diff --git a/net/ipv4/gre_demux.c b/net/ipv4/gre_demux.c
index 5fd6e8ed02b5..66fdbfe5447c 100644
--- a/net/ipv4/gre_demux.c
+++ b/net/ipv4/gre_demux.c
@@ -56,7 +56,9 @@ int gre_del_protocol(const struct gre_protocol *proto, u8 version)
 }
 EXPORT_SYMBOL_GPL(gre_del_protocol);
 
-/* Fills in tpi and returns header length to be pulled. */
+/* Fills in tpi and returns header length to be pulled.
+ * Note that caller must use pskb_may_pull() before pulling GRE header.
+ */
 int gre_parse_header(struct sk_buff *skb, struct tnl_ptk_info *tpi,
 		     bool *csum_err, __be16 proto, int nhs)
 {
@@ -110,8 +112,14 @@ int gre_parse_header(struct sk_buff *skb, struct tnl_ptk_info *tpi,
 	 * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header
 	 */
 	if (greh->flags == 0 && tpi->proto == htons(ETH_P_WCCP)) {
+		u8 _val, *val;
+
+		val = skb_header_pointer(skb, nhs + hdr_len,
+					 sizeof(_val), &_val);
+		if (!val)
+			return -EINVAL;
 		tpi->proto = proto;
-		if ((*(u8 *)options & 0xF0) != 0x40)
+		if ((*val & 0xF0) != 0x40)
 			hdr_len += 4;
 	}
 	tpi->hdr_len = hdr_len;