diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c
index 2a209e1ea76b..6b4dabdeb4a9 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_main.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
@@ -185,13 +185,16 @@ void hisi_sas_slot_task_free(struct hisi_hba *hisi_hba, struct sas_task *task,
 		struct domain_device *device = task->dev;
 		struct hisi_sas_device *sas_dev = device->lldd_dev;
 
+		if (!task->lldd_task)
+			return;
+
+		task->lldd_task = NULL;
+
 		if (!sas_protocol_ata(task->task_proto))
 			if (slot->n_elem)
 				dma_unmap_sg(dev, task->scatter, slot->n_elem,
 					     task->data_dir);
 
-		task->lldd_task = NULL;
-
 		if (sas_dev)
 			atomic64_dec(&sas_dev->running_req);
 	}
@@ -199,8 +202,8 @@ void hisi_sas_slot_task_free(struct hisi_hba *hisi_hba, struct sas_task *task,
 	if (slot->buf)
 		dma_pool_free(hisi_hba->buffer_pool, slot->buf, slot->buf_dma);
 
-
 	list_del_init(&slot->entry);
+	slot->buf = NULL;
 	slot->task = NULL;
 	slot->port = NULL;
 	hisi_sas_slot_index_free(hisi_hba, slot->idx);