Hi

This patch fixes a memory leak when an error occurs in nref_nos when 
calling sk_ASN1_INTEGER_push in libressl. If the push operation fails, 
aint is never freed.

While here, also use the proper operation in sk_ASN1_INTEGER_pop_free, 
although they're synonyms so it doesn't really matter except for code style.

This issue was found via an experimental static analyzer I'm working on,
and I manually read the code to verify whether this is a real bug or not.

---------------------------------------------------------------------------
diff --git lib/libcrypto/x509/x509_cpols.c lib/libcrypto/x509/x509_cpols.c
index b6a456023fb..b3e8a992c04 100644
--- lib/libcrypto/x509/x509_cpols.c
+++ lib/libcrypto/x509/x509_cpols.c
@@ -680,8 +680,10 @@ nref_nos(STACK_OF(ASN1_INTEGER) *nnums, 
STACK_OF(CONF_VALUE) *nos)
  			X509V3error(X509V3_R_INVALID_NUMBER);
  			goto err;
  		}
-		if (!sk_ASN1_INTEGER_push(nnums, aint))
+		if (!sk_ASN1_INTEGER_push(nnums, aint)) {
+			ASN1_INTEGER_free(aint);
  			goto merr;
+		}
  	}
  	return 1;

@@ -689,7 +691,7 @@ merr:
  	X509V3error(ERR_R_MALLOC_FAILURE);

  err:
-	sk_ASN1_INTEGER_pop_free(nnums, ASN1_STRING_free);
+	sk_ASN1_INTEGER_pop_free(nnums, ASN1_INTEGER_free);
  	return 0;
  }