I recently created a new mount point /usb to be able to mount USB sticks to my Fedora 32 Linux system and tried to run sudo chmod a+rwx /usb
on a shell, but accidentally mistyped it as sudo chmod a+rwx /usr
.
In panic, I thought I had broken my system. I found this post: Permissions/ownership of /usr/local/bin and reset the permissions for /usr to rwx for root, r-x for everyone else. Then I rebooted just to make sure, and everything worked OK.
To be safe in the future, what is the worst thing that could happen from accidentally setting the wrong permissions to /usr, and how can I recover from it?