How to fix SU authentication failure and Sudo: Permission denied Prompt in Ubuntu

In this short guide, you will learn how to fix the Su: Authentication Failure in Linux. With this error, you will also encounter the Permission denied message when trying to carry out any installation with sudo permission. In Linux, there are different types of users, and sudo or the root user is one of such users but a user with the full permission to execute any command in Linux. Sudo means…