Funny enough I was unable to log into my Linux (Ubuntu) session and I realized this might be a more common problem that it seemed. So, if you keep getting redirected to the login screen after typing your correct password over and over (and over and over), there’s no need to panic.
This usually has to do with the .Xauthority file, so from the login page press Ctrl+Alt+F1 which will bring you to the command line where you can login with your usual credentials. Once logged in, search for the .Xauthority file and check that it is owned by you and not the root
ls -l ~/.Xauthority
-rw------ 1 root root 1 feb 11 13:13 /home/joaquin/.Xauthority
Use the following command to change ownership
chown group:username ~/.Xauthority
in my case both group and username are joaquin. You may need to ‘sudo’ it. If that doesn’t work try deleting the file altogether, upon login it will be created again.
rm -rf ~/.Xauthority
In any case, if any of these solutions worked, press Ctrl+Alt+F7 to go back to the login screen and now you should be able to get in.
These solutions are quite straightfoward but if the problem persist you may need to update the system or downright install it again from the command line we opened at the begining.