Re: [PATCH RESEND] twl4030_charger: fix charging current out-of-bounds

From: Pavel Machek
Date: Sun Sep 30 2018 - 16:16:51 EST


On Mon 2018-09-17 07:20:35, Andreas Kemnade wrote:
> the charging current uses unsigned int variables, if we step back
> if the current is still low, we would run into negative which
> means setting the target to a huge value.
> Better add checks here.

Do you expect this to happen in practice? Too high current while
charging seems bad, right?

Cc: stable?
Pavel

> Signed-off-by: Andreas Kemnade <andreas@xxxxxxxxxxxx>
> ---
> drivers/power/supply/twl4030_charger.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/power/supply/twl4030_charger.c b/drivers/power/supply/twl4030_charger.c
> index b72838663872..c954b7234393 100644
> --- a/drivers/power/supply/twl4030_charger.c
> +++ b/drivers/power/supply/twl4030_charger.c
> @@ -421,7 +421,8 @@ static void twl4030_current_worker(struct work_struct *data)
>
> if (v < USB_MIN_VOLT) {
> /* Back up and stop adjusting. */
> - bci->usb_cur -= USB_CUR_STEP;
> + if (bci->usb_cur >= USB_CUR_STEP)
> + bci->usb_cur -= USB_CUR_STEP;
> bci->usb_cur_target = bci->usb_cur;
> } else if (bci->usb_cur >= bci->usb_cur_target ||
> bci->usb_cur + USB_CUR_STEP > USB_MAX_CURRENT) {

--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Attachment: signature.asc
Description: Digital signature