Why does Joomla change the file permissions on installation of plugins?

Question

I have the following problem: I have a apache server running under the user http:http. Further the php scripts are evaluated through fastcgi and php-fpm. The php scripts are running under the user foo:foo. The files of joomla are owned by foo:foo and uploads are done via FTP.

When I modify the index.php of joomla to touch a temporary file it gets the correct rights (owned by foo:foo and file permissions rw-r--r--).

However when I install a plugin from within the backend, the files get the same owner (foo:foo) but another set of permission (rw-------). Folders get the correct rwxr-xr-x. (Remark: I installed the plugin directly from the web. So I did not upload the extracted files via FTP or similar. Instead joomla did extract the zip file.)

I understand that my configuration is ok in general but in case of an installation using joomla backend some bug seems to be triggered. What do you think? Is there any way of further debugging?

Answer 1

Maybe check your PHP fpm configuration. This answer describes how umask is set https://stackoverflow.com/a/21319941/123594

Answer 2

By default, the file permissions on Joomla extracted files are 644 and the folder permissions are 755.

If you're seeing something different, then, as @jdog mentioned above, you will need check your umask settings (if you have a system administrator then I suggest you let him handle this). umask is used to remove deny default permissions (it is not used to add additional permissions). I would say you have your umask set to 077 for your Apache process.