net: keep original skb which only needs header checking during software GSO

Commit ce93718fb7 ("net: Don't keep
around original SKB when we software segment GSO frames") frees the
original skb after software GSO even for dodgy gso skbs. This breaks
the stream throughput from untrusted sources, since only header
checking was done during software GSO instead of a true
segmentation. This patch fixes this by freeing the original gso skb
only when it was really segmented by software.

Fixes ce93718fb7 ("net: Don't keep
around original SKB when we software segment GSO frames.")

Cc: David S. Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jason Wang 2014-09-19 16:04:38 +08:00 committed by David S. Miller
parent b749fc9bff
commit cecda693a9

View File

@ -2694,10 +2694,12 @@ struct sk_buff *validate_xmit_skb(struct sk_buff *skb, struct net_device *dev)
struct sk_buff *segs;
segs = skb_gso_segment(skb, features);
kfree_skb(skb);
if (IS_ERR(segs))
if (IS_ERR(segs)) {
segs = NULL;
skb = segs;
} else if (segs) {
consume_skb(skb);
skb = segs;
}
} else {
if (skb_needs_linearize(skb, features) &&
__skb_linearize(skb))