1 files changed, 10 insertions, 3 deletions

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 5c93435b0347..9e0597d189b0 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -204,6 +204,10 @@ struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask,
         skb->end = skb->tail + size;
         kmemcheck_annotate_bitfield(skb, flags1);
         kmemcheck_annotate_bitfield(skb, flags2);
+#ifdef NET_SKBUFF_DATA_USES_OFFSET
+        skb->mac_header = ~0U;
+#endif
+
         /* make sure we initialize shinfo sequentially */
         shinfo = skb_shinfo(skb);
         atomic_set(&shinfo->dataref, 1);
@@ -665,7 +669,8 @@ static void copy_skb_header(struct sk_buff *new, const struct sk_buff *old)
         /* {transport,network,mac}_header are relative to skb->head */
         new->transport_header += offset;
         new->network_header   += offset;
-        new->mac_header       += offset;
+        if (skb_mac_header_was_set(new))
+                new->mac_header       += offset;
 #endif
         skb_shinfo(new)->gso_size = skb_shinfo(old)->gso_size;
         skb_shinfo(new)->gso_segs = skb_shinfo(old)->gso_segs;
@@ -847,7 +852,8 @@ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail,
         skb->tail             += off;
         skb->transport_header += off;
         skb->network_header   += off;
-        skb->mac_header       += off;
+        if (skb_mac_header_was_set(skb))
+                skb->mac_header += off;
         skb->csum_start       += nhead;
         skb->cloned   = 0;
         skb->hdr_len  = 0;
@@ -939,7 +945,8 @@ struct sk_buff *skb_copy_expand(const struct sk_buff *skb,
 #ifdef NET_SKBUFF_DATA_USES_OFFSET
         n->transport_header += off;
         n->network_header   += off;
-        n->mac_header       += off;
+        if (skb_mac_header_was_set(skb))
+                n->mac_header += off;
 #endif
 
         return n;