======================================
| xx__-> [   16.302789] ------------[ cut here ]------------
| [   16.302837] WARNING: net/core/rtnetlink.c:4523 at rtmsg_ifinfo_build_skb+0xc8/0x110, CPU#3: ip/1324
| [   16.302888] Modules linked in: netconsole netdevsim
| [   16.302978] Tainted: [W]=WARN
[   16.303002] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   16.303036] RIP: 0010:rtmsg_ifinfo_build_skb (net/core/rtnetlink.c:4523 (discriminator 3))
[   16.303066] Code: 80 00 00 00 e8 09 d9 ff ff 48 83 c4 38 85 c0 75 18 48 83 c4 08 4c 89 f8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 44 8b 48 08 eb b4 90 <0f> 0b 90 ba 02 00 00 00 4c 89 fe 31 ff e8 76 a5 fb ff b9 a6 ff ff
All code
========
   0:	80 00 00             	addb   $0x0,(%rax)
   3:	00 e8                	add    %ch,%al
   5:	09 d9                	or     %ebx,%ecx
   7:	ff                   	(bad)
   8:	ff 48 83             	decl   -0x7d(%rax)
   b:	c4                   	(bad)
   c:	38 85 c0 75 18 48    	cmp    %al,0x481875c0(%rbp)
  12:	83 c4 08             	add    $0x8,%esp
  15:	4c 89 f8             	mov    %r15,%rax
  18:	5b                   	pop    %rbx
  19:	5d                   	pop    %rbp
  1a:	41 5c                	pop    %r12
  1c:	41 5d                	pop    %r13
  1e:	41 5e                	pop    %r14
  20:	41 5f                	pop    %r15
  22:	c3                   	ret
  23:	44 8b 48 08          	mov    0x8(%rax),%r9d
  27:	eb b4                	jmp    0xffffffffffffffdd
  29:	90                   	nop
  2a:*	0f 0b                	ud2		<-- trapping instruction
  2c:	90                   	nop
  2d:	ba 02 00 00 00       	mov    $0x2,%edx
  32:	4c 89 fe             	mov    %r15,%rsi
  35:	31 ff                	xor    %edi,%edi
  37:	e8 76 a5 fb ff       	call   0xfffffffffffba5b2
  3c:	b9                   	.byte 0xb9
  3d:	a6                   	cmpsb  (%rdi),(%rsi)
  3e:	ff                   	(bad)
  3f:	ff                   	.byte 0xff

Code starting with the faulting instruction
===========================================
   0:	0f 0b                	ud2
   2:	90                   	nop
   3:	ba 02 00 00 00       	mov    $0x2,%edx
   8:	4c 89 fe             	mov    %r15,%rsi
   b:	31 ff                	xor    %edi,%edi
   d:	e8 76 a5 fb ff       	call   0xfffffffffffba588
  12:	b9                   	.byte 0xb9
  13:	a6                   	cmpsb  (%rdi),(%rsi)
  14:	ff                   	(bad)
  15:	ff                   	.byte 0xff
[   16.303159] RSP: 0018:ff56fe98c0febcc8 EFLAGS: 00010286
[   16.303187] RAX: 00000000ffffffa6 RBX: 00000000ffffffff RCX: 0000000000000000
[   16.303226] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ff355f7601906f00
[   16.303266] RBP: 0000000000000000 R08: ff355f76048db650 R09: ff355f760c06902c
[   16.303309] R10: ff355f7602eac118 R11: fefefefefefefeff R12: 0000000000000000
[   16.303346] R13: 0000000000000010 R14: ff355f7602eac000 R15: ff355f7601906f00
[   16.303388] FS:  00007f994ca9a840(0000) GS:ff355f76b49d5000(0000) knlGS:0000000000000000
[   16.303436] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   16.303467] CR2: 00007f994cc9bc20 CR3: 000000000c0c7005 CR4: 0000000000771ef0
[   16.303505] PKRU: 55555554
[   16.303519] Call Trace:
[   16.303535]  <TASK>
[   16.303549]  rtmsg_ifinfo (net/core/rtnetlink.c:4551 net/core/rtnetlink.c:4541 net/core/rtnetlink.c:4560)
[   16.303571]  register_netdevice (net/core/dev.c:11488)
[   16.303593]  register_netdev (net/core/dev.c:11552)
[   16.303615]  loopback_net_init (drivers/net/loopback.c:218)
[   16.303638]  ? vsock_sysctl_init_net (net/vmw_vsock/af_vsock.c:2933 net/vmw_vsock/af_vsock.c:2973)
[   16.303666]  ops_init (net/core/net_namespace.c:137)
[   16.303687]  setup_net (net/core/net_namespace.c:446)
[   16.303707]  copy_net_ns (net/core/net_namespace.c:579)
[   16.303728]  create_new_namespaces (kernel/nsproxy.c:132)
[   16.303756]  unshare_nsproxy_namespaces (kernel/nsproxy.c:234 (discriminator 4))
[   16.303781]  ksys_unshare (kernel/fork.c:3243)
[   16.303803]  __x64_sys_unshare (kernel/fork.c:3317 kernel/fork.c:3315 kernel/fork.c:3315)
[   16.303824]  do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94)
[   16.303847]  entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)
[   16.303875] RIP: 0033:0x7f994cd5cbcb
[   16.303898] Code: 73 01 c3 48 8b 0d 2d 82 0f 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa b8 10 01 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d fd 81 0f 00 f7 d8 64 89 01 48
All code
========
   0:	73 01                	jae    0x3
   2:	c3                   	ret
   3:	48 8b 0d 2d 82 0f 00 	mov    0xf822d(%rip),%rcx        # 0xf8237
   a:	f7 d8                	neg    %eax
   c:	64 89 01             	mov    %eax,%fs:(%rcx)
   f:	48 83 c8 ff          	or     $0xffffffffffffffff,%rax
  13:	c3                   	ret
  14:	66 2e 0f 1f 84 00 00 	cs nopw 0x0(%rax,%rax,1)
  1b:	00 00 00 
  1e:	90                   	nop
  1f:	f3 0f 1e fa          	endbr64
  23:	b8 10 01 00 00       	mov    $0x110,%eax
  28:	0f 05                	syscall
  2a:*	48 3d 01 f0 ff ff    	cmp    $0xfffffffffffff001,%rax		<-- trapping instruction
  30:	73 01                	jae    0x33
  32:	c3                   	ret
  33:	48 8b 0d fd 81 0f 00 	mov    0xf81fd(%rip),%rcx        # 0xf8237
  3a:	f7 d8                	neg    %eax
  3c:	64 89 01             	mov    %eax,%fs:(%rcx)
  3f:	48                   	rex.W

Code starting with the faulting instruction
===========================================
   0:	48 3d 01 f0 ff ff    	cmp    $0xfffffffffffff001,%rax
   6:	73 01                	jae    0x9
   8:	c3                   	ret
   9:	48 8b 0d fd 81 0f 00 	mov    0xf81fd(%rip),%rcx        # 0xf820d
  10:	f7 d8                	neg    %eax
  12:	64 89 01             	mov    %eax,%fs:(%rcx)
  15:	48                   	rex.W
[   16.303986] RSP: 002b:00007fffbedd57c8 EFLAGS: 00000202 ORIG_RAX: 0000000000000110
[   16.304024] RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007f994cd5cbcb
[   16.304063] RDX: 0000000000000000 RSI: 0000000000477309 RDI: 0000000040000000
[   16.304099] RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000
[   16.304138] R10: 0000000000000000 R11: 0000000000000202 R12: 00007fffbedd79f0
[   16.304176] R13: 0000000000000001 R14: 0000000000000003 R15: 00007fffbedd889d
| [   16.304798] ------------[ cut here ]------------
| [   16.304867] WARNING: net/core/rtnetlink.c:4523 at rtmsg_ifinfo_build_skb+0xc8/0x110, CPU#2: python3/1323
| [   16.304970] Modules linked in: netconsole netdevsim
| [   16.305131] Tainted: [W]=WARN
[   16.305191] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   16.305259] RIP: 0010:rtmsg_ifinfo_build_skb (net/core/rtnetlink.c:4523 (discriminator 3))
[   16.305330] Code: 80 00 00 00 e8 09 d9 ff ff 48 83 c4 38 85 c0 75 18 48 83 c4 08 4c 89 f8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 44 8b 48 08 eb b4 90 <0f> 0b 90 ba 02 00 00 00 4c 89 fe 31 ff e8 76 a5 fb ff b9 a6 ff ff
All code
========
   0:	80 00 00             	addb   $0x0,(%rax)
   3:	00 e8                	add    %ch,%al
   5:	09 d9                	or     %ebx,%ecx
   7:	ff                   	(bad)
   8:	ff 48 83             	decl   -0x7d(%rax)
   b:	c4                   	(bad)
   c:	38 85 c0 75 18 48    	cmp    %al,0x481875c0(%rbp)
  12:	83 c4 08             	add    $0x8,%esp
  15:	4c 89 f8             	mov    %r15,%rax
  18:	5b                   	pop    %rbx
  19:	5d                   	pop    %rbp
  1a:	41 5c                	pop    %r12
  1c:	41 5d                	pop    %r13
  1e:	41 5e                	pop    %r14
  20:	41 5f                	pop    %r15
  22:	c3                   	ret
  23:	44 8b 48 08          	mov    0x8(%rax),%r9d
  27:	eb b4                	jmp    0xffffffffffffffdd
  29:	90                   	nop
  2a:*	0f 0b                	ud2		<-- trapping instruction
  2c:	90                   	nop
  2d:	ba 02 00 00 00       	mov    $0x2,%edx
  32:	4c 89 fe             	mov    %r15,%rsi
  35:	31 ff                	xor    %edi,%edi
  37:	e8 76 a5 fb ff       	call   0xfffffffffffba5b2
  3c:	b9                   	.byte 0xb9
  3d:	a6                   	cmpsb  (%rdi),(%rsi)
  3e:	ff                   	(bad)
  3f:	ff                   	.byte 0xff

Code starting with the faulting instruction
===========================================
   0:	0f 0b                	ud2
   2:	90                   	nop
   3:	ba 02 00 00 00       	mov    $0x2,%edx
   8:	4c 89 fe             	mov    %r15,%rsi
   b:	31 ff                	xor    %edi,%edi
   d:	e8 76 a5 fb ff       	call   0xfffffffffffba588
  12:	b9                   	.byte 0xb9
  13:	a6                   	cmpsb  (%rdi),(%rsi)
  14:	ff                   	(bad)
  15:	ff                   	.byte 0xff
[   16.305454] RSP: 0018:ff56fe98c0fab9d0 EFLAGS: 00010286
[   16.305519] RAX: 00000000ffffffa6 RBX: 00000000ffffffff RCX: 0000000000000000
[   16.305597] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ff355f76018e4600
[   16.305675] RBP: 0000000000000000 R08: ff355f76048b6410 R09: ff355f76032a8030
[   16.305754] R10: ff355f7606196118 R11: fefefefefefefeff R12: 0000000000000000
[   16.305831] R13: 0000000000000010 R14: ff355f7606196000 R15: ff355f76018e4600
[   16.305907] FS:  00007f89b3eb3400(0000) GS:ff355f76b4955000(0000) knlGS:0000000000000000
[   16.305986] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   16.306057] CR2: 000055cf4fc3f628 CR3: 000000000c2d1001 CR4: 0000000000771ef0
[   16.306135] PKRU: 55555554
[   16.306184] Call Trace:
[   16.306235]  <TASK>
[   16.306291]  rtmsg_ifinfo (net/core/rtnetlink.c:4551 net/core/rtnetlink.c:4541 net/core/rtnetlink.c:4560)
[   16.306351]  register_netdevice (net/core/dev.c:11488)
[   16.306411] nsim_create (drivers/net/netdevsim/netdev.c:1069 drivers/net/netdevsim/netdev.c:1151) netdevsim
[   16.306484] __nsim_dev_port_add (drivers/net/netdevsim/dev.c:1509) netdevsim
[   16.306556] nsim_drv_probe (drivers/net/netdevsim/dev.c:1570 drivers/net/netdevsim/dev.c:1731) netdevsim
[   16.306623]  really_probe (drivers/base/dd.c:631 drivers/base/dd.c:709)
[   16.306687]  ? driver_probe_device (./include/linux/list.h:164 (discriminator 3))
[   16.306754]  __driver_probe_device (drivers/base/dd.c:871)
[   16.306818]  driver_probe_device (drivers/base/dd.c:901)
[   16.306877]  __device_attach_driver (drivers/base/dd.c:1029)
[   16.306949]  bus_for_each_drv (drivers/base/bus.c:500)
[   16.307010]  __device_attach (drivers/base/dd.c:1101)
[   16.307073]  device_initial_probe (drivers/base/dd.c:1156)
[   16.307136]  bus_probe_device (drivers/base/bus.c:613)
[   16.307199]  device_add (drivers/base/core.c:3706)
[   16.307261] new_device_store (drivers/net/netdevsim/bus.c:471 drivers/net/netdevsim/bus.c:191) netdevsim
[   16.307336]  kernfs_fop_write_iter (fs/kernfs/file.c:352)
[   16.307407]  vfs_write (fs/read_write.c:595 fs/read_write.c:688)
[   16.307472]  ksys_write (fs/read_write.c:740)
[   16.307535]  do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94)
[   16.307598]  entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)
[   16.307666] RIP: 0033:0x7f89b403b08e
[   16.307728] Code: 4d 89 d8 e8 94 bd 00 00 4c 8b 5d f8 41 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 11 c9 c3 0f 1f 80 00 00 00 00 48 8b 45 10 0f 05 <c9> c3 83 e2 39 83 fa 08 75 e7 e8 03 ff ff ff 0f 1f 00 f3 0f 1e fa
All code
========
   0:	4d 89 d8             	mov    %r11,%r8
   3:	e8 94 bd 00 00       	call   0xbd9c
   8:	4c 8b 5d f8          	mov    -0x8(%rbp),%r11
   c:	41 8b 93 08 03 00 00 	mov    0x308(%r11),%edx
  13:	59                   	pop    %rcx
  14:	5e                   	pop    %rsi
  15:	48 83 f8 fc          	cmp    $0xfffffffffffffffc,%rax
  19:	74 11                	je     0x2c
  1b:	c9                   	leave
  1c:	c3                   	ret
  1d:	0f 1f 80 00 00 00 00 	nopl   0x0(%rax)
  24:	48 8b 45 10          	mov    0x10(%rbp),%rax
  28:	0f 05                	syscall
  2a:*	c9                   	leave		<-- trapping instruction
  2b:	c3                   	ret
  2c:	83 e2 39             	and    $0x39,%edx
  2f:	83 fa 08             	cmp    $0x8,%edx
  32:	75 e7                	jne    0x1b
  34:	e8 03 ff ff ff       	call   0xffffffffffffff3c
  39:	0f 1f 00             	nopl   (%rax)
  3c:	f3 0f 1e fa          	endbr64

Code starting with the faulting instruction
===========================================
   0:	c9                   	leave
   1:	c3                   	ret
   2:	83 e2 39             	and    $0x39,%edx
   5:	83 fa 08             	cmp    $0x8,%edx
   8:	75 e7                	jne    0xfffffffffffffff1
   a:	e8 03 ff ff ff       	call   0xffffffffffffff12
   f:	0f 1f 00             	nopl   (%rax)
  12:	f3 0f 1e fa          	endbr64
[   16.307857] RSP: 002b:00007fffa5f838d0 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
[   16.307938] RAX: ffffffffffffffda RBX: 0000000000000009 RCX: 00007f89b403b08e
[   16.308017] RDX: 0000000000000009 RSI: 000055cf4fbf6dc0 RDI: 0000000000000006
[   16.308096] RBP: 00007fffa5f838e0 R08: 0000000000000000 R09: 0000000000000000
[   16.308174] R10: 0000000000000000 R11: 0000000000000202 R12: 00007f89b3eb3390
[   16.308247] R13: 000055cf4fbf6dc0 R14: 0000000000000006 R15: 00007f89b3e410d0
| [   16.354953] ------------[ cut here ]------------
| [   16.355036] WARNING: net/core/rtnetlink.c:4523 at rtmsg_ifinfo_build_skb+0xc8/0x110, CPU#2: 1/65
| [   16.355147] Modules linked in: netconsole netdevsim
| [   16.355319] Tainted: [W]=WARN
[   16.355370] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   16.355438] Workqueue: netns cleanup_net
[   16.355499] RIP: 0010:rtmsg_ifinfo_build_skb (net/core/rtnetlink.c:4523 (discriminator 3))
[   16.355563] Code: 80 00 00 00 e8 09 d9 ff ff 48 83 c4 38 85 c0 75 18 48 83 c4 08 4c 89 f8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 44 8b 48 08 eb b4 90 <0f> 0b 90 ba 02 00 00 00 4c 89 fe 31 ff e8 76 a5 fb ff b9 a6 ff ff
All code
========
   0:	80 00 00             	addb   $0x0,(%rax)
   3:	00 e8                	add    %ch,%al
   5:	09 d9                	or     %ebx,%ecx
   7:	ff                   	(bad)
   8:	ff 48 83             	decl   -0x7d(%rax)
   b:	c4                   	(bad)
   c:	38 85 c0 75 18 48    	cmp    %al,0x481875c0(%rbp)
  12:	83 c4 08             	add    $0x8,%esp
  15:	4c 89 f8             	mov    %r15,%rax
  18:	5b                   	pop    %rbx
  19:	5d                   	pop    %rbp
  1a:	41 5c                	pop    %r12
  1c:	41 5d                	pop    %r13
  1e:	41 5e                	pop    %r14
  20:	41 5f                	pop    %r15
  22:	c3                   	ret
  23:	44 8b 48 08          	mov    0x8(%rax),%r9d
  27:	eb b4                	jmp    0xffffffffffffffdd
  29:	90                   	nop
  2a:*	0f 0b                	ud2		<-- trapping instruction
  2c:	90                   	nop
  2d:	ba 02 00 00 00       	mov    $0x2,%edx
  32:	4c 89 fe             	mov    %r15,%rsi
  35:	31 ff                	xor    %edi,%edi
  37:	e8 76 a5 fb ff       	call   0xfffffffffffba5b2
  3c:	b9                   	.byte 0xb9
  3d:	a6                   	cmpsb  (%rdi),(%rsi)
  3e:	ff                   	(bad)
  3f:	ff                   	.byte 0xff

Code starting with the faulting instruction
===========================================
   0:	0f 0b                	ud2
   2:	90                   	nop
   3:	ba 02 00 00 00       	mov    $0x2,%edx
   8:	4c 89 fe             	mov    %r15,%rsi
   b:	31 ff                	xor    %edi,%edi
   d:	e8 76 a5 fb ff       	call   0xfffffffffffba588
  12:	b9                   	.byte 0xb9
  13:	a6                   	cmpsb  (%rdi),(%rsi)
  14:	ff                   	(bad)
  15:	ff                   	.byte 0xff
[   16.355707] RSP: 0018:ff56fe98c023fc78 EFLAGS: 00010286
[   16.355767] RAX: 00000000ffffffa6 RBX: 00000000ffffffff RCX: 0000000000000000
[   16.355846] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ff355f76018e4600
[   16.355930] RBP: 0000000000000000 R08: ff355f76048db650 R09: ff355f7604b2b02c
[   16.356023] R10: ff355f7602eac118 R11: fefefefefefefeff R12: 0000000000000000
[   16.356114] R13: 0000000000000011 R14: ff355f7602eac000 R15: ff355f76018e4600
[   16.356205] FS:  0000000000000000(0000) GS:ff355f76b4955000(0000) knlGS:0000000000000000
[   16.356294] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   16.356367] CR2: 000055cf4fcb66b8 CR3: 000000000c2d1001 CR4: 0000000000771ef0
[   16.356447] PKRU: 55555554
[   16.356493] Call Trace:
[   16.356551]  <TASK>
[   16.356609]  unregister_netdevice_many_notify (net/core/dev.c:12439)
[   16.356688]  default_device_exit_batch (net/core/dev.c:12497 net/core/dev.c:13089)
[   16.356767]  ops_undo_list (net/core/net_namespace.c:205 net/core/net_namespace.c:252)
[   16.356843]  cleanup_net (net/core/net_namespace.c:702)
[   16.356918]  process_one_work (kernel/workqueue.c:3314)
[   16.357002]  worker_thread (kernel/workqueue.c:3397 kernel/workqueue.c:3478)
[   16.357084]  ? rescuer_thread (kernel/workqueue.c:3672)
[   16.357154]  kthread (kernel/kthread.c:436)
[   16.357212]  ? kthread_park (kernel/kthread.c:725 (discriminator 4))
[   16.357293]  ret_from_fork (arch/x86/kernel/process.c:158)
[   16.357365]  ? kthread_park (kernel/kthread.c:725 (discriminator 4))


Finger prints:
rtmsg_ifinfo_build_skb:rtmsg_ifinfo:register_netdevice:nsim_create:__nsim_dev_port_add
rtmsg_ifinfo_build_skb:unregister_netdevice_many_notify:default_device_exit_batch:ops_undo_list:cleanup_net
rtmsg_ifinfo_build_skb:rtmsg_ifinfo:register_netdevice:register_netdev:loopback_net_init