From b8e4effbcffd66dd8101d761bad5c7fc9d13b333 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ren=C3=A9=20Canna=C3=B2?= <rene.cannao@gmail.com>
Date: Mon, 18 Nov 2019 09:41:55 +1100
Subject: [PATCH] Fix buffer overflow for long GTID set #2395

---
 lib/mysql_connection.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/lib/mysql_connection.cpp b/lib/mysql_connection.cpp
index ae43a7381..b18f0abaa 100644
--- a/lib/mysql_connection.cpp
+++ b/lib/mysql_connection.cpp
@@ -2201,6 +2201,9 @@ bool MySQL_Connection::get_gtid(char *buff, uint64_t *trx_id) {
 				const char *data;
 				size_t length;
 				if (mysql_session_track_get_first(mysql, SESSION_TRACK_GTIDS, &data, &length) == 0) {
+					if (length >= (sizeof(gtid_uuid) - 1)) {
+						length = sizeof(gtid_uuid) - 1;
+					}
 					if (memcmp(gtid_uuid,data,length)) {
 						// copy to local buffer in MySQL_Connection
 						memcpy(gtid_uuid,data,length);