diff options
| author | Peter Maydell <peter.maydell@linaro.org> | 2013-07-26 16:41:27 +0100 |
|---|---|---|
| committer | Peter Maydell <peter.maydell@linaro.org> | 2013-08-09 16:50:23 +0100 |
| commit | f6049f4483d61fa911a0693c2c48ce8308451d33 (patch) | |
| tree | 6c476698805525ab764cf842175984130d58d383 | |
| parent | 2e985fe000e73097e325e18b943e8babfa96c35c (diff) | |
hw/virtio/virtio: Don't allow guests to add/remove queues
A queue size of 0 is used to indicate a nonexistent queue, so
don't allow the guest to flip a queue between zero-size and
non-zero-size. Don't permit setting of negative queue sizes
either.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1374853288-9912-2-git-send-email-peter.maydell@linaro.org
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
| -rw-r--r-- | hw/virtio/virtio.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 09f62c6c70..60653f764e 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -673,10 +673,16 @@ hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n) void virtio_queue_set_num(VirtIODevice *vdev, int n, int num) { - if (num <= VIRTQUEUE_MAX_SIZE) { - vdev->vq[n].vring.num = num; - virtqueue_init(&vdev->vq[n]); + /* Don't allow guest to flip queue between existent and + * nonexistent states, or to set it to an invalid size. + */ + if (!!num != !!vdev->vq[n].vring.num || + num > VIRTQUEUE_MAX_SIZE || + num < 0) { + return; } + vdev->vq[n].vring.num = num; + virtqueue_init(&vdev->vq[n]); } int virtio_queue_get_num(VirtIODevice *vdev, int n) |