This question already has an answer here:
I made a big mistake by running:
sudo chmod -R 777 /
After that, a problem appeared, which is that
sudo won't work anymore.
When I run
sudo in any command this error appears:
sudo: /usr/bin/sudo must be owned by uid 0 and have the setuid bit set
And when I searched for the problem I figured out that some permissions are messed up
/usr/bin/sudo file but I can no longer become root so I can change the permissions!