[PATCH AUTOSEL 4.19 21/26] net: hisilicon: Fix usage of uninitialized variable in function mdio_sc_cfg_reg_write()

Sasha Levin
2019-10-09T17:29:36Z

From: Yizhuo <yzhai003@ucr.edu>

[ 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 | 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 baf5cc251f329..9a3bc0994a1db 100644
--- a/drivers/net/ethernet/hisilicon/hns_mdio.c
+++ b/drivers/net/ethernet/hisilicon/hns_mdio.c
@@ -156,11 +156,15 @@ 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;
--
2.20.1