1 files changed, 62 insertions, 7 deletions

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index fc7942c0dddc..9240af2ea8c9 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -954,9 +954,13 @@ void __kfree_skb_defer(struct sk_buff *skb)
 
 void napi_skb_free_stolen_head(struct sk_buff *skb)
 {
-	nf_reset_ct(skb);
-	skb_dst_drop(skb);
-	skb_ext_put(skb);
+	if (unlikely(skb->slow_gro)) {
+		nf_reset_ct(skb);
+		skb_dst_drop(skb);
+		skb_ext_put(skb);
+		skb_orphan(skb);
+		skb->slow_gro = 0;
+	}
 	napi_skb_cache_put(skb);
 }
 
@@ -1786,6 +1790,48 @@ struct sk_buff *skb_realloc_headroom(struct sk_buff *skb, unsigned int headroom)
 EXPORT_SYMBOL(skb_realloc_headroom);
 
 /**
+ *	skb_expand_head - reallocate header of &sk_buff
+ *	@skb: buffer to reallocate
+ *	@headroom: needed headroom
+ *
+ *	Unlike skb_realloc_headroom, this one does not allocate a new skb
+ *	if possible; copies skb->sk to new skb as needed
+ *	and frees original skb in case of failures.
+ *
+ *	It expect increased headroom and generates warning otherwise.
+ */
+
+struct sk_buff *skb_expand_head(struct sk_buff *skb, unsigned int headroom)
+{
+	int delta = headroom - skb_headroom(skb);
+
+	if (WARN_ONCE(delta <= 0,
+		      "%s is expecting an increase in the headroom", __func__))
+		return skb;
+
+	/* pskb_expand_head() might crash, if skb is shared */
+	if (skb_shared(skb)) {
+		struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
+
+		if (likely(nskb)) {
+			if (skb->sk)
+				skb_set_owner_w(nskb, skb->sk);
+			consume_skb(skb);
+		} else {
+			kfree_skb(skb);
+		}
+		skb = nskb;
+	}
+	if (skb &&
+	    pskb_expand_head(skb, SKB_DATA_ALIGN(delta), 0, GFP_ATOMIC)) {
+		kfree_skb(skb);
+		skb = NULL;
+	}
+	return skb;
+}
+EXPORT_SYMBOL(skb_expand_head);
+
+/**
  *	skb_copy_expand	-	copy and expand sk_buff
  *	@skb: buffer to copy
  *	@newheadroom: new free bytes at head
@@ -3889,6 +3935,9 @@ int skb_gro_receive_list(struct sk_buff *p, struct sk_buff *skb)
 	NAPI_GRO_CB(p)->last = skb;
 	NAPI_GRO_CB(p)->count++;
 	p->data_len += skb->len;
+
+	/* sk owenrship - if any - completely transferred to the aggregated packet */
+	skb->destructor = NULL;
 	p->truesize += skb->truesize;
 	p->len += skb->len;
 
@@ -4256,6 +4305,7 @@ int skb_gro_receive(struct sk_buff *p, struct sk_buff *skb)
 	unsigned int headlen = skb_headlen(skb);
 	unsigned int len = skb_gro_len(skb);
 	unsigned int delta_truesize;
+	unsigned int new_truesize;
 	struct sk_buff *lp;
 
 	if (unlikely(p->len + len >= 65536 || NAPI_GRO_CB(skb)->flush))
@@ -4287,10 +4337,10 @@ int skb_gro_receive(struct sk_buff *p, struct sk_buff *skb)
 		skb_frag_size_sub(frag, offset);
 
 		/* all fragments truesize : remove (head size + sk_buff) */
-		delta_truesize = skb->truesize -
-				 SKB_TRUESIZE(skb_end_offset(skb));
+		new_truesize = SKB_TRUESIZE(skb_end_offset(skb));
+		delta_truesize = skb->truesize - new_truesize;
 
-		skb->truesize -= skb->data_len;
+		skb->truesize = new_truesize;
 		skb->len -= skb->data_len;
 		skb->data_len = 0;
 
@@ -4319,12 +4369,16 @@ int skb_gro_receive(struct sk_buff *p, struct sk_buff *skb)
 		memcpy(frag + 1, skbinfo->frags, sizeof(*frag) * skbinfo->nr_frags);
 		/* We dont need to clear skbinfo->nr_frags here */
 
-		delta_truesize = skb->truesize - SKB_DATA_ALIGN(sizeof(struct sk_buff));
+		new_truesize = SKB_DATA_ALIGN(sizeof(struct sk_buff));
+		delta_truesize = skb->truesize - new_truesize;
+		skb->truesize = new_truesize;
 		NAPI_GRO_CB(skb)->free = NAPI_GRO_FREE_STOLEN_HEAD;
 		goto done;
 	}
 
 merge:
+	/* sk owenrship - if any - completely transferred to the aggregated packet */
+	skb->destructor = NULL;
 	delta_truesize = skb->truesize;
 	if (offset > headlen) {
 		unsigned int eat = offset - headlen;
@@ -6449,6 +6503,7 @@ void *skb_ext_add(struct sk_buff *skb, enum skb_ext_id id)
 	new->chunks = newlen;
 	new->offset[id] = newoff;
 set_active:
+	skb->slow_gro = 1;
 	skb->extensions = new;
 	skb->active_extensions |= 1 << id;
 	return skb_ext_get_ptr(new, id);