Re: [PATCH 5.15.y] drm/virtio: Fix error code in virtio_gpu_object_shmem_init()

From: Dmitry Osipenko
Date: Fri Mar 03 2023 - 16:32:32 EST


On 3/2/23 20:25, Harshit Mogalapalli wrote:
> In virtio_gpu_object_shmem_init() we are passing NULL to PTR_ERR, which
> is returning 0/success.
>
> Fix this by storing error value in 'ret' variable before assigning
> shmem->pages to NULL.
>
> Found using static analysis with Smatch.
>
> Fixes: 64b88afbd92f ("drm/virtio: Correct drm_gem_shmem_get_sg_table() error handling")
> Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@xxxxxxxxxx>
> ---
> Only compile tested.
>
> Upstream commit b5c9ed70d1a9 ("drm/virtio: Improve DMA API usage for shmem BOs")
> deleted this code, so this patch is not necessary in linux-6.1.y and
> linux-6.2.y.
> ---
> drivers/gpu/drm/virtio/virtgpu_object.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/virtio/virtgpu_object.c b/drivers/gpu/drm/virtio/virtgpu_object.c
> index 7e75fb0fc7bd..25d399b00404 100644
> --- a/drivers/gpu/drm/virtio/virtgpu_object.c
> +++ b/drivers/gpu/drm/virtio/virtgpu_object.c
> @@ -169,8 +169,9 @@ static int virtio_gpu_object_shmem_init(struct virtio_gpu_device *vgdev,
> shmem->pages = drm_gem_shmem_get_sg_table(&bo->base);
> if (IS_ERR(shmem->pages)) {
> drm_gem_shmem_unpin(&bo->base);
> + ret = PTR_ERR(shmem->pages);
> shmem->pages = NULL;
> - return PTR_ERR(shmem->pages);
> + return ret;
> }
>
> if (use_dma_api) {

Reviewed-by: Dmitry Osipenko <dmitry.osipenko@xxxxxxxxxxxxx>

--
Best regards,
Dmitry