Mistakebly I have changed the permissions on OS
I was in a folder /obie
drwxr-x--x obie:obi .
drwxr-x--x obie:obi ..
In a rush I have changed the ownership of ". ."
chown -R root:system ..
This changed the whole OS permeissions to root:system
Please post all the steps as how to revert back changes