sudo: /usr/bin/sudo must be owned by uid 0 and have the setuid bit set error in Ubuntu 18.04

sudo_error.md

sudo: /usr/bin/sudo must be owned by uid 0 and have the setuid bit set error in Ubuntu

To fix

1. If root user is not set, goto recovery mode, select drop as root shell prompt, then it will goto root prompt, run

mount -o remount,rw /

to get read/write system

2. Set root password

passwd

3. Reset the permissions

chown root:root /usr/bin/sudo && chmod 4755 /usr/bin/sudo

Ref:- https://askubuntu.com/questions/452860/usr-bin-sudo-must-be-owned-by-uid-0-and-have-the-setuid-bit-set