diff --git a/net/netfilter/nf_synproxy_core.c b/net/netfilter/nf_synproxy_core.c
index 4bb4cfde28b4..c6c0d27caaed 100644
--- a/net/netfilter/nf_synproxy_core.c
+++ b/net/netfilter/nf_synproxy_core.c
@@ -31,6 +31,9 @@ synproxy_parse_options(const struct sk_buff *skb, unsigned int doff,
 	int length = (th->doff * 4) - sizeof(*th);
 	u8 buf[40], *ptr;
 
+	if (unlikely(length < 0))
+		return false;
+
 	ptr = skb_header_pointer(skb, doff + sizeof(*th), length, buf);
 	if (ptr == NULL)
 		return false;
@@ -47,6 +50,8 @@ synproxy_parse_options(const struct sk_buff *skb, unsigned int doff,
 			length--;
 			continue;
 		default:
+			if (length < 2)
+				return true;
 			opsize = *ptr++;
 			if (opsize < 2)
 				return true;