drm/radeon: fix a possible null pointer dereference

[ Upstream commit 2c1fe3c480f9e1deefd50d4b18be4a046011ee1f ]

In radeon_tv_get_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 null point dereference.

Signed-off-by: Ma Ke <make_ruc2021@163.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/radeon/radeon_connectors.c b/drivers/gpu/drm/radeon/radeon_connectors.c
index d2f02c3..b84b589 100644 (file)
--- a/drivers/gpu/drm/radeon/radeon_connectors.c
+++ b/drivers/gpu/drm/radeon/radeon_connectors.c
@@ -1119,6 +1119,8 @@ static int radeon_tv_get_modes(struct drm_connector *connector)
        else {
                /* only 800x600 is supported right now on pre-avivo chips */
                tv_mode = drm_cvt_mode(dev, 800, 600, 60, false, false, false);
+               if (!tv_mode)
+                       return 0;
                tv_mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
                drm_mode_probed_add(connector, tv_mode);
        }