Re: [PATCH] drm: bridge: sii8620: fix possible off-by-one

[Hangyu Hua]

On 2022/5/18 15:57, Andrzej Hajda wrote:
> On 18.05.2022 08:58, Hangyu Hua wrote:
> > The next call to sii8620_burst_get_tx_buf will result in off-by-one
> > When ctx->burst.tx_count + size == ARRAY_SIZE(ctx->burst.tx_buf). The 
> > same
> > thing happens in sii8620_burst_get_rx_buf.
> >
> > This patch also change tx_count and tx_buf to rx_count and rx_buf in
> > sii8620_burst_get_rx_buf. It is unreasonable to check tx_buf's size and
> > use rx_buf.
> >
> > Fixes: e19e9c692f81 ("drm/bridge/sii8620: add support for burst eMSC 
> > transmissions")
> > Signed-off-by: Hangyu Hua <hbh25y@xxxxxxxxx>
> Reviewed-by: Andrzej Hajda <andrzej.hajda@xxxxxxxxx>
>
> Regards
> Andrzej
> > ---
> >   drivers/gpu/drm/bridge/sil-sii8620.c | 4 ++--
> >   1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/bridge/sil-sii8620.c 
> > b/drivers/gpu/drm/bridge/sil-sii8620.c
> > index ec7745c31da0..ab0bce4a988c 100644
> > --- a/drivers/gpu/drm/bridge/sil-sii8620.c
> > +++ b/drivers/gpu/drm/bridge/sil-sii8620.c
> > @@ -605,7 +605,7 @@ static void *sii8620_burst_get_tx_buf(struct 
> > sii8620 *ctx, int len)
> >       u8 *buf = &ctx->burst.tx_buf[ctx->burst.tx_count];
> >       int size = len + 2;
> > -    if (ctx->burst.tx_count + size > ARRAY_SIZE(ctx->burst.tx_buf)) {
> > +    if (ctx->burst.tx_count + size >= ARRAY_SIZE(ctx->burst.tx_buf)) {
> >           dev_err(ctx->dev, "TX-BLK buffer exhausted\n");
> >           ctx->error = -EINVAL;
> >           return NULL;
> > @@ -622,7 +622,7 @@ static u8 *sii8620_burst_get_rx_buf(struct sii8620 
> > *ctx, int len)
> >       u8 *buf = &ctx->burst.rx_buf[ctx->burst.rx_count];
> >       int size = len + 1;
> > -    if (ctx->burst.tx_count + size > ARRAY_SIZE(ctx->burst.tx_buf)) {
> > +    if (ctx->burst.rx_count + size >= ARRAY_SIZE(ctx->burst.rx_buf)) {
> >           dev_err(ctx->dev, "RX-BLK buffer exhausted\n");
> >           ctx->error = -EINVAL;
> >           return NULL;

Hi guys,

Another patches for this module that I submitted at the same time as
this one have been merged. Is this patch forgotten to merge?

Thanks,
Hangyu