Commit 87dcef49 authored by Amit Shah's avatar Amit Shah Committed by Greg Kroah-Hartman

virtio: rng: disallow multiple device registrations, fixes crashes

commit e84e7a56 upstream.

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: default avatarPeter Krempa <pkrempa@redhat.com>
Reported-by: <yunzheng@redhat.com>
Signed-off-by: default avatarAmit Shah <amit.shah@redhat.com>
Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 05b96a05
...@@ -92,14 +92,22 @@ static int probe_common(struct virtio_device *vdev) ...@@ -92,14 +92,22 @@ static int probe_common(struct virtio_device *vdev)
{ {
int err; int err;
if (vq) {
/* We only support one device for now */
return -EBUSY;
}
/* We expect a single virtqueue. */ /* We expect a single virtqueue. */
vq = virtio_find_single_vq(vdev, random_recv_done, "input"); vq = virtio_find_single_vq(vdev, random_recv_done, "input");
if (IS_ERR(vq)) if (IS_ERR(vq)) {
return PTR_ERR(vq); err = PTR_ERR(vq);
vq = NULL;
return err;
}
err = hwrng_register(&virtio_hwrng); err = hwrng_register(&virtio_hwrng);
if (err) { if (err) {
vdev->config->del_vqs(vdev); vdev->config->del_vqs(vdev);
vq = NULL;
return err; return err;
} }
...@@ -112,6 +120,7 @@ static void remove_common(struct virtio_device *vdev) ...@@ -112,6 +120,7 @@ static void remove_common(struct virtio_device *vdev)
busy = false; busy = false;
hwrng_unregister(&virtio_hwrng); hwrng_unregister(&virtio_hwrng);
vdev->config->del_vqs(vdev); vdev->config->del_vqs(vdev);
vq = NULL;
} }
static int virtrng_probe(struct virtio_device *vdev) static int virtrng_probe(struct virtio_device *vdev)
......
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