serverinfo_process_buffer: check result of realloc(ctx->cert->key->serverinfo) and don't leak memory if it fails

Signed-off-by: Kurt Roeckx <kurt@roeckx.be>
Reviewed-by: Matt Caswell <matt@openssl.org>
diff --git a/ssl/ssl_rsa.c b/ssl/ssl_rsa.c
index 6f9337e..006c02e 100644
--- a/ssl/ssl_rsa.c
+++ b/ssl/ssl_rsa.c
@@ -948,6 +948,8 @@
 int SSL_CTX_use_serverinfo(SSL_CTX *ctx, const unsigned char *serverinfo,
 			   size_t serverinfo_length)
 	{
+	unsigned char *new_serverinfo;
+
 	if (ctx == NULL || serverinfo == NULL || serverinfo_length == 0)
 		{
 		SSLerr(SSL_F_SSL_CTX_USE_SERVERINFO,ERR_R_PASSED_NULL_PARAMETER);
@@ -968,13 +970,14 @@
 		SSLerr(SSL_F_SSL_CTX_USE_SERVERINFO,ERR_R_INTERNAL_ERROR);
 		return 0;
 		}
-	ctx->cert->key->serverinfo = OPENSSL_realloc(ctx->cert->key->serverinfo,
+	new_serverinfo = OPENSSL_realloc(ctx->cert->key->serverinfo,
 						     serverinfo_length);
-	if (ctx->cert->key->serverinfo == NULL)
+	if (new_serverinfo == NULL)
 		{
 		SSLerr(SSL_F_SSL_CTX_USE_SERVERINFO,ERR_R_MALLOC_FAILURE);
 		return 0;
 		}
+	ctx->cert->key->serverinfo = new_serverinfo;
 	memcpy(ctx->cert->key->serverinfo, serverinfo, serverinfo_length);
 	ctx->cert->key->serverinfo_length = serverinfo_length;