virtio: rng: disallow multiple device registrations, fixes crashes

The code currently only supports one virtio-rng device at a time.
Invoking guests with multiple devices causes the guest to blow up.

Check if we've already registered and initialised the driver.  Also
cleanup in case of registration errors or hot-unplug so that a new
device can be used.

Reported-by: Peter Krempa <pkrempa@redhat.com>
Reported-by: <yunzheng@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: stable@kernel.org
This commit is contained in:
Amit Shah 2013-03-08 11:30:18 +11:00 committed by Rusty Russell
parent f7f154f124
commit e84e7a56a3

View file

@ -92,14 +92,22 @@ static int probe_common(struct virtio_device *vdev)
{
int err;
if (vq) {
/* We only support one device for now */
return -EBUSY;
}
/* We expect a single virtqueue. */
vq = virtio_find_single_vq(vdev, random_recv_done, "input");
if (IS_ERR(vq))
return PTR_ERR(vq);
if (IS_ERR(vq)) {
err = PTR_ERR(vq);
vq = NULL;
return err;
}
err = hwrng_register(&virtio_hwrng);
if (err) {
vdev->config->del_vqs(vdev);
vq = NULL;
return err;
}
@ -112,6 +120,7 @@ static void remove_common(struct virtio_device *vdev)
busy = false;
hwrng_unregister(&virtio_hwrng);
vdev->config->del_vqs(vdev);
vq = NULL;
}
static int virtrng_probe(struct virtio_device *vdev)