CVE-2013-4540
Within scoop_gpio_handler_update, if prev_level has a high bit set, then
we get bit > 16 and that causes a buffer overrun.
Since prev_level comes from wire indirectly, this can
happen on invalid state load.
Similarly for gpio_level and gpio_dir.
To fix, limit to 16 bit.
Reported-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
52f91c3723