Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
IronPort-SDR: AHMz0diXmTyHaUcN8WEw4F0Je/MtA4X9ReWqGmyM+avrBPKP6XXUwAADOqv93pHokd7fab0ww4
 me7wb05Tq+Tc3VqPTfT3Qs4x+AkOon0NusyRH/4RXtQs75f0RGrPrXR1xReMS9008iBDv0UfGn
 pYLPGiGm3SO3HHgNfrZ5JikNU5YfToKLw1nDsK4ecsANib36hXA30znOntCR/E+MXDM1NTf0ub
 OwDB0f1Q9rvFkvZV6zlftSY6PfDZ4gv2Wmk+cDgLcGNpgimoE3bvxEBwQaWDNI53qUUHRKCR8/
 Svs=
IronPort-PHdr: =?us-ascii?q?9a23=3APrN/IhWB+Yl3LN6R5a17Wx8C9hnV8LGtZVwlr6?=
 =?us-ascii?q?E/grcLSJyIuqrYYx2Gt8tkgFKBZ4jH8fUM07OQ7/m7HzBeqsfZ+Fk5M7V0Hy?=
 =?us-ascii?q?cfjssXmwFySOWkMmbcaMDQUiohAc5ZX0Vk9XzoeWJcGcL5ekGA6ibqtW1aFR?=
 =?us-ascii?q?rwLxd6KfroEYDOkcu3y/qy+5rOaAlUmTaxe7x/IAi4oAnLucQbgIRuJ6Itxh?=
 =?us-ascii?q?DUvnZGZuNayH9yK1mOhRj8/MCw/JBi8yRUpf0s8tNLXLv5caolU7FWFSwqPG?=
 =?us-ascii?q?8p6sLlsxnDVhaP6WAHUmoKiBpIAhPK4w/8U5zsryb1rOt92C2dPc3rUbA5XC?=
 =?us-ascii?q?mp4ql3RBP0jioMKiU0+3/LhMNukK1boQqhpx1hzI7SfIGVL+d1cqfEcd8HWW?=
 =?us-ascii?q?ZNQsNdWipEAoO9dIsPFOsBPeBXr4LguVUAtAa1BQetBOzxzj9Hm2L90ak03u?=
 =?us-ascii?q?g9FA3L2hErEdATv3TOtNj7NLkcX/27wqfLyjvOdO9a1Svn5YTUaB0tve2AUL?=
 =?us-ascii?q?RtesTR00kvEAbFg02SpozkPjKV1vkNs2+G5OdnVeOuim4npBtwojSz2sshhJ?=
 =?us-ascii?q?LEhp8JxVDe7yl23ps6JcChRUN9fNWqE4NQujmEO4dqRs4uWWJltSYgxrEYpJ?=
 =?us-ascii?q?K2fDIGxIkjyhPdc/CLbomF7xb5WOqPLzp1hGhpdKy+ihqo80WtxevxXdSu3l?=
 =?us-ascii?q?lQtCpKiNzMu2gI1xzU98eIVONw/lyk2TaTzwDT7fxEIVwsmarbNZEhxrkwm4?=
 =?us-ascii?q?IWsUvZHy/2nFz6jLeZdkk54+So5fnrb7Hkq5OGOI90jQb+MqsqmsOhG+g3Lg?=
 =?us-ascii?q?8OX22D9eS90r3s41H5Ta1UgvEqlqTVqpPXKMQBqqKnHgNY0pwv5wu7AjqkyN?=
 =?us-ascii?q?gYmGMILFNBeBKJlYjpPFTOLej4DPa+g1SjijZry+zaMrDvGZjNM2TMkK37cb?=
 =?us-ascii?q?lj9kFc1RI/zcpD6JJMFrEBPPXzV1f1tNzZCB85LgO1z//kCNpjzIMeX3yAAq?=
 =?us-ascii?q?uCPaPMvl+H+PgvL/OPZIALojb9LeYq5/r0gX8+g18dcvrh84EQbSWJH+ZmPk?=
 =?us-ascii?q?LRNWv+gt4AST9Rlhc1VqrnhEDUAm0bXGq7Q69pvmJzM4mhF4qWA9/1jQ=3D?=
 =?us-ascii?q?=3D?=
From:   Yizhuo <yzhai003@ucr.edu>
Cc:     csong@cs.ucr.edu, zhiyunq@cs.ucr.edu, Yizhuo <yzhai003@ucr.edu>,
        Sebastian Reichel <sre@kernel.org>, linux-pm@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH] power: supply: max17042_battery: fix the potential uninitialized use in max17042_write_verify_reg()
Date:   Wed,  2 Oct 2019 08:44:06 -0700
Message-Id: <20191002154406.8875-1-yzhai003@ucr.edu>
To:     unlisted-recipients:; (no To-header on input)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

In function max17042_write_verify_reg(), variable "read_value"
could be uninitialized if regmap_read() fails. However,
"read_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/power/supply/max17042_battery.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/power/supply/max17042_battery.c b/drivers/power/supply/max17042_battery.c
index 0dfad2cf13fe..e6a2dacaa730 100644
--- a/drivers/power/supply/max17042_battery.c
+++ b/drivers/power/supply/max17042_battery.c
@@ -486,12 +486,15 @@ static void max17042_external_power_changed(struct power_supply *psy)
 static int max17042_write_verify_reg(struct regmap *map, u8 reg, u32 value)
 {
 	int retries = 8;
-	int ret;
+	int ret, err;
 	u32 read_value;
 
 	do {
 		ret = regmap_write(map, reg, value);
-		regmap_read(map, reg, &read_value);
+		err = regmap_read(map, reg, &read_value);
+		if (err)
+			return err;
+
 		if (read_value != value) {
 			ret = -EIO;
 			retries--;
-- 
2.17.1