This question already has an answer here:
I have recursively changed owner and group of /var to root:root. I have mistakenly ran following command while standing in /var. I thought I was in /var/www,
sudo chown root:root . R
Now many things are stopped working, my system was fresh, only LAMP was installed. Now what should I do? Reinstall my system or is there any way to change owner and group to default state?
It is Debian 8 with LXDE.