Commit cecda693 authored Sep 19, 2014 by Jason Wang Committed by David S. Miller Sep 22, 2014

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



Commit ce93718f ("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 ce93718f ("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>

parent b749fc9b

net/core/dev.c

+5 −3

Original line number	Diff line number	Diff line
		@@ -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;
		} else if (segs) {
		consume_skb(skb);
		skb = segs;
		}
		} else {
		if (skb_needs_linearize(skb, features) &&
		__skb_linearize(skb))

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