======================================
| [  111.527534] ------------[ cut here ]------------
| [  111.527691] refcount_t: underflow; use-after-free.
| [  111.527758] WARNING: CPU: 3 PID: 367 at lib/refcount.c:28 refcount_warn_saturate (lib/refcount.c:28 (discriminator 3))
| [  111.527838] Modules linked in: bridge stp llc vrf veth
[  111.528008] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  111.528056] RIP: 0010:refcount_warn_saturate (lib/refcount.c:28 (discriminator 3))
[  111.528097] Code: a8 e8 18 df ba ff 90 0f 0b 90 90 c3 80 3d f9 da eb 00 00 75 89 c6 05 f0 da eb 00 01 90 48 c7 c7 28 e0 71 a8 e8 f5 de ba ff 90 <0f> 0b 90 90 c3 80 3d d4 da eb 00 00 0f 85 62 ff ff ff c6 05 c7 da
All code
========
   0:	a8 e8                	test   $0xe8,%al
   2:	18 df                	sbb    %bl,%bh
   4:	ba ff 90 0f 0b       	mov    $0xb0f90ff,%edx
   9:	90                   	nop
   a:	90                   	nop
   b:	c3                   	ret
   c:	80 3d f9 da eb 00 00 	cmpb   $0x0,0xebdaf9(%rip)        # 0xebdb0c
  13:	75 89                	jne    0xffffffffffffff9e
  15:	c6 05 f0 da eb 00 01 	movb   $0x1,0xebdaf0(%rip)        # 0xebdb0c
  1c:	90                   	nop
  1d:	48 c7 c7 28 e0 71 a8 	mov    $0xffffffffa871e028,%rdi
  24:	e8 f5 de ba ff       	call   0xffffffffffbadf1e
  29:	90                   	nop
  2a:*	0f 0b                	ud2		<-- trapping instruction
  2c:	90                   	nop
  2d:	90                   	nop
  2e:	c3                   	ret
  2f:	80 3d d4 da eb 00 00 	cmpb   $0x0,0xebdad4(%rip)        # 0xebdb0a
  36:	0f 85 62 ff ff ff    	jne    0xffffffffffffff9e
  3c:	c6                   	.byte 0xc6
  3d:	05                   	.byte 0x5
  3e:	c7                   	(bad)
  3f:	da                   	.byte 0xda

Code starting with the faulting instruction
===========================================
   0:	0f 0b                	ud2
   2:	90                   	nop
   3:	90                   	nop
   4:	c3                   	ret
   5:	80 3d d4 da eb 00 00 	cmpb   $0x0,0xebdad4(%rip)        # 0xebdae0
   c:	0f 85 62 ff ff ff    	jne    0xffffffffffffff74
  12:	c6                   	.byte 0xc6
  13:	05                   	.byte 0x5
  14:	c7                   	(bad)
  15:	da                   	.byte 0xda
[  111.528235] RSP: 0018:ffffaf16c02a3730 EFLAGS: 00010282
[  111.528275] RAX: 0000000000000000 RBX: ffffaf16c02a3740 RCX: 00000000ffffdfff
[  111.528354] RDX: 0000000000000000 RSI: 00000000ffffffea RDI: 0000000000000001
[  111.528410] RBP: ffffaf16c02a3248 R08: ffffffffa8b56a28 R09: 00000000ffffdfff
[  111.528499] R10: ffffffffa8a76a40 R11: ffffffffa8b26a40 R12: dead000000000122
[  111.528557] R13: 00000000fffd1f3c R14: 0000000000000001 R15: ffffa0b086460000
[  111.528646] FS:  00007fdc249fab80(0000) GS:ffffa0b115b59000(0000) knlGS:0000000000000000
[  111.528710] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  111.528760] CR2: 00007f34f6fe9760 CR3: 0000000003361001 CR4: 0000000000772ef0
[  111.528812] PKRU: 55555554
[  111.528836] Call Trace:
[  111.528871]  <TASK>
[  111.528902]  netdev_run_todo (./include/linux/list.h:381 net/core/dev.c:11670)
[  111.528954]  rtnl_dellink (net/core/rtnetlink.c:3580)
[  111.529002]  ? kmem_cache_alloc_node_noprof (./include/linux/kernel.h:61 ./include/linux/sched/mm.h:321 mm/slub.c:4921 mm/slub.c:5256 mm/slub.c:5332)
[  111.529050]  ? finish_task_switch.isra.0 (./arch/x86/include/asm/irqflags.h:42 ./arch/x86/include/asm/irqflags.h:119 kernel/sched/sched.h:1559 kernel/sched/core.c:5073 kernel/sched/core.c:5191)
[  111.529097]  ? kmalloc_reserve (net/core/skbuff.c:586 (discriminator 2))
[  111.529142]  ? kmalloc_reserve (net/core/skbuff.c:586 (discriminator 2))
[  111.529173]  ? rtnl_bridge_getlink (net/core/rtnetlink.c:3536)
[  111.529217]  rtnetlink_rcv_msg (net/core/rtnetlink.c:6959)
[  111.529248]  ? netlink_unicast (net/netlink/af_netlink.c:1269 net/netlink/af_netlink.c:1359)
[  111.529284]  ? rtnl_calcit.isra.0 (net/core/rtnetlink.c:6861)
[  111.529334]  netlink_rcv_skb (net/netlink/af_netlink.c:2550)
[  111.529384]  netlink_unicast (net/netlink/af_netlink.c:1319 net/netlink/af_netlink.c:1344)
[  111.529428]  ? __alloc_skb (net/core/skbuff.c:690)
[  111.529477]  netlink_sendmsg (net/netlink/af_netlink.c:1894)
[  111.529523]  ____sys_sendmsg (net/socket.c:727 net/socket.c:742 net/socket.c:2630)
[  111.529571]  ? copy_msghdr_from_user (net/socket.c:2570)
[  111.529634]  ___sys_sendmsg (net/socket.c:2686)
[  111.529681]  ? __handle_mm_fault (mm/memory.c:5690 mm/memory.c:5832 mm/memory.c:4361 mm/memory.c:6177 mm/memory.c:6318)
[  111.529743]  ? anon_pipe_write (fs/pipe.c:598)
[  111.529792]  __sys_sendmsg (net/socket.c:2716)
[  111.529838]  do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94)
[  111.529889]  entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[  111.529952] RIP: 0033:0x7fdc24b3b1d7
[  111.530002] 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)
[  111.530182] RSP: 002b:00007ffd8496ec08 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[  111.530265] RAX: ffffffffffffffda RBX: 0000000003d26320 RCX: 00007fdc24b3b1d7
[  111.530340] RDX: 0000000000000000 RSI: 00007ffd8496ec40 RDI: 0000000000000005
[  111.530420] RBP: 0000000003d26230 R08: 0000000000000003 R09: 0000000000000000
[  111.530507] R10: 0000000000000020 R11: 0000000000000246 R12: 0000000003d499a0


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