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Date:   Wed, 12 Apr 2023 09:39:25 +0200
From:   Miquel Raynal <miquel.raynal@bootlin.com>
To:     Arseniy Krasnov <AVKrasnov@sberdevices.ru>
Cc:     Liang Yang <liang.yang@amlogic.com>,
        Richard Weinberger <richard@nod.at>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        Neil Armstrong <neil.armstrong@linaro.org>,
        Kevin Hilman <khilman@baylibre.com>,
        Jerome Brunet <jbrunet@baylibre.com>,
        Martin Blumenstingl <martin.blumenstingl@googlemail.com>,
        Yixun Lan <yixun.lan@amlogic.com>,
        Jianxin Pan <jianxin.pan@amlogic.com>, <oxffffaa@gmail.com>,
        <kernel@sberdevices.ru>, <linux-mtd@lists.infradead.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-amlogic@lists.infradead.org>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v1 3/5] mtd: rawnand: meson: check buffer length
Message-ID: <20230412093925.4718ac6f@xps-13>
In-Reply-To: <20230412061700.1492474-4-AVKrasnov@sberdevices.ru>
References: <20230412061700.1492474-1-AVKrasnov@sberdevices.ru>
 <20230412061700.1492474-4-AVKrasnov@sberdevices.ru>
Organization: Bootlin
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Hi Arseniy,

AVKrasnov@sberdevices.ru wrote on Wed, 12 Apr 2023 09:16:57 +0300:

> With this chip, buffer length is limited by hardware, so check it before
> command execution to avoid length trim.

What is "this chip"? Are you talking about the controller itself? Is
there any specific SoC version targeted?

>=20
> Signed-off-by: Arseniy Krasnov <AVKrasnov@sberdevices.ru>
> ---
>  drivers/mtd/nand/raw/meson_nand.c | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
>=20
> diff --git a/drivers/mtd/nand/raw/meson_nand.c b/drivers/mtd/nand/raw/mes=
on_nand.c
> index 45b53d420aed..f84a10238e4d 100644
> --- a/drivers/mtd/nand/raw/meson_nand.c
> +++ b/drivers/mtd/nand/raw/meson_nand.c
> @@ -543,6 +543,9 @@ static int meson_nfc_read_buf(struct nand_chip *nand,=
 u8 *buf, int len)
>  	u32 cmd;
>  	u8 *info;
> =20
> +	if (len > NFC_CMD_RAW_LEN)
> +		return -EINVAL;
> +
>  	info =3D kzalloc(PER_INFO_BYTE, GFP_KERNEL);
>  	if (!info)
>  		return -ENOMEM;
> @@ -571,6 +574,9 @@ static int meson_nfc_write_buf(struct nand_chip *nand=
, u8 *buf, int len)
>  	int ret =3D 0;
>  	u32 cmd;
> =20
> +	if (len > NFC_CMD_RAW_LEN)
> +		return -EINVAL;
> +
>  	ret =3D meson_nfc_dma_buffer_setup(nand, buf, len, NULL,
>  					 0, DMA_TO_DEVICE);
>  	if (ret)
> @@ -1269,6 +1275,7 @@ static int meson_nand_attach_chip(struct nand_chip =
*nand)
>  	struct meson_nfc_nand_chip *meson_chip =3D to_meson_nand(nand);
>  	struct mtd_info *mtd =3D nand_to_mtd(nand);
>  	int nsectors =3D mtd->writesize / 1024;
> +	int raw_writesize;
>  	int ret;
> =20
>  	if (!mtd->name) {
> @@ -1280,6 +1287,13 @@ static int meson_nand_attach_chip(struct nand_chip=
 *nand)
>  			return -ENOMEM;
>  	}
> =20
> +	raw_writesize =3D mtd->writesize + mtd->oobsize;
> +	if (raw_writesize > NFC_CMD_RAW_LEN) {
> +		dev_err(nfc->dev, "too big write size in raw mode: %d > %ld\n",
> +			raw_writesize, NFC_CMD_RAW_LEN);
> +		return -EINVAL;
> +	}
> +
>  	if (nand->bbt_options & NAND_BBT_USE_FLASH)
>  		nand->bbt_options |=3D NAND_BBT_NO_OOB;
> =20


Thanks,
Miqu=C3=A8l