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From:   Jani Nikula <jani.nikula@linux.intel.com>
To:     Ma Ke <make_ruc2021@163.com>, maarten.lankhorst@linux.intel.com,
        mripard@kernel.org, tzimmermann@suse.de, airlied@gmail.com,
        daniel@ffwll.ch
Cc:     linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
        Ma Ke <make_ruc2021@163.com>
Subject: Re: [PATCH] drm/edid: fix a possible null pointer dereference
In-Reply-To: <20231011013316.4091845-1-make_ruc2021@163.com>
Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo
References: <20231011013316.4091845-1-make_ruc2021@163.com>
Date:   Wed, 11 Oct 2023 10:10:30 +0300
Message-ID: <874jix63dl.fsf@intel.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

On Wed, 11 Oct 2023, Ma Ke <make_ruc2021@163.com> wrote:
> In drm_mode_std(), the return value of drm_gtf_mode(),
> drm_gtf_mode() and drm_cvt_mode() is assigned to mode,
> which will lead to a NULL pointer dereference on failure
> of drm_gtf_mode(), drm_gtf_mode() and drm_cvt_mode().
> Add a check to avoid null point dereference.
>
> Signed-off-by: Ma Ke <make_ruc2021@163.com>
> ---
>  drivers/gpu/drm/drm_edid.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> index 340da8257b51..e2c154c2b896 100644
> --- a/drivers/gpu/drm/drm_edid.c
> +++ b/drivers/gpu/drm/drm_edid.c
> @@ -3381,6 +3381,8 @@ static struct drm_display_mode *drm_mode_std(struct drm_connector *connector,
>  				    false);
>  		break;
>  	}
> +	if (!mode)
> +		return NULL;

This doesn't change anything.

BR,
Jani.


>  	return mode;
>  }

-- 
Jani Nikula, Intel