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

From: Ma Ke <make_ruc2021@163.com>
To: maarten.lankhorst@linux.intel.com, mripard@kernel.org,
	tzimmermann@suse.de, airlied@gmail.com, daniel@ffwll.ch
Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
	Ma Ke <make_ruc2021@163.com>
Subject: [PATCH] drm/edid: fix a possible null pointer dereference
Date: Wed, 11 Oct 2023 09:33:16 +0800	[thread overview]
Message-ID: <20231011013316.4091845-1-make_ruc2021@163.com> (raw)

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;
 	return mode;
 }
 
-- 
2.37.2

