From b4074069b2a89a14d9406f4c10c92811cdd78c79 Mon Sep 17 00:00:00 2001
From: Vladislav Vaintroub <wlad@mariadb.com>
Date: Tue, 21 Sep 2021 19:14:07 +0200
Subject: [PATCH] MDEV-26657 : Initialize some fields in
 create_background_thd()

Avoid reading uninitialized memory by  thd_get_error_context_description().
Note, that THD::real_id can't be initialized at this stage, so it will be zeroed.
---
 sql/sql_class.cc | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/sql/sql_class.cc b/sql/sql_class.cc
index 0d9a8439ccb..883e9c688ff 100644
--- a/sql/sql_class.cc
+++ b/sql/sql_class.cc
@@ -4922,6 +4922,9 @@ MYSQL_THD create_background_thd()
   thd->set_command(COM_DAEMON);
   thd->system_thread= SYSTEM_THREAD_GENERIC;
   thd->security_ctx->host_or_ip= "";
+  thd->real_id= 0;
+  thd->thread_id= 0;
+  thd->query_id= 0;
   return thd;
 }