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Date:   Wed, 9 Aug 2023 11:43:55 +0800
From:   Chen-Yu Tsai <wenst@chromium.org>
To:     Wei Chen <harperchen1110@gmail.com>
Cc:     tiffany.lin@mediatek.com, andrew-ct.chen@mediatek.com,
        yunfei.dong@mediatek.com, mchehab@kernel.org,
        matthias.bgg@gmail.com, angelogioacchino.delregno@collabora.com,
        linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org
Subject: Re: [PATCH] media: vcodec: Fix potential array out-of-bounds in
 vb2ops_venc_queue_setup
Message-ID: <20230809034355.GA589411@google.com>
References: <20230328092608.523933-1-harperchen1110@gmail.com>
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In-Reply-To: <20230328092608.523933-1-harperchen1110@gmail.com>
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On Tue, Mar 28, 2023 at 09:26:08AM +0000, Wei Chen wrote:
> variable *nplanes is provided by user via system call argument. The
> possible value of q_data->fmt->num_planes is 1-3, while the value
> of *nplanes can be 1-8. The array access by index i can cause array
> out-of-bounds.
> 
> Fix this bug by checking *nplanes against the array size.

This should have a fixes tag:

Fixes: 4e855a6efa54 ("[media] vcodec: mediatek: Add Mediatek V4L2 Video Encoder Driver")

And also CC the stable list:

Cc: stable@vger.kernel.org

> Signed-off-by: Wei Chen <harperchen1110@gmail.com>

Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>

> ---
>  drivers/media/platform/mediatek/vcodec/mtk_vcodec_enc.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/media/platform/mediatek/vcodec/mtk_vcodec_enc.c b/drivers/media/platform/mediatek/vcodec/mtk_vcodec_enc.c
> index d65800a3b89d..1ea02f9136f6 100644
> --- a/drivers/media/platform/mediatek/vcodec/mtk_vcodec_enc.c
> +++ b/drivers/media/platform/mediatek/vcodec/mtk_vcodec_enc.c
> @@ -821,6 +821,8 @@ static int vb2ops_venc_queue_setup(struct vb2_queue *vq,
>  		return -EINVAL;
>  
>  	if (*nplanes) {
> +		if (*nplanes != q_data->fmt->num_planes)
> +			return -EINVAL;
>  		for (i = 0; i < *nplanes; i++)
>  			if (sizes[i] < q_data->sizeimage[i])
>  				return -EINVAL;
> -- 
> 2.25.1
>