diff --git a/net/openvswitch/flow.c b/net/openvswitch/flow.c
index 1252c30..2a11ec2 100644
--- a/net/openvswitch/flow.c
+++ b/net/openvswitch/flow.c
@@ -183,7 +183,8 @@
 	u8 tcp_flags = 0;
 
 	if (flow->key.eth.type == htons(ETH_P_IP) &&
-	    flow->key.ip.proto == IPPROTO_TCP) {
+	    flow->key.ip.proto == IPPROTO_TCP &&
+	    likely(skb->len >= skb_transport_offset(skb) + sizeof(struct tcphdr))) {
 		u8 *tcp = (u8 *)tcp_hdr(skb);
 		tcp_flags = *(tcp + TCP_FLAGS_OFFSET) & TCP_FLAG_MASK;
 	}