[SK_BUFF]: Fix missing offset adjustment in skb_copy_expand

skb_copy_expand changes the headroom, so it needs to adjust the header
offsets by the difference between the old and the new value.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 10 insertions, 1 deletions

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 52a4fdd4f31c..c7a1b24b7374 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -736,7 +736,9 @@ struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
          */
         struct sk_buff *n = alloc_skb(newheadroom + skb->len + newtailroom,
                                       gfp_mask);
+        int oldheadroom = skb_headroom(skb);
         int head_copy_len, head_copy_off;
+        int off = 0;
 
         if (!n)
                 return NULL;
@@ -746,7 +748,7 @@ struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
         /* Set the tail pointer and length */
         skb_put(n, skb->len);
 
-        head_copy_len = skb_headroom(skb);
+        head_copy_len = oldheadroom;
         head_copy_off = 0;
         if (newheadroom <= head_copy_len)
                 head_copy_len = newheadroom;
@@ -760,6 +762,13 @@ struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
 
         copy_skb_header(n, skb);
 
+#ifdef NET_SKBUFF_DATA_USES_OFFSET
+        off                  = newheadroom - oldheadroom;
+#endif
+        n->transport_header += off;
+        n->network_header   += off;
+        n->mac_header       += off;
+
         return n;
 }