[PATCH] gma500/cdv: fix null pointer dereference in cdv_intel_dp_get_modes

[Chenyuan Yang]

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

This is similar to the fix commit cb520c3f366c
("drm/gma500: fix null pointer dereference in cdv_intel_lvds_get_modes").

This is found by our static analysis tool KNighter.

Signed-off-by: Chenyuan Yang <chenyua...@gmail.com>
Fixes: d112a8163f83 ("gma500/cdv: Add eDP support")
---
 drivers/gpu/drm/gma500/cdv_intel_dp.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/gma500/cdv_intel_dp.c 
b/drivers/gpu/drm/gma500/cdv_intel_dp.c
index c85143792019..4bd66804bc09 100644
--- a/drivers/gpu/drm/gma500/cdv_intel_dp.c
+++ b/drivers/gpu/drm/gma500/cdv_intel_dp.c
@@ -1767,6 +1767,9 @@ static int cdv_intel_dp_get_modes(struct drm_connector 
*connector)
                if (intel_dp->panel_fixed_mode != NULL) {
                        struct drm_display_mode *mode;
                        mode = drm_mode_duplicate(dev, 
intel_dp->panel_fixed_mode);
+                       if (!mode)
+                               return ret;
+
                        drm_mode_probed_add(connector, mode);
                        return 1;
                }
-- 
2.34.1