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

[Ben Hutchings]

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@xxxxxxxxxxxx>
> > 
> > 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@xxxxxxxxxxxx>
> > Acked-by: Pavel Machek <pavel@xxxxxx>
> > Signed-off-by: Jacek Anaszewski <jacek.anaszewski@xxxxxxxxx>
> > Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
> > ---
> >  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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