======================================
| [ 29.489269][ T10] #1: ffffc900000a7d40 ((work_completion)(&port->wq)){+.+.}-{0:0}, at: process_one_work (kernel/workqueue.c:3214) 
| [ 29.489636][ T10] #2: ffffffff9ad5b5c0 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit (./include/linux/bottom_half.h:20 ./include/linux/rcupdate.h:901 net/core/dev.c:4555) 
| [   29.489946][   T10]
| [   29.489946][   T10] stack backtrace:
[   29.490185][   T10] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   29.490188][   T10] Workqueue: events ipvlan_process_multicast
[   29.490202][   T10] Call Trace:
[   29.490206][   T10]  <TASK>
[ 29.490210][ T10] dump_stack_lvl (lib/dump_stack.c:123) 
[ 29.490223][ T10] lockdep_rcu_suspicious (kernel/locking/lockdep.c:6848) 
[ 29.490239][ T10] dev_hard_start_xmit (./include/net/net_namespace.h:418 ./include/linux/netdevice.h:2695 net/core/dev.c:2466 net/core/dev.c:3772 net/core/dev.c:3793) 
[ 29.490251][ T10] __dev_queue_xmit (net/core/dev.h:340 net/core/dev.c:4631) 
[ 29.490267][ T10] ? __pfx___dev_queue_xmit (net/core/dev.c:4538) 
[ 29.490270][ T10] ? find_held_lock (kernel/locking/lockdep.c:5341) 
[ 29.490278][ T10] ? __lock_release (kernel/locking/lockdep.c:5527) 
[ 29.490281][ T10] ? ipvlan_process_multicast (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 drivers/net/ipvlan/ipvlan_core.c:284) 
[ 29.490285][ T10] ? __pfx___lock_release (kernel/locking/lockdep.c:5503) 
[ 29.490289][ T10] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5816) 
[ 29.490304][ T10] ? ipvlan_process_multicast (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 drivers/net/ipvlan/ipvlan_core.c:284) 
[ 29.490317][ T10] ipvlan_process_multicast (./include/linux/netdevice.h:3331 drivers/net/ipvlan/ipvlan_core.c:290) 
[ 29.490341][ T10] ? __pfx_ipvlan_process_multicast (drivers/net/ipvlan/ipvlan_core.c:229) 
[ 29.490347][ T10] ? __pfx___lock_release (kernel/locking/lockdep.c:5503) 
[ 29.490352][ T10] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5816) 
[ 29.490357][ T10] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 21)) 
[ 29.490360][ T10] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 21)) 
[ 29.490368][ T10] ? lock_acquire (kernel/locking/lockdep.c:5824) 
[ 29.490376][ T10] ? process_one_work (kernel/workqueue.c:3238) 
[ 29.490380][ T10] ? process_one_work (kernel/workqueue.c:3214) 
[ 29.490383][ T10] process_one_work (kernel/workqueue.c:3238) 
[ 29.490396][ T10] ? __pfx___lock_release (kernel/locking/lockdep.c:5503) 
[ 29.490401][ T10] ? __pfx_process_one_work (kernel/workqueue.c:3140) 
[ 29.490414][ T10] ? assign_work (kernel/workqueue.c:1200) 
[ 29.490423][ T10] worker_thread (kernel/workqueue.c:3313 kernel/workqueue.c:3400) 
[ 29.490428][ T10] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4349 kernel/locking/lockdep.c:4408) 
[ 29.490439][ T10] ? __pfx_worker_thread (kernel/workqueue.c:3346) 
[ 29.490446][ T10] kthread (kernel/kthread.c:464) 
[ 29.490452][ T10] ? __pfx_kthread (kernel/kthread.c:413) 
[ 29.490462][ T10] ? __pfx_kthread (kernel/kthread.c:413) 
[ 29.490468][ T10] ret_from_fork (arch/x86/kernel/process.c:148) 
[ 29.490474][ T10] ? __pfx_kthread (kernel/kthread.c:413) 


Finger prints:
lockdep_rcu_suspicious:dev_hard_start_xmit:__dev_queue_xmit:ipvlan_process_multicast:process_one_work