======================================
| [  949.999844][T16252] l2tp_ip: L2TP IP encapsulation support (L2TPv3)
| [  950.066925][T16254] l2tp_eth: L2TP ethernet pseudowire support (L2TPv3)
| [  950.070635][T16253] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000012: 0000 [#1] SMP KASAN
| [  950.070858][T16253] KASAN: null-ptr-deref in range [0x0000000000000090-0x0000000000000097]
[  950.071156][T16253] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  950.071271][T16253] RIP: 0010:l2tp_eth_create (net/l2tp/l2tp_core.h:340 net/l2tp/l2tp_core.h:346 net/l2tp/l2tp_eth.c:202 net/l2tp/l2tp_eth.c:250) l2tp_eth
[  950.071391][T16253] Code: 48 c1 e9 03 80 3c 01 00 0f 85 b7 06 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8b 7b 20 49 8d bf 94 00 00 00 48 89 f9 48 c1 e9 03 <0f> b6 0c 01 48 89 f8 83 e0 07 83 c0 03 38 c8 7c 08 84 c9 0f 85 51
All code
========
   0:	48 c1 e9 03          	shr    $0x3,%rcx
   4:	80 3c 01 00          	cmpb   $0x0,(%rcx,%rax,1)
   8:	0f 85 b7 06 00 00    	jne    0x6c5
   e:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  15:	fc ff df 
  18:	4c 8b 7b 20          	mov    0x20(%rbx),%r15
  1c:	49 8d bf 94 00 00 00 	lea    0x94(%r15),%rdi
  23:	48 89 f9             	mov    %rdi,%rcx
  26:	48 c1 e9 03          	shr    $0x3,%rcx
  2a:*	0f b6 0c 01          	movzbl (%rcx,%rax,1),%ecx		<-- trapping instruction
  2e:	48 89 f8             	mov    %rdi,%rax
  31:	83 e0 07             	and    $0x7,%eax
  34:	83 c0 03             	add    $0x3,%eax
  37:	38 c8                	cmp    %cl,%al
  39:	7c 08                	jl     0x43
  3b:	84 c9                	test   %cl,%cl
  3d:	0f                   	.byte 0xf
  3e:	85                   	.byte 0x85
  3f:	51                   	push   %rcx

Code starting with the faulting instruction
===========================================
   0:	0f b6 0c 01          	movzbl (%rcx,%rax,1),%ecx
   4:	48 89 f8             	mov    %rdi,%rax
   7:	83 e0 07             	and    $0x7,%eax
   a:	83 c0 03             	add    $0x3,%eax
   d:	38 c8                	cmp    %cl,%al
   f:	7c 08                	jl     0x19
  11:	84 c9                	test   %cl,%cl
  13:	0f                   	.byte 0xf
  14:	85                   	.byte 0x85
  15:	51                   	push   %rcx
[  950.071703][T16253] RSP: 0018:ffa000000079f3b8 EFLAGS: 00010217
[  950.071817][T16253] RAX: dffffc0000000000 RBX: ff11000014beb400 RCX: 0000000000000012
[  950.071951][T16253] RDX: ff11000008bac21c RSI: 0000000000000014 RDI: 0000000000000094
[  950.072087][T16253] RBP: 1ff40000000f3e7c R08: 0000000000000010 R09: 000000347074326c
[  950.072216][T16253] R10: ff11000008bac120 R11: ffa000000079f400 R12: ff11000017071400
[  950.072348][T16253] R13: 0000000000000003 R14: ff11000008bac000 R15: 0000000000000000
[  950.072481][T16253] FS:  00007fdb58462400(0000) GS:ff110000cde59000(0000) knlGS:0000000000000000
[  950.072635][T16253] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  950.072751][T16253] CR2: 00007fdb5857c690 CR3: 00000000248f4002 CR4: 0000000000771ef0
[  950.072887][T16253] PKRU: 55555554
[  950.072959][T16253] Call Trace:
[  950.073027][T16253]  <TASK>
[  950.073079][T16253]  ? sk_dst_get (net/l2tp/l2tp_eth.c:216) l2tp_eth
[  950.073176][T16253] l2tp_nl_cmd_session_create (net/l2tp/l2tp_netlink.c:644) l2tp_netlink
[  950.073285][T16253]  ? l2tp_session_notify.constprop.0 (net/l2tp/l2tp_netlink.c:529) l2tp_netlink
[  950.073416][T16253]  ? __nla_validate_parse (lib/nlattr.c:638)
[  950.073508][T16253]  ? __nla_parse (lib/nlattr.c:732 (discriminator 2))
[  950.073595][T16253]  ? genl_family_rcv_msg_attrs_parse.isra.0 (net/netlink/genetlink.c:946)
[  950.073712][T16253]  genl_family_rcv_msg_doit (net/netlink/genetlink.c:1116)
[  950.073802][T16253]  ? genl_family_rcv_msg_attrs_parse.isra.0 (net/netlink/genetlink.c:1087)
[  950.073917][T16253]  ? rcu_is_watching (./include/linux/context_tracking.h:128 (discriminator 1) kernel/rcu/tree.c:752 (discriminator 1))
[  950.074006][T16253]  ? cap_capable (./include/trace/events/capability.h:26 (discriminator 33) security/commoncap.c:130 (discriminator 33))
[  950.074097][T16253]  ? kernel_text_address (kernel/extable.c:125 (discriminator 1) kernel/extable.c:94 (discriminator 1))
[  950.074188][T16253]  genl_family_rcv_msg (net/netlink/genetlink.c:1194)
[  950.074275][T16253]  ? genl_family_rcv_msg_dumpit (net/netlink/genetlink.c:1159)
[  950.074386][T16253]  ? l2tp_session_notify.constprop.0 (net/l2tp/l2tp_netlink.c:529) l2tp_netlink
[  950.074514][T16253]  ? __lock_acquire (kernel/locking/lockdep.c:5237 (discriminator 1))
[  950.074603][T16253]  genl_rcv_msg (net/netlink/genetlink.c:65 net/netlink/genetlink.c:1210)
[  950.074689][T16253]  netlink_rcv_skb (net/netlink/af_netlink.c:2550)
[  950.074774][T16253]  ? genl_family_rcv_msg (net/netlink/genetlink.c:1200)
[  950.074865][T16253]  ? netlink_ack (net/netlink/af_netlink.c:2527)
[  950.074951][T16253]  ? 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))
[  950.075039][T16253]  ? 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))
[  950.075126][T16253]  genl_rcv (net/netlink/genetlink.c:1219)
[  950.075192][T16253]  netlink_unicast (net/netlink/af_netlink.c:1319 net/netlink/af_netlink.c:1344)
[  950.075280][T16253]  ? netlink_attachskb (net/netlink/af_netlink.c:1329)
[  950.075367][T16253]  ? __alloc_skb (./include/linux/bottom_half.h:20 (discriminator 1) net/core/skbuff.c:695 (discriminator 1))
[  950.075457][T16253]  ? napi_skb_cache_get (net/core/skbuff.c:674)
[  950.075545][T16253]  ? __lock_acquire (kernel/locking/lockdep.c:5237 (discriminator 1))
[  950.075633][T16253]  netlink_sendmsg (net/netlink/af_netlink.c:1894)
[  950.075719][T16253]  ? netlink_unicast (net/netlink/af_netlink.c:1813)
[  950.075807][T16253]  ? __might_fault (mm/memory.c:7217 (discriminator 4))
[  950.075903][T16253]  ____sys_sendmsg (net/socket.c:727 (discriminator 4) net/socket.c:742 (discriminator 4) net/socket.c:2592 (discriminator 4))
[  950.075992][T16253]  ? copy_msghdr_from_user (net/socket.c:2532)
[  950.076079][T16253]  ? get_timestamp.constprop.0 (net/socket.c:2538)
[  950.076186][T16253]  ? move_addr_to_kernel (net/socket.c:2518)
[  950.076273][T16253]  ? __lock_acquire (kernel/locking/lockdep.c:5237 (discriminator 1))
[  950.076366][T16253]  ___sys_sendmsg (net/socket.c:2648)
[  950.076452][T16253]  ? copy_msghdr_from_user (net/socket.c:2635)
[  950.076540][T16253]  ? do_fault_around (./include/linux/rcupdate.h:322 (discriminator 1) ./include/linux/rcupdate.h:881 (discriminator 1) mm/memory.c:5759 (discriminator 1))
[  950.076628][T16253]  ? do_pte_missing (mm/memory.c:5789 mm/memory.c:5932 mm/memory.c:4477)
[  950.076716][T16253]  ? lock_vma_under_rcu (./include/linux/rcupdate.h:322 (discriminator 1) ./include/linux/rcupdate.h:881 (discriminator 1) mm/mmap_lock.c:329 (discriminator 1))
[  950.076804][T16253]  __sys_sendmsg (net/socket.c:2678 (discriminator 1))
[  950.076894][T16253]  ? __sys_sendmsg_sock (net/socket.c:2663)
[  950.076985][T16253]  ? do_user_addr_fault (./arch/x86/include/asm/atomic.h:93 (discriminator 4) ./include/linux/atomic/atomic-arch-fallback.h:949 (discriminator 4) ./include/linux/atomic/atomic-instrumented.h:401 (discriminator 4) ./include/linux/refcount.h:389 (discriminator 4) ./include/linux/refcount.h:432 (discriminator 4) ./include/linux/mmap_lock.h:196 (discriminator 4) ./include/linux/mmap_lock.h:217 (discriminator 4) ./include/linux/mmap_lock.h:264 (discriminator 4) arch/x86/mm/fault.c:1336 (discriminator 4))
[  950.077075][T16253]  ? rcu_is_watching (./include/linux/context_tracking.h:128 (discriminator 1) kernel/rcu/tree.c:752 (discriminator 1))
[  950.077169][T16253]  ? rcu_is_watching (./include/linux/context_tracking.h:128 (discriminator 1) kernel/rcu/tree.c:752 (discriminator 1))
[  950.077256][T16253]  do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1))
[  950.077347][T16253]  ? exc_page_fault (arch/x86/mm/fault.c:1480 (discriminator 3) arch/x86/mm/fault.c:1527 (discriminator 3))
[  950.077436][T16253]  entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[  950.077545][T16253] RIP: 0033:0x7fdb585bcc5e
[  950.077644][T16253] 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
[  950.077953][T16253] RSP: 002b:00007ffca985a830 EFLAGS: 00000202 ORIG_RAX: 000000000000002e
[  950.078084][T16253] RAX: ffffffffffffffda RBX: 00007ffca985abf0 RCX: 00007fdb585bcc5e
[  950.078216][T16253] RDX: 0000000000000000 RSI: 00007ffca985a8f0 RDI: 0000000000000006
[  950.078348][T16253] RBP: 00007ffca985a840 R08: 0000000000000000 R09: 0000000000000000
[  950.078478][T16253] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000001


Finger prints:
l2tp_eth_create:l2tp_nl_cmd_session_create:genl_family_rcv_msg_doit:genl_family_rcv_msg:genl_rcv_msg