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 коммит произвёл David S. Miller
Родитель cca134fe78
Коммит 541ac7c9b3
1 изменённых файлов: 6 добавлений и 2 удалений

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@ -1511,9 +1511,13 @@ static struct sk_buff *bond_handle_frame(struct sk_buff *skb)
if (bond_dev->priv_flags & IFF_MASTER_ALB && if (bond_dev->priv_flags & IFF_MASTER_ALB &&
bond_dev->priv_flags & IFF_BRIDGE_PORT && bond_dev->priv_flags & IFF_BRIDGE_PORT &&
skb->pkt_type == PACKET_HOST) { 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; return skb;