[PATCH v3] drm/amdgpu: fix a possible null pointer dereference

[Alex Deucher]

Applied.  Thanks!

On Thu, Jul 18, 2024 at 10:12 AM Ma Ke <make24 at iscas.ac.cn> wrote:
>
> In amdgpu_connector_add_common_modes(), the return value of drm_cvt_mode()
> is assigned to mode, which will lead to a NULL pointer dereference on
> failure of drm_cvt_mode(). Add a check to avoid npd.
>
> Cc: stable at vger.kernel.org
> Fixes: d38ceaf99ed0 ("drm/amdgpu: add core driver (v4)")
> Signed-off-by: Ma Ke <make24 at iscas.ac.cn>
> ---
> Changes in v3:
> - added Cc stable line.
> Changes in v2:
> - modified the patch according to suggestions;
> - added Fixes line.
> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
> index 9caba10315a8..25b51b600f6f 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
> @@ -458,6 +458,9 @@ static void amdgpu_connector_add_common_modes(struct drm_encoder *encoder,
>                         continue;
>
>                 mode = drm_cvt_mode(dev, common_modes[i].w, common_modes[i].h, 60, false, false, false);
> +               if (!mode)
> +                       return;
> +
>                 drm_mode_probed_add(connector, mode);
>         }
>  }
> --
> 2.25.1
>