Commit 99f34b38 authored Oct 20, 2011 by Eric W. Biederman Committed by David S. Miller Oct 21, 2011

macvtap: Close a race between macvtap_open and macvtap_dellink.



There is a small window in macvtap_open between looking up a
networking device and calling macvtap_set_queue in which
macvtap_del_queues called from macvtap_dellink.   After
calling macvtap_del_queues it is totally incorrect to
allow macvtap_set_queue to proceed so prevent success by
reporting that all of the available queues are in use.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 4b727361

drivers/net/macvtap.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -231,6 +231,8 @@ static void macvtap_del_queues(struct net_device *dev)
		}
		}
		BUG_ON(vlan->numvtaps != 0);
		/* guarantee that any future macvtap_set_queue will fail */
		vlan->numvtaps = MAX_MACVTAP_QUEUES;
		spin_unlock(&macvtap_lock);

		synchronize_rcu();