Re: [PATCH 3/3] mfd: rave-sp: Check received frame length before accepting next byte

[Lucas Stach <l.stach@pengutronix.de>]

Am Montag, den 26.02.2018, 07:07 -0800 schrieb Andrey Smirnov:
> Check received frame length _before_ accepting next byte in order to
> avoid incorrectly rejecting payloads that are RAVE_SP_RX_BUFFER_SIZE
> long.
> 
> Cc: linux-kernel@vger.kernel.org
> Cc: cphealy@gmail.com
> > Cc: Lucas Stach <l.stach@pengutronix.de>
> > Cc: Lee Jones <lee.jones@linaro.org>
> > Cc: Guenter Roeck <linux@roeck-us.net>
> Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>

Tested-by: Lucas Stach <l.stach@pengutronix.de>

> ---
>  drivers/mfd/rave-sp.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/mfd/rave-sp.c b/drivers/mfd/rave-sp.c
> index cec1e309b31f..76fa32006a1b 100644
> --- a/drivers/mfd/rave-sp.c
> +++ b/drivers/mfd/rave-sp.c
> @@ -548,8 +548,6 @@ static int rave_sp_receive_buf(struct serdev_device *serdev,
> >  			/* FALLTHROUGH */
>  
> >  		case RAVE_SP_EXPECT_ESCAPED_DATA:
> > -			deframer->data[deframer->length++] = byte;
> -
> >  			if (deframer->length == sizeof(deframer->data)) {
> >  				dev_warn(dev, "Bad frame: Too long\n");
> >  				/*
> @@ -564,6 +562,8 @@ static int rave_sp_receive_buf(struct serdev_device *serdev,
> >  				goto reset_framer;
> >  			}
>  
> > +			deframer->data[deframer->length++] = byte;
> +
> >  			/*
> >  			 * We've extracted out special byte, now we
> >  			 * can go back to regular data collecting