[PATCH AUTOSEL 6.1 05/58] drm/amd/display: Fix potential null-deref in dm_resume

Sasha Levin
2023-02-27T02:07:50Z

From: Roman Li <roman.li@amd.com>

[ 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>
---
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

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 e9c4f22696c5c..6028e332e35d9 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -2750,12 +2750,14 @@ 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);
--
2.39.0