Merge tag 'v4.4.73' into toradex_vf_4.4-nextColibri-VF_LXDE-Image_2.7b3-20170630

This is the 4.4.73 stable release

1 files changed, 8 insertions, 6 deletions

diff --git a/net/ipv6/output_core.c b/net/ipv6/output_core.c
index 1d184322a7b1..8b56c5240429 100644
--- a/net/ipv6/output_core.c
+++ b/net/ipv6/output_core.c
@@ -79,14 +79,13 @@ EXPORT_SYMBOL(ipv6_select_ident);
 int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
 {
 	u16 offset = sizeof(struct ipv6hdr);
-	struct ipv6_opt_hdr *exthdr =
-				(struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
 	unsigned int packet_len = skb_tail_pointer(skb) -
 		skb_network_header(skb);
 	int found_rhdr = 0;
 	*nexthdr = &ipv6_hdr(skb)->nexthdr;
 
-	while (offset + 1 <= packet_len) {
+	while (offset <= packet_len) {
+		struct ipv6_opt_hdr *exthdr;
 
 		switch (**nexthdr) {
 
@@ -107,13 +106,16 @@ int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
 			return offset;
 		}
 
-		offset += ipv6_optlen(exthdr);
-		*nexthdr = &exthdr->nexthdr;
+		if (offset + sizeof(struct ipv6_opt_hdr) > packet_len)
+			return -EINVAL;
+
 		exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) +
 						 offset);
+		offset += ipv6_optlen(exthdr);
+		*nexthdr = &exthdr->nexthdr;
 	}
 
-	return offset;
+	return -EINVAL;
 }
 EXPORT_SYMBOL(ip6_find_1stfragopt);