[PATCH v2] drm/amdkfd: Dereference null return value

[Andrew Martin]

In the function pqm_uninit there is a call-assignment of "pdd =
kfd_get_process_device_data" which could be null, and this value was
later dereferenced without checking.

Fixes: fb91065851cd ("drm/amdkfd: Refactor queue wptr_bo GART mapping")
Signed-off-by: Andrew Martin <Andrew.Martin at amd.com>
---
 drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c b/drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c
index c76db22a1000..89aa578f6c68 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c
@@ -212,11 +212,13 @@ static void pqm_clean_queue_resource(struct process_queue_manager *pqm,
 void pqm_uninit(struct process_queue_manager *pqm)
 {
 	struct process_queue_node *pqn, *next;
-	struct kfd_process_device *pdd;
 
 	list_for_each_entry_safe(pqn, next, &pqm->queues, process_queue_list) {
 		if (pqn->q) {
-			pdd = kfd_get_process_device_data(pqn->q->device, pqm->process);
+			struct kfd_process_device *pdd = kfd_get_process_device_data(pqn->q->device,
+										     pqm->process);
+			if (WARN_ON(!pdd))
+				return;
 			kfd_queue_unref_bo_vas(pdd, &pqn->q->properties);
 			kfd_queue_release_buffers(pdd, &pqn->q->properties);
 			pqm_clean_queue_resource(pqm, pqn);
-- 
2.43.0