======================================
| [  197.878108] br0: port 1(vxlan0) entered disabled state
| [  197.903984] ------------[ cut here ]------------
| [  197.904280] WARNING: CPU: 2 PID: 68 at net/core/dev.c:11120 unregister_netdevice_many_notify (net/core/dev.c:11120 (discriminator 1)) 
| [  197.905256] Modules linked in: vxlan sch_etf sch_fq ip6_gre gre cls_bpf sctp_diag sctp ip6_udp_tunnel udp_tunnel libcrc32c drop_monitor act_gact cls_flower sch_ingress netdevsim psample [last unloaded: test_bpf]
[  197.908035] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[  197.909274] Workqueue: netns cleanup_net
[  197.909956] RIP: 0010:unregister_netdevice_many_notify (net/core/dev.c:11120 (discriminator 1)) 
[ 197.910895] Code: 05 2e 4c 09 01 01 90 ba 32 1b 00 00 48 c7 c6 e8 eb 2e b5 48 c7 c7 e0 39 32 b5 e8 2f 9c 55 ff 90 0f 0b 90 90 e9 15 fc ff ff 90 <0f> 0b 90 e9 23 fc ff ff e8 17 27 2e 00 0f 1f 80 00 00 00 00 90 90
All code
========
   0:	05 2e 4c 09 01       	add    $0x1094c2e,%eax
   5:	01 90 ba 32 1b 00    	add    %edx,0x1b32ba(%rax)
   b:	00 48 c7             	add    %cl,-0x39(%rax)
   e:	c6                   	(bad)
   f:	e8 eb 2e b5 48       	call   0x48b52eff
  14:	c7 c7 e0 39 32 b5    	mov    $0xb53239e0,%edi
  1a:	e8 2f 9c 55 ff       	call   0xffffffffff559c4e
  1f:	90                   	nop
  20:	0f 0b                	ud2
  22:	90                   	nop
  23:	90                   	nop
  24:	e9 15 fc ff ff       	jmp    0xfffffffffffffc3e
  29:	90                   	nop
  2a:*	0f 0b                	ud2		<-- trapping instruction
  2c:	90                   	nop
  2d:	e9 23 fc ff ff       	jmp    0xfffffffffffffc55
  32:	e8 17 27 2e 00       	call   0x2e274e
  37:	0f 1f 80 00 00 00 00 	nopl   0x0(%rax)
  3e:	90                   	nop
  3f:	90                   	nop

Code starting with the faulting instruction
===========================================
   0:	0f 0b                	ud2
   2:	90                   	nop
   3:	e9 23 fc ff ff       	jmp    0xfffffffffffffc2b
   8:	e8 17 27 2e 00       	call   0x2e2724
   d:	0f 1f 80 00 00 00 00 	nopl   0x0(%rax)
  14:	90                   	nop
  15:	90                   	nop
[  197.913581] RSP: 0018:ffffad4880263d78 EFLAGS: 00010287
[  197.914350] RAX: ffff9d7bc53a81c0 RBX: ffffad4880263e08 RCX: 0000000000000000
[  197.915371] RDX: ffff9d7bc5191198 RSI: 0000000000000000 RDI: ffffffffb584aa80
[  197.916343] RBP: ffff9d7bc53a8000 R08: 0000000000000001 R09: 0000000000000001
[  197.917362] R10: 0000000000000004 R11: 0000000000000001 R12: ffff9d7bc57b5500
[  197.917876] R13: ffff9d7bc5191d80 R14: dead000000000100 R15: ffff9d7bc5191d80
[  197.918256] FS:  0000000000000000(0000) GS:ffff9d7bfed00000(0000) knlGS:0000000000000000
[  197.918840] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  197.919212] CR2: 00007f22dda08000 CR3: 0000000022860004 CR4: 0000000000770ef0
[  197.919647] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  197.920337] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  197.921048] PKRU: 55555554
[  197.921319] Call Trace:
[  197.921691]  <TASK>
[  197.921996] ? __warn (kernel/panic.c:677) 
[  197.922598] ? unregister_netdevice_many_notify (net/core/dev.c:11120 (discriminator 1)) 
[  197.923536] ? report_bug (lib/bug.c:201 lib/bug.c:219) 
[  197.924152] ? handle_bug (arch/x86/kernel/traps.c:238) 
[  197.924778] ? exc_invalid_op (arch/x86/kernel/traps.c:259 (discriminator 1)) 
[  197.925415] ? asm_exc_invalid_op (./arch/x86/include/asm/idtentry.h:568) 
[  197.926163] ? unregister_netdevice_many_notify (net/core/dev.c:11120 (discriminator 1)) 
[  197.927131] ? unregister_netdevice_many_notify (net/core/dev.c:6962 net/core/dev.c:11120) 
[  197.928036] cleanup_net (net/core/net_namespace.c:633) 
[  197.928644] ? process_one_work (kernel/workqueue.c:2606) 
[  197.929379] process_one_work (kernel/workqueue.c:2633) 
[  197.930038] worker_thread (kernel/workqueue.c:2700 kernel/workqueue.c:2787) 
[  197.930657] ? __pfx_worker_thread (kernel/workqueue.c:2733) 
[  197.931393] kthread (kernel/kthread.c:388) 
[  197.931855] ? __pfx_kthread (kernel/kthread.c:341) 
[  197.932338] ret_from_fork (arch/x86/kernel/process.c:147) 
[  197.932791] ? __pfx_kthread (kernel/kthread.c:341) 


Finger prints:
unregister_netdevice_many_notify:cleanup_net:process_one_work:worker_thread