[PATCH] drm/client: fix null pointer dereference in drm_client_modeset_probe

[Ma Ke]

In drm_client_modeset_probe(), the return value of drm_mode_duplicate() is
assigned to modeset->mode, which will lead to a possible NULL pointer
dereference on failure of drm_mode_duplicate(). Add a check to avoid npd.

Signed-off-by: Ma Ke <make24 at iscas.ac.cn>
---
 drivers/gpu/drm/drm_client_modeset.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/drm_client_modeset.c b/drivers/gpu/drm/drm_client_modeset.c
index 31af5cf37a09..bbe21522dc6a 100644
--- a/drivers/gpu/drm/drm_client_modeset.c
+++ b/drivers/gpu/drm/drm_client_modeset.c
@@ -880,6 +880,8 @@ int drm_client_modeset_probe(struct drm_client_dev *client, unsigned int width,
 
 			kfree(modeset->mode);
 			modeset->mode = drm_mode_duplicate(dev, mode);
+			if (!modeset->mode)
+				continue;
 			drm_connector_get(connector);
 			modeset->connectors[modeset->num_connectors++] = connector;
 			modeset->x = offset->x;
-- 
2.25.1