diff --git a/net/netfilter/xt_tcpmss.c b/net/netfilter/xt_tcpmss.c
index 37704ab01799..0d32d4841cb3 100644
--- a/net/netfilter/xt_tcpmss.c
+++ b/net/netfilter/xt_tcpmss.c
@@ -61,7 +61,7 @@ tcpmss_mt(const struct sk_buff *skb, struct xt_action_param *par)
 			return (mssval >= info->mss_min &&
 				mssval <= info->mss_max) ^ info->invert;
 		}
-		if (op[i] < 2)
+		if (op[i] < 2 || i == optlen - 1)
 			i++;
 		else
 			i += op[i+1] ? : 1;