| Message ID | 1374853288-9912-2-git-send-email-peter.maydell@linaro.org |
|---|---|
| State | New |
| Headers | show |
On Fri, Jul 26, 2013 at 04:41:27PM +0100, Peter Maydell wrote: > 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> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> > --- > hw/virtio/virtio.c | 12 +++++++++--- > 1 file changed, 9 insertions(+), 3 deletions(-) > > diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c > index 09f62c6..60653f7 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) > -- > 1.7.9.5
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 09f62c6..60653f7 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)
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> --- hw/virtio/virtio.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-)