diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
index 2bb750617c08..8914ccb1cb60 100644
--- a/net/ipv4/cipso_ipv4.c
+++ b/net/ipv4/cipso_ipv4.c
@@ -1595,7 +1595,7 @@ static int cipso_v4_parsetag_loc(const struct cipso_v4_doi *doi_def,
  *
  * Description:
  * Parse the packet's IP header looking for a CIPSO option.  Returns a pointer
- * to the start of the CIPSO option on success, NULL if one if not found.
+ * to the start of the CIPSO option on success, NULL if one is not found.
  *
  */
 unsigned char *cipso_v4_optptr(const struct sk_buff *skb)
@@ -1605,10 +1605,8 @@ unsigned char *cipso_v4_optptr(const struct sk_buff *skb)
 	int optlen;
 	int taglen;
 
-	for (optlen = iph->ihl*4 - sizeof(struct iphdr); optlen > 0; ) {
+	for (optlen = iph->ihl*4 - sizeof(struct iphdr); optlen > 1; ) {
 		switch (optptr[0]) {
-		case IPOPT_CIPSO:
-			return optptr;
 		case IPOPT_END:
 			return NULL;
 		case IPOPT_NOOP:
@@ -1617,6 +1615,11 @@ unsigned char *cipso_v4_optptr(const struct sk_buff *skb)
 		default:
 			taglen = optptr[1];
 		}
+		if (!taglen || taglen > optlen)
+			return NULL;
+		if (optptr[0] == IPOPT_CIPSO)
+			return optptr;
+
 		optlen -= taglen;
 		optptr += taglen;
 	}