Input: leds - fix out of bound access

UI_SET_LEDBIT ioctl() causes the following KASAN splat when used with
led > LED_CHARGING:

[ 1274.663418] BUG: KASAN: slab-out-of-bounds in input_leds_connect+0x611/0x730 [input_leds]
[ 1274.663426] Write of size 8 at addr ffff88003377b2c0 by task ckb-next-daemon/5128

This happens because we were writing to the led structure before making
sure that it exists.

Reported-by: Tasos Sahanidis <tasos@tasossah.com>
Tested-by: Tasos Sahanidis <tasos@tasossah.com>
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
This commit is contained in:
Dmitry Torokhov 2018-04-06 10:23:05 -07:00
parent 839c422736
commit 6bd6ae6396

View File

@ -88,6 +88,7 @@ static int input_leds_connect(struct input_handler *handler,
const struct input_device_id *id)
{
struct input_leds *leds;
struct input_led *led;
unsigned int num_leds;
unsigned int led_code;
int led_no;
@ -119,14 +120,13 @@ static int input_leds_connect(struct input_handler *handler,
led_no = 0;
for_each_set_bit(led_code, dev->ledbit, LED_CNT) {
struct input_led *led = &leds->leds[led_no];
led->handle = &leds->handle;
led->code = led_code;
if (!input_led_info[led_code].name)
continue;
led = &leds->leds[led_no];
led->handle = &leds->handle;
led->code = led_code;
led->cdev.name = kasprintf(GFP_KERNEL, "%s::%s",
dev_name(&dev->dev),
input_led_info[led_code].name);