| Message ID | 1426153818-28804-1-git-send-email-jasowang@redhat.com |
|---|---|
| State | New |
| Headers | show |
On Thu, 12 Mar 2015 17:50:18 +0800 Jason Wang <jasowang@redhat.com> wrote: > We don't validate the existence of handle_output which may let a buggy > guest to trigger a SIGSEV easily. E.g: > > 1) write 10 to queue_sel to a virtio net device with only 1 queue > 2) setup an arbitrary pfn > 3) then notify queue 10 > > Fixing this by validating the existence of handle_output before. > > Cc: qemu-stable@nongnu.org > Cc: Michael S. Tsirkin <mst@redhat.com> > Signed-off-by: Jason Wang <jasowang@redhat.com> > --- Reviewed-by: Don Koch <dkoch@verizon.com> > Changes from V1: > - check the existence of both vring.desc and handle_output in the same > line > - describe the reproducer in the commit log > --- > hw/virtio/virtio.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c > index 3c6e430..17c1260 100644 > --- a/hw/virtio/virtio.c > +++ b/hw/virtio/virtio.c > @@ -759,8 +759,9 @@ void virtio_queue_set_align(VirtIODevice *vdev, int n, int align) > > void virtio_queue_notify_vq(VirtQueue *vq) > { > - if (vq->vring.desc) { > + if (vq->vring.desc && vq->handle_output) { > VirtIODevice *vdev = vq->vdev; > + > trace_virtio_queue_notify(vdev, vq - vdev->vq, vq); > vq->handle_output(vdev, vq); > } > -- > 2.1.0 > >
On Thu, 03/12 17:50, Jason Wang wrote: > We don't validate the existence of handle_output which may let a buggy > guest to trigger a SIGSEV easily. E.g: > > 1) write 10 to queue_sel to a virtio net device with only 1 queue > 2) setup an arbitrary pfn > 3) then notify queue 10 > > Fixing this by validating the existence of handle_output before. > > Cc: qemu-stable@nongnu.org > Cc: Michael S. Tsirkin <mst@redhat.com> > Signed-off-by: Jason Wang <jasowang@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> > --- > Changes from V1: > - check the existence of both vring.desc and handle_output in the same > line > - describe the reproducer in the commit log > --- > hw/virtio/virtio.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c > index 3c6e430..17c1260 100644 > --- a/hw/virtio/virtio.c > +++ b/hw/virtio/virtio.c > @@ -759,8 +759,9 @@ void virtio_queue_set_align(VirtIODevice *vdev, int n, int align) > > void virtio_queue_notify_vq(VirtQueue *vq) > { > - if (vq->vring.desc) { > + if (vq->vring.desc && vq->handle_output) { > VirtIODevice *vdev = vq->vdev; > + > trace_virtio_queue_notify(vdev, vq - vdev->vq, vq); > vq->handle_output(vdev, vq); > } > -- > 2.1.0 > >
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 3c6e430..17c1260 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -759,8 +759,9 @@ void virtio_queue_set_align(VirtIODevice *vdev, int n, int align) void virtio_queue_notify_vq(VirtQueue *vq) { - if (vq->vring.desc) { + if (vq->vring.desc && vq->handle_output) { VirtIODevice *vdev = vq->vdev; + trace_virtio_queue_notify(vdev, vq - vdev->vq, vq); vq->handle_output(vdev, vq); }
We don't validate the existence of handle_output which may let a buggy guest to trigger a SIGSEV easily. E.g: 1) write 10 to queue_sel to a virtio net device with only 1 queue 2) setup an arbitrary pfn 3) then notify queue 10 Fixing this by validating the existence of handle_output before. Cc: qemu-stable@nongnu.org Cc: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Jason Wang <jasowang@redhat.com> --- Changes from V1: - check the existence of both vring.desc and handle_output in the same line - describe the reproducer in the commit log --- hw/virtio/virtio.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)