Commit c8884edd authored Oct 29, 2006 by Herbert Xu Committed by David S. Miller Oct 30, 2006

[NET]: Fix segmentation of linear packets



skb_segment fails to segment linear packets correctly because it
tries to write all linear parts of the original skb into each
segment.  This will always panic as each segment only contains
enough space for one MSS.

This was not detected earlier because linear packets should be
rare for GSO.  In fact it still remains to be seen what exactly
created the linear packets that triggered this bug.  Basically
the only time this should happen is if someone enables GSO
emulation on an interface that does not support SG.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 54489c14

net/core/skbuff.c

+4 −5

Original line number	Diff line number	Diff line
		@@ -1946,7 +1946,7 @@ struct sk_buff skb_segment(struct sk_buff skb, int features)
		do {
		struct sk_buff *nskb;
		skb_frag_t *frag;
		int hsize, nsize;
		int hsize;
		int k;
		int size;

		@@ -1957,11 +1957,10 @@ struct sk_buff skb_segment(struct sk_buff skb, int features)
		hsize = skb_headlen(skb) - offset;
		if (hsize < 0)
		hsize = 0;
		nsize = hsize + doffset;
		if (nsize > len + doffset \|\| !sg)
		nsize = len + doffset;
		if (hsize > len \|\| !sg)
		hsize = len;

		nskb = alloc_skb(nsize + headroom, GFP_ATOMIC);
		nskb = alloc_skb(hsize + doffset + headroom, GFP_ATOMIC);
		if (unlikely(!nskb))
		goto err;

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