======================================
| [ 1201.894846] br2: port 1(vethhv-21) entered disabled state
| [ 1201.929318] ------------[ cut here ]------------
| [ 1201.929636] WARNING: CPU: 0 PID: 11 at net/core/dev.c:11120 unregister_netdevice_many_notify (net/core/dev.c:11120 (discriminator 1)) 
| [ 1201.930248] Modules linked in: bonding xfrm_user psample macsec fou ip6_gre ip_gre gre cls_u32 sch_htb poly1305_generic libpoly1305 chacha_generic libchacha chacha20poly1305 tls act_gact cls_flower sch_ingress vxlan ip6_udp_tunnel udp_tunnel [last unloaded: netdevsim]
[ 1201.932179] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[ 1201.932871] Workqueue: netns cleanup_net
[ 1201.933089] RIP: 0010:unregister_netdevice_many_notify (net/core/dev.c:11120 (discriminator 1)) 
[ 1201.933471] Code: 05 2e 4c 09 01 01 90 ba 32 1b 00 00 48 c7 c6 e8 eb 6e 87 48 c7 c7 e0 39 72 87 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 6e 87 48       	call   0x48876eff
  14:	c7 c7 e0 39 72 87    	mov    $0x877239e0,%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
[ 1201.934470] RSP: 0018:ffffb86700063d78 EFLAGS: 00010283
[ 1201.934790] RAX: ffff88e5095301c0 RBX: ffffb86700063e08 RCX: 0000000000000000
[ 1201.935194] RDX: ffff88e5036ded18 RSI: 0000000000000000 RDI: ffffffff87c4aa80
[ 1201.935576] RBP: ffff88e509530000 R08: 0000000000000001 R09: 0000000000000001
[ 1201.935986] R10: 0000000000000004 R11: 0000000000000001 R12: ffff88e501bd8400
[ 1201.936382] R13: ffff88e5036de680 R14: dead000000000100 R15: ffff88e5036de680
[ 1201.936796] FS:  0000000000000000(0000) GS:ffff88e53ec00000(0000) knlGS:0000000000000000
[ 1201.937244] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1201.937559] CR2: 00007f2f34b1f270 CR3: 000000000bc60002 CR4: 0000000000770ef0
[ 1201.937972] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 1201.938367] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 1201.938766] PKRU: 55555554
[ 1201.938943] Call Trace:
[ 1201.939092]  <TASK>
[ 1201.939239] ? __warn (kernel/panic.c:677) 
[ 1201.939444] ? unregister_netdevice_many_notify (net/core/dev.c:11120 (discriminator 1)) 
[ 1201.939756] ? report_bug (lib/bug.c:201 lib/bug.c:219) 
[ 1201.939974] ? handle_bug (arch/x86/kernel/traps.c:238) 
[ 1201.940202] ? exc_invalid_op (arch/x86/kernel/traps.c:259 (discriminator 1)) 
[ 1201.940432] ? asm_exc_invalid_op (./arch/x86/include/asm/idtentry.h:568) 
[ 1201.940689] ? unregister_netdevice_many_notify (net/core/dev.c:11120 (discriminator 1)) 
[ 1201.941009] ? unregister_netdevice_many_notify (net/core/dev.c:6962 net/core/dev.c:11120) 
[ 1201.941316] cleanup_net (net/core/net_namespace.c:633) 
[ 1201.941514] ? process_one_work (kernel/workqueue.c:2606) 
[ 1201.941762] process_one_work (kernel/workqueue.c:2633) 
[ 1201.942018] worker_thread (kernel/workqueue.c:2700 kernel/workqueue.c:2787) 
[ 1201.942243] ? __pfx_worker_thread (kernel/workqueue.c:2733) 
[ 1201.942486] kthread (kernel/kthread.c:388) 
[ 1201.942703] ? __pfx_kthread (kernel/kthread.c:341) 
[ 1201.942990] ret_from_fork (arch/x86/kernel/process.c:147) 
[ 1201.943207] ? __pfx_kthread (kernel/kthread.c:341) 
[ 1201.943439] ret_from_fork_asm (arch/x86/entry/entry_64.S:250) 
| [ 1201.945991] ---[ end trace 0000000000000000 ]---
| [ 1201.946857] ------------[ cut here ]------------
| [ 1201.947622] WARNING: CPU: 1 PID: 11 at net/core/dev.c:11120 unregister_netdevice_many_notify (net/core/dev.c:11120 (discriminator 1)) 
| [ 1201.949046] Modules linked in: bonding xfrm_user psample macsec fou ip6_gre ip_gre gre cls_u32 sch_htb poly1305_generic libpoly1305 chacha_generic libchacha chacha20poly1305 tls act_gact cls_flower sch_ingress vxlan ip6_udp_tunnel udp_tunnel [last unloaded: netdevsim]
[ 1201.954565] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[ 1201.955743] Workqueue: netns cleanup_net
[ 1201.956090] RIP: 0010:unregister_netdevice_many_notify (net/core/dev.c:11120 (discriminator 1)) 
[ 1201.956584] Code: 05 2e 4c 09 01 01 90 ba 32 1b 00 00 48 c7 c6 e8 eb 6e 87 48 c7 c7 e0 39 72 87 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 6e 87 48       	call   0x48876eff
  14:	c7 c7 e0 39 72 87    	mov    $0x877239e0,%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
[ 1201.958682] RSP: 0018:ffffb86700063d78 EFLAGS: 00010283
[ 1201.959674] RAX: ffff88e5035201c0 RBX: ffffb86700063e08 RCX: 0000000000000000
[ 1201.961122] RDX: ffff88e5034eda18 RSI: 0000000000000000 RDI: ffffffff87c4aa80
[ 1201.962442] RBP: ffff88e503520000 R08: 0000000000000001 R09: 0000000000000001
[ 1201.963732] R10: 0000000000000004 R11: 0000000000000001 R12: ffff88e502bf4500
[ 1201.965097] R13: ffff88e5034ed080 R14: dead000000000100 R15: ffff88e5034ed080
[ 1201.966264] FS:  0000000000000000(0000) GS:ffff88e53ec80000(0000) knlGS:0000000000000000
[ 1201.967404] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1201.968199] CR2: 00007ff72adae000 CR3: 000000000bc60004 CR4: 0000000000770ef0
[ 1201.969097] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 1201.969842] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 1201.970523] PKRU: 55555554
[ 1201.970883] Call Trace:
[ 1201.971091]  <TASK>
[ 1201.971398] ? __warn (kernel/panic.c:677) 
[ 1201.971669] ? unregister_netdevice_many_notify (net/core/dev.c:11120 (discriminator 1)) 
[ 1201.972091] ? report_bug (lib/bug.c:201 lib/bug.c:219) 
[ 1201.972373] ? handle_bug (arch/x86/kernel/traps.c:238) 
[ 1201.972740] ? exc_invalid_op (arch/x86/kernel/traps.c:259 (discriminator 1)) 
[ 1201.973249] ? asm_exc_invalid_op (./arch/x86/include/asm/idtentry.h:568) 
[ 1201.973597] ? unregister_netdevice_many_notify (net/core/dev.c:11120 (discriminator 1)) 
[ 1201.974168] ? unregister_netdevice_many_notify (net/core/dev.c:6962 net/core/dev.c:11120) 
[ 1201.974906] cleanup_net (net/core/net_namespace.c:633) 
[ 1201.975382] ? process_one_work (kernel/workqueue.c:2606) 
[ 1201.975957] process_one_work (kernel/workqueue.c:2633) 
[ 1201.976516] worker_thread (kernel/workqueue.c:2700 kernel/workqueue.c:2787) 
[ 1201.977055] ? __pfx_worker_thread (kernel/workqueue.c:2733) 
[ 1201.977674] kthread (kernel/kthread.c:388) 
[ 1201.978185] ? __pfx_kthread (kernel/kthread.c:341) 
[ 1201.978749] ret_from_fork (arch/x86/kernel/process.c:147) 
[ 1201.979289] ? __pfx_kthread (kernel/kthread.c:341) 


Finger prints:
unregister_netdevice_many_notify:cleanup_net:process_one_work:worker_thread
unregister_netdevice_many_notify:cleanup_net:process_one_work:worker_thread