As part of a cleanup amdgpu_dm_fini() function, which is typically
called when a device is being shut down or a driver is being unloaded
The below error message suggests that there is a potential null pointer
dereference issue with adev->dm.dc.
In the below, line of code where adev->dm.dc is used without a preceding
null check:
for (i = 0; i < adev->dm.dc->caps.max_links; i++) {
To fix this issue, add a null check for adev->dm.dc before this line.
Reported by smatch:
drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm.c:1959 amdgpu_dm_fini() error: we previously assumed 'adev->dm.dc' could be null (see line 1943)
Fixes: 006c26a0f1c8 ("drm/amd/display: Fix crash on device remove/driver unload")
Cc: Andrey Grodzovsky <andrey.grodzovsky@xxxxxxx>
Cc: Harry Wentland <harry.wentland@xxxxxxx>
Cc: Rodrigo Siqueira <Rodrigo.Siqueira@xxxxxxx>
Cc: Aurabindo Pillai <aurabindo.pillai@xxxxxxx>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@xxxxxxx>
---
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
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 b3a5e730be24..d4c1415f4562 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -1956,7 +1956,7 @@ static void amdgpu_dm_fini(struct amdgpu_device *adev)
&adev->dm.dmub_bo_gpu_addr,
&adev->dm.dmub_bo_cpu_addr);
- if (adev->dm.hpd_rx_offload_wq) {
+ if (adev->dm.hpd_rx_offload_wq && adev->dm.dc) {
for (i = 0; i < adev->dm.dc->caps.max_links; i++) {
if (adev->dm.hpd_rx_offload_wq[i].wq) {
destroy_workqueue(adev->dm.hpd_rx_offload_wq[i].wq);
--
2.34.1
