qemu: fix CVE-2020-10702/10761/13362/13659/13800

fix these CVE:
CVE-2020-10702
CVE-2020-10761
CVE-2020-13362
CVE-2020-13659
CVE-2020-13800

Signed-off-by: Lee Chee Yang <chee.yang.lee@intel.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>