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From: Yizhuo <yzhai003@ucr.edu>
To: unlisted-recipients:; (no To-header on input)
Cc: csong@cs.ucr.edu, zhiyunq@cs.ucr.edu, Yizhuo <yzhai003@ucr.edu>,
	Yisen Zhuang <yisen.zhuang@huawei.com>,
	Salil Mehta <salil.mehta@huawei.com>,
	"David S. Miller" <davem@davemloft.net>,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] net: hisilicon: Fix usage of uninitialized variable in function mdio_sc_cfg_reg_write()
Date: Tue,  1 Oct 2019 13:24:39 -0700	[thread overview]
Message-ID: <20191001202439.15766-1-yzhai003@ucr.edu> (raw)

In function mdio_sc_cfg_reg_write(), variable "reg_value" could be
uninitialized if regmap_read() fails. However, "reg_value" is used
to decide the control flow later in the if statement, which is
potentially unsafe.

Signed-off-by: Yizhuo <yzhai003@ucr.edu>
---
 drivers/net/ethernet/hisilicon/hns_mdio.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/hisilicon/hns_mdio.c b/drivers/net/ethernet/hisilicon/hns_mdio.c
index 3e863a71c513..7df5d7d211d4 100644
--- a/drivers/net/ethernet/hisilicon/hns_mdio.c
+++ b/drivers/net/ethernet/hisilicon/hns_mdio.c
@@ -148,11 +148,15 @@ static int mdio_sc_cfg_reg_write(struct hns_mdio_device *mdio_dev,
 {
 	u32 time_cnt;
 	u32 reg_value;
+	int ret;
 
 	regmap_write(mdio_dev->subctrl_vbase, cfg_reg, set_val);
 
 	for (time_cnt = MDIO_TIMEOUT; time_cnt; time_cnt--) {
-		regmap_read(mdio_dev->subctrl_vbase, st_reg, &reg_value);
+		ret = regmap_read(mdio_dev->subctrl_vbase, st_reg, &reg_value);
+		if (ret)
+			return ret;
+
 		reg_value &= st_msk;
 		if ((!!check_st) == (!!reg_value))
 			break;
-- 
2.17.1


             reply	other threads:[~2019-10-01 20:24 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-01 20:24 Yizhuo [this message]
2019-10-02 21:22 ` [PATCH] net: hisilicon: Fix usage of uninitialized variable in function mdio_sc_cfg_reg_write() David Miller
2019-10-03 17:42   ` Yizhuo Zhai

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