net: hns3: add a check for index in hclge_get_rss_key()

The index is received from vf, if use it directly,
an out-of-bound issue may be caused, so add a check for
this index before using it in hclge_get_rss_key().

Fixes: a638b1d ("net: hns3: fix get VF RSS issue")
Signed-off-by: Yufeng Mo <moyufeng@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_mbx.c

@@ -607,6 +607,17 @@ static void hclge_get_rss_key(struct hclge_vport *vport,
 
 	index = mbx_req->msg.data[0];
 
+	/* Check the query index of rss_hash_key from VF, make sure no
+	 * more than the size of rss_hash_key.
+	 */
+	if (((index + 1) * HCLGE_RSS_MBX_RESP_LEN) >
+	      sizeof(vport[0].rss_hash_key)) {
+		dev_warn(&hdev->pdev->dev,
+			 "failed to get the rss hash key, the index(%u) invalid !\n",
+			 index);
+		return;
+	}
+
 	memcpy(resp_msg->data,
 	       &hdev->vport[0].rss_hash_key[index * HCLGE_RSS_MBX_RESP_LEN],
 	       HCLGE_RSS_MBX_RESP_LEN);