diff --git a/include/net/cipso_ipv4.h b/include/net/cipso_ipv4.h
index 9808877c2ab91a609a79494fbd4945dd8def5bd3..a7a683e30b64e6beb2bc87907c85576d85385007 100644
--- a/include/net/cipso_ipv4.h
+++ b/include/net/cipso_ipv4.h
@@ -42,6 +42,7 @@
 #include <net/netlabel.h>
 #include <net/request_sock.h>
 #include <linux/atomic.h>
+#include <asm/unaligned.h>
 
 /* known doi values */
 #define CIPSO_V4_DOI_UNKNOWN          0x00000000
@@ -285,7 +286,33 @@ static inline int cipso_v4_skbuff_getattr(const struct sk_buff *skb,
 static inline int cipso_v4_validate(const struct sk_buff *skb,
 				    unsigned char **option)
 {
-	return -ENOSYS;
+	unsigned char *opt = *option;
+	unsigned char err_offset = 0;
+	u8 opt_len = opt[1];
+	u8 opt_iter;
+
+	if (opt_len < 8) {
+		err_offset = 1;
+		goto out;
+	}
+
+	if (get_unaligned_be32(&opt[2]) == 0) {
+		err_offset = 2;
+		goto out;
+	}
+
+	for (opt_iter = 6; opt_iter < opt_len;) {
+		if (opt[opt_iter + 1] > (opt_len - opt_iter)) {
+			err_offset = opt_iter + 1;
+			goto out;
+		}
+		opt_iter += opt[opt_iter + 1];
+	}
+
+out:
+	*option = opt + err_offset;
+	return err_offset;
+
 }
 #endif /* CONFIG_NETLABEL */