From: jsg <jsg@openbsd.org>
Date: Mon, 27 Mar 2023 03:43:02 +0000 (+0000)
Subject: drm/amd/display: Fix potential null-deref in dm_resume
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=d821b1c71e7b320c2abf0a3c8c92be6de52619f4;p=openbsd

drm/amd/display: Fix potential null-deref in dm_resume

From Roman Li
8e365f1bd672cc9320a936f6ae6f8087aa40e9bc in linux-6.1.y/6.1.16
7a7175a2cd84b7874bebbf8e59f134557a34161b in mainline linux
---

diff --git a/sys/dev/pci/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/sys/dev/pci/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 0f6d9ba64f0..d9b2cfbd98c 100644
--- a/sys/dev/pci/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/sys/dev/pci/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -2746,12 +2746,14 @@ static int dm_resume(void *handle)
 	drm_for_each_connector_iter(connector, &iter) {
 		aconnector = to_amdgpu_dm_connector(connector);
 
+		if (!aconnector->dc_link)
+			continue;
+
 		/*
 		 * this is the case when traversing through already created
 		 * MST connectors, should be skipped
 		 */
-		if (aconnector->dc_link &&
-		    aconnector->dc_link->type == dc_connection_mst_branch)
+		if (aconnector->dc_link->type == dc_connection_mst_branch)
 			continue;
 
 		mutex_lock(&aconnector->hpd_lock);