How to Disable Shutdown and Reboot Commands in Linux

The shutdown command schedules a time for a Linux system to be powered down, it may as well be used to halt, power-off or reboot the machine when invoked with particular options and reboot instructs the system to restart.

Certain Linux distros such as Ubuntu, Linux Mint, Mandriva just to mention but a few, make it possible to reboot/halt/shutdown the system as a normal user, by default. This is not ideal setting especially on servers, it must be something to worry about especially for a system administrator.

In this article, we will show how to disable shutdown and reboot commands for normal users in Linux.

Disable Shutdown and Reboot Commands in Linux

The easiest way to disable shutdown and reboot commands using the /etc/sudoers file, here you can specify a user (tecmint) or group (developers) which are not allowed to execute these commands.

# vi /etc/sudoers

Add these lines to Command Aliases section.

Cmnd_Alias     SHUTDOWN = /sbin/shutdown,/sbin/reboot,/sbin/halt,/sbin/poweroff
# User privilege specification
tecmint   ALL=(ALL:ALL) ALL, !SHUTDOWN
# Allow members of group sudo to execute any command
%developers  ALL=(ALL:ALL) ALL,  !SHUTDOWN

Now try to execute shutdown and reboot commands as normail user (tecmint).

Command shutdown and Reboot Disabled for User

Another way is to remove execution permissions on shutdown and reboot commands for all users except root.

# chmod o-x /sbin/shutdown
# chmod o-x /sbin/reboot

Note: Under systemd, these file(/sbin/shutdown, /sbin/reboot, /sbin/halt, /sbin/poweroff) are only symbolic links to /bin/systemctl:

# ls -l /sbin/shutdown
# ls -l /sbin/reboot
# ls -l /sbin/halt
# ls -l /sbin/poweroff

SystemD Symbolic Links

To prevent other users from running these commands, you would simply remove execution permissions as explained above, but this is not effective under systemd. You can remove execution permissions on /bin/systemctl meaning all other users except root will only run systemctl.

      ▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬

                                                    ► Read more: http://adf.ly/1n5ZRK

      ▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬