This is a note to let you know that I've just added the patch titled
drm/amd/display: Fix potential null-deref in dm_resume
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-amd-display-fix-potential-null-deref-in-dm_resum.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit b0273907f4523a13a1f67a2dc7feb67dd1fc2f31
Author: Roman Li <roman.li@xxxxxxx>
Date: Thu Dec 1 09:06:42 2022 -0500
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@xxxxxxxxx>
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Reviewed-by: Wayne Lin <Wayne.Lin@xxxxxxx>
Acked-by: Jasdeep Dhillon <jdhillon@xxxxxxx>
Signed-off-by: Roman Li <roman.li@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
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 57678e6dcdc4c..98d51bc204172 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -773,12 +773,14 @@ 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);
