cms_SignerInfo_content_sign: free sig on failure path

Signed-off-by: NKurt Roeckx <kurt@openssl.org>
Reviewed-by: NRich Salz <rsalz@openssl.org>

crypto/cms/cms_sd.c

@@ -680,7 +680,10 @@ static int cms_SignerInfo_content_sign(CMS_ContentInfo *cms,
 			goto err;
 			}
 		if (EVP_PKEY_sign(pctx, sig, &siglen, md, mdlen) <= 0)
+			{
+			OPENSSL_free(sig);
 			goto err;
+			}
 		ASN1_STRING_set0(si->signature, sig, siglen);
 		}
 	else