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Commit 541ac7c9 authored by Changli Gao's avatar Changli Gao Committed by David S. Miller
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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: default avatarChangli Gao <xiaosuo@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent cca134fe

drivers/net/bonding/bond_main.c

+6 −2
Original line number Diff line number Diff line
@@ -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;