What's the default MySQL my.cnf configuration from default WordPress One-Click app in Linode

The Wordpress One-Click App doesn't make significant changes to the MySQL installation beyond ensuring it installs in a secure manner. The contents of the my.cnf file for the default installation refer to two other directories: /etc/mysql/mariadb.conf.d and /etc/mysql/conf.d, where each directory contains additional configuration files. This is a snippet of the default /etc/mysql/mariadb.conf.d/50-client.cnf file which is referenced in the my.cnf file:

# * Basic Settings
#
user                    = mysql
pid-file                = /run/mysqld/mysqld.pid
socket                  = /run/mysqld/mysqld.sock
#port                   = 3306
basedir                 = /usr
datadir                 = /var/lib/mysql
tmpdir                  = /tmp
lc-messages-dir         = /usr/share/mysql
#skip-external-locking

# Instead of skip-networking the default is now to listen only on
# localhost which is more compatible and is not less secure.
bind-address            = 127.0.0.1

#
# * Fine Tuning
#
#key_buffer_size        = 16M
#max_allowed_packet     = 16M
#thread_stack           = 192K
#thread_cache_size      = 8
# This replaces the startup script and checks MyISAM tables if needed
# the first time they are touched
#myisam_recover_options = BACKUP
#max_connections        = 100
#table_cache            = 64
#thread_concurrency     = 10

#
# * Query Cache Configuration
#
#query_cache_limit      = 1M
query_cache_size        = 16M

Because you have root access to your Linode, you're able to make changes to any of the configuration files as needed. This would need to be done via the command line after the One-Click App deployment is completed.