Q: OpenGL applications exit with the following error message:
 
        Error: Could not open /dev/nvidiactl because the permissions
        are too restrictive.  Please see the FREQUENTLY ASKED QUESTIONS
        section of /usr/share/doc/NVIDIA_GLX-1.0/README for steps
        to correct.
 
A: It is likely that a security module for the PAM system may be
   changing the permissions on the NVIDIA device files.  In most cases
   this security system works, but it can get confused.  To correct this
   problem it is recommended that you disable this security feature.
   Different Linux distributions have different files to control this;
   please consult with your distributor for the correct method of
   disabling this security feature.  As an example, if your system has
   the file
        /etc/security/console.perms
   then you should edit the file and remove the line that starts with
   "<dri>" (we have also received reports that additional references to
   <dri> in console.perms must be removed, but this has not been verified
   by NVIDIA).  If instead your system has the file
        /etc/logindevperms
   then you should edit the file and remove the line that lists
   /dev/nvidiactl.  The above steps will prevent the PAM security system
   from modifying the permissions on the NVIDIA device files.  Next,
   you will need to reset the permissions on the device files back
   to their original permissions and owner.  You can do that with the
   following commands:
        chmod 0666 /dev/nvidia* chown root /dev/nvidia*