sudo: bad onwership of /usr/bin/sudo and /usr/lib/sudo/sudoers.so (2001:2501)

[Andrea Righi]

After enabling the -proposed ppa in Hirsute (21.04) I'm getting the following error:

ubuntu@hirsute:~$ sudo su -
sudo: /usr/bin/sudo must be owned by uid 0 and have the setuid bit set
ubuntu@hirsute:~$ ls -l /usr/bin/sudo
-rwsr-xr-x 1 2001 2501 190952 Feb 10 11:42 /usr/bin/sudo

I had a root session open so I could fix it by manually setting user and group ownership back to root.

After that I noticed that also /usr/lib/sudo/sudoers.so had the wrong ownership:

ubuntu@hirsute:~$ sudo su -
sudo: error in /etc/sudo.conf, line 0 while loading plugin "sudoers_policy"
sudo: /usr/lib/sudo/sudoers.so must be owned by uid 0
sudo: fatal error, unable to load plugins

I manually fixed also this one and now my system seems to work normally.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.