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 <ta...@tasossah.com>
Tested-by: Tasos Sahanidis <ta...@tasossah.com>
Cc: sta...@vger.kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torok...@gmail.com>
---
 drivers/input/input-leds.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/input/input-leds.c b/drivers/input/input-leds.c
index 766bf26601163..5f04b2d946350 100644
--- a/drivers/input/input-leds.c
+++ b/drivers/input/input-leds.c
@@ -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];
+               if (!input_led_info[led_code].name)
+                       continue;
 
+               led = &leds->leds[led_no];
                led->handle = &leds->handle;
                led->code = led_code;
 
-               if (!input_led_info[led_code].name)
-                       continue;
-
                led->cdev.name = kasprintf(GFP_KERNEL, "%s::%s",
                                           dev_name(&dev->dev),
                                           input_led_info[led_code].name);
-- 
2.17.0.484.g0c8726318c-goog


-- 
Dmitry

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