usb: sanity check setup_index+setup_len in post_load

CVE-2013-4541

s->setup_len and s->setup_index are fed into usb_packet_copy as
size/offset into s->data_buf, it's possible for invalid state to exploit
this to load arbitrary data.

setup_len and setup_index should be checked to make sure
they are not negative.

Cc: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
This commit is contained in:
Michael S. Tsirkin 2014-04-03 19:52:25 +03:00 committed by Juan Quintela
parent 3476436a44
commit 9f8e9895c5

View file

@ -49,7 +49,9 @@ static int usb_device_post_load(void *opaque, int version_id)
} else {
dev->attached = 1;
}
if (dev->setup_index >= sizeof(dev->data_buf) ||
if (dev->setup_index < 0 ||
dev->setup_len < 0 ||
dev->setup_index >= sizeof(dev->data_buf) ||
dev->setup_len >= sizeof(dev->data_buf)) {
return -EINVAL;
}