commit f549c98ada3321ad01485fafa3c556eac406dd7f
author Yizhuo <yzhai003@ucr.edu> Tue Oct 01 13:24:39 2019 -0700
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> Tue Oct 29 09:15:05 2019 +0100
tree 28e37f664ed4edeca830c3132cfc1a5db1498e0b
parent b742b54cb85e049bb4992dce19977014d9b6473f

net: hisilicon: Fix usage of uninitialized variable in function mdio_sc_cfg_reg_write()

[ Upstream commit 53de429f4e88f538f7a8ec2b18be8c0cd9b2c8e1 ]

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>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/net/ethernet/hisilicon/hns_mdio.c

diff --git a/drivers/net/ethernet/hisilicon/hns_mdio.c b/drivers/net/ethernet/hisilicon/hns_mdio.c
index de23a0e..d06efcd 100644
--- a/drivers/net/ethernet/hisilicon/hns_mdio.c
+++ b/drivers/net/ethernet/hisilicon/hns_mdio.c
@@ -166,11 +166,15 @@
 {
 	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;