[openssl] master update

[Dr. Paul Dale]

The branch master has been updated
       via  625679b6d79296e020bb0cad31d6ac24ad547a39 (commit)
      from  a149f7502458dc022501c2347629cc847f2e1298 (commit)


- Log -----------------------------------------------------------------
commit 625679b6d79296e020bb0cad31d6ac24ad547a39
Author: Pauli <paul.dale at oracle.com>
Date:   Wed Aug 26 14:36:50 2020 +1000

    EVP: NULL pctx pointer after free.
    
    Not doing so can result in a double free.
    
    Reviewed-by: Richard Levitte <levitte at openssl.org>
    (Merged from https://github.com/openssl/openssl/pull/12718)

-----------------------------------------------------------------------

Summary of changes:
 crypto/evp/digest.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/crypto/evp/digest.c b/crypto/evp/digest.c
index f9ba59ca63..c9b4e3fd6e 100644
--- a/crypto/evp/digest.c
+++ b/crypto/evp/digest.c
@@ -34,8 +34,10 @@ int EVP_MD_CTX_reset(EVP_MD_CTX *ctx)
      * pctx should be freed by the user of EVP_MD_CTX
      * if EVP_MD_CTX_FLAG_KEEP_PKEY_CTX is set
      */
-    if (!EVP_MD_CTX_test_flags(ctx, EVP_MD_CTX_FLAG_KEEP_PKEY_CTX))
+    if (!EVP_MD_CTX_test_flags(ctx, EVP_MD_CTX_FLAG_KEEP_PKEY_CTX)) {
         EVP_PKEY_CTX_free(ctx->pctx);
+        ctx->pctx = NULL;
+    }
 #endif
 
     EVP_MD_free(ctx->fetched_digest);