======================================
| [    4.754520] bond0: (slave eth1): Releasing backup interface
| [    4.775763] ------------[ cut here ]------------
| [    4.775855] kernel BUG at net/core/net-sysfs.c:2246!
| [    4.775928] Oops: invalid opcode: 0000 [#1] SMP
[    4.776091] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[    4.776157] Workqueue: netns cleanup_net
[    4.776225] RIP: 0010:netdev_release (net/core/net-sysfs.c:2246 net/core/net-sysfs.c:2242)
[    4.776284] 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
[    4.776444] RSP: 0018:ffffb5dc00067be8 EFLAGS: 00010297
[    4.776491] RAX: ffffffffb2d5a5d0 RBX: 00000000ffffffff RCX: 0000000000000004
[    4.776574] RDX: 0000000000000008 RSI: ffffffffb2b53ba4 RDI: ffff89dc42cf2530
[    4.776661] RBP: ffff89dc42cf2530 R08: 0000000000000290 R09: 0000000000000230
[    4.776740] R10: 0000000000000240 R11: 0000000000000230 R12: ffff89dc4544ca00
[    4.776818] R13: ffffffffb30b1d20 R14: ffff89dc418c13a8 R15: ffff89dc42cf2000
[    4.776891] FS:  0000000000000000(0000) GS:ffff89dccadb7000(0000) knlGS:0000000000000000
[    4.776967] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    4.777031] CR2: 000055b204328b28 CR3: 0000000003244001 CR4: 0000000000772ef0
[    4.777105] PKRU: 55555554
[    4.777133] Call Trace:
[    4.777161]  <TASK>
[    4.777185]  device_release (drivers/base/core.c:2569)
[    4.777244]  kobject_put (lib/kobject.c:693 lib/kobject.c:720 ./include/linux/kref.h:65 lib/kobject.c:737)
[    4.777296]  netdev_run_todo (./include/linux/list.h:381 net/core/dev.c:11670)
[    4.777342] nsim_destroy (drivers/net/netdevsim/netdevsim.h:396 drivers/net/netdevsim/netdev.c:1186) netdevsim
[    4.777402] __nsim_dev_port_del (drivers/net/netdevsim/dev.c:441 drivers/net/netdevsim/dev.c:1474) netdevsim
[    4.777459] nsim_dev_reload_destroy (drivers/net/netdevsim/dev.c:1483 drivers/net/netdevsim/dev.c:1707) netdevsim
[    4.777510] nsim_dev_reload_down (drivers/net/netdevsim/dev.c:984) netdevsim
[    4.777558]  devlink_reload (net/devlink/dev.c:462)
[    4.777604]  devlink_pernet_pre_exit (net/devlink/core.c:288 net/devlink/devl_internal.h:114 net/devlink/core.c:513)
[    4.777654]  ops_undo_list (net/core/net_namespace.c:160 net/core/net_namespace.c:234)
[    4.777694]  ? 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)
[    4.777760]  cleanup_net (net/core/net_namespace.c:698)
[    4.777796]  process_one_work (kernel/workqueue.c:3268)
[    4.777841]  worker_thread (kernel/workqueue.c:3340 kernel/workqueue.c:3427)
[    4.777885]  ? rescuer_thread (kernel/workqueue.c:3373)
[    4.777923]  kthread (kernel/kthread.c:463)
[    4.777966]  ? kthreads_online_cpu (kernel/kthread.c:412)
[    4.778021]  ? kthreads_online_cpu (kernel/kthread.c:412)
[    4.778077]  ret_from_fork (arch/x86/kernel/process.c:164)
[    4.778130]  ? kthreads_online_cpu (kernel/kthread.c:412)


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