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-rw-r--r--net/core/skbuff.c36
1 files changed, 26 insertions, 10 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index bb7210f4005..fe63d4efbd4 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -781,24 +781,40 @@ struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
* filled. Used by network drivers which may DMA or transfer data
* beyond the buffer end onto the wire.
*
- * May return NULL in out of memory cases.
+ * May return error in out of memory cases. The skb is freed on error.
*/
-struct sk_buff *skb_pad(struct sk_buff *skb, int pad)
+int skb_pad(struct sk_buff *skb, int pad)
{
- struct sk_buff *nskb;
+ int err;
+ int ntail;
/* If the skbuff is non linear tailroom is always zero.. */
- if (skb_tailroom(skb) >= pad) {
+ if (!skb_cloned(skb) && skb_tailroom(skb) >= pad) {
memset(skb->data+skb->len, 0, pad);
- return skb;
+ return 0;
}
-
- nskb = skb_copy_expand(skb, skb_headroom(skb), skb_tailroom(skb) + pad, GFP_ATOMIC);
+
+ ntail = skb->data_len + pad - (skb->end - skb->tail);
+ if (likely(skb_cloned(skb) || ntail > 0)) {
+ err = pskb_expand_head(skb, 0, ntail, GFP_ATOMIC);
+ if (unlikely(err))
+ goto free_skb;
+ }
+
+ /* FIXME: The use of this function with non-linear skb's really needs
+ * to be audited.
+ */
+ err = skb_linearize(skb);
+ if (unlikely(err))
+ goto free_skb;
+
+ memset(skb->data + skb->len, 0, pad);
+ return 0;
+
+free_skb:
kfree_skb(skb);
- if (nskb)
- memset(nskb->data+nskb->len, 0, pad);
- return nskb;
+ return err;
}
/* Trims skb to length len. It can change skb pointers.