Re: [PATCH 3.16 04/72] leds: leds-lp5562 allow firmware files up to the maximum length

Ben Hutchings
2019-12-14T18:44:46Z

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On Sat, 2019-12-14 at 09:37 +0100, Pavel Machek wrote:
> On Sun 2019-12-08 13:52:48, Ben Hutchings wrote:
> > 3.16.79-rc1 review patch. If anyone has any objections, please let
> > me know.
>
> Nobody is hitting this one and noone cares. Not a serious bug as
> described in stable rules.
>
> I'd recommend dropping.

This has already been included in 3.16.79 (and updates for other stable
branches), so unless it causes a problem I don't intend to revert it.

Ben.

> > ------------------
> >
> > From: Nick Stoughton <nstoughton@logitech.com>
> >
> > commit ed2abfebb041473092b41527903f93390d38afa7 upstream.
> >
> > Firmware files are in ASCII, using 2 hex characters per byte. The
> > maximum length of a firmware string is therefore
> >
> > 16 (commands) * 2 (bytes per command) * 2 (characters per byte) = 64
> >
> > Fixes: ff45262a85db ("leds: add new LP5562 LED driver")
> > Signed-off-by: Nick Stoughton <nstoughton@logitech.com>
> > Acked-by: Pavel Machek <pavel@ucw.cz>
> > Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
> > Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
> > ---
> > drivers/leds/leds-lp5562.c | 6 +++++-
> > 1 file changed, 5 insertions(+), 1 deletion(-)
> >
> > --- a/drivers/leds/leds-lp5562.c
> > +++ b/drivers/leds/leds-lp5562.c
> > @@ -263,7 +263,11 @@ static void lp5562_firmware_loaded(struc
> > {
> > const struct firmware *fw = chip->fw;
> >
> > - if (fw->size > LP5562_PROGRAM_LENGTH) {
> > + /*
> > + * the firmware is encoded in ascii hex character, with 2 chars
> > + * per byte
> > + */
> > + if (fw->size > (LP5562_PROGRAM_LENGTH * 2)) {
> > dev_err(&chip->cl->dev, "firmware data size overflow: %zu\n",
> > fw->size);
> > return;
--
Ben Hutchings
Anthony's Law of Force: Don't force it, get a larger hammer.

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