[PATCH 2/3] leds/class: Check snprintf return value

[Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>]

If the final name does not fit the string there is a potential
endless-loop.

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
---
 drivers/leds/led-class.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index 294d6d6..2ffe8b1 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -223,12 +223,17 @@ static int led_classdev_next_name(const char *init_name, char *name,
 				  size_t len)
 {
 	int i = 0;
+	int ret = 0;
 
 	strlcpy(name, init_name, len);
 
-	while (class_find_device(leds_class, NULL, name, match_name))
+	while (class_find_device(leds_class, NULL, name, match_name) &&
+	       (ret < len))
 		snprintf(name, len, "%s_%d", init_name, ++i);
 
+	if (ret >= len)
+		return -ENOMEM;
+
 	return i;
 }
 
@@ -243,6 +248,9 @@ int led_classdev_register(struct device *parent, struct led_classdev *led_cdev)
 	int ret;
 
 	ret = led_classdev_next_name(led_cdev->name, name, sizeof(name));
+	if (ret < 0)
+		return ret;
+
 	led_cdev->dev = device_create_with_groups(leds_class, parent, 0,
 				led_cdev, led_cdev->groups, "%s", name);
 	if (IS_ERR(led_cdev->dev))
-- 
2.1.4