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Commit 573201f3 authored by Herbert Xu's avatar Herbert Xu Committed by David S. Miller
Browse files

bridge: Partially disable netpoll support 



The new netpoll code in bridging contains use-after-free bugs
that are non-trivial to fix.

This patch fixes this by removing the code that uses skbs after
they're freed.

As a consequence, this means that we can no longer call bridge
from the netpoll path, so this patch also removes the controller
function in order to disable netpoll.

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

Thanks,
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 45e77d31

net/bridge/br_device.c

+0 −9
Original line number Diff line number Diff line
@@ -217,14 +217,6 @@ static bool br_devices_support_netpoll(struct net_bridge *br) 
	return count != 0 && ret;

}



static void br_poll_controller(struct net_device *br_dev)

{

	struct netpoll *np = br_dev->npinfo->netpoll;



	if (np->real_dev != br_dev)

		netpoll_poll_dev(np->real_dev);

}



void br_netpoll_cleanup(struct net_device *dev)

{

	struct net_bridge *br = netdev_priv(dev);
@@ -295,7 +287,6 @@ static const struct net_device_ops br_netdev_ops = { 
	.ndo_do_ioctl		 = br_dev_ioctl,

#ifdef CONFIG_NET_POLL_CONTROLLER

	.ndo_netpoll_cleanup	 = br_netpoll_cleanup,

	.ndo_poll_controller	 = br_poll_controller,

#endif

};

net/bridge/br_forward.c

+1 −22
Original line number Diff line number Diff line
@@ -50,13 +50,6 @@ int br_dev_queue_push_xmit(struct sk_buff *skb) 
			kfree_skb(skb);

		else {

			skb_push(skb, ETH_HLEN);



#ifdef CONFIG_NET_POLL_CONTROLLER

			if (unlikely(skb->dev->priv_flags & IFF_IN_NETPOLL)) {

				netpoll_send_skb(skb->dev->npinfo->netpoll, skb);

				skb->dev->priv_flags &= ~IFF_IN_NETPOLL;

			} else

#endif

			dev_queue_xmit(skb);

		}

	}
@@ -73,23 +66,9 @@ int br_forward_finish(struct sk_buff *skb) 


static void __br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)

{

#ifdef CONFIG_NET_POLL_CONTROLLER

	struct net_bridge *br = to->br;

	if (unlikely(br->dev->priv_flags & IFF_IN_NETPOLL)) {

		struct netpoll *np;

		to->dev->npinfo = skb->dev->npinfo;

		np = skb->dev->npinfo->netpoll;

		np->real_dev = np->dev = to->dev;

		to->dev->priv_flags |= IFF_IN_NETPOLL;

	}

#endif

	skb->dev = to->dev;

	NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_OUT, skb, NULL, skb->dev,

		br_forward_finish);

#ifdef CONFIG_NET_POLL_CONTROLLER

	if (skb->dev->npinfo)

		skb->dev->npinfo->netpoll->dev = br->dev;

#endif

}



static void __br_forward(const struct net_bridge_port *to, struct sk_buff *skb)