From: Bernd Edlinger <bernd.edlinger@hotmail.de>
Date: Tue, 13 Jun 2017 19:22:45 +0000 (+0200)
Subject: Fix a possible crash in dsa_builtin_paramgen2.
X-Git-Tag: OpenSSL_1_1_0g~172
X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=388105fff3a3290806f411f0ea1d384adecb7ffa;p=oweals%2Fopenssl.git

Fix a possible crash in dsa_builtin_paramgen2.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/3675)
(cherry picked from commit fb0a64126b8c11a6961dfa1323c3602b591af7df)
---

diff --git a/crypto/dsa/dsa_gen.c b/crypto/dsa/dsa_gen.c
index 3efeab84fa..e58ad8d70d 100644
--- a/crypto/dsa/dsa_gen.c
+++ b/crypto/dsa/dsa_gen.c
@@ -376,6 +376,8 @@ int dsa_builtin_paramgen2(DSA *ret, size_t L, size_t N,
     } else {
         p = BN_CTX_get(ctx);
         q = BN_CTX_get(ctx);
+        if (q == NULL)
+            goto err;
     }
 
     if (!BN_lshift(test, BN_value_one(), L - 1))