======================================
| [ 29.146659][ T272] #1: ffffc90000d47d40 ((work_completion)(&port->wq)){+.+.}-{0:0}, at: process_one_work (kernel/workqueue.c:3214) 
| [ 29.146962][ T272] #2: ffffffffa535b5c0 (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) 
| [   29.147448][  T272]
| [   29.147448][  T272] stack backtrace:
[   29.147651][  T272] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   29.147653][  T272] Workqueue: events ipvlan_process_multicast
[   29.147661][  T272] Call Trace:
[   29.147663][  T272]  <TASK>
[ 29.147667][ T272] dump_stack_lvl (lib/dump_stack.c:123) 
[ 29.147674][ T272] lockdep_rcu_suspicious (kernel/locking/lockdep.c:6848) 
[ 29.147685][ T272] 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) 
[ 29.147697][ T272] __dev_queue_xmit (net/core/dev.h:340 net/core/dev.c:4631) 
[ 29.147713][ T272] ? __pfx___dev_queue_xmit (net/core/dev.c:4538) 
[ 29.147716][ T272] ? find_held_lock (kernel/locking/lockdep.c:5341) 
[ 29.147723][ T272] ? __lock_release (kernel/locking/lockdep.c:5527) 
[ 29.147726][ T272] ? ipvlan_process_multicast (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 drivers/net/ipvlan/ipvlan_core.c:284) 
[ 29.147731][ T272] ? __pfx___lock_release (kernel/locking/lockdep.c:5503) 
[ 29.147734][ T272] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5816) 
[ 29.147746][ T272] ? ipvlan_process_multicast (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 drivers/net/ipvlan/ipvlan_core.c:284) 
[ 29.147754][ T272] ipvlan_process_multicast (./include/linux/netdevice.h:3331 drivers/net/ipvlan/ipvlan_core.c:290) 
[ 29.147771][ T272] ? __pfx_ipvlan_process_multicast (drivers/net/ipvlan/ipvlan_core.c:229) 
[ 29.147777][ T272] ? __pfx___lock_release (kernel/locking/lockdep.c:5503) 
[ 29.147781][ T272] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5816) 
[ 29.147786][ T272] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 21)) 
[ 29.147789][ T272] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 21)) 
[ 29.147796][ T272] ? lock_acquire (kernel/locking/lockdep.c:5824) 
[ 29.147804][ T272] ? process_one_work (kernel/workqueue.c:3238) 
[ 29.147807][ T272] ? process_one_work (kernel/workqueue.c:3214) 
[ 29.147810][ T272] process_one_work (kernel/workqueue.c:3238) 
[ 29.147823][ T272] ? __pfx___lock_release (kernel/locking/lockdep.c:5503) 
[ 29.147828][ T272] ? __pfx_process_one_work (kernel/workqueue.c:3140) 
[ 29.147841][ T272] ? assign_work (kernel/workqueue.c:1200) 
[ 29.147850][ T272] worker_thread (kernel/workqueue.c:3313 kernel/workqueue.c:3400) 
[ 29.147855][ T272] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4349 kernel/locking/lockdep.c:4408) 
[ 29.147866][ T272] ? __pfx_worker_thread (kernel/workqueue.c:3346) 
[ 29.147873][ T272] kthread (kernel/kthread.c:464) 
[ 29.147879][ T272] ? __pfx_kthread (kernel/kthread.c:413) 
[ 29.147888][ T272] ? __pfx_kthread (kernel/kthread.c:413) 
[ 29.147894][ T272] ret_from_fork (arch/x86/kernel/process.c:148) 
[ 29.147898][ T272] ? __pfx_kthread (kernel/kthread.c:413) 


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