Dear users,

following problem:
When trying to set my MAC address permanently, I changed the owner of /etc (and all subfolders) to my own account (since otherwise I could not change /etc/network as it was writing protected), not knowing that this might cause troubles for sudo.

Now of course, if I want to use sudo, I get the error message
"no valid sudoers sources found, quitting". Could you please help me restore it?

Two things I've tried, that don't work:
- pkexec ... --> an authorization is required with a password, to run "/bin/bash", however, this password is NOT the one from my account, so I do not know it!
- something like chown root:root /etc/sudoers --> "Operation not permitted"

There are also suggestions to start Linux in recovery mode or s.th. like that - but I do not know how (holding shift at restart doesn't work).

Thanks in advance!

Well, you have got yourself into a mess! You have at any rate learned an important lesson for the future: never change the ownership or permissions of system files. They are what they are for a reason. If you need to modify configuration files, use sudo to do your edits. That's what it's there for.

Endless is a very atypical Linux. It's designed as a playpen for users who don't know much about computers but just want simple functionality. It is deliberately crippled in many ways, so it's a bad distro to experiment with. In a standard Linux, there would be several ways of getting out of this bind, the simplest being to use su with the root password, but it seems that you weren't given a known root password (as in the *buntus).

If it were Windows, you'd be told "Just reinstall", and of course that would work here too. But a slightly less drastic solution would be to boot from a SystemRescue CD or USB drive (which automatically gives you root access), mount the root partition and chown /etc back to root:root.

You might also want to think of installing a second, more standard system like Debian alongside Endless and doing your experiments there. You learn by this kind of thing, but Endless is not a good system for learning. It wasn't designed for that.

Thanks for the reply, hazel.
Yes, me, as being new to the operating system, thought, "Well, this ACER has a Linux distribution, and Linux is what I want" and didn't know that there are so large differences.

However, I actually found a way to restore it!

1.) Instead of Shift, press "Esc" to get to the GRUB menu.
2.) Then basically follow the instructions from
https://support.endlessm.com/hc/en-u...ot-my-password

at the bottom (case without USB stick) up to the point where the command line should start (points 1-7).

3.) Enter chown .... (whatever should change ownership, in my case chown -R root:root /etc).

Voila, all works perfectly again

Good! I'm glad you found an answer by yourself. You definitely have the right attitude for a Linux user. Many people here would say, "Play with it until it breaks, then learn how to mend it." But that's easier to do in some Linux distros than others. One of my beefs with the Ubuntu family and the reason I don't use them is that they don't give you a root password, so if you mess up sudo, you've had it.