evp: address a use after free state when using HMAC and MD copy.

Fixes #17261

Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/17263)

(cherry picked from commit ad2fcee1632d3f21a37e8e108d4c0dcf9099686d)

diff --git a/crypto/evp/digest.c b/crypto/evp/digest.c
index d3a28fa3515f701eee6c6fc3b7274621e0d1896c..d92059cbccb0369d1928a1af6ff7288bb59cf285 100644 (file)
--- a/crypto/evp/digest.c
+++ b/crypto/evp/digest.c
@@ -520,7 +520,7 @@ int EVP_MD_CTX_copy_ex(EVP_MD_CTX *out, const EVP_MD_CTX *in)
         if (out->fetched_digest != NULL)
             EVP_MD_free(out->fetched_digest);
         *out = *in;
-        return 1;
+        goto clone_pkey;
     }
 
     if (in->digest->prov == NULL
@@ -551,6 +551,7 @@ int EVP_MD_CTX_copy_ex(EVP_MD_CTX *out, const EVP_MD_CTX *in)
         }
     }
 
+ clone_pkey:
     /* copied EVP_MD_CTX should free the copied EVP_PKEY_CTX */
     EVP_MD_CTX_clear_flags(out, EVP_MD_CTX_FLAG_KEEP_PKEY_CTX);
 #ifndef FIPS_MODULE