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From:   Robert Foss <robert.foss@linaro.org>
Date:   Mon, 4 Jul 2022 20:40:38 +0200
Message-ID: <CAG3jFytopyV+gN3QAVAZYd_HYWeAygTZkb7iQAA-jmSBMQexfw@mail.gmail.com>
Subject: Re: [PATCH] drm: bridge: sii8620: fix possible off-by-one
To:     Hangyu Hua <hbh25y@gmail.com>
Cc:     Andrzej Hajda <andrzej.hajda@intel.com>, narmstrong@baylibre.com,
        Laurent.pinchart@ideasonboard.com, jonas@kwiboo.se,
        jernej.skrabec@gmail.com, airlied@linux.ie, daniel@ffwll.ch,
        architt@codeaurora.org, dri-devel@lists.freedesktop.org,
        linux-kernel@vger.kernel.org
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On Thu, 23 Jun 2022 at 04:55, Hangyu Hua <hbh25y@gmail.com> wrote:
>
> 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@gmail.com>
> > Reviewed-by: Andrzej Hajda <andrzej.hajda@intel.com>
> >
> > 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?

Applied to drm-misc-next.