======================================
| [ 13.184409][ C0] #3: ffffffffa945a088 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list (net/core/net_namespace.c:176 net/core/net_namespace.c:249) 
| [ 13.184970][ C0] #4: ffffffffa8b793c0 (rcu_callback){....}-{0:0}, at: rcu_do_batch (./include/linux/rcupdate.h:331 kernel/rcu/tree.c:2570) 
| [   13.185532][    C0]
| [   13.185532][    C0] stack backtrace:
[   13.185930][    C0] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   13.185933][    C0] Workqueue: netns cleanup_net
[   13.185939][    C0] Call Trace:
[   13.185942][    C0]  <IRQ>
[ 13.185945][ C0] dump_stack_lvl (lib/dump_stack.c:123) 
[ 13.185954][ C0] print_usage_bug.part.0 (kernel/locking/lockdep.c:4048) 
[ 13.185962][ C0] mark_lock_irq (kernel/locking/lockdep.c:4013 kernel/locking/lockdep.c:4059 kernel/locking/lockdep.c:4270) 
[ 13.185971][ C0] ? save_trace (kernel/locking/lockdep.c:595) 
[ 13.185979][ C0] mark_lock (kernel/locking/lockdep.c:4756) 
[ 13.185984][ C0] mark_usage (kernel/locking/lockdep.c:4645) 
[ 13.185989][ C0] __lock_acquire (kernel/locking/lockdep.c:5194) 
[ 13.185994][ C0] ? unwind_next_frame (./include/linux/rcupdate.h:874 ./include/linux/rcupdate.h:1155 arch/x86/kernel/unwind_orc.c:479) 
[ 13.186002][ C0] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
[ 13.186010][ C0] lock_acquire.part.0 (kernel/locking/lockdep.c:473 kernel/locking/lockdep.c:5873) 
[ 13.186014][ C0] ? xa_set_mark (lib/xarray.c:2076 lib/xarray.c:2146) 
[ 13.186021][ C0] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 13.186027][ C0] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5834) 
[ 13.186031][ C0] ? xa_set_mark (lib/xarray.c:2076 lib/xarray.c:2146) 
[ 13.186038][ C0] _raw_spin_lock (./include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) 
[ 13.186043][ C0] ? xa_set_mark (lib/xarray.c:2076 lib/xarray.c:2146) 
[ 13.186047][ C0] xa_set_mark (lib/xarray.c:2076 lib/xarray.c:2146) 
[ 13.186052][ C0] ? __pfx_xa_set_mark (lib/xarray.c:2144) 
[ 13.186056][ C0] ? __lock_acquire (kernel/locking/lockdep.c:5240) 
[ 13.186065][ C0] ? find_held_lock (kernel/locking/lockdep.c:5353) 
[ 13.186072][ C0] ref_tracker_dir_exit (lib/ref_tracker.c:54 lib/ref_tracker.c:223) 
[ 13.186080][ C0] ? trace_kfree (./include/trace/events/kmem.h:94 (discriminator 21)) 
[ 13.186087][ C0] ? kfree (mm/slub.c:4831) 
[ 13.186093][ C0] ? _raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194) 
[ 13.186098][ C0] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:213) 
[ 13.186104][ C0] ? ref_tracker_free (lib/ref_tracker.c:281) 
[ 13.186110][ C0] ? __lock_acquire (kernel/locking/lockdep.c:5240) 
[ 13.186114][ C0] ? __pfx_ref_tracker_free (lib/ref_tracker.c:281) 
[ 13.186119][ C0] ? __sk_destruct (./include/linux/instrumented.h:96 ./include/linux/atomic/atomic-instrumented.h:400 ./include/linux/refcount.h:389 ./include/linux/refcount.h:432 ./include/linux/refcount.h:450 ./include/net/net_namespace.h:287 ./include/net/net_namespace.h:390 net/core/sock.c:2368) 
[ 13.186125][ C0] ? rcu_do_batch (./include/linux/rcupdate.h:341 kernel/rcu/tree.c:2578) 
[ 13.186130][ C0] ? rcu_core (kernel/rcu/tree.c:2834) 
[ 13.186135][ C0] ? handle_softirqs (kernel/softirq.c:580) 
[ 13.186143][ C0] __put_net (./include/linux/llist.h:238 ./include/linux/llist.h:265 net/core/net_namespace.c:732) 
[ 13.186150][ C0] ? ret_from_fork (arch/x86/kernel/process.c:148) 
[ 13.186155][ C0] ? __pfx___put_net (net/core/net_namespace.c:729) 
[ 13.186163][ C0] ? bpf_sk_storage_free (./include/linux/rcupdate.h:341 ./include/linux/rcupdate.h:871 net/core/bpf_sk_storage.c:61) 
[ 13.186171][ C0] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2368) 
[ 13.186176][ C0] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 13.186182][ C0] rcu_do_batch (./include/linux/rcupdate.h:341 kernel/rcu/tree.c:2578) 
[ 13.186189][ C0] ? do_raw_spin_unlock (./arch/x86/include/asm/atomic.h:23 ./include/linux/atomic/atomic-arch-fallback.h:457 ./include/linux/atomic/atomic-instrumented.h:33 ./include/asm-generic/qspinlock.h:57 kernel/locking/spinlock_debug.c:101 kernel/locking/spinlock_debug.c:141) 
[ 13.186197][ C0] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2500) 
[ 13.186203][ C0] ? mark_held_locks (kernel/locking/lockdep.c:4328) 
[ 13.186208][ C0] ? note_gp_changes (kernel/rcu/tree.c:1326 (discriminator 1)) 
[ 13.186214][ C0] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4475) 
[ 13.186222][ C0] rcu_core (kernel/rcu/tree.c:2834) 
[ 13.186229][ C0] handle_softirqs (kernel/softirq.c:580) 
[ 13.186244][ C0] ? unregister_netdevice_many_notify (net/core/dev.c:12127) 
[ 13.186251][ C0] do_softirq (kernel/softirq.c:480 kernel/softirq.c:467) 
[   13.186255][    C0]  </IRQ>
[   13.186256][    C0]  <TASK>
[ 13.186258][ C0] __local_bh_enable_ip (kernel/softirq.c:407) 
[ 13.186263][ C0] unregister_netdevice_many_notify (net/core/dev.c:12127) 
[ 13.186273][ C0] ? __pfx_unregister_netdevice_many_notify (net/core/dev.c:12043) 
[ 13.186278][ C0] ? rtnl_is_locked (net/core/rtnetlink.c:169) 
[ 13.186285][ C0] ? unregister_netdevice_queue (net/core/dev.c:12015) 
[ 13.186291][ C0] ? __pfx_unregister_netdevice_queue (net/core/dev.c:12014) 
[ 13.186301][ C0] ? lockdep_rtnl_is_held (net/core/rtnetlink.c:182) 
[ 13.186306][ C0] ? sit_exit_rtnl_net (net/ipv6/sit.c:1822 (discriminator 1)) 
[ 13.186317][ C0] ops_undo_list (net/core/net_namespace.c:190 net/core/net_namespace.c:249) 
[ 13.186326][ C0] ? __pfx_ops_undo_list (net/core/net_namespace.c:224) 
[ 13.186332][ C0] ? __local_bh_enable_ip (./arch/x86/include/asm/irqflags.h:42 ./arch/x86/include/asm/irqflags.h:119 kernel/softirq.c:412) 
[ 13.186339][ C0] cleanup_net (net/core/net_namespace.c:688) 
[ 13.186346][ C0] ? __pfx_cleanup_net (net/core/net_namespace.c:652) 
[ 13.186352][ C0] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 13.186359][ C0] process_one_work (kernel/workqueue.c:3243) 
[ 13.186372][ C0] ? __pfx_process_one_work (kernel/workqueue.c:3140) 
[ 13.186381][ C0] ? assign_work (kernel/workqueue.c:1200) 
[ 13.186388][ C0] worker_thread (kernel/workqueue.c:3315 kernel/workqueue.c:3402) 
[ 13.186400][ C0] ? __pfx_worker_thread (kernel/workqueue.c:3348) 
[ 13.186406][ C0] kthread (kernel/kthread.c:464) 
[ 13.186414][ C0] ? __pfx_kthread (kernel/kthread.c:413) 
[ 13.186418][ C0] ? ret_from_fork (arch/x86/kernel/process.c:147) 
[ 13.186422][ C0] ? __lock_release (kernel/locking/lockdep.c:5539) 
[ 13.186428][ C0] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 13.186432][ C0] ? __pfx_kthread (kernel/kthread.c:413) 
[ 13.186439][ C0] ret_from_fork (arch/x86/kernel/process.c:148) 
[ 13.186443][ C0] ? __pfx_kthread (kernel/kthread.c:413) 


Finger prints:
mark_lock_irq:mark_lock:mark_usage:__lock_acquire:_raw_spin_lock