======================================
| xx__-> [    2.377402] ------------[ cut here ]------------
| [    2.377493] WARNING: net/core/rtnetlink.c:4523 at rtmsg_ifinfo_build_skb+0xc8/0x110, CPU#2: ip/167
| [    2.377582] Modules linked in:
| [    2.377728] Tainted: [W]=WARN
[    2.377781] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[    2.377855] RIP: 0010:rtmsg_ifinfo_build_skb (net/core/rtnetlink.c:4523 (discriminator 3))
[    2.377917] 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
[    2.378053] RSP: 0018:ff911e308030bcc8 EFLAGS: 00010286
[    2.378114] RAX: 00000000ffffffa6 RBX: 00000000ffffffff RCX: 0000000000000000
[    2.378189] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ff487fd742fa3400
[    2.378269] RBP: 0000000000000000 R08: ff487fd74311b1d0 R09: ff487fd7445ca02c
[    2.378342] R10: ff487fd7430b5118 R11: fefefefefefefeff R12: 0000000000000000
[    2.378415] R13: 0000000000000010 R14: ff487fd7430b5000 R15: ff487fd742fa3400
[    2.378493] FS:  00007fe2f26d4840(0000) GS:ff487fd7e5b55000(0000) knlGS:0000000000000000
[    2.378569] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    2.378635] CR2: 0000000000479648 CR3: 0000000004789006 CR4: 0000000000771ef0
[    2.378711] PKRU: 55555554
[    2.378757] Call Trace:
[    2.378810]  <TASK>
[    2.378858]  rtmsg_ifinfo (net/core/rtnetlink.c:4551 net/core/rtnetlink.c:4541 net/core/rtnetlink.c:4560)
[    2.378913]  register_netdevice (net/core/dev.c:11488)
[    2.378970]  register_netdev (net/core/dev.c:11552)
[    2.379025]  loopback_net_init (drivers/net/loopback.c:218)
[    2.379082]  ? vsock_sysctl_init_net (net/vmw_vsock/af_vsock.c:2933 net/vmw_vsock/af_vsock.c:2973)
[    2.379145]  ops_init (net/core/net_namespace.c:137)
[    2.379206]  setup_net (net/core/net_namespace.c:446)
[    2.379267]  copy_net_ns (net/core/net_namespace.c:579)
[    2.379322]  create_new_namespaces (kernel/nsproxy.c:132)
[    2.379386]  unshare_nsproxy_namespaces (kernel/nsproxy.c:234 (discriminator 4))
[    2.379447]  ksys_unshare (kernel/fork.c:3243)
[    2.379504]  __x64_sys_unshare (kernel/fork.c:3317 kernel/fork.c:3315 kernel/fork.c:3315)
[    2.379559]  do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94)
[    2.379615]  entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)
[    2.379677] RIP: 0033:0x7fe2f2996bcb
[    2.379731] 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
[    2.379864] RSP: 002b:00007ffeeef37d08 EFLAGS: 00000202 ORIG_RAX: 0000000000000110
[    2.379937] RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007fe2f2996bcb
[    2.380010] RDX: 0000000000000000 RSI: 0000000000477309 RDI: 0000000040000000
[    2.380083] RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
[    2.380155] R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffeeef39f30
[    2.380229] R13: 0000000000000001 R14: 00007fe2f26d46f8 R15: 00007ffeeef3a88f
| [    2.396467] ------------[ cut here ]------------
| [    2.396504] WARNING: net/core/rtnetlink.c:4523 at rtmsg_ifinfo_build_skb+0xc8/0x110, CPU#0: python3/166
| [    2.396560] Modules linked in: netdevsim
| [    2.396646] Tainted: [W]=WARN
[    2.396666] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[    2.396701] RIP: 0010:rtmsg_ifinfo_build_skb (net/core/rtnetlink.c:4523 (discriminator 3))
[    2.396725] 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
[    2.396825] RSP: 0018:ff911e30803e79d0 EFLAGS: 00010286
[    2.396858] RAX: 00000000ffffffa6 RBX: 00000000ffffffff RCX: 0000000000000000
[    2.396901] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ff487fd7426ca700
[    2.396948] RBP: 0000000000000000 R08: ff487fd743309250 R09: ff487fd7430a6030
[    2.396992] R10: ff487fd74198a118 R11: fefefefefefefeff R12: 0000000000000000
[    2.397035] R13: 0000000000000010 R14: ff487fd74198a000 R15: ff487fd7426ca700
[    2.397078] FS:  00007f8c1c23c400(0000) GS:ff487fd7e5a55000(0000) knlGS:0000000000000000
[    2.397117] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    2.397144] CR2: 00007f8c1c63d0a1 CR3: 0000000004622004 CR4: 0000000000771ef0
[    2.397189] PKRU: 55555554
[    2.397202] Call Trace:
[    2.397216]  <TASK>
[    2.397229]  rtmsg_ifinfo (net/core/rtnetlink.c:4551 net/core/rtnetlink.c:4541 net/core/rtnetlink.c:4560)
[    2.397254]  register_netdevice (net/core/dev.c:11488)
[    2.397277] nsim_create (drivers/net/netdevsim/netdev.c:1069 drivers/net/netdevsim/netdev.c:1151) netdevsim
[    2.397310] __nsim_dev_port_add (drivers/net/netdevsim/dev.c:1509) netdevsim
[    2.397339] nsim_drv_probe (drivers/net/netdevsim/dev.c:1570 drivers/net/netdevsim/dev.c:1731) netdevsim
[    2.397368]  really_probe (drivers/base/dd.c:631 drivers/base/dd.c:709)
[    2.397393]  ? driver_probe_device (./include/linux/list.h:164 (discriminator 3))
[    2.397422]  __driver_probe_device (drivers/base/dd.c:871)
[    2.397452]  driver_probe_device (drivers/base/dd.c:901)
[    2.397475]  __device_attach_driver (drivers/base/dd.c:1029)
[    2.397506]  bus_for_each_drv (drivers/base/bus.c:500)
[    2.397528]  __device_attach (drivers/base/dd.c:1101)
[    2.397552]  device_initial_probe (drivers/base/dd.c:1156)
[    2.397574]  bus_probe_device (drivers/base/bus.c:613)
[    2.397600]  device_add (drivers/base/core.c:3706)
[    2.397622] new_device_store (drivers/net/netdevsim/bus.c:471 drivers/net/netdevsim/bus.c:191) netdevsim
[    2.397652]  kernfs_fop_write_iter (fs/kernfs/file.c:352)
[    2.397681]  vfs_write (fs/read_write.c:595 fs/read_write.c:688)
[    2.397706]  ksys_write (fs/read_write.c:740)
[    2.397728]  do_syscall_64 (arch/x86/entry/syscall_64.c:63 arch/x86/entry/syscall_64.c:94)
[    2.397750]  entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)
[    2.397779] RIP: 0033:0x7f8c1c3c408e
[    2.397803] 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
[    2.397901] RSP: 002b:00007ffc6189c7f0 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
[    2.397942] RAX: ffffffffffffffda RBX: 0000000000000009 RCX: 00007f8c1c3c408e
[    2.397985] RDX: 0000000000000009 RSI: 000055efd6dab8e0 RDI: 0000000000000006
[    2.398026] RBP: 00007ffc6189c800 R08: 0000000000000000 R09: 0000000000000000
[    2.398066] R10: 0000000000000000 R11: 0000000000000202 R12: 00007f8c1c23c390
[    2.398109] R13: 000055efd6dab8e0 R14: 0000000000000006 R15: 00007f8c1c1c90d0
| [    2.519589] ------------[ cut here ]------------
| [    2.519637] WARNING: net/core/rtnetlink.c:4523 at rtmsg_ifinfo_build_skb+0xc8/0x110, CPU#0: 1/64
| [    2.519697] Modules linked in: netdevsim
| [    2.519779] Tainted: [W]=WARN
[    2.519799] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[    2.519835] Workqueue: netns cleanup_net
[    2.519859] RIP: 0010:rtmsg_ifinfo_build_skb (net/core/rtnetlink.c:4523 (discriminator 3))
[    2.519887] 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
[    2.519965] RSP: 0018:ff911e3080237c78 EFLAGS: 00010286
[    2.519993] RAX: 00000000ffffffa6 RBX: 00000000ffffffff RCX: 0000000000000000
[    2.520034] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ff487fd74332ab00
[    2.520075] RBP: 0000000000000000 R08: ff487fd74311b1d0 R09: ff487fd7445c482c
[    2.520113] R10: ff487fd7430b5118 R11: fefefefefefefeff R12: 0000000000000000
[    2.520152] R13: 0000000000000011 R14: ff487fd7430b5000 R15: ff487fd74332ab00
[    2.520194] FS:  0000000000000000(0000) GS:ff487fd7e5a55000(0000) knlGS:0000000000000000
[    2.520236] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    2.520279] CR2: 00007fa8a2d71690 CR3: 0000000004442002 CR4: 0000000000771ef0
[    2.520322] PKRU: 55555554
[    2.520335] Call Trace:
[    2.520348]  <TASK>
[    2.520364]  unregister_netdevice_many_notify (net/core/dev.c:12439)
[    2.520393]  default_device_exit_batch (net/core/dev.c:12497 net/core/dev.c:13089)
[    2.520423]  ops_undo_list (net/core/net_namespace.c:205 net/core/net_namespace.c:252)
[    2.520447]  cleanup_net (net/core/net_namespace.c:702)
[    2.520468]  process_one_work (kernel/workqueue.c:3314)
[    2.520492]  worker_thread (kernel/workqueue.c:3397 kernel/workqueue.c:3478)
[    2.520512]  ? rescuer_thread (kernel/workqueue.c:3672)
[    2.520536]  kthread (kernel/kthread.c:436)
[    2.520555]  ? kthread_park (kernel/kthread.c:725 (discriminator 4))
[    2.520575]  ret_from_fork (arch/x86/kernel/process.c:158)
[    2.520598]  ? 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