From f3eb9b8f67bc28783eddc142ad805ebdc53d6339 Mon Sep 17 00:00:00 2001
From: Jia-Ju Bai <baijiaju1990@gmail.com>
Date: Mon, 29 Jul 2019 16:36:44 +0800
Subject: [PATCH] gpu: drm: radeon: Fix a possible null-pointer dereference in radeon_connector_set_property()
Git-commit: f3eb9b8f67bc28783eddc142ad805ebdc53d6339
Patch-mainline: v5.4-rc1
References: bsc#1051510

In radeon_connector_set_property(), there is an if statement on line 743
to check whether connector->encoder is NULL:
    if (connector->encoder)

When connector->encoder is NULL, it is used on line 755:
    if (connector->encoder->crtc)

Thus, a possible null-pointer dereference may occur.

To fix this bug, connector->encoder is checked before being used.

This bug is found by a static analysis tool STCheck written by us.

Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/radeon/radeon_connectors.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/gpu/drm/radeon/radeon_connectors.c
+++ b/drivers/gpu/drm/radeon/radeon_connectors.c
@@ -751,7 +751,7 @@ static int radeon_connector_set_property
 
 		radeon_encoder->output_csc = val;
 
-		if (connector->encoder->crtc) {
+		if (connector->encoder && connector->encoder->crtc) {
 			struct drm_crtc *crtc  = connector->encoder->crtc;
 			struct radeon_crtc *radeon_crtc = to_radeon_crtc(crtc);