	f7 d8                	neg    %eax
   4:	64 89 02             	mov    %eax,%fs:(%rdx)
   7:	b8 ff ff ff ff       	mov    $0xffffffff,%eax
   c:	eb bc                	jmp    0xffffffffffffffca
   e:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
  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 2a 00 00 00       	mov    $0x2a,%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 18          	sub    $0x18,%rsp
  37:	89 54 24 0c          	mov    %edx,0xc(%rsp)
  3b:	48 89 34 24          	mov    %rsi,(%rsp)
  3f:	89                   	.byte 0x89

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 18          	sub    $0x18,%rsp
   d:	89 54 24 0c          	mov    %edx,0xc(%rsp)
  11:	48 89 34 24          	mov    %rsi,(%rsp)
  15:	89                   	.byte 0x89
[ 2122.109430][ T8943] RSP: 002b:00007ffc7be2ad28 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
[ 2122.109678][ T8943] RAX: ffffffffffffffda RBX: 0000000000000020 RCX: 00007f8e3db965c7
[ 2122.109931][ T8943] RDX: 000000000000001c RSI: 000000000041861c RDI: 0000000000000006
[ 2122.110172][ T8943] RBP: 00007ffc7be2b010 R08: 0000000020d3e4d0 R09: 0000000000000000
[ 2122.110419][ T8943] R10: 00007f8e3da4e598 R11: 0000000000000246 R12: 00007ffc7be2b368


Finger prints:
lockdep_rcu_suspicious:dev_get_by_index_rcu:ip6_create_rt_oif_rcu:ip6_dst_lookup_flow:ip6_datagram_dst_update