On 04 November 2021 at 10:42 pm, Vivek Kasireddy wrote:
> When virgl is not enabled, vfpriv pointer would not be allocated.
> Therefore, check for a valid value before dereferencing.
>
> Reported-by: Christian Zigotzky <chzigotzky@xxxxxxxxxxx>
> Cc: Gurchetan Singh <gurchetansingh@xxxxxxxxxxxx>
> Cc: Gerd Hoffmann <kraxel@xxxxxxxxxx>
> Signed-off-by: Vivek Kasireddy <vivek.kasireddy@xxxxxxxxx>
> ---
> drivers/gpu/drm/virtio/virtgpu_drv.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.c
b/drivers/gpu/drm/virtio/virtgpu_drv.c
> index 749db18dcfa2..d86e1ad4a972 100644
> --- a/drivers/gpu/drm/virtio/virtgpu_drv.c
> +++ b/drivers/gpu/drm/virtio/virtgpu_drv.c
> @@ -163,10 +163,11 @@ static __poll_t virtio_gpu_poll(struct file *filp,
> struct drm_file *drm_file = filp->private_data;
> struct virtio_gpu_fpriv *vfpriv = drm_file->driver_priv;
> struct drm_device *dev = drm_file->minor->dev;
> + struct virtio_gpu_device *vgdev = dev->dev_private;
> struct drm_pending_event *e = NULL;
> __poll_t mask = 0;
>
> - if (!vfpriv->ring_idx_mask)
> + if (!vgdev->has_virgl_3d || !vfpriv || !vfpriv->ring_idx_mask)
> return drm_poll(filp, wait);
>
> poll_wait(filp, &drm_file->event_wait, wait);
Tested-by: Christian Zigotzky <chzigotzky@xxxxxxxxxxx> [1]
[1] https://i.ibb.co/N1vL5Kd/Kernel-5-16-alpha3-Power-PC.png
