[added,to,the,4.1,stable,tree] hwmon: (asus_atk0110) fix uninitialized data access

Message ID 20180301152116.1486-30-alexander.levin@microsoft.com
State New
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  • [added,to,the,4.1,stable,tree] hwmon: (asus_atk0110) fix uninitialized data access
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Commit Message

Sasha Levin March 1, 2018, 3:22 p.m.
From: Arnd Bergmann <arnd@arndb.de>

This patch has been added to the 4.1 stable tree. If you have any
objections, please let us know.




[ Upstream commit a2125d02443e9a4e68bcfd9f8004fa23239e8329 ]

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: Sasha Levin <alexander.levin@microsoft.com>
 drivers/hwmon/asus_atk0110.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/hwmon/asus_atk0110.c b/drivers/hwmon/asus_atk0110.c
index cccef87963e0..975c43d446f8 100644
--- a/drivers/hwmon/asus_atk0110.c
+++ b/drivers/hwmon/asus_atk0110.c
@@ -646,6 +646,9 @@  static int atk_read_value(struct atk_sensor_data *sensor, u64 *value)
 			err = atk_read_value_new(sensor, value);
+		if (err)
+			return err;
 		sensor->is_valid = true;
 		sensor->last_updated = jiffies;
 		sensor->cached_value = *value;