gso: Fix support for linear packets

upstream commit: 2f181855a0b3c2b39314944add7b41c15647cf86

When GRO/frag_list support was added to GSO, I made an error
which broke the support for segmenting linear GSO packets (GSO
packets are normally non-linear in the payload).

These days most of these packets are constructed by the tun
driver, which prefers to allocate linear memory if possible.
This is fixed in the latest kernel, but for 2.6.29 and earlier
it is still the norm.

Therefore this bug causes failures with GSO when used with tun
in 2.6.29.

Reported-by: James Huang <jamesclhuang@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index c6a6b166f8d6f733a4dc9f7143bd565aaddf7e8f..eae69549ccb9fa9c5b039a315147a67f9fa78a69 100644 (file)
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -2496,7 +2496,7 @@ struct sk_buff *skb_segment(struct sk_buff *skb, int features)
                                          skb_network_header_len(skb));
                skb_copy_from_linear_data(skb, nskb->data, doffset);
 
-               if (pos >= offset + len)
+               if (fskb != skb_shinfo(skb)->frag_list)
                        continue;
 
                if (!sg) {