qcacmn: Fix array out of bound write in scheduler queue registration

Scheduler is directly assigning last incremented queue index without
validating if max number of message queues are already registered.
Add sanity check to make sure after registering max no of message
queues new queue registration request fails gracefully.

Change-Id: I0c608d06e05d25a2f8003630d04a74b6a30802e8
CRs-Fixed: 1102097

sch/src/scheduler_api.c

@@ -255,7 +255,7 @@ QDF_STATUS scheduler_register_module(QDF_MODULE_ID qid,
 	struct scheduler_mq_ctx *ctx;
 	struct scheduler_ctx *sched_ctx = scheduler_get_context();
 
-	QDF_TRACE(QDF_MODULE_ID_SCHEDULER, QDF_TRACE_LEVEL_ERROR,
+	QDF_TRACE(QDF_MODULE_ID_SCHEDULER, QDF_TRACE_LEVEL_INFO,
 		FL("Enter"));
 	if (!sched_ctx) {
 		QDF_ASSERT(0);
@@ -263,12 +263,21 @@ QDF_STATUS scheduler_register_module(QDF_MODULE_ID qid,
 			FL("sched_ctx is NULL"));
 		return QDF_STATUS_E_FAILURE;
 	}
+
+	if (sched_ctx->sch_last_qidx >= SCHEDULER_NUMBER_OF_MSG_QUEUE) {
+		QDF_TRACE(QDF_MODULE_ID_SCHEDULER,
+			QDF_TRACE_LEVEL_ERROR,
+			FL("Already registered max %d no of message queues"),
+				SCHEDULER_NUMBER_OF_MSG_QUEUE);
+		return QDF_STATUS_E_FAILURE;
+	}
+
 	ctx = &sched_ctx->queue_ctx;
 	ctx->scheduler_msg_qid_to_qidx[qid] = sched_ctx->sch_last_qidx;
 	ctx->sch_msg_q[sched_ctx->sch_last_qidx].qid = qid;
 	ctx->scheduler_msg_process_fn[sched_ctx->sch_last_qidx] = callback;
 	sched_ctx->sch_last_qidx++;
-	QDF_TRACE(QDF_MODULE_ID_SCHEDULER, QDF_TRACE_LEVEL_ERROR,
+	QDF_TRACE(QDF_MODULE_ID_SCHEDULER, QDF_TRACE_LEVEL_INFO,
 		FL("Exit"));
 	return QDF_STATUS_SUCCESS;
 }