From: Roman Li <roman.li@amd.com>
Date: Thu, 1 Dec 2022 14:06:42 +0000 (-0500)
Subject: drm/amd/display: Fix potential null-deref in dm_resume
X-Git-Tag: baikal/mips/sdk5.8.2~385
X-Git-Url: https://git.baikalelectronics.ru/sdk/?a=commitdiff_plain;h=6c8bda51b9527b5148fb99a1c5525cb2932cd1b4;p=kernel.git

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

[ Upstream commit 7a7175a2cd84b7874bebbf8e59f134557a34161b ]

[Why]
Fixing smatch error:
dm_resume() error: we previously assumed 'aconnector->dc_link' could be null

[How]
Check if dc_link null at the beginning of the loop,
so further checks can be dropped.

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>

Reviewed-by: Wayne Lin <Wayne.Lin@amd.com>
Acked-by: Jasdeep Dhillon <jdhillon@amd.com>
Signed-off-by: Roman Li <roman.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 9fd711005c1f5..1e7083bc8a527 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -1206,12 +1206,14 @@ static int dm_resume(void *handle)
 	list_for_each_entry(connector, &ddev->mode_config.connector_list, head) {
 		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);