======================================
| xx__-> [  288.672832][   T11] ------------[ cut here ]------------
| [  288.673144][   T11] RTNL: assertion failed at net/core/link_watch.c (59)
| [ 288.673404][ T11] WARNING: CPU: 3 PID: 11 at net/core/link_watch.c:59 default_operstate (net/core/link_watch.c:59 (discriminator 3))
| [  288.673713][   T11] Modules linked in: poly1305_generic libpoly1305 chacha_generic libchacha chacha20poly1305 tls
[  288.674378][   T11] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  288.674593][   T11] Workqueue: netns cleanup_net
[ 288.674877][ T11] RIP: 0010:default_operstate (net/core/link_watch.c:59 (discriminator 3))
[ 288.675064][ 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 77 87 48 c7 c7 40 7c 77 87 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 77 87 	mov    $0xffffffff87777c00,%rsi
  1d:	48 c7 c7 40 7c 77 87 	mov    $0xffffffff87777c40,%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
[  288.675675][   T11] RSP: 0018:ffffc900000b7a48 EFLAGS: 00010282
[  288.675890][   T11] RAX: 0000000000000000 RBX: ffff8880089f9000 RCX: 1ffffffff0ffdd8c
[  288.676155][   T11] RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000001
[  288.676412][   T11] RBP: 0000000000000000 R08: 0000000000000000 R09: fffffbfff0ffdd8c
[  288.676688][   T11] R10: 0000000000000003 R11: ffff888001ae2300 R12: 0000000000000000
[  288.676946][   T11] R13: dffffc0000000000 R14: ffff8880093d9000 R15: ffff8880089f95c0
[  288.677218][   T11] FS:  0000000000000000(0000) GS:ffff888066180000(0000) knlGS:0000000000000000
[  288.677512][   T11] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  288.677726][   T11] CR2: 00007f0924f74000 CR3: 000000006df3a002 CR4: 0000000000772ef0
[  288.677990][   T11] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  288.678265][   T11] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  288.678533][   T11] PKRU: 55555554
[  288.678665][   T11] Call Trace:
[  288.678797][   T11]  <TASK>
[ 288.678891][ T11] ? default_operstate (net/core/link_watch.c:59 (discriminator 3))
[ 288.679068][ T11] ? __warn (kernel/panic.c:748)
[ 288.679215][ T11] ? default_operstate (net/core/link_watch.c:59 (discriminator 3))
[ 288.679385][ T11] ? report_bug (lib/bug.c:201 lib/bug.c:219)
[ 288.679560][ T11] ? handle_bug (arch/x86/kernel/traps.c:285)
[ 288.679696][ T11] ? exc_invalid_op (arch/x86/kernel/traps.c:309 (discriminator 1))
[ 288.679945][ T11] ? asm_exc_invalid_op (./arch/x86/include/asm/idtentry.h:621)
[ 288.680145][ T11] ? default_operstate (net/core/link_watch.c:59 (discriminator 3))
[ 288.680317][ T11] ? default_operstate (net/core/link_watch.c:59 (discriminator 3))
[ 288.680485][ T11] rfc2863_policy (net/core/link_watch.c:78)
[ 288.680660][ T11] linkwatch_do_dev (net/core/link_watch.c:180)
[ 288.680828][ T11] netdev_run_todo (net/core/dev.c:10894 (discriminator 2))
[ 288.681014][ T11] ? __pfx_netdev_run_todo (net/core/dev.c:10867)
[ 288.681200][ T11] ? __pfx_unregister_netdevice_queue (net/core/dev.c:11455)
[ 288.681415][ T11] default_device_exit_batch (net/core/dev.c:12051)
[ 288.681586][ T11] ? __pfx_default_device_exit_batch (net/core/dev.c:12051)
[ 288.681796][ T11] ? ops_exit_list (net/core/net_namespace.c:171 (discriminator 3))
[ 288.681972][ T11] cleanup_net (net/core/net_namespace.c:647 (discriminator 3))
[ 288.682151][ T11] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 288.682332][ T11] ? __pfx_cleanup_net (net/core/net_namespace.c:592)
[ 288.682498][ T11] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 37))
[ 288.682669][ T11] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 288.682836][ T11] ? process_one_work (kernel/workqueue.c:3205)
[ 288.683013][ T11] process_one_work (kernel/workqueue.c:3229)
[ 288.683210][ T11] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 288.683387][ T11] ? __pfx_process_one_work (kernel/workqueue.c:3131)
[ 288.683571][ T11] ? assign_work (kernel/workqueue.c:1200)
[ 288.683747][ T11] worker_thread (kernel/workqueue.c:3304 kernel/workqueue.c:3391)
[ 288.683932][ T11] ? __pfx_worker_thread (kernel/workqueue.c:3337)
[ 288.684103][ T11] kthread (kernel/kthread.c:389)
[ 288.684245][ T11] ? __pfx_kthread (kernel/kthread.c:342)
[ 288.684417][ T11] ret_from_fork (arch/x86/kernel/process.c:147)
[ 288.684588][ T11] ? __pfx_kthread (kernel/kthread.c:342)


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