[PATCH v7 2/9] drm/virtio: Check whether transferred 2D BO is shmem

From: Dmitry Osipenko <dmitry.osipenko@collabora.com>
To: "David Airlie" <airlied@linux.ie>,
	"Gerd Hoffmann" <kraxel@redhat.com>,
	"Gurchetan Singh" <gurchetansingh@chromium.org>,
	"Chia-I Wu" <olvaffe@gmail.com>,
	"Daniel Vetter" <daniel@ffwll.ch>,
	"Thomas Zimmermann" <tzimmermann@suse.de>,
	"Emil Velikov" <emil.l.velikov@gmail.com>,
	"Robin Murphy" <robin.murphy@arm.com>,
	"Thomas Hellström" <thomas_os@shipmail.org>
Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
	virtualization@lists.linux-foundation.org,
	Dmitry Osipenko <digetx@gmail.com>,
	kernel@collabora.com
Subject: [PATCH v7 2/9] drm/virtio: Check whether transferred 2D BO is shmem
Date: Thu, 30 Jun 2022 23:07:19 +0300	[thread overview]
Message-ID: <20220630200726.1884320-3-dmitry.osipenko@collabora.com> (raw)
In-Reply-To: <20220630200726.1884320-1-dmitry.osipenko@collabora.com>

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@vger.kernel.org
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/gpu/drm/virtio/virtgpu_vq.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c
index b7529b2b9883..1262fd0b3bef 100644
--- 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(struct virtio_gpu_device *vgdev,
 	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);
 
-- 
2.36.1

