everytime I enter in a command that requires root access using sudo, i get an error message :
sudo: must be setuid root

and I can't perform any action that requires me to be root. I even tried using gksu instead of sudo, but I still get the same exact error message.

The only thing that I had done previous was:
sudo chmod 777 /usr/bin/*

and it worked. The very next command I used was sudo apt-get and that's when I got my error message. I rebooted my computer, but still nothing.

Any insight would be greatly appreciated.

giuseppe

Well, oops.. 'chmod 777 /usr/bin/*' sets the mode of all files exactly to 777. In particular, SUID bit (that means that the binary is executed with root privileges initially, but knows who called it). And the only way a process started by an ordinary users gains root privileges is through a similar SUID "gate". So you need to chmod sudo executable 'u+s'. For it you will probably need to boot from installation media and mount your system.

Shouldn't it be enough to boot into single-user mode? That should give a root login without passwords usually..I haven't tried with Ubuntu recently, but that's probably easier than booting off the installation media and mounting the partitions..

When GRUB pops up, enter the menu, press 'e' to edit the boot section you usually use (the hilighted one I guess; it should tell about the 'e' button at the bottom), hilight the line that starts with word 'kernel', press 'e' again to edit the line, add the word 'single' to the line among the other options, press ENTER and 'b' to boot. Hopefully you end up logged in as root on the command line..then issue the chmod explained in the previous post and reboot.

I'd say that booting from LiveCD is simpler sometimes. Personally I would use not just single-user mode, but plainly init=/bin/sh, but whatever of these ways you choose, you have to remember about Ctrl-Alt-Del and how should it work here, without init you even need to think about filesystem state on reboot.

Forgive me for my ignorance but doesn't this effectively break your install?

In a sense. If you have no root password, and sudo is in /usr/bin, it deprives you of it.. Really only so many programs need to be SUID.