======================================
| [ 130.809329][ T271] #3: ffffffff92e01dc8 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch (net/core/dev.c:12109)
| [ 130.809780][ T271] #4: ffffffff92df0a70 ((netdev_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
| [  130.810229][  T271]
| [  130.810229][  T271] stack backtrace:
[  130.810922][  T271] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  130.811213][  T271] Workqueue: netns cleanup_net
[  130.811470][  T271] Call Trace:
[  130.811655][  T271]  <TASK>
[ 130.811782][ T271] dump_stack_lvl (lib/dump_stack.c:123)
[ 130.812024][ T271] print_deadlock_bug (kernel/locking/lockdep.c:3040)
[ 130.812270][ T271] validate_chain (kernel/locking/lockdep.c:3894)
[ 130.812514][ T271] ? __pfx_validate_chain (kernel/locking/lockdep.c:3860)
[ 130.812768][ T271] ? 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:228)
[ 130.813009][ T271] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 130.813195][ T271] __lock_acquire (kernel/locking/lockdep.c:5226)
[ 130.813434][ T271] lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851)
[ 130.813679][ T271] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 130.813982][ T271] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 130.814226][ T271] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 37))
[ 130.814468][ T271] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 130.814630][ T271] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 130.814832][ T271] down_read (./arch/x86/include/asm/preempt.h:79 kernel/locking/rwsem.c:1246 kernel/locking/rwsem.c:1261 kernel/locking/rwsem.c:1526)
[ 130.814956][ T271] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 130.815157][ T271] ? __pfx_down_read (kernel/locking/rwsem.c:1522)
[ 130.815315][ T271] ? __pfx_validate_chain (kernel/locking/lockdep.c:3860)
[ 130.815509][ T271] ? 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:228)
[ 130.815698][ T271] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 130.815852][ T271] blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 130.816013][ T271] netdev_lower_state_changed (net/core/dev.c:8709 (discriminator 11))
[ 130.816180][ T271] ? __pfx_netdev_lower_state_changed (net/core/dev.c:8709)
[ 130.816375][ T271] ? __pfx_netdev_has_upper_dev (net/core/dev.c:7170)
[ 130.816538][ T271] __bond_release_one (drivers/net/bonding/bond_main.c:1890 ./include/net/bonding.h:391 ./include/net/bonding.h:382 ./include/net/bonding.h:570 drivers/net/bonding/bond_main.c:2516)
[ 130.816702][ T271] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 130.816866][ T271] ? __try_to_del_timer_sync (kernel/time/timer.c:1498)
[ 130.817032][ T271] ? __pfx___bond_release_one (drivers/net/bonding/bond_main.c:2492)
[ 130.817200][ T271] ? 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:228)
[ 130.817360][ T271] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 130.817483][ T271] ? mark_held_locks (kernel/locking/lockdep.c:4321)
[ 130.817645][ T271] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406)
[ 130.817844][ T271] ? __try_to_del_timer_sync (kernel/time/timer.c:1498)
[ 130.818004][ T271] ? __pfx___try_to_del_timer_sync (kernel/time/timer.c:1498)
[ 130.818245][ T271] ? mark_held_locks (kernel/locking/lockdep.c:4321)
[ 130.818431][ T271] bond_slave_netdev_event (drivers/net/bonding/bond_main.c:4034)
[ 130.818591][ T271] ? ipmr_device_event (net/ipv4/ipmr.c:1781)
[ 130.818753][ T271] notifier_call_chain (kernel/notifier.c:85 (discriminator 2))
[ 130.818916][ T271] blocking_notifier_call_chain (kernel/notifier.c:381 kernel/notifier.c:368)
[ 130.819073][ T271] unregister_netdevice_many_notify (net/core/dev.c:11575)
[ 130.819282][ T271] ? __pfx_unregister_netdevice_many_notify (net/core/dev.c:11516)
[ 130.819478][ T271] ? default_device_exit_batch (net/core/dev.c:12109)
[ 130.819635][ T271] ? rtnl_is_locked (net/core/rtnetlink.c:163)
[ 130.819787][ T271] ? unregister_netdevice_queue (net/core/dev.c:11501)
[ 130.819977][ T271] ? __pfx_unregister_netdevice_queue (net/core/dev.c:11500)
[ 130.820171][ T271] ? __pfx_unregister_netdevice_queue (net/core/dev.c:11500)
[ 130.820372][ T271] default_device_exit_batch (net/core/dev.c:12123)
[ 130.820532][ T271] ? __pfx_default_device_exit_batch (net/core/dev.c:12098)
[ 130.820727][ T271] ? 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.h:47 kernel/locking/mutex.c:66)
[ 130.820965][ T271] ? nexthop_net_exit_batch_rtnl (net/ipv4/nexthop.c:585 net/ipv4/nexthop.c:2158 net/ipv4/nexthop.c:2666 net/ipv4/nexthop.c:4010)
[ 130.821172][ T271] cleanup_net (net/core/net_namespace.c:647 (discriminator 3))
[ 130.821342][ T271] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 130.821503][ T271] ? __pfx_cleanup_net (net/core/net_namespace.c:592)
[ 130.821736][ T271] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 37))
[ 130.821897][ T271] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 130.822054][ T271] ? process_one_work (kernel/workqueue.c:3205)
[ 130.822223][ T271] process_one_work (kernel/workqueue.c:3229)
[ 130.822457][ T271] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 130.822625][ T271] ? __pfx_process_one_work (kernel/workqueue.c:3131)
[ 130.822787][ T271] ? assign_work (kernel/workqueue.c:1200)
[ 130.822951][ T271] worker_thread (kernel/workqueue.c:3304 kernel/workqueue.c:3391)
[ 130.823199][ T271] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406)
[ 130.823399][ T271] ? __pfx_worker_thread (kernel/workqueue.c:3337)
[ 130.823560][ T271] ? __pfx_worker_thread (kernel/workqueue.c:3337)
[ 130.823721][ T271] kthread (kernel/kthread.c:389)
[ 130.823928][ T271] ? __pfx_kthread (kernel/kthread.c:342)
[ 130.824089][ T271] ret_from_fork (arch/x86/kernel/process.c:147)
[ 130.824270][ T271] ? __pfx_kthread (kernel/kthread.c:342)


Finger prints:
print_deadlock_bug:validate_chain:__lock_acquire:down_read:blocking_notifier_call_chain