virtio: validate config_len on load

Malformed input can have config_len in migration stream
exceed the array size allocated on destination, the
result will be heap overflow.

To fix, that config_len matches on both sides.

CVE-2014-0182

Reported-by: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

--

v2: use %ix and %zx to print config_len values
Signed-off-by: Juan Quintela <quintela@redhat.com>
This commit is contained in:
Michael S. Tsirkin 2014-04-28 16:08:23 +03:00 committed by Juan Quintela
parent 98f93ddd84
commit a890a2f913

View file

@ -898,6 +898,7 @@ int virtio_set_features(VirtIODevice *vdev, uint32_t val)
int virtio_load(VirtIODevice *vdev, QEMUFile *f)
{
int i, ret;
int32_t config_len;
uint32_t num;
uint32_t features;
uint32_t supported_features;
@ -924,7 +925,12 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f)
features, supported_features);
return -1;
}
vdev->config_len = qemu_get_be32(f);
config_len = qemu_get_be32(f);
if (config_len != vdev->config_len) {
error_report("Unexpected config length 0x%x. Expected 0x%zx",
config_len, vdev->config_len);
return -1;
}
qemu_get_buffer(f, vdev->config, vdev->config_len);
num = qemu_get_be32(f);