======================================
| [ 132.471049][ T293] #3: ffffffffab801dc8 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch (net/core/dev.c:12109)
| [ 132.471378][ T293] #4: ffffffffab7f0a70 ((netdev_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
| [  132.471703][  T293]
| [  132.471703][  T293] stack backtrace:
[  132.472174][  T293] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[  132.472372][  T293] Workqueue: netns cleanup_net
[  132.472541][  T293] Call Trace:
[  132.472665][  T293]  <TASK>
[ 132.472750][ T293] dump_stack_lvl (lib/dump_stack.c:123)
[ 132.472916][ T293] print_deadlock_bug (kernel/locking/lockdep.c:3040)
[ 132.473081][ T293] validate_chain (kernel/locking/lockdep.c:3894)
[ 132.473249][ T293] ? __pfx_validate_chain (kernel/locking/lockdep.c:3860)
[ 132.473414][ T293] ? 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)
[ 132.473576][ T293] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 132.473696][ T293] __lock_acquire (kernel/locking/lockdep.c:5226)
[ 132.473860][ T293] lock_acquire.part.0 (kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851)
[ 132.474018][ T293] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 132.474213][ T293] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 132.474373][ T293] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 37))
[ 132.474532][ T293] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 132.474693][ T293] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 132.474895][ T293] down_read (./arch/x86/include/asm/preempt.h:79 kernel/locking/rwsem.c:1246 kernel/locking/rwsem.c:1261 kernel/locking/rwsem.c:1526)
[ 132.475019][ T293] ? blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 132.475215][ T293] ? __pfx_down_read (kernel/locking/rwsem.c:1522)
[ 132.475373][ T293] ? __pfx_validate_chain (kernel/locking/lockdep.c:3860)
[ 132.475538][ T293] ? 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)
[ 132.475694][ T293] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 132.475815][ T293] blocking_notifier_call_chain (kernel/notifier.c:380 kernel/notifier.c:368)
[ 132.475977][ T293] netdev_lower_state_changed (net/core/dev.c:8709 (discriminator 11))
[ 132.476135][ T293] ? __pfx_netdev_lower_state_changed (net/core/dev.c:8709)
[ 132.476328][ T293] ? __pfx_netdev_has_upper_dev (net/core/dev.c:7170)
[ 132.476490][ T293] __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)
[ 132.476654][ T293] ? __lock_release (kernel/locking/lockdep.c:5525)
[ 132.476810][ T293] ? __try_to_del_timer_sync (kernel/time/timer.c:1498)
[ 132.476972][ T293] ? __pfx___bond_release_one (drivers/net/bonding/bond_main.c:2492)
[ 132.477137][ T293] ? 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)
[ 132.477293][ T293] ? mark_lock (kernel/locking/lockdep.c:4727 (discriminator 3))
[ 132.477414][ T293] ? mark_held_locks (kernel/locking/lockdep.c:4321)
[ 132.477574][ T293] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406)
[ 132.477775][ T293] ? __try_to_del_timer_sync (kernel/time/timer.c:1498)
[ 132.477934][ T293] ? __pfx___try_to_del_timer_sync (kernel/time/timer.c:1498)
[ 132.478143][ T293] ? mark_held_locks (kernel/locking/lockdep.c:4321)
[ 132.478304][ T293] bond_slave_netdev_event (drivers/net/bonding/bond_main.c:4034)
[ 132.478461][ T293] ? ipmr_device_event (net/ipv4/ipmr.c:1781)
[ 132.478620][ T293] notifier_call_chain (kernel/notifier.c:85 (discriminator 2))
[ 132.478783][ T293] blocking_notifier_call_chain (kernel/notifier.c:381 kernel/notifier.c:368)
[ 132.478940][ T293] unregister_netdevice_many_notify (net/core/dev.c:11575)
[ 132.479139][ T293] ? __pfx_unregister_netdevice_many_notify (net/core/dev.c:11516)
[ 132.479338][ T293] ? default_device_exit_batch (net/core/dev.c:12109)
[ 132.479497][ T293] ? rtnl_is_locked (net/core/rtnetlink.c:163)
[ 132.479657][ T293] ? unregister_netdevice_queue (net/core/dev.c:11501)
[ 132.479851][ T293] ? __pfx_unregister_netdevice_queue (net/core/dev.c:11500)
[ 132.480049][ T293] ? __pfx_unregister_netdevice_queue (net/core/dev.c:11500)
[ 132.480251][ T293] default_device_exit_batch (net/core/dev.c:12123)
[ 132.480493][ T293] ? __pfx_default_device_exit_batch (net/core/dev.c:12098)
[ 132.480687][ T293] ? 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)
[ 132.480845][ T293] ? 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)
[ 132.481045][ T293] cleanup_net (net/core/net_namespace.c:647 (discriminator 3))
[ 132.481284][ T293] ? __pfx_lock_acquire.part.0 (kernel/locking/lockdep.c:5814)
[ 132.481447][ T293] ? __pfx_cleanup_net (net/core/net_namespace.c:592)
[ 132.481604][ T293] ? trace_lock_acquire (./include/trace/events/lock.h:24 (discriminator 37))
[ 132.481765][ T293] ? lock_acquire (kernel/locking/lockdep.c:5822)
[ 132.481997][ T293] ? process_one_work (kernel/workqueue.c:3205)
[ 132.482160][ T293] process_one_work (kernel/workqueue.c:3229)
[ 132.482320][ T293] ? __pfx___lock_release (kernel/locking/lockdep.c:5501)
[ 132.482480][ T293] ? __pfx_process_one_work (kernel/workqueue.c:3131)
[ 132.482727][ T293] ? assign_work (kernel/workqueue.c:1200)
[ 132.482883][ T293] worker_thread (kernel/workqueue.c:3304 kernel/workqueue.c:3391)
[ 132.483039][ T293] ? lockdep_hardirqs_on_prepare (kernel/locking/lockdep.c:4347 kernel/locking/lockdep.c:4406)
[ 132.483236][ T293] ? __pfx_worker_thread (kernel/workqueue.c:3337)
[ 132.483394][ T293] ? __pfx_worker_thread (kernel/workqueue.c:3337)
[ 132.483549][ T293] kthread (kernel/kthread.c:389)
[ 132.483669][ T293] ? __pfx_kthread (kernel/kthread.c:342)
[ 132.483827][ T293] ret_from_fork (arch/x86/kernel/process.c:147)
[ 132.484067][ T293] ? __pfx_kthread (kernel/kthread.c:342)


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