======================================
| [  150.872065][   T67] br0: port 1(veth1) entered disabled state
| [  150.937443][   T67] ------------[ cut here ]------------
| [ 150.937707][ T67] WARNING: CPU: 0 PID: 67 at net/core/rtnetlink.c:135 __rtnl_unlock (net/core/rtnetlink.c:135 (discriminator 1))
| [  150.937984][   T67] Modules linked in: nft_meta_bridge br_netfilter macvlan nft_masq nft_chain_nat nf_nat ts_kmp ts_bm xt_string dummy ebtable_filter ebt_redirect ebt_ip ebtable_broute ebtables bridge stp llc nf_conntrack_netlink tcp_diag inet_diag nf_conntrack_ftp nft_synproxy nf_synproxy_core nft_ct sctp ip6_udp_tunnel udp_tunnel xt_conntrack nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nft_compat nf_tables libcrc32c sch_netem cls_u32 sch_htb veth
[  150.939462][   T67] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  150.939650][   T67] Workqueue: netns cleanup_net
[ 150.939812][ T67] RIP: 0010:__rtnl_unlock (net/core/rtnetlink.c:135 (discriminator 1))
[ 150.939968][ T67] Code: ff 31 d2 be 8f 00 00 00 48 c7 c7 60 34 37 8a e8 3a 3f f3 fd e8 05 ad 72 00 48 85 db 75 c4 48 83 c4 08 5b 5d c3 cc cc cc cc 90 <0f> 0b 90 eb 8e 48 89 f7 48 89 34 24 e8 53 dd 71 fe 48 8b 34 24 eb
All code
========
   0:	ff 31                	push   (%rcx)
   2:	d2 be 8f 00 00 00    	sarb   %cl,0x8f(%rsi)
   8:	48 c7 c7 60 34 37 8a 	mov    $0xffffffff8a373460,%rdi
   f:	e8 3a 3f f3 fd       	call   0xfffffffffdf33f4e
  14:	e8 05 ad 72 00       	call   0x72ad1e
  19:	48 85 db             	test   %rbx,%rbx
  1c:	75 c4                	jne    0xffffffffffffffe2
  1e:	48 83 c4 08          	add    $0x8,%rsp
  22:	5b                   	pop    %rbx
  23:	5d                   	pop    %rbp
  24:	c3                   	ret
  25:	cc                   	int3
  26:	cc                   	int3
  27:	cc                   	int3
  28:	cc                   	int3
  29:	90                   	nop
  2a:*	0f 0b                	ud2		<-- trapping instruction
  2c:	90                   	nop
  2d:	eb 8e                	jmp    0xffffffffffffffbd
  2f:	48 89 f7             	mov    %rsi,%rdi
  32:	48 89 34 24          	mov    %rsi,(%rsp)
  36:	e8 53 dd 71 fe       	call   0xfffffffffe71dd8e
  3b:	48 8b 34 24          	mov    (%rsp),%rsi
  3f:	eb                   	.byte 0xeb

Code starting with the faulting instruction
===========================================
   0:	0f 0b                	ud2
   2:	90                   	nop
   3:	eb 8e                	jmp    0xffffffffffffff93
   5:	48 89 f7             	mov    %rsi,%rdi
   8:	48 89 34 24          	mov    %rsi,(%rsp)
   c:	e8 53 dd 71 fe       	call   0xfffffffffe71dd64
  11:	48 8b 34 24          	mov    (%rsp),%rsi
  15:	eb                   	.byte 0xeb
[  150.940496][   T67] RSP: 0018:ffffc90000487a60 EFLAGS: 00010287
[  150.940690][   T67] RAX: ffff8880024b45b0 RBX: ffff888008c90040 RCX: ffffffff89b048aa
[  150.940913][   T67] RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffff88800b3ba178
[  150.941151][   T67] RBP: ffff88800b3ba1b8 R08: 0000000000000001 R09: fffff52000090f26
[  150.941373][   T67] R10: ffffc90000487937 R11: ffff888008c90040 R12: ffffc90000487be0
[  150.941595][   T67] R13: 0000000000000000 R14: dffffc0000000000 R15: ffffc90000487b10
[  150.941816][   T67] FS:  0000000000000000(0000) GS:ffff888036000000(0000) knlGS:0000000000000000
[  150.942157][   T67] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  150.942344][   T67] CR2: 00007ff2401a0290 CR3: 0000000031326002 CR4: 0000000000772ef0
[  150.942564][   T67] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  150.942783][   T67] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  150.943070][   T67] PKRU: 55555554
[  150.943205][   T67] Call Trace:
[  150.943321][   T67]  <TASK>
[ 150.943402][ T67] ? __rtnl_unlock (net/core/rtnetlink.c:135 (discriminator 1))
[ 150.943555][ T67] ? __warn (kernel/panic.c:748)
[ 150.943673][ T67] ? __rtnl_unlock (net/core/rtnetlink.c:135 (discriminator 1))
[ 150.943822][ T67] ? report_bug (lib/bug.c:201 lib/bug.c:219)
[ 150.943984][ T67] ? handle_bug (arch/x86/kernel/traps.c:285)
[ 150.944164][ T67] ? exc_invalid_op (arch/x86/kernel/traps.c:309 (discriminator 1))
[ 150.944315][ T67] ? asm_exc_invalid_op (./arch/x86/include/asm/idtentry.h:621)
[ 150.944477][ T67] ? __mutex_unlock_slowpath (./arch/x86/include/asm/atomic64_64.h:101 ./include/linux/atomic/atomic-arch-fallback.h:4329 ./include/linux/atomic/atomic-long.h:1506 ./include/linux/atomic/atomic-instrumented.h:4481 kernel/locking/mutex.c:913)
[ 150.944630][ T67] ? __rtnl_unlock (net/core/rtnetlink.c:135 (discriminator 1))
[ 150.944782][ T67] unregister_netdevice_many_notify (net/core/dev.c:11453 net/core/dev.c:11638)
[ 150.944978][ T67] ? mark_held_locks (kernel/locking/lockdep.c:4321)
[ 150.945192][ T67] ? __pfx_unregister_netdevice_many_notify (net/core/dev.c:11536)
[ 150.945380][ T67] ? mutex_is_locked (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2583 ./include/linux/atomic/atomic-long.h:38 ./include/linux/atomic/atomic-instrumented.h:3189 kernel/locking/mutex.h:47 kernel/locking/mutex.c:66)
[ 150.945532][ T67] ? rtnl_is_locked (net/core/rtnetlink.c:163)
[ 150.945697][ T67] ? mutex_is_locked (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2583 ./include/linux/atomic/atomic-long.h:38 ./include/linux/atomic/atomic-instrumented.h:3189 kernel/locking/mutex.h:47 kernel/locking/mutex.c:66)
[ 150.945851][ T67] ? nexthop_net_exit_batch_rtnl (net/ipv4/nexthop.c:585 net/ipv4/nexthop.c:2158 net/ipv4/nexthop.c:2666 net/ipv4/nexthop.c:4010)
[ 150.946104][ T67] cleanup_net (net/core/net_namespace.c:648)
[ 150.946253][ T67] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 150.946400][ T67] ? __pfx_cleanup_net (net/core/net_namespace.c:594)
[ 150.946546][ T67] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 37))
[ 150.946700][ T67] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 150.946853][ T67] ? process_one_work (kernel/workqueue.c:3205)
[ 150.947073][ T67] process_one_work (kernel/workqueue.c:3229)
[ 150.947237][ T67] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 150.947387][ T67] ? __pfx_process_one_work (kernel/workqueue.c:3131)
[ 150.947548][ T67] ? assign_work (kernel/workqueue.c:1200)
[ 150.947704][ T67] worker_thread (kernel/workqueue.c:3304 kernel/workqueue.c:3391)
[ 150.947859][ T67] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406)
[ 150.948119][ T67] ? __pfx_worker_thread (kernel/workqueue.c:3337)
[ 150.948276][ T67] ? __pfx_worker_thread (kernel/workqueue.c:3337)
[ 150.948424][ T67] kthread (kernel/kthread.c:389)
[ 150.948540][ T67] ? __pfx_kthread (kernel/kthread.c:342)
[ 150.948691][ T67] ret_from_fork (arch/x86/kernel/process.c:147)
[ 150.948850][ T67] ? __pfx_kthread (kernel/kthread.c:342)


Finger prints:
__rtnl_unlock:unregister_netdevice_many_notify:cleanup_net:process_one_work:worker_thread