leds: lp55xx: fix null deref on firmware load failure

I've stumbled upon a kernel crash and the logs
pointed me towards the lp5562 driver:

> <4>[306013.841294] lp5562 0-0030: Direct firmware load for lp5562 failed with error -2
> <4>[306013.894990] lp5562 0-0030: Falling back to user helper
> ...
> <3>[306073.924886] lp5562 0-0030: firmware request failed
> <1>[306073.939456] Unable to handle kernel NULL pointer dereference at virtual address 00000000
> <4>[306074.251011] PC is at _raw_spin_lock+0x1c/0x58
> <4>[306074.255539] LR is at release_firmware+0x6c/0x138
> ...

After taking a look I noticed firmware_release()
could be called with either NULL or a dangling
pointer.

Fixes: 10c06d178d ("leds-lp55xx: support firmware interface")
Signed-off-by: Michal Kazior <michal@plume.com>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
This commit is contained in:
Michal Kazior 2019-02-11 10:29:27 +01:00 committed by Jacek Anaszewski
parent 0f85e8498a
commit 5ddb0869bf
1 changed files with 2 additions and 2 deletions

View File

@ -201,7 +201,7 @@ static void lp55xx_firmware_loaded(const struct firmware *fw, void *context)
if (!fw) {
dev_err(dev, "firmware request failed\n");
goto out;
return;
}
/* handling firmware data is chip dependent */
@ -214,9 +214,9 @@ static void lp55xx_firmware_loaded(const struct firmware *fw, void *context)
mutex_unlock(&chip->lock);
out:
/* firmware should be released for other channel use */
release_firmware(chip->fw);
chip->fw = NULL;
}
static int lp55xx_request_firmware(struct lp55xx_chip *chip)