======================================
| [   26.677307][  T269] veth0: renamed from veth-rt-1
| [   27.004443][  T271] ip (271) used greatest stack depth: 24176 bytes left
| [   27.653166][   T51] BUG: spinlock bad magic on CPU#3, kworker/3:1/51
| [ 27.653367][ T51] lock: noop_qdisc+0x240/0x300, .magic: 00000000, .owner: kworker/3:1/51, .owner_cpu: 3 
[   27.653783][   T51] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[   27.654053][   T51] Workqueue: mld mld_ifc_work
[   27.654183][   T51] Call Trace:
[   27.654280][   T51]  <TASK>
[ 27.654346][ T51] dump_stack_lvl (lib/dump_stack.c:122) 
[ 27.654473][ T51] do_raw_spin_unlock (kernel/locking/spinlock_debug.c:100 kernel/locking/spinlock_debug.c:141) 
[ 27.654600][ T51] _raw_spin_unlock (./arch/x86/include/asm/preempt.h:94 ./include/linux/spinlock_api_smp.h:143 kernel/locking/spinlock.c:186) 
[ 27.654725][ T51] __dev_xmit_skb (./include/net/sch_generic.h:226 ./include/net/sch_generic.h:217 net/core/dev.c:3879) 
[ 27.654855][ T51] ? __pfx___dev_xmit_skb (net/core/dev.c:3784) 
[ 27.654982][ T51] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4291 kernel/locking/lockdep.c:4358) 
[ 27.655135][ T51] __dev_queue_xmit (net/core/dev.c:4389) 
[ 27.655262][ T51] ? __lock_release (kernel/locking/lockdep.c:5435) 
[ 27.655387][ T51] ? ip6_finish_output2 (./include/net/neighbour.h:542 net/ipv6/ip6_output.c:137) 
[ 27.655517][ T51] ? __pfx___lock_release (kernel/locking/lockdep.c:5411) 
[ 27.655642][ T51] ? __pfx___dev_queue_xmit (net/core/dev.c:4332) 
[ 27.655770][ T51] ? mark_held_locks (kernel/locking/lockdep.c:4273) 
[ 27.655896][ T51] ? eth_header (net/ethernet/eth.c:100) 
[ 27.656024][ T51] ? neigh_resolve_output (./include/linux/netdevice.h:3159 net/core/neighbour.c:1560 net/core/neighbour.c:1545) 
[ 27.656152][ T51] ip6_finish_output2 (./include/net/neighbour.h:542 net/ipv6/ip6_output.c:137) 
[ 27.656279][ T51] ip6_finish_output (net/ipv6/ip6_output.c:211 net/ipv6/ip6_output.c:222) 
[ 27.656406][ T51] ip6_output (./include/linux/netfilter.h:303 net/ipv6/ip6_output.c:243) 
[ 27.656505][ T51] ? __pfx_ip6_output (net/ipv6/ip6_output.c:230) 
[ 27.656632][ T51] ? lock_acquire.part.0 (kernel/locking/lockdep.c:466 kernel/locking/lockdep.c:5761) 
[ 27.656758][ T51] ? find_held_lock (kernel/locking/lockdep.c:5249) 
[ 27.656884][ T51] ? __lock_release (kernel/locking/lockdep.c:5435) 
[ 27.657006][ T51] ? icmp6_dst_alloc (net/ipv6/route.c:3295) 
[ 27.657131][ T51] NF_HOOK.constprop.0 (./include/linux/rcupdate.h:326 ./include/linux/rcupdate.h:838 ./include/linux/netfilter.h:238 ./include/linux/netfilter.h:312) 
[ 27.657255][ T51] ? __pfx_NF_HOOK.constprop.0 (./include/linux/netfilter.h:308) 
[ 27.657384][ T51] ? __pfx_xfrm_lookup_with_ifid (net/xfrm/xfrm_policy.c:3140) 
[ 27.657545][ T51] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4299 kernel/locking/lockdep.c:4358) 
[ 27.657701][ T51] ? icmp6_dst_alloc (net/ipv6/route.c:3295) 
[ 27.657829][ T51] ? __local_bh_enable_ip (./arch/x86/include/asm/irqflags.h:42 ./arch/x86/include/asm/irqflags.h:97 kernel/softirq.c:387) 
[ 27.657957][ T51] mld_sendpack (net/ipv6/mcast.c:1822) 
[ 27.658081][ T51] ? __pfx_mld_sendpack (net/ipv6/mcast.c:1779) 
[ 27.658209][ T51] ? mld_send_cr (net/ipv6/mcast.c:2096 (discriminator 11)) 
[ 27.658336][ T51] mld_ifc_work (net/ipv6/mcast.c:2652) 
[ 27.658462][ T51] process_one_work (kernel/workqueue.c:3231) 
[ 27.658590][ T51] ? __pfx___lock_release (kernel/locking/lockdep.c:5411) 
[ 27.658720][ T51] ? __pfx_process_one_work (kernel/workqueue.c:3133) 
[ 27.658845][ T51] ? assign_work (kernel/workqueue.c:1202) 
[ 27.658969][ T51] worker_thread (kernel/workqueue.c:3306 kernel/workqueue.c:3390) 
[ 27.659092][ T51] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4299 kernel/locking/lockdep.c:4358) 
[ 27.659246][ T51] ? __pfx_worker_thread (kernel/workqueue.c:3339) 
[ 27.659374][ T51] ? __pfx_worker_thread (kernel/workqueue.c:3339) 
[ 27.659497][ T51] kthread (kernel/kthread.c:389) 
[ 27.659594][ T51] ? __pfx_kthread (kernel/kthread.c:342) 
[ 27.659719][ T51] ret_from_fork (arch/x86/kernel/process.c:147) 
[ 27.659843][ T51] ? __pfx_kthread (kernel/kthread.c:342) 


Finger prints:
do_raw_spin_unlock:_raw_spin_unlock:__dev_xmit_skb:__dev_queue_xmit:ip6_finish_output2