From: Jiaran Zhang <zhangjiaran@huawei.com>
Date: Mon, 13 Sep 2021 21:08:24 +0800
Subject: net: hns3: fix the exception when query imp info
Patch-mainline: v5.15-rc2
Git-commit: 472430a7b066f19afa1b55867d621b2d6d323e0d
References: bsc#1190336 stable-5.14.7

When the command for querying imp info is issued to the firmware,
if the firmware does not support the command, the returned value
of bd num is 0.
Add protection mechanism before alloc memory to prevent apply for
0-length memory.

Fixes: 0b198b0d80ea ("net: hns3: refactor dump m7 info of debugfs")
Signed-off-by: Jiaran Zhang <zhangjiaran@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_debugfs.c
@@ -1724,6 +1724,10 @@ hclge_dbg_get_imp_stats_info(struct hclg
 	}
 
 	bd_num = le32_to_cpu(req->bd_num);
+	if (!bd_num) {
+		dev_err(&hdev->pdev->dev, "imp statistics bd number is 0!\n");
+		return -EINVAL;
+	}
 
 	desc_src = kcalloc(bd_num, sizeof(struct hclge_desc), GFP_KERNEL);
 	if (!desc_src)