Date: Mon, 18 Sep 2017 11:39:45 +0200
From: Boris Brezillon <boris.brezillon@free-electrons.com>
To: Richard Weinberger <richard@nod.at>
Cc: linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org,
        marek.vasut@gmail.com, cyrille.pitchen@wedev4u.fr,
        computersforpeace@gmail.com, dwmw2@infradead.org
Subject: Re: [PATCH] mtd: spi-nor: Check for spi_nor_hwcaps_read2cmd()
 return value
Message-ID: <20170918113945.1549571f@bbrezillon>
In-Reply-To: <20170917095750.14059-1-richard@nod.at>
References: <20170917095750.14059-1-richard@nod.at>
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On Sun, 17 Sep 2017 11:57:50 +0200
Richard Weinberger <richard@nod.at> wrote:

> The function can return a negativ value in case of errors,
> don't use it blindly as array index.
> 
> Detected by CoverityScan CID#1418067 ("Memory - illegal accesses")
> Fixes: f384b352cbf0 ("mtd: spi-nor: parse Serial Flash Discoverable
> Parameters (SFDP) tables")

Hm, not sure but I think "Fixes:" should not be wrapped.

> Signed-off-by: Richard Weinberger <richard@nod.at>
> ---
>  drivers/mtd/spi-nor/spi-nor.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
> index cf1d4a15e10a..d71765739a93 100644
> --- a/drivers/mtd/spi-nor/spi-nor.c
> +++ b/drivers/mtd/spi-nor/spi-nor.c
> @@ -2145,6 +2145,9 @@ static int spi_nor_parse_bfpt(struct spi_nor *nor,
>  
>  		params->hwcaps.mask |= rd->hwcaps;
>  		cmd = spi_nor_hwcaps_read2cmd(rd->hwcaps);
> +		if (cmd < 0)
> +			return -EINVAL;

Why not returning cmd directly?

> +
>  		read = &params->reads[cmd];
>  		half = bfpt.dwords[rd->settings_dword] >> rd->settings_shift;
>  		spi_nor_set_read_settings_from_bfpt(read, half, rd->proto);