======================================
| [   30.877071][  T232] TCP: AO key ifindex 200 != sk bound ifindex 3
| [   30.954761][  T232] key-management_ (232) used greatest stack depth: 23936 bytes left
| [   30.975373][    C1] BUG: spinlock bad magic on CPU#1, kworker/u16:0/11
| [ 30.975606][ C1] lock: noop_qdisc+0x240/0x300, .magic: 00000000, .owner: kworker/u16:0/11, .owner_cpu: 1 
[   30.976137][    C1] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[   30.976458][    C1] Workqueue: netns cleanup_net
[   30.976616][    C1] Call Trace:
[   30.976730][    C1]  <IRQ>
[ 30.976803][ C1] dump_stack_lvl (lib/dump_stack.c:122) 
[ 30.976984][ C1] do_raw_spin_unlock (kernel/locking/spinlock_debug.c:100 kernel/locking/spinlock_debug.c:141) 
[ 30.977147][ C1] _raw_spin_unlock (./arch/x86/include/asm/preempt.h:94 ./include/linux/spinlock_api_smp.h:143 kernel/locking/spinlock.c:186) 
[ 30.977287][ C1] net_tx_action (./include/net/sch_generic.h:226 ./include/net/sch_generic.h:217 ./include/net/pkt_sched.h:128 ./include/net/pkt_sched.h:124 net/core/dev.c:5323) 
[ 30.977433][ C1] handle_softirqs (kernel/softirq.c:554) 
[ 30.977575][ C1] ? dev_deactivate_many (./include/linux/bottom_half.h:33 ./include/linux/netdevice.h:4448 net/sched/sch_generic.c:571 net/sched/sch_generic.c:1363) 
[ 30.977715][ C1] do_softirq (kernel/softirq.c:455 kernel/softirq.c:442) 
[   30.977826][    C1]  </IRQ>
[   30.977897][    C1]  <TASK>
[ 30.977989][ C1] __local_bh_enable_ip (kernel/softirq.c:382) 
[ 30.978142][ C1] dev_deactivate_many (net/sched/sch_generic.c:1356) 
[ 30.978299][ C1] __dev_close_many (net/core/dev.c:1547) 
[ 30.978455][ C1] ? __pfx___dev_close_many (net/core/dev.c:1522) 
[ 30.978592][ C1] dev_close_many (net/core/dev.c:1585) 
[ 30.978732][ C1] ? __pfx_dev_close_many (net/core/dev.c:1575) 
[ 30.978883][ C1] ? hlock_class (./arch/x86/include/asm/bitops.h:227 ./arch/x86/include/asm/bitops.h:239 ./include/asm-generic/bitops/instrumented-non-atomic.h:142 kernel/locking/lockdep.c:227) 
[ 30.979023][ C1] ? mark_lock (kernel/locking/lockdep.c:4655 (discriminator 3)) 
[ 30.979130][ C1] unregister_netdevice_many_notify (net/core/dev.c:11321) 
[ 30.979331][ C1] ? __lock_release (kernel/locking/lockdep.c:5435) 
[ 30.979487][ C1] ? unregister_netdevice_queue (net/core/dev.c:11273) 
[ 30.979660][ C1] ? __pfx_unregister_netdevice_many_notify (net/core/dev.c:11288) 
[ 30.979836][ C1] ? __pfx_unregister_netdevice_queue (net/core/dev.c:11272) 
[ 30.980027][ C1] ? 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.c:81 kernel/locking/mutex.c:91) 
[ 30.980164][ C1] ? rtnl_is_locked (net/core/rtnetlink.c:164) 
[ 30.980304][ C1] ? unregister_netdevice_queue (net/core/dev.c:11273) 
[ 30.980476][ C1] ? __pfx_unregister_netdevice_queue (net/core/dev.c:11272) 
[ 30.980650][ C1] ? vrf_dellink (drivers/net/vrf.c:1686) 
[ 30.980800][ C1] ? __pfx_unregister_netdevice_queue (net/core/dev.c:11272) 
[ 30.980989][ C1] default_device_exit_batch (net/core/dev.c:11890) 
[ 30.981127][ C1] ? __pfx_default_device_exit_batch (net/core/dev.c:11865) 
[ 30.981322][ C1] ? 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.c:81 kernel/locking/mutex.c:91) 
[ 30.981465][ C1] ? nexthop_net_exit_batch_rtnl (net/ipv4/nexthop.c:585 net/ipv4/nexthop.c:2146 net/ipv4/nexthop.c:2654 net/ipv4/nexthop.c:4004) 
[ 30.981662][ C1] cleanup_net (net/core/net_namespace.c:625 (discriminator 3)) 
[ 30.981832][ C1] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5724) 
[ 30.981974][ C1] ? __pfx_cleanup_net (net/core/net_namespace.c:570) 
[ 30.982119][ C1] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 52)) 
[ 30.982260][ C1] ? process_one_work (kernel/workqueue.c:3207) 
[ 30.982401][ C1] ? lock_acquire (kernel/locking/lockdep.c:5732) 
[ 30.982550][ C1] ? process_one_work (kernel/workqueue.c:3207) 
[ 30.982688][ C1] process_one_work (kernel/workqueue.c:3231) 
[ 30.982834][ C1] ? __pfx___lock_release (kernel/locking/lockdep.c:5411) 
[ 30.982971][ C1] ? __pfx_process_one_work (kernel/workqueue.c:3133) 
[ 30.983114][ C1] ? assign_work (kernel/workqueue.c:1202) 
[ 30.983252][ C1] worker_thread (kernel/workqueue.c:3306 kernel/workqueue.c:3390) 
[ 30.983395][ C1] ? __pfx_worker_thread (kernel/workqueue.c:3339) 
[ 30.983560][ C1] kthread (kernel/kthread.c:389) 
[ 30.983670][ C1] ? __pfx_kthread (kernel/kthread.c:342) 
[ 30.983808][ C1] ret_from_fork (arch/x86/kernel/process.c:147) 
[ 30.983966][ C1] ? __pfx_kthread (kernel/kthread.c:342) 


Finger prints:
do_raw_spin_unlock:_raw_spin_unlock:net_tx_action:handle_softirqs:do_softirq