macvlan: Fix device ref leak when purging bc_queue (f6478218) · Commits · 戴 / test

When a parent macvlan device is destroyed we end up purging its broadcast queue without dropping the device reference count on the packet source device. This causes the source device to linger. This patch drops that reference count. Fixes: ("macvlan: Fix potential use-after free for...") Reported-by:

Joe Ghalam <Joe.Ghalam@dell.com> Signed-off-by:

Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by:

David S. Miller <davem@davemloft.net>

drivers/net/macvlan.c

+10 −1

Original line number	Diff line number	Diff line
		@@ -1139,6 +1139,7 @@ static int macvlan_port_create(struct net_device *dev)
		static void macvlan_port_destroy(struct net_device *dev)
		{
		struct macvlan_port *port = macvlan_port_get_rtnl(dev);
		struct sk_buff *skb;

		dev->priv_flags &= ~IFF_MACVLAN_PORT;
		netdev_rx_handler_unregister(dev);
		@@ -1147,7 +1148,15 @@ static void macvlan_port_destroy(struct net_device *dev)
		* but we need to cancel it and purge left skbs if any.
		*/
		cancel_work_sync(&port->bc_work);
		__skb_queue_purge(&port->bc_queue);

		while ((skb = __skb_dequeue(&port->bc_queue))) {
		const struct macvlan_dev *src = MACVLAN_SKB_CB(skb)->src;

		if (src)
		dev_put(src->dev);

		kfree_skb(skb);
		}

		kfree(port);
		}

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