[PATCH 3.18 27/28] PM / QoS: return -EINVAL for bogus strings

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

3.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dan Carpenter <dan.carpenter@oracle.com>

commit 2ca30331c156ca9e97643ad05dd8930b8fe78b01 upstream.

In the current code, if the user accidentally writes a bogus command to
this sysfs file, then we set the latency tolerance to an uninitialized
variable.

Fixes: 2d984ad132a8 (PM / QoS: Introcuce latency tolerance device PM QoS type)
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/base/power/sysfs.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/drivers/base/power/sysfs.c
+++ b/drivers/base/power/sysfs.c
@@ -269,6 +269,8 @@ static ssize_t pm_qos_latency_tolerance_
 			value = PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT;
 		else if (!strcmp(buf, "any") || !strcmp(buf, "any\n"))
 			value = PM_QOS_LATENCY_ANY;
+		else
+			return -EINVAL;
 	}
 	ret = dev_pm_qos_update_user_latency_tolerance(dev, value);
 	return ret < 0 ? ret : n;