1 files changed, 75 insertions, 53 deletions

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 5d6236d9fdce..90b96a11b974 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -2127,25 +2127,31 @@ EXPORT_SYMBOL_GPL(skb_zerocopy_headlen);
  *
  *	The `hlen` as calculated by skb_zerocopy_headlen() specifies the
  *	headroom in the `to` buffer.
+ *
+ *	Return value:
+ *	0: everything is OK
+ *	-ENOMEM: couldn't orphan frags of @from due to lack of memory
+ *	-EFAULT: skb_copy_bits() found some problem with skb geometry
  */
-void
-skb_zerocopy(struct sk_buff *to, const struct sk_buff *from, int len, int hlen)
+int
+skb_zerocopy(struct sk_buff *to, struct sk_buff *from, int len, int hlen)
 {
 	int i, j = 0;
 	int plen = 0; /* length of skb->head fragment */
+	int ret;
 	struct page *page;
 	unsigned int offset;
 
 	BUG_ON(!from->head_frag && !hlen);
 
 	/* dont bother with small payloads */
-	if (len <= skb_tailroom(to)) {
-		skb_copy_bits(from, 0, skb_put(to, len), len);
-		return;
-	}
+	if (len <= skb_tailroom(to))
+		return skb_copy_bits(from, 0, skb_put(to, len), len);
 
 	if (hlen) {
-		skb_copy_bits(from, 0, skb_put(to, hlen), hlen);
+		ret = skb_copy_bits(from, 0, skb_put(to, hlen), hlen);
+		if (unlikely(ret))
+			return ret;
 		len -= hlen;
 	} else {
 		plen = min_t(int, skb_headlen(from), len);
@@ -2163,6 +2169,11 @@ skb_zerocopy(struct sk_buff *to, const struct sk_buff *from, int len, int hlen)
 	to->len += len + plen;
 	to->data_len += len + plen;
 
+	if (unlikely(skb_orphan_frags(from, GFP_ATOMIC))) {
+		skb_tx_error(from);
+		return -ENOMEM;
+	}
+
 	for (i = 0; i < skb_shinfo(from)->nr_frags; i++) {
 		if (!len)
 			break;
@@ -2173,6 +2184,8 @@ skb_zerocopy(struct sk_buff *to, const struct sk_buff *from, int len, int hlen)
 		j++;
 	}
 	skb_shinfo(to)->nr_frags = j;
+
+	return 0;
 }
 EXPORT_SYMBOL_GPL(skb_zerocopy);
 
@@ -2838,81 +2851,85 @@ EXPORT_SYMBOL_GPL(skb_pull_rcsum);
 
 /**
  *	skb_segment - Perform protocol segmentation on skb.
- *	@skb: buffer to segment
+ *	@head_skb: buffer to segment
  *	@features: features for the output path (see dev->features)
  *
  *	This function performs segmentation on the given skb.  It returns
  *	a pointer to the first in a list of new skbs for the segments.
  *	In case of error it returns ERR_PTR(err).
  */
-struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features)
+struct sk_buff *skb_segment(struct sk_buff *head_skb,
+			    netdev_features_t features)
 {
 	struct sk_buff *segs = NULL;
 	struct sk_buff *tail = NULL;
-	struct sk_buff *fskb = skb_shinfo(skb)->frag_list;
-	skb_frag_t *skb_frag = skb_shinfo(skb)->frags;
-	unsigned int mss = skb_shinfo(skb)->gso_size;
-	unsigned int doffset = skb->data - skb_mac_header(skb);
+	struct sk_buff *list_skb = skb_shinfo(head_skb)->frag_list;
+	skb_frag_t *frag = skb_shinfo(head_skb)->frags;
+	unsigned int mss = skb_shinfo(head_skb)->gso_size;
+	unsigned int doffset = head_skb->data - skb_mac_header(head_skb);
+	struct sk_buff *frag_skb = head_skb;
 	unsigned int offset = doffset;
-	unsigned int tnl_hlen = skb_tnl_header_len(skb);
+	unsigned int tnl_hlen = skb_tnl_header_len(head_skb);
 	unsigned int headroom;
 	unsigned int len;
 	__be16 proto;
 	bool csum;
 	int sg = !!(features & NETIF_F_SG);
-	int nfrags = skb_shinfo(skb)->nr_frags;
+	int nfrags = skb_shinfo(head_skb)->nr_frags;
 	int err = -ENOMEM;
 	int i = 0;
 	int pos;
+	int dummy;
 
-	proto = skb_network_protocol(skb);
+	proto = skb_network_protocol(head_skb, &dummy);
 	if (unlikely(!proto))
 		return ERR_PTR(-EINVAL);
 
 	csum = !!can_checksum_protocol(features, proto);
-	__skb_push(skb, doffset);
-	headroom = skb_headroom(skb);
-	pos = skb_headlen(skb);
+	__skb_push(head_skb, doffset);
+	headroom = skb_headroom(head_skb);
+	pos = skb_headlen(head_skb);
 
 	do {
 		struct sk_buff *nskb;
-		skb_frag_t *frag;
+		skb_frag_t *nskb_frag;
 		int hsize;
 		int size;
 
-		len = skb->len - offset;
+		len = head_skb->len - offset;
 		if (len > mss)
 			len = mss;
 
-		hsize = skb_headlen(skb) - offset;
+		hsize = skb_headlen(head_skb) - offset;
 		if (hsize < 0)
 			hsize = 0;
 		if (hsize > len || !sg)
 			hsize = len;
 
-		if (!hsize && i >= nfrags && skb_headlen(fskb) &&
-		    (skb_headlen(fskb) == len || sg)) {
-			BUG_ON(skb_headlen(fskb) > len);
+		if (!hsize && i >= nfrags && skb_headlen(list_skb) &&
+		    (skb_headlen(list_skb) == len || sg)) {
+			BUG_ON(skb_headlen(list_skb) > len);
 
 			i = 0;
-			nfrags = skb_shinfo(fskb)->nr_frags;
-			skb_frag = skb_shinfo(fskb)->frags;
-			pos += skb_headlen(fskb);
+			nfrags = skb_shinfo(list_skb)->nr_frags;
+			frag = skb_shinfo(list_skb)->frags;
+			frag_skb = list_skb;
+			pos += skb_headlen(list_skb);
 
 			while (pos < offset + len) {
 				BUG_ON(i >= nfrags);
 
-				size = skb_frag_size(skb_frag);
+				size = skb_frag_size(frag);
 				if (pos + size > offset + len)
 					break;
 
 				i++;
 				pos += size;
-				skb_frag++;
+				frag++;
 			}
 
-			nskb = skb_clone(fskb, GFP_ATOMIC);
-			fskb = fskb->next;
+			nskb = skb_clone(list_skb, GFP_ATOMIC);
+			list_skb = list_skb->next;
 
 			if (unlikely(!nskb))
 				goto err;
@@ -2933,7 +2950,7 @@ struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features)
 			__skb_push(nskb, doffset);
 		} else {
 			nskb = __alloc_skb(hsize + doffset + headroom,
-					   GFP_ATOMIC, skb_alloc_rx_flag(skb),
+					   GFP_ATOMIC, skb_alloc_rx_flag(head_skb),
 					   NUMA_NO_NODE);
 
 			if (unlikely(!nskb))
@@ -2949,12 +2966,12 @@ struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features)
 			segs = nskb;
 		tail = nskb;
 
-		__copy_skb_header(nskb, skb);
-		nskb->mac_len = skb->mac_len;
+		__copy_skb_header(nskb, head_skb);
+		nskb->mac_len = head_skb->mac_len;
 
 		skb_headers_offset_update(nskb, skb_headroom(nskb) - headroom);
 
-		skb_copy_from_linear_data_offset(skb, -tnl_hlen,
+		skb_copy_from_linear_data_offset(head_skb, -tnl_hlen,
 						 nskb->data - tnl_hlen,
 						 doffset + tnl_hlen);
 
@@ -2963,30 +2980,32 @@ struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features)
 
 		if (!sg) {
 			nskb->ip_summed = CHECKSUM_NONE;
-			nskb->csum = skb_copy_and_csum_bits(skb, offset,
+			nskb->csum = skb_copy_and_csum_bits(head_skb, offset,
 							    skb_put(nskb, len),
 							    len, 0);
 			continue;
 		}
 
-		frag = skb_shinfo(nskb)->frags;
+		nskb_frag = skb_shinfo(nskb)->frags;
 
-		skb_copy_from_linear_data_offset(skb, offset,
+		skb_copy_from_linear_data_offset(head_skb, offset,
 						 skb_put(nskb, hsize), hsize);
 
-		skb_shinfo(nskb)->tx_flags = skb_shinfo(skb)->tx_flags & SKBTX_SHARED_FRAG;
+		skb_shinfo(nskb)->tx_flags = skb_shinfo(head_skb)->tx_flags &
+			SKBTX_SHARED_FRAG;
 
 		while (pos < offset + len) {
 			if (i >= nfrags) {
-				BUG_ON(skb_headlen(fskb));
+				BUG_ON(skb_headlen(list_skb));
 
 				i = 0;
-				nfrags = skb_shinfo(fskb)->nr_frags;
-				skb_frag = skb_shinfo(fskb)->frags;
+				nfrags = skb_shinfo(list_skb)->nr_frags;
+				frag = skb_shinfo(list_skb)->frags;
+				frag_skb = list_skb;
 
 				BUG_ON(!nfrags);
 
-				fskb = fskb->next;
+				list_skb = list_skb->next;
 			}
 
 			if (unlikely(skb_shinfo(nskb)->nr_frags >=
@@ -2997,27 +3016,30 @@ struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features)
 				goto err;
 			}
 
-			*frag = *skb_frag;
-			__skb_frag_ref(frag);
-			size = skb_frag_size(frag);
+			if (unlikely(skb_orphan_frags(frag_skb, GFP_ATOMIC)))
+				goto err;
+
+			*nskb_frag = *frag;
+			__skb_frag_ref(nskb_frag);
+			size = skb_frag_size(nskb_frag);
 
 			if (pos < offset) {
-				frag->page_offset += offset - pos;
-				skb_frag_size_sub(frag, offset - pos);
+				nskb_frag->page_offset += offset - pos;
+				skb_frag_size_sub(nskb_frag, offset - pos);
 			}
 
 			skb_shinfo(nskb)->nr_frags++;
 
 			if (pos + size <= offset + len) {
 				i++;
-				skb_frag++;
+				frag++;
 				pos += size;
 			} else {
-				skb_frag_size_sub(frag, pos + size - (offset + len));
+				skb_frag_size_sub(nskb_frag, pos + size - (offset + len));
 				goto skip_fraglist;
 			}
 
-			frag++;
+			nskb_frag++;
 		}
 
 skip_fraglist:
@@ -3031,7 +3053,7 @@ perform_csum_check:
 						  nskb->len - doffset, 0);
 			nskb->ip_summed = CHECKSUM_NONE;
 		}
-	} while ((offset += len) < skb->len);
+	} while ((offset += len) < head_skb->len);
 
 	return segs;