bonding: COW before overwriting the destination MAC address

When there is a ptype handler holding a clone of this skb, whose
destination MAC addresse is overwritten, the owner of this handler may
get a corrupted packet.

Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Changli Gao 2011-03-02 21:07:14 +00:00 committed by David S. Miller
parent cca134fe78
commit 541ac7c9b3

View File

@ -1511,9 +1511,13 @@ static struct sk_buff *bond_handle_frame(struct sk_buff *skb)
if (bond_dev->priv_flags & IFF_MASTER_ALB &&
bond_dev->priv_flags & IFF_BRIDGE_PORT &&
skb->pkt_type == PACKET_HOST) {
u16 *dest = (u16 *) eth_hdr(skb)->h_dest;
memcpy(dest, bond_dev->dev_addr, ETH_ALEN);
if (unlikely(skb_cow_head(skb,
skb->data - skb_mac_header(skb)))) {
kfree_skb(skb);
return NULL;
}
memcpy(eth_hdr(skb)->h_dest, bond_dev->dev_addr, ETH_ALEN);
}
return skb;