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Commit f45a5c26 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

veth: fix NULL dereference in veth_dellink() 



commit d0e2c55e (veth: avoid a NULL deref in veth_stats_one)
added another NULL deref in veth_dellink().

# ip link add name veth1 type veth peer name veth0
# rmmod veth

We crash because veth_dellink() is called twice, so we must
take care of NULL peer.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 715448ff

drivers/net/veth.c

+6 −5
Original line number Original line Diff line number Diff line
@@ -426,13 +426,14 @@ static void veth_dellink(struct net_device *dev, struct list_head *head) 
	 * not being freed before one RCU grace period.

	 * not being freed before one RCU grace period.

	 */

	 */

	RCU_INIT_POINTER(priv->peer, NULL);

	RCU_INIT_POINTER(priv->peer, NULL);

	unregister_netdevice_queue(dev, head);





	if (peer) {

		priv = netdev_priv(peer);

		priv = netdev_priv(peer);

		RCU_INIT_POINTER(priv->peer, NULL);

		RCU_INIT_POINTER(priv->peer, NULL);



	unregister_netdevice_queue(dev, head);

		unregister_netdevice_queue(peer, head);

		unregister_netdevice_queue(peer, head);

	}

	}

}





static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = {

static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = {

	[VETH_INFO_PEER]	= { .len = sizeof(struct ifinfomsg) },

	[VETH_INFO_PEER]	= { .len = sizeof(struct ifinfomsg) },