net: hns3: add validity check for message data length

Add validity check for message data length in function
hclge_send_mbx_msg(), avoid unexpected overflow.

Fixes: dde1a86e ("net: hns3: Add mailbox support to PF driver")
Signed-off-by: Jian Shen <shenjian15@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -94,6 +94,13 @@ static int hclge_send_mbx_msg(struct hclge_vport *vport, u8 *msg, u16 msg_len,
 	enum hclge_comm_cmd_status status;
 	struct hclge_desc desc;
 
+	if (msg_len > HCLGE_MBX_MAX_MSG_SIZE) {
+		dev_err(&hdev->pdev->dev,
+			"msg data length(=%u) exceeds maximum(=%u)\n",
+			msg_len, HCLGE_MBX_MAX_MSG_SIZE);
+		return -EMSGSIZE;
+	}
+
 	resp_pf_to_vf = (struct hclge_mbx_pf_to_vf_cmd *)desc.data;
 
 	hclge_cmd_setup_basic_desc(&desc, HCLGEVF_OPC_MBX_PF_TO_VF, false);