--- mariadb-10.3-10.3.22.orig/libmariadb/libmariadb/mariadb_lib.c
+++ mariadb-10.3-10.3.22/libmariadb/libmariadb/mariadb_lib.c
@@ -2000,6 +2000,8 @@ mysql_close(MYSQL *mysql)
     if (mysql->extension)
       free(mysql->extension);
 
+    mysql->net.extension = NULL;
+    mysql->extension = NULL;
     mysql->net.pvio= 0;
     if (mysql->free_me)
       free(mysql);