[PATCH 6.0 074/862] drm/virtio: Check whether transferred 2D BO is shmem

[Greg Kroah-Hartman]

From: Dmitry Osipenko <dmitry.osipenko@xxxxxxxxxxxxx>

commit e473216b42aa1fd9fc6b94b608b42c210c655908 upstream.

Transferred 2D BO always must be a shmem BO. Add check for that to prevent
NULL dereference if userspace passes a VRAM BO.

Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Emil Velikov <emil.l.velikov@xxxxxxxxx>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@xxxxxxxxxxxxx>
Link: http://patchwork.freedesktop.org/patch/msgid/20220630200726.1884320-3-dmitry.osipenko@xxxxxxxxxxxxx
Signed-off-by: Gerd Hoffmann <kraxel@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/gpu/drm/virtio/virtgpu_vq.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/gpu/drm/virtio/virtgpu_vq.c
+++ b/drivers/gpu/drm/virtio/virtgpu_vq.c
@@ -597,7 +597,7 @@ void virtio_gpu_cmd_transfer_to_host_2d(
 	bool use_dma_api = !virtio_has_dma_quirk(vgdev->vdev);
 	struct virtio_gpu_object_shmem *shmem = to_virtio_gpu_shmem(bo);
 
-	if (use_dma_api)
+	if (virtio_gpu_is_shmem(bo) && use_dma_api)
 		dma_sync_sgtable_for_device(vgdev->vdev->dev.parent,
 					    shmem->pages, DMA_TO_DEVICE);