[PATCH 2/5] drm/i915/gvt: Do not copy the uninitialized pointer from fb_info

[Colin Xu]

On 2019-04-08 13:54, Aleksei Gimbitskii wrote:
> In the code the memcpy() function copied uninitialized pointer in fb_info
> to dmabuf_obj->info. Later the pointer in dmabuf_obj->info will be
> initialized. To make the code aligned with requirements of the klocwork
> static code analyzer, the uninitialized pointer should be initialized
> before memcpy().
>
> This patch fixed the critical issue #632 reported by klockwork.
>
> Signed-off-by: Aleksei Gimbitskii <aleksei.gimbitskii at intel.com>
> Cc: Zhenyu Wang <zhenyuw at linux.intel.com>
> Cc: Zhi Wang <zhi.a.wang at intel.com>
> ---
>   drivers/gpu/drm/i915/gvt/dmabuf.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gvt/dmabuf.c b/drivers/gpu/drm/i915/gvt/dmabuf.c
> index f6be97119968..d86055c144c2 100644
> --- a/drivers/gpu/drm/i915/gvt/dmabuf.c
> +++ b/drivers/gpu/drm/i915/gvt/dmabuf.c
> @@ -418,9 +418,9 @@ int intel_vgpu_query_plane(struct intel_vgpu *vgpu, void *args)
>   		ret = -ENOMEM;
>   		goto out_free_dmabuf;
>   	}
> -	memcpy(dmabuf_obj->info, &fb_info, sizeof(struct intel_vgpu_fb_info));
>   
> -	((struct intel_vgpu_fb_info *)dmabuf_obj->info)->obj = dmabuf_obj;
> +	fb_info.obj = dmabuf_obj;
> +	memcpy(dmabuf_obj->info, &fb_info, sizeof(struct intel_vgpu_fb_info));
>   

Since dmabuf_obj->info is cloned from fb_info, and obj is assigned the newly alloced
dmabuf_obj in this same function, regardless what fb_info->obj original was, will
it be better to initialize fb_info->obj in vgpu_get_plane_info() like other members?
Like a simple zero-out fb_info before assign members, or an explicit NULL to obj?

>   	dmabuf_obj->vgpu = vgpu;
>   

-- 
Best Regards,
Colin Xu