======================================
| [   11.295088][  T288] l2tp_ip: L2TP IP encapsulation support (L2TPv3)
| [   11.370221][  T291] l2tp_eth: L2TP ethernet pseudowire support (L2TPv3)
| [   11.374353][  T290] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000012: 0000 [#1] SMP KASAN
| [   11.374574][  T290] KASAN: null-ptr-deref in range [0x0000000000000090-0x0000000000000097]
[   11.374877][  T290] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   11.374990][  T290] 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
[   11.375107][  T290] 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
[   11.375417][  T290] RSP: 0018:ffa00000006a73b8 EFLAGS: 00010217
[   11.375533][  T290] RAX: dffffc0000000000 RBX: ff1100000fddc000 RCX: 0000000000000012
[   11.375668][  T290] RDX: ff1100000590121c RSI: 0000000000000014 RDI: 0000000000000094
[   11.375803][  T290] RBP: 1ff40000000d4e7c R08: 0000000000000010 R09: 000000347074326c
[   11.375935][  T290] R10: ff11000005901120 R11: ffa00000006a7400 R12: ff1100000fa51a00
[   11.376068][  T290] R13: 0000000000000003 R14: ff11000005901000 R15: 0000000000000000
[   11.376204][  T290] FS:  00007fc21c497400(0000) GS:ff110000df3d9000(0000) knlGS:0000000000000000
[   11.376360][  T290] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   11.376472][  T290] CR2: 0000000027079018 CR3: 0000000004b18003 CR4: 0000000000771ef0
[   11.376605][  T290] PKRU: 55555554
[   11.376673][  T290] Call Trace:
[   11.376747][  T290]  <TASK>
[   11.376795][  T290]  ? sk_dst_get (net/l2tp/l2tp_eth.c:216) l2tp_eth
[   11.376885][  T290] l2tp_nl_cmd_session_create (net/l2tp/l2tp_netlink.c:644) l2tp_netlink
[   11.376996][  T290]  ? l2tp_session_notify.constprop.0 (net/l2tp/l2tp_netlink.c:529) l2tp_netlink
[   11.377128][  T290]  ? __nla_validate_parse (lib/nlattr.c:638)
[   11.377220][  T290]  ? __nla_parse (lib/nlattr.c:732 (discriminator 2))
[   11.377308][  T290]  ? genl_family_rcv_msg_attrs_parse.isra.0 (net/netlink/genetlink.c:946)
[   11.377421][  T290]  genl_family_rcv_msg_doit (net/netlink/genetlink.c:1116)
[   11.377508][  T290]  ? genl_family_rcv_msg_attrs_parse.isra.0 (net/netlink/genetlink.c:1087)
[   11.377619][  T290]  ? rcu_is_watching (./include/linux/context_tracking.h:128 (discriminator 1) kernel/rcu/tree.c:752 (discriminator 1))
[   11.377710][  T290]  ? cap_capable (./include/trace/events/capability.h:26 (discriminator 33) security/commoncap.c:130 (discriminator 33))
[   11.377800][  T290]  ? kernel_text_address (kernel/extable.c:125 (discriminator 1) kernel/extable.c:94 (discriminator 1))
[   11.377889][  T290]  genl_family_rcv_msg (net/netlink/genetlink.c:1194)
[   11.377979][  T290]  ? genl_family_rcv_msg_dumpit (net/netlink/genetlink.c:1159)
[   11.378089][  T290]  ? l2tp_session_notify.constprop.0 (net/l2tp/l2tp_netlink.c:529) l2tp_netlink
[   11.378220][  T290]  ? __lock_acquire (kernel/locking/lockdep.c:5237 (discriminator 1))
[   11.378311][  T290]  genl_rcv_msg (net/netlink/genetlink.c:65 net/netlink/genetlink.c:1210)
[   11.378400][  T290]  netlink_rcv_skb (net/netlink/af_netlink.c:2550)
[   11.378487][  T290]  ? genl_family_rcv_msg (net/netlink/genetlink.c:1200)
[   11.378575][  T290]  ? netlink_ack (net/netlink/af_netlink.c:2527)
[   11.378665][  T290]  ? 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))
[   11.378753][  T290]  ? 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))
[   11.378840][  T290]  genl_rcv (net/netlink/genetlink.c:1219)
[   11.378906][  T290]  netlink_unicast (net/netlink/af_netlink.c:1319 net/netlink/af_netlink.c:1344)
[   11.378994][  T290]  ? netlink_attachskb (net/netlink/af_netlink.c:1329)
[   11.379080][  T290]  ? __alloc_skb (./include/linux/bottom_half.h:20 (discriminator 1) net/core/skbuff.c:695 (discriminator 1))
[   11.379170][  T290]  ? napi_skb_cache_get (net/core/skbuff.c:674)
[   11.379257][  T290]  ? __lock_acquire (kernel/locking/lockdep.c:5237 (discriminator 1))
[   11.379346][  T290]  netlink_sendmsg (net/netlink/af_netlink.c:1894)
[   11.379434][  T290]  ? netlink_unicast (net/netlink/af_netlink.c:1813)
[   11.379521][  T290]  ? __might_fault (mm/memory.c:7217 (discriminator 4))
[   11.379612][  T290]  ____sys_sendmsg (net/socket.c:727 (discriminator 4) net/socket.c:742 (discriminator 4) net/socket.c:2592 (discriminator 4))
[   11.379698][  T290]  ? copy_msghdr_from_user (net/socket.c:2532)
[   11.379789][  T290]  ? get_timestamp.constprop.0 (net/socket.c:2538)
[   11.379896][  T290]  ? move_addr_to_kernel (net/socket.c:2518)
[   11.379983][  T290]  ? vma_shrink (mm/vma.c:1567)
[   11.380073][  T290]  ___sys_sendmsg (net/socket.c:2648)
[   11.380164][  T290]  ? copy_msghdr_from_user (net/socket.c:2635)
[   11.380255][  T290]  __sys_sendmsg (net/socket.c:2678 (discriminator 1))
[   11.380342][  T290]  ? __sys_sendmsg_sock (net/socket.c:2663)
[   11.380431][  T290]  ? 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))
[   11.380518][  T290]  ? rcu_is_watching (./include/linux/context_tracking.h:128 (discriminator 1) kernel/rcu/tree.c:752 (discriminator 1))
[   11.380605][  T290]  ? rcu_is_watching (./include/linux/context_tracking.h:128 (discriminator 1) kernel/rcu/tree.c:752 (discriminator 1))
[   11.380693][  T290]  do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1))
[   11.380783][  T290]  ? exc_page_fault (arch/x86/mm/fault.c:1480 (discriminator 3) arch/x86/mm/fault.c:1527 (discriminator 3))
[   11.380871][  T290]  entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[   11.380981][  T290] RIP: 0033:0x7fc21c5f1c5e
[   11.381075][  T290] 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
[   11.381383][  T290] RSP: 002b:00007ffca8262330 EFLAGS: 00000202 ORIG_RAX: 000000000000002e
[   11.381514][  T290] RAX: ffffffffffffffda RBX: 00007ffca82626f0 RCX: 00007fc21c5f1c5e
[   11.381644][  T290] RDX: 0000000000000000 RSI: 00007ffca82623f0 RDI: 0000000000000006
[   11.381776][  T290] RBP: 00007ffca8262340 R08: 0000000000000000 R09: 0000000000000000
[   11.381907][  T290] 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