Error in phpMyAdmin after updating to v4.8.0: The $cfg['TempDir'] (./tmp/) is not accessible

Question

phpMyAdmin worked fine with v4.7.9. Now after updating to v4.8.0 today (replacing the old phpmyadmin folder against the new one) I\'m getting this mess

Answer 1

From the phpMyAdmin documentation:

$cfg['TempDir']
    Type:   string
    Default value:  './tmp/'

The name of the directory where temporary files can be stored. It is used for several purposes, currently:

The templates cache which speeds up page loading. ESRI Shapefiles import, see 6.30 Import: How can I import ESRI Shapefiles?.

To work around limitations of open_basedir for uploaded files, see 1.11 I get an ‘open_basedir restriction’ while uploading a file from the import tab..

This directory should have as strict permissions as possible as the only user required to access this directory is the one who runs the webserver. If you have root privileges, simply make this user owner of this directory and make it accessible only by it:

chown www-data:www-data tmp
chmod 700 tmp

If you cannot change owner of the directory, you can achieve a similar setup using ACL:

chmod 700 tmp
setfacl -m "g:www-data:rwx" tmp
setfacl -d -m "g:www-data:rwx" tmp

If neither of above works for you, you can still make the directory chmod 777, but it might impose risk of other users on system reading and writing data in this directory.