======================================
| [    4.649115] bond0: (slave eth1): Releasing backup interface
| [    4.665071] ------------[ cut here ]------------
| [    4.665184] kernel BUG at net/core/net-sysfs.c:2246!
| [    4.665257] Oops: invalid opcode: 0000 [#1] SMP
[    4.665396] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[    4.665454] Workqueue: netns cleanup_net
[    4.665505] RIP: 0010:netdev_release (net/core/net-sysfs.c:2246 net/core/net-sysfs.c:2242)
[    4.665560] Code: fa 0f 1f 44 00 00 80 7f e0 04 75 1d 55 48 8d af d0 fa ff ff 48 8b bf 00 fc ff ff e8 cd ff a3 ff 48 89 ef 5d e9 84 06 a4 ff 90 <0f> 0b 90 f3 0f 1e fa 0f 1f 44 00 00 55 48 89 f5 48 8d 97 e8 fb ff
All code
========
   0:	fa                   	cli
   1:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
   6:	80 7f e0 04          	cmpb   $0x4,-0x20(%rdi)
   a:	75 1d                	jne    0x29
   c:	55                   	push   %rbp
   d:	48 8d af d0 fa ff ff 	lea    -0x530(%rdi),%rbp
  14:	48 8b bf 00 fc ff ff 	mov    -0x400(%rdi),%rdi
  1b:	e8 cd ff a3 ff       	call   0xffffffffffa3ffed
  20:	48 89 ef             	mov    %rbp,%rdi
  23:	5d                   	pop    %rbp
  24:	e9 84 06 a4 ff       	jmp    0xffffffffffa406ad
  29:	90                   	nop
  2a:*	0f 0b                	ud2		<-- trapping instruction
  2c:	90                   	nop
  2d:	f3 0f 1e fa          	endbr64
  31:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
  36:	55                   	push   %rbp
  37:	48 89 f5             	mov    %rsi,%rbp
  3a:	48                   	rex.W
  3b:	8d                   	.byte 0x8d
  3c:	97                   	xchg   %eax,%edi
  3d:	e8                   	.byte 0xe8
  3e:	fb                   	sti
  3f:	ff                   	.byte 0xff

Code starting with the faulting instruction
===========================================
   0:	0f 0b                	ud2
   2:	90                   	nop
   3:	f3 0f 1e fa          	endbr64
   7:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
   c:	55                   	push   %rbp
   d:	48 89 f5             	mov    %rsi,%rbp
  10:	48                   	rex.W
  11:	8d                   	.byte 0x8d
  12:	97                   	xchg   %eax,%edi
  13:	e8                   	.byte 0xe8
  14:	fb                   	sti
  15:	ff                   	.byte 0xff
[    4.665717] RSP: 0018:ffffc0654026fbe8 EFLAGS: 00010297
[    4.665769] RAX: ffffffff8775a5d0 RBX: 00000000ffffffff RCX: 0000000000000004
[    4.665835] RDX: 0000000000000008 RSI: ffffffff87553ba4 RDI: ffff98e888ad2530
[    4.665911] RBP: ffff98e888ad2530 R08: 00000000000002ba R09: 000000000000021c
[    4.665988] R10: 0000000000000230 R11: 0000000000000220 R12: ffff98e8888a5900
[    4.666061] R13: ffffffff87ab1d20 R14: ffff98e881050768 R15: ffff98e888ad2000
[    4.666131] FS:  0000000000000000(0000) GS:ffff98e9364b7000(0000) knlGS:0000000000000000
[    4.666209] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    4.666275] CR2: 000055ce5332cdec CR3: 00000000086c6003 CR4: 0000000000772ef0
[    4.666349] PKRU: 55555554
[    4.666369] Call Trace:
[    4.666405]  <TASK>
[    4.666434]  device_release (drivers/base/core.c:2569)
[    4.666479]  kobject_put (lib/kobject.c:693 lib/kobject.c:720 ./include/linux/kref.h:65 lib/kobject.c:737)
[    4.666517]  netdev_run_todo (./include/linux/list.h:381 net/core/dev.c:11670)
[    4.666560] nsim_destroy (drivers/net/netdevsim/netdevsim.h:396 drivers/net/netdevsim/netdev.c:1186) netdevsim
[    4.666615] __nsim_dev_port_del (drivers/net/netdevsim/dev.c:441 drivers/net/netdevsim/dev.c:1474) netdevsim
[    4.666669] nsim_dev_reload_destroy (drivers/net/netdevsim/dev.c:1483 drivers/net/netdevsim/dev.c:1707) netdevsim
[    4.666723] nsim_dev_reload_down (drivers/net/netdevsim/dev.c:984) netdevsim
[    4.666782]  devlink_reload (net/devlink/dev.c:462)
[    4.666823]  devlink_pernet_pre_exit (net/devlink/core.c:288 net/devlink/devl_internal.h:114 net/devlink/core.c:513)
[    4.666872]  ops_undo_list (net/core/net_namespace.c:160 net/core/net_namespace.c:234)
[    4.666914]  ? 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)
[    4.666973]  cleanup_net (net/core/net_namespace.c:698)
[    4.667015]  process_one_work (kernel/workqueue.c:3268)
[    4.667056]  worker_thread (kernel/workqueue.c:3340 kernel/workqueue.c:3427)
[    4.667094]  ? rescuer_thread (kernel/workqueue.c:3373)
[    4.667127]  kthread (kernel/kthread.c:463)
[    4.667162]  ? kthreads_online_cpu (kernel/kthread.c:412)
[    4.667221]  ? kthreads_online_cpu (kernel/kthread.c:412)
[    4.667275]  ret_from_fork (arch/x86/kernel/process.c:164)
[    4.667317]  ? kthreads_online_cpu (kernel/kthread.c:412)


Finger prints:
netdev_release:device_release:kobject_put:netdev_run_todo:nsim_destroy