On 2015년 03월 04일 23:02, Marek Szyprowski wrote:
> From: Beata Michalska <b.michalska at samsung.com>
> 
> As for now there is no validation of incoming buffer
> enqueue request as far as the gem buffers are being
> concerned. This might lead to some undesired cases
> when the driver tries to operate on invalid buffers
> (wiht no valid gem object handle i.e.).
> Add some basic checks to rule out those potential issues.

Applied.

Thanks,
Inki Dae

> 
> Signed-off-by: Beata Michalska <b.michalska at samsung.com>
> [mszyprow: rebased onto v4.0-rc1 and adapted to recent ipp changes]
> Signed-off-by: Marek Szyprowski <m.szyprowski at samsung.com>
> ---
>  drivers/gpu/drm/exynos/exynos_drm_ipp.c | 44 
> +++++++++++++++++++++++++++++++++
>  1 file changed, 44 insertions(+)
> 
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_ipp.c 
> b/drivers/gpu/drm/exynos/exynos_drm_ipp.c
> index 12ae9c4..ac35625 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_ipp.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_ipp.c
> @@ -476,6 +476,45 @@ err_clear:
>       return ret;
>  }
>  
> +static int ipp_validate_mem_node(struct drm_device *drm_dev,
> +                              struct drm_exynos_ipp_mem_node *m_node,
> +                              struct drm_exynos_ipp_cmd_node *c_node)
> +{
> +     struct drm_exynos_ipp_config *ipp_cfg;
> +     unsigned int num_plane;
> +     unsigned long min_size, size;
> +     unsigned int bpp;
> +     int i;
> +
> +     /* The property id should already be varified */
> +     ipp_cfg = &c_node->property.config[m_node->prop_id];
> +     num_plane = drm_format_num_planes(ipp_cfg->fmt);
> +
> +     /**
> +      * This is a rather simplified validation of a memory node.
> +      * It basically verifies provided gem object handles
> +      * and the buffer sizes with respect to current configuration.
> +      * This is not the best that can be done
> +      * but it seems more than enough
> +      */
> +     for (i = 0; i < num_plane; ++i) {
> +             if (!m_node->buf_info.handles[i]) {
> +                     DRM_ERROR("invalid handle for plane %d\n", i);
> +                     return -EINVAL;
> +             }
> +             bpp = drm_format_plane_cpp(ipp_cfg->fmt, i);
> +             min_size = (ipp_cfg->sz.hsize * ipp_cfg->sz.vsize * bpp) >> 3;
> +             size = exynos_drm_gem_get_size(drm_dev,
> +                                            m_node->buf_info.handles[i],
> +                                            c_node->filp);
> +             if (min_size > size) {
> +                     DRM_ERROR("invalid size for plane %d\n", i);
> +                     return -EINVAL;
> +             }
> +     }
> +     return 0;
> +}
> +
>  static int ipp_put_mem_node(struct drm_device *drm_dev,
>               struct drm_exynos_ipp_cmd_node *c_node,
>               struct drm_exynos_ipp_mem_node *m_node)
> @@ -552,6 +591,11 @@ static struct drm_exynos_ipp_mem_node
>       }
>  
>       mutex_lock(&c_node->mem_lock);
> +     if (ipp_validate_mem_node(drm_dev, m_node, c_node)) {
> +             ipp_put_mem_node(drm_dev, c_node, m_node);
> +             mutex_unlock(&c_node->mem_lock);
> +             return ERR_PTR(-EFAULT);
> +     }
>       list_add_tail(&m_node->list, &c_node->mem_list[qbuf->ops_id]);
>       mutex_unlock(&c_node->mem_lock);
>  
> 

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