--- openssl-1.0.2u/crypto/x509/x509_cmp.c.cve-2021-23841	2019-12-20 14:02:41.000000000 +0000
+++ openssl-1.0.2u/crypto/x509/x509_cmp.c	2022-04-04 20:58:23.996994000 +0000
@@ -87,6 +87,8 @@
 
     EVP_MD_CTX_init(&ctx);
     f = X509_NAME_oneline(a->cert_info->issuer, NULL, 0);
+    if (f == NULL)
+        goto err;
     if (!EVP_DigestInit_ex(&ctx, EVP_md5(), NULL))
         goto err;
     if (!EVP_DigestUpdate(&ctx, (unsigned char *)f, strlen(f)))