======================================
| [   82.768281][   T11] ------------[ cut here ]------------
| [   82.768679][   T11] RTNL: assertion failed at net/core/link_watch.c (59)
| [ 82.768917][ T11] WARNING: CPU: 2 PID: 11 at net/core/link_watch.c:59 default_operstate (net/core/link_watch.c:59 (discriminator 3))
| [   82.769230][   T11] Modules linked in: l2tp_ip6 l2tp_eth l2tp_ip l2tp_netlink l2tp_core xfrm_interface sha1_generic xfrm_user
[   82.769940][   T11] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   82.770148][   T11] Workqueue: netns cleanup_net
[ 82.770342][ T11] RIP: 0010:default_operstate (net/core/link_watch.c:59 (discriminator 3))
[ 82.770524][ T11] Code: 83 e4 01 0f 85 03 ff ff ff c6 05 08 23 5c 02 01 90 ba 3b 00 00 00 48 c7 c6 00 7c f7 9b 48 c7 c7 40 7c f7 9b e8 b3 b2 e5 fd 90 <0f> 0b 90 90 e9 d9 fe ff ff 48 89 ef e8 81 63 6d fe e9 f7 fd ff ff
All code
========
   0:	83 e4 01             	and    $0x1,%esp
   3:	0f 85 03 ff ff ff    	jne    0xffffffffffffff0c
   9:	c6 05 08 23 5c 02 01 	movb   $0x1,0x25c2308(%rip)        # 0x25c2318
  10:	90                   	nop
  11:	ba 3b 00 00 00       	mov    $0x3b,%edx
  16:	48 c7 c6 00 7c f7 9b 	mov    $0xffffffff9bf77c00,%rsi
  1d:	48 c7 c7 40 7c f7 9b 	mov    $0xffffffff9bf77c40,%rdi
  24:	e8 b3 b2 e5 fd       	call   0xfffffffffde5b2dc
  29:	90                   	nop
  2a:*	0f 0b                	ud2		<-- trapping instruction
  2c:	90                   	nop
  2d:	90                   	nop
  2e:	e9 d9 fe ff ff       	jmp    0xffffffffffffff0c
  33:	48 89 ef             	mov    %rbp,%rdi
  36:	e8 81 63 6d fe       	call   0xfffffffffe6d63bc
  3b:	e9 f7 fd ff ff       	jmp    0xfffffffffffffe37

Code starting with the faulting instruction
===========================================
   0:	0f 0b                	ud2
   2:	90                   	nop
   3:	90                   	nop
   4:	e9 d9 fe ff ff       	jmp    0xfffffffffffffee2
   9:	48 89 ef             	mov    %rbp,%rdi
   c:	e8 81 63 6d fe       	call   0xfffffffffe6d6392
  11:	e9 f7 fd ff ff       	jmp    0xfffffffffffffe0d
[   82.771085][   T11] RSP: 0018:ffffc900000b7a48 EFLAGS: 00010282
[   82.771317][   T11] RAX: 0000000000000000 RBX: ffff88800d629000 RCX: 1ffffffff38fdd8c
[   82.771579][   T11] RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000001
[   82.771844][   T11] RBP: 0000000000000000 R08: 0000000000000000 R09: fffffbfff38fdd8c
[   82.772100][   T11] R10: 0000000000000003 R11: ffff888001ae2300 R12: 0000000000000000
[   82.772409][   T11] R13: dffffc0000000000 R14: ffff88800fec1000 R15: ffff88800d6295c0
[   82.772665][   T11] FS:  0000000000000000(0000) GS:ffff88806d100000(0000) knlGS:0000000000000000
[   82.772975][   T11] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   82.773209][   T11] CR2: 00007ff2ecb95000 CR3: 000000006933a006 CR4: 0000000000772ef0
[   82.773483][   T11] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   82.773755][   T11] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   82.774181][   T11] PKRU: 55555554
[   82.774325][   T11] Call Trace:
[   82.774481][   T11]  <TASK>
[ 82.774583][ T11] ? default_operstate (net/core/link_watch.c:59 (discriminator 3))
[ 82.774771][ T11] ? __warn (kernel/panic.c:748)
[ 82.774922][ T11] ? default_operstate (net/core/link_watch.c:59 (discriminator 3))
[ 82.775101][ T11] ? report_bug (lib/bug.c:201 lib/bug.c:219)
[ 82.775286][ T11] ? handle_bug (arch/x86/kernel/traps.c:285)
[ 82.775439][ T11] ? exc_invalid_op (arch/x86/kernel/traps.c:309 (discriminator 1))
[ 82.775618][ T11] ? asm_exc_invalid_op (./arch/x86/include/asm/idtentry.h:621)
[ 82.775809][ T11] ? default_operstate (net/core/link_watch.c:59 (discriminator 3))
[ 82.775993][ T11] ? default_operstate (net/core/link_watch.c:59 (discriminator 3))
[ 82.776181][ T11] rfc2863_policy (net/core/link_watch.c:78)
[ 82.776371][ T11] linkwatch_do_dev (net/core/link_watch.c:180)
[ 82.776552][ T11] netdev_run_todo (net/core/dev.c:10894 (discriminator 2))
[ 82.776740][ T11] ? __pfx_netdev_run_todo (net/core/dev.c:10867)
[ 82.776920][ T11] ? __pfx_unregister_netdevice_queue (net/core/dev.c:11455)
[ 82.777142][ T11] default_device_exit_batch (net/core/dev.c:12051)
[ 82.777322][ T11] ? __pfx_default_device_exit_batch (net/core/dev.c:12051)
[ 82.777551][ T11] ? ops_exit_list (net/core/net_namespace.c:171 (discriminator 3))
[ 82.777735][ T11] cleanup_net (net/core/net_namespace.c:647 (discriminator 3))
[ 82.777910][ T11] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 82.778097][ T11] ? __pfx_cleanup_net (net/core/net_namespace.c:592)
[ 82.778271][ T11] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 37))
[ 82.778465][ T11] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 82.778639][ T11] ? process_one_work (kernel/workqueue.c:3205)
[ 82.778823][ T11] process_one_work (kernel/workqueue.c:3229)
[ 82.779009][ T11] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 82.779189][ T11] ? __pfx_process_one_work (kernel/workqueue.c:3131)
[ 82.779394][ T11] ? assign_work (kernel/workqueue.c:1200)
[ 82.779579][ T11] worker_thread (kernel/workqueue.c:3304 kernel/workqueue.c:3391)
[ 82.779771][ T11] ? __pfx_worker_thread (kernel/workqueue.c:3337)
[ 82.779949][ T11] kthread (kernel/kthread.c:389)
[ 82.780091][ T11] ? __pfx_kthread (kernel/kthread.c:342)
[ 82.780270][ T11] ret_from_fork (arch/x86/kernel/process.c:147)
[ 82.780461][ T11] ? __pfx_kthread (kernel/kthread.c:342)


Finger prints:
default_operstate:rfc2863_policy:linkwatch_do_dev:netdev_run_todo:default_device_exit_batch