Let's say that you have set up a multi-seat system for use in a school or library, allowing GDM to launch multiple X sessions to run simultaneously with different users/keyboards/monitors.

By default in Debian/Ubuntu in Gnome, you don't have to be root to shutdown or reboot. But this means any user can choose "reboot" or "shutdown" and kick off the other three users.

You have blocked physical access to the server so they can't simply push the power or reset buttons.

What is the correct way of disabling the "shutdown" and "reboot" functionality which is exposed to regular users through GDM/Gnome/whatever window manager you're using?

  • 1
    What if they pull the plug?
    – wizlog
    Commented Nov 7, 2011 at 7:20
  • 2
    @wizlog, see "You have blocked physical access to the server". This goes for its power plug too. Commented Nov 7, 2011 at 22:09

3 Answers 3


First, note that ConsoleKit's shutdown function considers "single user" and "multiple users" as two different situations – shutting down the system always requires administrator authentication if other users are logged in.

All such actions are managed by PolicyKit. If you want to adjust the policies, you can do so as described in polkit(8) – /etc/polkit-1/rules.d/20-disallow-shutdown.rules:

polkit.addRule(function(action, subject) {
    if ((action.id == "org.freedesktop.consolekit.system.stop" ||
         action.id == "org.freedesktop.consolekit.system.restart") &&
        subject.isInGroup("users")) {
            return subject.active ? polkit.Result.AUTH_ADMIN : polkit.Result.NO;

PolicyKit 0.105 and earlier versions document this in pklocalauthority(8)/etc/polkit-1/localauthority/50-local.d/20-disallow-shutdown.pkla:

[Disallow shutdown]

The Actions are listed in the ConsoleKit policy file or by running pkaction.

  • pklocalauthority is deprecated
  • You need systemd with logind and polkit.

Available actions

# or /usr/share/polkit-1/actions/

You should look at /usr/share/polkit-1/actions/org.freedesktop.login1.policy

Add rule

First start monitoring system messages, so we can see if our new rule works:

journalctl -f

Then create file /etc/polkit-1/rules.d/60-noreboot_norestart.rules (in javascript).

In this file we add logic to check for actions and allow users in power group or require su authorization:

const power_actions = [

polkit.addRule(function ({ id }, subject) {
  if (power_actions.includes(id)) {
    return subject.isInGroup('power') ? polkit.Result.YES : polkit.Result.AUTH_ADMIN;

Rule should be loaded and it should work. References below.

  1. https://lists.fedoraproject.org/pipermail/users/2013-September/440457.html
  2. https://wiki.archlinux.org/index.php/Polkit#Authorization_rules
  3. http://www.freedesktop.org/software/polkit/docs/latest/polkit.8.html
  4. https://bbs.archlinux.org/viewtopic.php?pid=1335204#p1335204
  • 2
    Are you sure that needs to be return polkit.Result.NO? I would've thought it'd be polkit.Result.YES to allow users in group "power"
    – ffledgling
    Commented Aug 28, 2014 at 17:32
  • @ffledgling That's correct. I've edited the answer to reflect this, and to add a missing curly brace.
    – Legooolas
    Commented Nov 5, 2014 at 16:25
  • 1
    It's also possible to use "NO" instead of "AUTH_ADMIN" to disable the menu on the login screen entirely, and the "org.freedesktop.login1.suspend" and "org.freedesktop.login1.suspend-multiple-sessions" options for controlling the Suspend menu item.
    – Legooolas
    Commented Nov 5, 2014 at 16:27
  • Wish I could upvote this multiple times Commented Dec 18, 2016 at 2:42

Here's a more polished and modern ES6 version of this.


/* jshint esnext:true */                                                                                                                                                                                                                      

 * @see https://superuser.com/questions/354678/what-is-the-correct-way-to-prevent-non-root-users-from-issuing-shutdowns-or-rebo
 * @since 2019.05.26
polkit.addRule( function(action, subject) {
    const power_actions = [

    if ( power_actions.includes( action.id ) ) {

        let result = polkit.Result.AUTH_ADMIN;

        if ( subject.isInGroup( 'wheel' ) ) {
            result = polkit.Result.YES;

        return result;


} );

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .