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

From: Dmitry Osipenko
Date: Thu Jun 30 2022 - 16:08:02 EST


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>
---
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