1 files changed, 38 insertions, 15 deletions

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 0f0933b338d7..a95877a8ac8b 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -932,17 +932,20 @@ EXPORT_SYMBOL_GPL(skb_morph);
  */
 int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask)
 {
-	int i;
+	struct ubuf_info *uarg = skb_shinfo(skb)->destructor_arg;
 	int num_frags = skb_shinfo(skb)->nr_frags;
 	struct page *page, *head = NULL;
-	struct ubuf_info *uarg = skb_shinfo(skb)->destructor_arg;
+	int i, new_frags;
+	u32 d_off;
 
-	for (i = 0; i < num_frags; i++) {
-		skb_frag_t *f = &skb_shinfo(skb)->frags[i];
-		u32 p_off, p_len, copied;
-		struct page *p;
-		u8 *vaddr;
+	if (!num_frags)
+		return 0;
+
+	if (skb_shared(skb) || skb_unclone(skb, gfp_mask))
+		return -EINVAL;
 
+	new_frags = (__skb_pagelen(skb) + PAGE_SIZE - 1) >> PAGE_SHIFT;
+	for (i = 0; i < new_frags; i++) {
 		page = alloc_page(gfp_mask);
 		if (!page) {
 			while (head) {
@@ -952,17 +955,36 @@ int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask)
 			}
 			return -ENOMEM;
 		}
+		set_page_private(page, (unsigned long)head);
+		head = page;
+	}
+
+	page = head;
+	d_off = 0;
+	for (i = 0; i < num_frags; i++) {
+		skb_frag_t *f = &skb_shinfo(skb)->frags[i];
+		u32 p_off, p_len, copied;
+		struct page *p;
+		u8 *vaddr;
 
 		skb_frag_foreach_page(f, f->page_offset, skb_frag_size(f),
 				      p, p_off, p_len, copied) {
+			u32 copy, done = 0;
 			vaddr = kmap_atomic(p);
-			memcpy(page_address(page) + copied, vaddr + p_off,
-			       p_len);
+
+			while (done < p_len) {
+				if (d_off == PAGE_SIZE) {
+					d_off = 0;
+					page = (struct page *)page_private(page);
+				}
+				copy = min_t(u32, PAGE_SIZE - d_off, p_len - done);
+				memcpy(page_address(page) + d_off,
+				       vaddr + p_off + done, copy);
+				done += copy;
+				d_off += copy;
+			}
 			kunmap_atomic(vaddr);
 		}
-
-		set_page_private(page, (unsigned long)head);
-		head = page;
 	}
 
 	/* skb frags release userspace buffers */
@@ -972,11 +994,12 @@ int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask)
 	uarg->callback(uarg, false);
 
 	/* skb frags point to kernel buffers */
-	for (i = num_frags - 1; i >= 0; i--) {
-		__skb_fill_page_desc(skb, i, head, 0,
-				     skb_shinfo(skb)->frags[i].size);
+	for (i = 0; i < new_frags - 1; i++) {
+		__skb_fill_page_desc(skb, i, head, 0, PAGE_SIZE);
 		head = (struct page *)page_private(head);
 	}
+	__skb_fill_page_desc(skb, new_frags - 1, head, 0, d_off);
+	skb_shinfo(skb)->nr_frags = new_frags;
 
 	skb_shinfo(skb)->tx_flags &= ~SKBTX_DEV_ZEROCOPY;
 	return 0;