Merging upstream version 4.19.269.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 19 insertions, 17 deletions

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index e0be1f865..4178fc28c 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -3560,23 +3560,25 @@ struct sk_buff *skb_segment(struct sk_buff *head_skb,
 	int pos;
 	int dummy;
 
-	if (list_skb && !list_skb->head_frag && skb_headlen(list_skb) &&
-	    (skb_shinfo(head_skb)->gso_type & SKB_GSO_DODGY)) {
-		/* gso_size is untrusted, and we have a frag_list with a linear
-		 * non head_frag head.
-		 *
-		 * (we assume checking the first list_skb member suffices;
-		 * i.e if either of the list_skb members have non head_frag
-		 * head, then the first one has too).
-		 *
-		 * If head_skb's headlen does not fit requested gso_size, it
-		 * means that the frag_list members do NOT terminate on exact
-		 * gso_size boundaries. Hence we cannot perform skb_frag_t page
-		 * sharing. Therefore we must fallback to copying the frag_list
-		 * skbs; we do so by disabling SG.
-		 */
-		if (mss != GSO_BY_FRAGS && mss != skb_headlen(head_skb))
-			features &= ~NETIF_F_SG;
+	if ((skb_shinfo(head_skb)->gso_type & SKB_GSO_DODGY) &&
+	    mss != GSO_BY_FRAGS && mss != skb_headlen(head_skb)) {
+		struct sk_buff *check_skb;
+
+		for (check_skb = list_skb; check_skb; check_skb = check_skb->next) {
+			if (skb_headlen(check_skb) && !check_skb->head_frag) {
+				/* gso_size is untrusted, and we have a frag_list with
+				 * a linear non head_frag item.
+				 *
+				 * If head_skb's headlen does not fit requested gso_size,
+				 * it means that the frag_list members do NOT terminate
+				 * on exact gso_size boundaries. Hence we cannot perform
+				 * skb_frag_t page sharing. Therefore we must fallback to
+				 * copying the frag_list skbs; we do so by disabling SG.
+				 */
+				features &= ~NETIF_F_SG;
+				break;
+			}
+		}
 	}
 
 	__skb_push(head_skb, doffset);