syzbot

device bridge_slave_1 left promiscuous mode
bridge0: port 2(bridge_slave_1) entered disabled state
device bridge_slave_0 left promiscuous mode
bridge0: port 1(bridge_slave_0) entered disabled state
INFO: task kworker/0:1:24 blocked for more than 140 seconds.
      Not tainted 4.14.182-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/0:1     D27624    24      2 0x80000000
Workqueue: ipv6_addrconf addrconf_verify_work
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893
 addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4412
 process_one_work+0x7c0/0x14c0 kernel/workqueue.c:2116
 worker_thread+0x5d7/0x1080 kernel/workqueue.c:2250
 kthread+0x30d/0x420 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
INFO: task kworker/u4:2:31 blocked for more than 140 seconds.
      Not tainted 4.14.182-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/u4:2    D26400    31      2 0x80000000
Workqueue: netns cleanup_net
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893
 kobject_uevent_env+0x5a4/0xc50 lib/kobject_uevent.c:459
 device_del+0x642/0xa80 drivers/base/core.c:2081
 device_unregister drivers/base/core.c:2103 [inline]
 device_destroy+0x86/0xb0 drivers/base/core.c:2661
 macvtap_device_event+0x220/0x360 drivers/net/macvtap.c:187
 notifier_call_chain+0x107/0x1a0 kernel/notifier.c:93
 call_netdevice_notifiers net/core/dev.c:1687 [inline]
 rollback_registered_many+0x694/0xa70 net/core/dev.c:7206
 unregister_netdevice_many.part.0+0x16/0x1d0 net/core/dev.c:8281
 unregister_netdevice_many net/core/dev.c:8280 [inline]
 default_device_exit_batch+0x2dd/0x380 net/core/dev.c:8742
 ops_exit_list.isra.0+0xef/0x140 net/core/net_namespace.c:145
 cleanup_net+0x3bb/0x820 net/core/net_namespace.c:484
 process_one_work+0x7c0/0x14c0 kernel/workqueue.c:2116
 worker_thread+0x5d7/0x1080 kernel/workqueue.c:2250
 kthread+0x30d/0x420 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
INFO: task kworker/1:2:2724 blocked for more than 140 seconds.
      Not tainted 4.14.182-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/1:2     D26256  2724      2 0x80000000
Workqueue: events switchdev_deferred_process_work
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893
 switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:150
 process_one_work+0x7c0/0x14c0 kernel/workqueue.c:2116
 worker_thread+0x5d7/0x1080 kernel/workqueue.c:2250
 kthread+0x30d/0x420 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
INFO: task syz-executor.4:17178 blocked for more than 140 seconds.
      Not tainted 4.14.182-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.4  D28896 17178   6347 0x80000006
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893
 kobject_uevent_env+0x5a4/0xc50 lib/kobject_uevent.c:459
 kvm_uevent_notify_change.part.0+0x2b9/0x420 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4004
 kvm_uevent_notify_change arch/x86/kvm/../../../virt/kvm/kvm_main.c:3963 [inline]
 kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:763 [inline]
 kvm_put_kvm+0x96/0xa90 arch/x86/kvm/../../../virt/kvm/kvm_main.c:806
 kvm_vm_release+0x3f/0x50 arch/x86/kvm/../../../virt/kvm/kvm_main.c:817
 __fput+0x25f/0x7a0 fs/file_table.c:210