Ubuntu – Broken sudo: can’t open /etc/sudoers: No such file or directory

Ok. I have fixed my issue. And like I thought, it was not the file.

Solution

I had up until 10 minutes ago, only noticed that sudo wasn't working. As most of my work takes place in tmux, I never noticed my user account.

Upon first logging in I would get the following error:

-bash: /etc/profile Permission denied

And it would set me to: I have no name@<ipaddress> as my account.

So I did some research on this issue and found more results then the other issue. Including one result that was a perfect match for my situation, as found here.

The issue was that my /etc/ folder was missing the execute permission on the group. So executing: chmod g+x /etc fixed the issue after logging out and back in.

Thanks

Thanks for the help in the comments, the suggestions you gave were still valuable and helped narrow down the problem more. In the end it was far simpler then it seemed.

In order to fix this, you can either reinstall sudo, or download a default /etc/sudoers and edit it. Both ways require these steps: First, restart your computer. When the Grub screen displays, instead of choosing Ubuntu xxx, choose Advanced options for Ubuntu xxx. Under Advanced Options, choose Recovery mode. The second step is to mount your partitions rw. To do this, choose Clean packages, Ok, and then when you see the recovery screen again, select Root shell. Enable the wifi from the root shell. Either reinstall sudo:

apt-get install --reinstall sudo

or insert this into /etc/sudoers:

# /etc/sudoers
#
# This file MUST be edited with the 'visudo' command as root.
#
# See the man page for details on how to write a sudoers file.
#

Defaults    env_reset

# Uncomment to allow members of group sudo to not need a password
%sudo ALL=NOPASSWD: ALL

# Host alias specification

# User alias specification

# Cmnd alias specification

# User privilege specification
root    ALL=(ALL) ALL

# Members of the admin group may gain root privileges
# %admin ALL=(ALL) ALL

(from Sudoers Ubuntu Wiki)

Before restarting, su back to your normal user, and try sudo apt-get upgrade or anything with sudo. If it works, then reboot. Otherwise, comment with the error message.