From: Pauli <paul.dale@oracle.com>
Date: Mon, 12 Aug 2019 10:07:39 +0000 (+1000)
Subject: Access data after obtaining the lock not before.
X-Git-Tag: openssl-3.0.0-alpha1~1618
X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=aee6e29f0e88df18ebc21dbcf9d4d5794d7511e0;p=oweals%2Fopenssl.git

Access data after obtaining the lock not before.

It isn't completely clear that this constitutes a race condition, but it will
always be conservative to access the locked data after getting the lock.

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
(Merged from https://github.com/openssl/openssl/pull/9579)
---

diff --git a/crypto/ex_data.c b/crypto/ex_data.c
index a49aa087c8..cd8e695855 100644
--- a/crypto/ex_data.c
+++ b/crypto/ex_data.c
@@ -49,8 +49,8 @@ static EX_CALLBACKS *get_and_lock(OPENSSL_CTX *ctx, int class_index)
          return NULL;
     }
 
-    ip = &global->ex_data[class_index];
     CRYPTO_THREAD_write_lock(global->ex_data_lock);
+    ip = &global->ex_data[class_index];
     return ip;
 }