======================================
| [    7.232661] ------------[ cut here ]------------
| [    7.232800] refcount_t: underflow; use-after-free.
| [    7.232879] WARNING: CPU: 3 PID: 695 at lib/refcount.c:28 refcount_warn_saturate (lib/refcount.c:28 (discriminator 3))
| [    7.232994] Modules linked in: 8021q bridge stp llc nft_masq nft_nat nft_chain_nat nf_nat tcp_diag inet_diag nft_flow_offload nft_ct nf_flow_table_inet nf_flow_table nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nf_tables veth
[    7.233383] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[    7.233462] RIP: 0010:refcount_warn_saturate (lib/refcount.c:28 (discriminator 3))
[    7.233535] Code: 87 e8 18 ed b9 ff 90 0f 0b 90 90 c3 80 3d d9 ea ea 00 00 75 89 c6 05 d0 ea ea 00 01 90 48 c7 c7 78 de b1 87 e8 f5 ec b9 ff 90 <0f> 0b 90 90 c3 80 3d b4 ea ea 00 00 0f 85 62 ff ff ff c6 05 a7 ea
All code
========
   0:	87 e8                	xchg   %ebp,%eax
   2:	18 ed                	sbb    %ch,%ch
   4:	b9 ff 90 0f 0b       	mov    $0xb0f90ff,%ecx
   9:	90                   	nop
   a:	90                   	nop
   b:	c3                   	ret
   c:	80 3d d9 ea ea 00 00 	cmpb   $0x0,0xeaead9(%rip)        # 0xeaeaec
  13:	75 89                	jne    0xffffffffffffff9e
  15:	c6 05 d0 ea ea 00 01 	movb   $0x1,0xeaead0(%rip)        # 0xeaeaec
  1c:	90                   	nop
  1d:	48 c7 c7 78 de b1 87 	mov    $0xffffffff87b1de78,%rdi
  24:	e8 f5 ec b9 ff       	call   0xffffffffffb9ed1e
  29:	90                   	nop
  2a:*	0f 0b                	ud2		<-- trapping instruction
  2c:	90                   	nop
  2d:	90                   	nop
  2e:	c3                   	ret
  2f:	80 3d b4 ea ea 00 00 	cmpb   $0x0,0xeaeab4(%rip)        # 0xeaeaea
  36:	0f 85 62 ff ff ff    	jne    0xffffffffffffff9e
  3c:	c6                   	.byte 0xc6
  3d:	05                   	.byte 0x5
  3e:	a7                   	cmpsl  %es:(%rdi),%ds:(%rsi)
  3f:	ea                   	(bad)

Code starting with the faulting instruction
===========================================
   0:	0f 0b                	ud2
   2:	90                   	nop
   3:	90                   	nop
   4:	c3                   	ret
   5:	80 3d b4 ea ea 00 00 	cmpb   $0x0,0xeaeab4(%rip)        # 0xeaeac0
   c:	0f 85 62 ff ff ff    	jne    0xffffffffffffff74
  12:	c6                   	.byte 0xc6
  13:	05                   	.byte 0x5
  14:	a7                   	cmpsl  %es:(%rdi),%ds:(%rsi)
  15:	ea                   	(bad)
[    7.233771] RSP: 0018:ffffb86a80403730 EFLAGS: 00010282
[    7.233846] RAX: 0000000000000000 RBX: ffffb86a80403740 RCX: 00000000ffffdfff
[    7.233941] RDX: 0000000000000000 RSI: 00000000ffffffea RDI: 0000000000000001
[    7.234036] RBP: ffffb86a80403248 R08: ffffffff87f56d28 R09: 00000000ffffdfff
[    7.234131] R10: ffffffff87e76d40 R11: ffffffff87f26d40 R12: dead000000000122
[    7.234228] R13: 00000000fffb87d7 R14: 0000000000000001 R15: ffff89ec0514b000
[    7.234326] FS:  00007fa299728800(0000) GS:ffff89ecb6758000(0000) knlGS:0000000000000000
[    7.234422] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    7.234499] CR2: 00000000004a1778 CR3: 000000000b8aa002 CR4: 0000000000772ef0
[    7.234603] PKRU: 55555554
[    7.234643] Call Trace:
[    7.234679]  <TASK>
[    7.234720]  netdev_run_todo (./include/linux/list.h:381 net/core/dev.c:11670)
[    7.234778]  rtnl_dellink (net/core/rtnetlink.c:3580)
[    7.234840]  ? rtnl_bridge_getlink (net/core/rtnetlink.c:3536)
[    7.234906]  rtnetlink_rcv_msg (net/core/rtnetlink.c:6959)
[    7.234959]  ? get_page_from_freelist (mm/page_alloc.c:1226 mm/page_alloc.c:1848 mm/page_alloc.c:1858 mm/page_alloc.c:3884)
[    7.235029]  ? rtnl_calcit.isra.0 (net/core/rtnetlink.c:6861)
[    7.235089]  netlink_rcv_skb (net/netlink/af_netlink.c:2550)
[    7.235146]  netlink_unicast (net/netlink/af_netlink.c:1319 net/netlink/af_netlink.c:1344)
[    7.235196]  ? __alloc_skb (net/core/skbuff.c:690)
[    7.235249]  netlink_sendmsg (net/netlink/af_netlink.c:1894)
[    7.235301]  ____sys_sendmsg (net/socket.c:727 net/socket.c:742 net/socket.c:2630)
[    7.235354]  ? copy_msghdr_from_user (net/socket.c:2570)
[    7.235425]  ___sys_sendmsg (net/socket.c:2686)
[    7.235477]  ? do_wp_page (./include/linux/mmu_notifier.h:468 mm/memory.c:3786 mm/memory.c:4140)
[    7.235532]  ? __handle_mm_fault (mm/memory.c:6193 mm/memory.c:6318)
[    7.235606]  __sys_sendmsg (net/socket.c:2716)
[    7.235664]  do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94)
[    7.235722]  entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
[    7.235791] RIP: 0033:0x7fa2998f61d7
[    7.235847] 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)
[    7.236066] RSP: 002b:00007ffdab2d91e8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[    7.236159] RAX: ffffffffffffffda RBX: 00007ffdab2d9920 RCX: 00007fa2998f61d7
[    7.236250] RDX: 0000000000000000 RSI: 00007ffdab2d9250 RDI: 0000000000000005
[    7.236340] RBP: 0000000000000000 R08: 000000000000002c R09: 0000000000404178
[    7.236433] R10: 0000000000404178 R11: 0000000000000246 R12: 00007ffdab2d9938


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