Installing xrandr and using the transform command can help fix an overscan issue in linux using HDMI or another output to TV.
First try finding if your TV has the option to fix overscan or underscan before using this fix. If you have ATI or Nvidia use their tools to resize the screen.
If you have Intel video with no resize options, use this command.
xrandr –output HDMI1 –transform 1.05,0,-35,0,1.05,-19,0,0,1