From ab547fc005307ecf48451638e947cdabca147159 Mon Sep 17 00:00:00 2001
From: Pauli <pauli@openssl.org>
Date: Thu, 4 Nov 2021 08:23:32 +1000
Subject: [PATCH] avoid a NULL dereference when getting digest

Fixes #16961

Reviewed-by: Matthias St. Pierre <Matthias.St.Pierre@ncp-e.com>
(Merged from https://github.com/openssl/openssl/pull/16969)
---
 crypto/evp/evp_lib.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/crypto/evp/evp_lib.c b/crypto/evp/evp_lib.c
index 64d7fb046de..24092cfd5be 100644
--- a/crypto/evp/evp_lib.c
+++ b/crypto/evp/evp_lib.c
@@ -999,7 +999,7 @@ EVP_MD *EVP_MD_CTX_get1_md(EVP_MD_CTX *ctx)
     if (ctx == NULL)
         return NULL;
     md = (EVP_MD *)ctx->reqdigest;
-    if (!EVP_MD_up_ref(md))
+    if (md == NULL || !EVP_MD_up_ref(md))
         return NULL;
     return md;
 }
-- 
2.47.2