======================================
| [    5.087042] ------------[ cut here ]------------
| [    5.087171] refcount_t: underflow; use-after-free.
| [    5.087229] WARNING: CPU: 0 PID: 334 at lib/refcount.c:28 refcount_warn_saturate (lib/refcount.c:28 (discriminator 3))
| [    5.087313] Modules linked in: ip6_gre gre
[    5.087427] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[    5.087471] RIP: 0010:refcount_warn_saturate (lib/refcount.c:28 (discriminator 3))
[    5.087511] Code: a2 e8 e8 54 ba ff 90 0f 0b 90 90 c3 80 3d 00 e6 2b 01 00 75 89 c6 05 f7 e5 2b 01 01 90 48 c7 c7 f8 48 b5 a2 e8 c5 54 ba ff 90 <0f> 0b 90 90 c3 80 3d db e5 2b 01 00 0f 85 62 ff ff ff c6 05 ce e5
All code
========
   0:	a2 e8 e8 54 ba ff 90 	movabs %al,0xb0f90ffba54e8e8
   7:	0f 0b 
   9:	90                   	nop
   a:	90                   	nop
   b:	c3                   	ret
   c:	80 3d 00 e6 2b 01 00 	cmpb   $0x0,0x12be600(%rip)        # 0x12be613
  13:	75 89                	jne    0xffffffffffffff9e
  15:	c6 05 f7 e5 2b 01 01 	movb   $0x1,0x12be5f7(%rip)        # 0x12be613
  1c:	90                   	nop
  1d:	48 c7 c7 f8 48 b5 a2 	mov    $0xffffffffa2b548f8,%rdi
  24:	e8 c5 54 ba ff       	call   0xffffffffffba54ee
  29:	90                   	nop
  2a:*	0f 0b                	ud2		<-- trapping instruction
  2c:	90                   	nop
  2d:	90                   	nop
  2e:	c3                   	ret
  2f:	80 3d db e5 2b 01 00 	cmpb   $0x0,0x12be5db(%rip)        # 0x12be611
  36:	0f 85 62 ff ff ff    	jne    0xffffffffffffff9e
  3c:	c6                   	.byte 0xc6
  3d:	05                   	.byte 0x5
  3e:	ce                   	(bad)
  3f:	e5                   	.byte 0xe5

Code starting with the faulting instruction
===========================================
   0:	0f 0b                	ud2
   2:	90                   	nop
   3:	90                   	nop
   4:	c3                   	ret
   5:	80 3d db e5 2b 01 00 	cmpb   $0x0,0x12be5db(%rip)        # 0x12be5e7
   c:	0f 85 62 ff ff ff    	jne    0xffffffffffffff74
  12:	c6                   	.byte 0xc6
  13:	05                   	.byte 0x5
  14:	ce                   	(bad)
  15:	e5                   	.byte 0xe5
[    5.087634] RSP: 0018:ffffb79600283730 EFLAGS: 00010282
[    5.087671] RAX: 0000000000000000 RBX: ffffb79600283740 RCX: 00000000ffffdfff
[    5.087742] RDX: 0000000000000000 RSI: 00000000ffffffea RDI: 0000000000000001
[    5.087797] RBP: ffffb79600283238 R08: ffffffffa335ba28 R09: 00000000ffffdfff
[    5.087914] R10: ffffffffa327ba40 R11: ffffffffa332ba40 R12: dead000000000122
[    5.087996] R13: 00000000fffb7f75 R14: 0000000000000001 R15: ffff962001bda000
[    5.088065] FS:  00007fe465503800(0000) GS:ffff96209b191000(0000) knlGS:0000000000000000
[    5.088131] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    5.088188] CR2: 0000560797e79148 CR3: 0000000003354005 CR4: 0000000000772ef0
[    5.088249] PKRU: 55555554
[    5.088273] Call Trace:
[    5.088293]  <TASK>
[    5.088310]  netdev_run_todo (./include/linux/list.h:381 net/core/dev.c:11670)
[    5.088346]  rtnl_dellink (net/core/rtnetlink.c:3580)
[    5.088403]  ? virtio_fs_enqueue_req (fs/fuse/virtio_fs.c:1473)
[    5.088454]  ? netdev_run_todo (./include/linux/list.h:381 net/core/dev.c:11653)
[    5.088481]  ? rtnl_bridge_getlink (net/core/rtnetlink.c:3536)
[    5.088538]  rtnetlink_rcv_msg (net/core/rtnetlink.c:6959)
[    5.088575]  ? get_page_from_freelist (mm/page_alloc.c:1226 mm/page_alloc.c:1848 mm/page_alloc.c:1858 mm/page_alloc.c:3884)
[    5.088622]  ? rtnl_calcit.isra.0 (net/core/rtnetlink.c:6861)
[    5.088662]  netlink_rcv_skb (net/netlink/af_netlink.c:2550)
[    5.088704]  netlink_unicast (net/netlink/af_netlink.c:1319 net/netlink/af_netlink.c:1344)
[    5.088738]  ? __alloc_skb (net/core/skbuff.c:690)
[    5.088770]  netlink_sendmsg (net/netlink/af_netlink.c:1894)
[    5.088803]  ____sys_sendmsg (net/socket.c:727 net/socket.c:742 net/socket.c:2630)
[    5.088839]  ? copy_msghdr_from_user (net/socket.c:2570)
[    5.088879]  ___sys_sendmsg (net/socket.c:2686)
[    5.088911]  ? do_wp_page (./include/linux/mmu_notifier.h:468 mm/memory.c:3786 mm/memory.c:4140)
[    5.088960]  ? ___pte_offset_map (./include/linux/pgtable.h:347 ./include/linux/pgtable.h:635 mm/pgtable-generic.c:288)
[    5.089005]  ? nfulnl_rcv_nl_event (net/netfilter/nfnetlink_log.c:836)
[    5.089051]  ? fsnotify_grab_connector (fs/notify/mark.c:709)
[    5.089102]  ? fsnotify_destroy_marks (fs/notify/mark.c:937)
[    5.089141]  __sys_sendmsg (net/socket.c:2716)
[    5.089175]  do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94)
[    5.089216]  entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[    5.089254] RIP: 0033:0x7fe4656d11d7
[    5.089293] Code: 0e 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:	0e                   	(bad)
   1:	00 f7                	add    %dh,%bh
   3:	d8 64 89 02          	fsubs  0x2(%rcx,%rcx,4)
   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)
[    5.089423] RSP: 002b:00007ffe3113f4b8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[    5.089482] RAX: ffffffffffffffda RBX: 00007ffe3113fbe0 RCX: 00007fe4656d11d7
[    5.089538] RDX: 0000000000000000 RSI: 00007ffe3113f520 RDI: 0000000000000005
[    5.089595] RBP: 0000000000000002 R08: 0000000000000003 R09: 0000000000000078
[    5.089658] R10: 00007fe4655cdf60 R11: 0000000000000246 R12: 0000000000000002


Finger prints:
refcount_warn_saturate:netdev_run_todo:rtnl_dellink:rtnetlink_rcv_msg:netlink_rcv_skb