======================================
| [ 132.501408][ T269] #3: ffffffff8aa01dc8 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch (net/core/dev.c:12103)
| [ 132.501720][ T269] #4: ffffffff8a9f0a70 ((netdev_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
| [  132.502033][  T269]
| [  132.502033][  T269] stack backtrace:
[  132.502492][  T269] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  132.502685][  T269] Workqueue: netns cleanup_net
[  132.502853][  T269] Call Trace:
[  132.502972][  T269]  <TASK>
[ 132.503055][ T269] dump_stack_lvl (lib/dump_stack.c:123)
[ 132.503222][ T269] print_deadlock_bug (kernel/locking/lockdep.c:3040)
[ 132.503381][ T269] validate_chain (kernel/locking/lockdep.c:3894)
[ 132.503538][ T269] ? __pfx_validate_chain (kernel/locking/lockdep.c:3860)
[ 132.503693][ T269] ? 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)
[ 132.503852][ T269] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 132.503978][ T269] __lock_acquire (kernel/locking/lockdep.c:5226)
[ 132.504164][ T269] lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851)
[ 132.504342][ T269] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 132.504587][ T269] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 132.504821][ T269] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 37))
[ 132.505057][ T269] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 132.505285][ T269] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 132.505578][ T269] down_read (./arch/x86/include/asm/preempt.h:79 kernel/locking/rwsem.c:1246 kernel/locking/rwsem.c:1261 kernel/locking/rwsem.c:1526)
[ 132.505757][ T269] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 132.506033][ T269] ? __pfx_down_read (kernel/locking/rwsem.c:1522)
[ 132.506266][ T269] ? __pfx_validate_chain (kernel/locking/lockdep.c:3860)
[ 132.506491][ T269] ? 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)
[ 132.506713][ T269] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 132.506883][ T269] blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 132.507112][ T269] netdev_lower_state_changed (net/core/dev.c:8709 (discriminator 11))
[ 132.507346][ T269] ? __pfx_netdev_lower_state_changed (net/core/dev.c:8709)
[ 132.507640][ T269] ? __pfx_netdev_has_upper_dev (net/core/dev.c:7170)
[ 132.507877][ T269] __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)
[ 132.508116][ T269] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 132.508348][ T269] ? __try_to_del_timer_sync (kernel/time/timer.c:1498)
[ 132.508583][ T269] ? __pfx___bond_release_one (drivers/net/bonding/bond_main.c:2492)
[ 132.508810][ T269] ? 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)
[ 132.509009][ T269] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 132.509153][ T269] ? mark_held_locks (kernel/locking/lockdep.c:4321)
[ 132.509379][ T269] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406)
[ 132.509690][ T269] ? __try_to_del_timer_sync (kernel/time/timer.c:1498)
[ 132.509855][ T269] ? __pfx___try_to_del_timer_sync (kernel/time/timer.c:1498)
[ 132.510054][ T269] ? mark_held_locks (kernel/locking/lockdep.c:4321)
[ 132.510212][ T269] bond_slave_netdev_event (drivers/net/bonding/bond_main.c:4034)
[ 132.510376][ T269] ? ipmr_device_event (net/ipv4/ipmr.c:1781)
[ 132.510534][ T269] notifier_call_chain (kernel/notifier.c:85 (discriminator 2))
[ 132.510782][ T269] blocking_notifier_call_chain (kernel/notifier.c:381 kernel/notifier.c:368)
[ 132.510936][ T269] unregister_netdevice_many_notify (net/core/dev.c:11571)
[ 132.511128][ T269] ? __pfx_unregister_netdevice_many_notify (net/core/dev.c:11512)
[ 132.511326][ T269] ? default_device_exit_batch (net/core/dev.c:12103)
[ 132.511564][ T269] ? rtnl_is_locked (net/core/rtnetlink.c:164)
[ 132.511720][ T269] ? unregister_netdevice_queue (net/core/dev.c:11497)
[ 132.511906][ T269] ? __pfx_unregister_netdevice_queue (net/core/dev.c:11496)
[ 132.512202][ T269] ? __pfx_unregister_netdevice_queue (net/core/dev.c:11496)
[ 132.512395][ T269] default_device_exit_batch (net/core/dev.c:12117)
[ 132.512551][ T269] ? __pfx_default_device_exit_batch (net/core/dev.c:12092)
[ 132.512755][ T269] ? 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)
[ 132.512995][ T269] ? 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)
[ 132.513183][ T269] cleanup_net (net/core/net_namespace.c:647 (discriminator 3))
[ 132.513366][ T269] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 132.513521][ T269] ? __pfx_cleanup_net (net/core/net_namespace.c:592)
[ 132.513765][ T269] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 37))
[ 132.513929][ T269] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 132.514088][ T269] ? process_one_work (kernel/workqueue.c:3205)
[ 132.514270][ T269] process_one_work (kernel/workqueue.c:3229)
[ 132.514509][ T269] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 132.514665][ T269] ? __pfx_process_one_work (kernel/workqueue.c:3131)
[ 132.514817][ T269] ? assign_work (kernel/workqueue.c:1200)
[ 132.514971][ T269] worker_thread (kernel/workqueue.c:3304 kernel/workqueue.c:3391)
[ 132.515199][ T269] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406)
[ 132.515391][ T269] ? __pfx_worker_thread (kernel/workqueue.c:3337)
[ 132.515544][ T269] ? __pfx_worker_thread (kernel/workqueue.c:3337)
[ 132.515769][ T269] kthread (kernel/kthread.c:389)
[ 132.515887][ T269] ? __pfx_kthread (kernel/kthread.c:342)
[ 132.516041][ T269] ret_from_fork (arch/x86/kernel/process.c:147)
[ 132.516196][ T269] ? __pfx_kthread (kernel/kthread.c:342)


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