[PATCH AUTOSEL 6.1 19/25] drm/radeon: fix a possible null pointer dereference

[Sasha Levin]

From: Ma Ke <make_ruc2021 at 163.com>

[ 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 at 163.com>
Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
Signed-off-by: Sasha Levin <sashal at kernel.org>
---
 drivers/gpu/drm/radeon/radeon_connectors.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/radeon/radeon_connectors.c b/drivers/gpu/drm/radeon/radeon_connectors.c
index f7431d2246044..5837af5123a9f 100644
--- a/drivers/gpu/drm/radeon/radeon_connectors.c
+++ b/drivers/gpu/drm/radeon/radeon_connectors.c
@@ -1122,6 +1122,8 @@ 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);
 	}
-- 
2.42.0