virtio-balloon: initialize all vq callbacks

Ensure that elements of the callbacks array that correspond to
unavailable features are set to NULL; previously, they would be left
uninitialized.

Since the corresponding names array elements were explicitly set to
NULL, the uninitialized callback pointers would not actually be
dereferenced; however, the uninitialized callbacks elements would still
be read in vp_find_vqs_msix() and used to calculate the number of MSI-X
vectors required.

Cc: stable@vger.kernel.org
Fixes: 86a559787e6f ("virtio-balloon: VIRTIO_BALLOON_F_FREE_PAGE_HINT")
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Daniel Verkamp <dverkamp@chromium.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index 93f995f6cf3645bab73cfe6def29c83a54b2e1d7..8e400ece92735c92c9985cf31d6f1511f03201d8 100644 (file)
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -475,7 +475,9 @@ static int init_vqs(struct virtio_balloon *vb)
        names[VIRTIO_BALLOON_VQ_INFLATE] = "inflate";
        callbacks[VIRTIO_BALLOON_VQ_DEFLATE] = balloon_ack;
        names[VIRTIO_BALLOON_VQ_DEFLATE] = "deflate";
+       callbacks[VIRTIO_BALLOON_VQ_STATS] = NULL;
        names[VIRTIO_BALLOON_VQ_STATS] = NULL;
+       callbacks[VIRTIO_BALLOON_VQ_FREE_PAGE] = NULL;
        names[VIRTIO_BALLOON_VQ_FREE_PAGE] = NULL;
 
        if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_STATS_VQ)) {