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authorPrasad J Pandit <pjp@fedoraproject.org>2017-11-29 23:14:27 +0530
committerMichael S. Tsirkin <mst@redhat.com>2017-12-01 19:05:58 +0200
commit758ead31c7e17bf17a9ef2e0ca1c3e86ab296b43 (patch)
treebd19c0514a7c1ed1e90bdf6df63d8e28744d3c8b /hw
parent2fe45ec3bffbd3a26f2ed39f60bab0ca5217d8f6 (diff)
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virtio: check VirtQueue Vring object is set
A guest could attempt to use an uninitialised VirtQueue object or unset Vring.align leading to a arithmetic exception. Add check to avoid it. Reported-by: Zhangboxian <zhangboxian@huawei.com> Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Diffstat (limited to 'hw')
-rw-r--r--hw/virtio/virtio.c14
1 files changed, 11 insertions, 3 deletions
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 703e672..ad564b0 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -182,7 +182,7 @@ void virtio_queue_update_rings(VirtIODevice *vdev, int n)
{
VRing *vring = &vdev->vq[n].vring;
- if (!vring->desc) {
+ if (!vring->num || !vring->desc || !vring->align) {
/* not yet setup -> nothing to do */
return;
}
@@ -1414,6 +1414,9 @@ void virtio_config_modern_writel(VirtIODevice *vdev,
void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr)
{
+ if (!vdev->vq[n].vring.num) {
+ return;
+ }
vdev->vq[n].vring.desc = addr;
virtio_queue_update_rings(vdev, n);
}
@@ -1426,6 +1429,9 @@ hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n)
void virtio_queue_set_rings(VirtIODevice *vdev, int n, hwaddr desc,
hwaddr avail, hwaddr used)
{
+ if (!vdev->vq[n].vring.num) {
+ return;
+ }
vdev->vq[n].vring.desc = desc;
vdev->vq[n].vring.avail = avail;
vdev->vq[n].vring.used = used;
@@ -1494,8 +1500,10 @@ void virtio_queue_set_align(VirtIODevice *vdev, int n, int align)
*/
assert(k->has_variable_vring_alignment);
- vdev->vq[n].vring.align = align;
- virtio_queue_update_rings(vdev, n);
+ if (align) {
+ vdev->vq[n].vring.align = align;
+ virtio_queue_update_rings(vdev, n);
+ }
}
static bool virtio_queue_notify_aio_vq(VirtQueue *vq)