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

From: Ricardo Ribalda Delgado
Date: Mon Mar 30 2015 - 05:08:18 EST


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

Reported-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@xxxxxxxxx>
---
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

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