Today's implementation doesn't check whether the length of descriptor is valid before using it. The patch fixes this issue. Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Ruiyu Ni <ruiyu.ni@intel.com> Cc: Star Zeng <star.zeng@intel.com> Cc: Jiewen Yao <jiewen.yao@intel.com> Reviewed-by: Star Zeng <star.zeng@intel.com>