I think it's a permissions issue on /tmp but I can't seem to find a solution.

I'm using PHP to create a registration and login page; I can see that when the user logs in, the session data is passed to the /tmp folder, but when they are redirected to the home/index page, the session data is returned NULL .

I use the following to verify that the correct path has permissions:

<?php

    var_dump($_SESSION);
    if (!is_writable(session_save_path()))
    {
            echo 'Session path "'.session_save_path().'" is not writable for PHP!'; 
    }
    else
    {
        echo 'Session path "'.session_save_path().'" is writable for PHP!'; 
    }

?>

I ended up with:

NULL Session path "/var/lib/php/sessions" is writable for PHP!

Checking the folder, I can see the session data is saved to /tmp, so it's definitely writable.

So my best guess is that start_session() has permission to write to /tmp, but not read? But that doesn't make any sense to me.

Checking the permissions in var/lib/php/sessions I got (example):

drwx-wx-wt 2 root root 151552 Dec 22 05:09

Change the permissions of the folder to:

-rw-rw-rw-

Cause any security or other functional issues?