From: Arnd Bergmann <arnd@arndb.de>
Date: Thu, 23 Mar 2017 15:03:11 +0000 (+0100)
Subject: hwmon: (asus_atk0110) fix uninitialized data access
X-Git-Tag: v3.2.91~52
X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=commitdiff_plain;h=274b827b507f40a73437e8a10bc7217ddd49861d

hwmon: (asus_atk0110) fix uninitialized data access

commit a2125d02443e9a4e68bcfd9f8004fa23239e8329 upstream.

The latest gcc-7 snapshot adds a warning to point out that when
atk_read_value_old or atk_read_value_new fails, we copy
uninitialized data into sensor->cached_value:

drivers/hwmon/asus_atk0110.c: In function 'atk_input_show':
drivers/hwmon/asus_atk0110.c:651:26: error: 'value' may be used uninitialized in this function [-Werror=maybe-uninitialized]

Adding an error check avoids this. All versions of the driver
are affected.

Fixes: 2c03d07ad54d ("hwmon: Add Asus ATK0110 support")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Luca Tettamanti <kronos.it@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---

diff --git a/drivers/hwmon/asus_atk0110.c b/drivers/hwmon/asus_atk0110.c
index 83d2fbd670d6..b2a0badc66b3 100644
--- a/drivers/hwmon/asus_atk0110.c
+++ b/drivers/hwmon/asus_atk0110.c
@@ -645,6 +645,9 @@ static int atk_read_value(struct atk_sensor_data *sensor, u64 *value)
 		else
 			err = atk_read_value_new(sensor, value);
 
+		if (err)
+			return err;
+
 		sensor->is_valid = true;
 		sensor->last_updated = jiffies;
 		sensor->cached_value = *value;