macvlan: Fix use after free of struct macvlan_port.
macvlan: Fix use after free of struct macvlan_port.

When the macvlan driver was extended to call unregisgter_netdevice_queue
in 23289a37e2b127dfc4de1313fba15bb4c9f0cd5b, a use after free of struct
macvlan_port was introduced.  The code in dellink relied on unregister_netdevice
actually unregistering the net device so it would be safe to free macvlan_port.

Since unregister_netdevice_queue can just queue up the unregister instead of
performing the unregiser immediately we free the macvlan_port too soon and
then the code in macvlan_stop removes the macaddress for the set of macaddress
to listen for and uses memory that has already been freed.

To fix this add a reference count to track when it is safe to free the macvlan_port
and move the call of macvlan_port_destroy into macvlan_uninit which is guaranteed
to be called after the final macvlan_port_close.

Signed-off-by: Eric W. Biederman <8a741aa8cbd77ebc4a56ddb528ce9fd15d42f034@aristanetworks.com>
Signed-off-by: David S. Miller <fe08d3c717adf2ae63592e4c9aec6e3e404d8e3e@davemloft.net>

TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas