Check for V_ASN1_BOOLEAN/V_ASN1_NULL in X509_ATTRIBUTE_get0_data

The member value.ptr is undefined for those ASN1 types.
Reviewed-by: NMatt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/9278)

(cherry picked from commit 94f4d58a87eac9c6fe4cb46b998656bd6d6f03a5)

crypto/x509/x509_att.c

@@ -314,7 +314,9 @@ void *X509_ATTRIBUTE_get0_data(X509_ATTRIBUTE *attr, int idx,
     ttmp = X509_ATTRIBUTE_get0_type(attr, idx);
     if (!ttmp)
         return NULL;
-    if (atrtype != ASN1_TYPE_get(ttmp)) {
+    if (atrtype == V_ASN1_BOOLEAN
+            || atrtype == V_ASN1_NULL
+            || atrtype != ASN1_TYPE_get(ttmp)) {
         X509err(X509_F_X509_ATTRIBUTE_GET0_DATA, X509_R_WRONG_TYPE);
         return NULL;
     }