Message ID | 1458842214-11450-7-git-send-email-stefanha@redhat.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
On Thu, 03/24 17:56, Stefan Hajnoczi wrote: > If the index avail ring index is bogus virtqueue_num_heads() must return s/index avail/avail/ ? > -EINVAL. > > The only caller is virtqueue_get_avail_bytes(). Return saying no bytes > are available when virtqueue_num_heads() fails. > > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> > --- > hw/virtio/virtio.c | 11 ++++++++--- > 1 file changed, 8 insertions(+), 3 deletions(-) > > diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c > index f845df2..525af8b 100644 > --- a/hw/virtio/virtio.c > +++ b/hw/virtio/virtio.c > @@ -320,9 +320,9 @@ static int virtqueue_num_heads(VirtQueue *vq, unsigned int idx) > > /* Check it isn't doing very strange things with descriptor numbers. */ > if (num_heads > vq->vring.num) { > - error_report("Guest moved used index from %u to %u", > + virtio_error(vq->vdev, "Guest moved used index from %u to %u", > idx, vq->shadow_avail_idx); > - exit(1); > + return -EINVAL; > } > /* On success, callers read a descriptor at vq->last_avail_idx. > * Make sure descriptor read does not bypass avail index read. */ > @@ -390,7 +390,7 @@ void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes, > idx = vq->last_avail_idx; > > total_bufs = in_total = out_total = 0; > - while (virtqueue_num_heads(vq, idx)) { > + while ((rc = virtqueue_num_heads(vq, idx)) > 0) { > VirtIODevice *vdev = vq->vdev; > unsigned int max, num_bufs, indirect = 0; > VRingDesc desc; > @@ -451,6 +451,11 @@ void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes, > else > total_bufs++; > } > + > + if (rc < 0) { > + goto err; > + } > + > done: > if (in_bytes) { > *in_bytes = in_total; > -- > 2.5.5 >
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index f845df2..525af8b 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -320,9 +320,9 @@ static int virtqueue_num_heads(VirtQueue *vq, unsigned int idx) /* Check it isn't doing very strange things with descriptor numbers. */ if (num_heads > vq->vring.num) { - error_report("Guest moved used index from %u to %u", + virtio_error(vq->vdev, "Guest moved used index from %u to %u", idx, vq->shadow_avail_idx); - exit(1); + return -EINVAL; } /* On success, callers read a descriptor at vq->last_avail_idx. * Make sure descriptor read does not bypass avail index read. */ @@ -390,7 +390,7 @@ void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes, idx = vq->last_avail_idx; total_bufs = in_total = out_total = 0; - while (virtqueue_num_heads(vq, idx)) { + while ((rc = virtqueue_num_heads(vq, idx)) > 0) { VirtIODevice *vdev = vq->vdev; unsigned int max, num_bufs, indirect = 0; VRingDesc desc; @@ -451,6 +451,11 @@ void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes, else total_bufs++; } + + if (rc < 0) { + goto err; + } + done: if (in_bytes) { *in_bytes = in_total;
If the index avail ring index is bogus virtqueue_num_heads() must return -EINVAL. The only caller is virtqueue_get_avail_bytes(). Return saying no bytes are available when virtqueue_num_heads() fails. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> --- hw/virtio/virtio.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)