linux-mediatek.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
From: Miquel Raynal <miquel.raynal@bootlin.com>
To: Evgeny Novikov <novikov@ispras.ru>
Cc: ldv-project@linuxtesting.org,
	Vignesh Raghavendra <vigneshr@ti.com>,
	"Gustavo A. R. Silva" <gustavo@embeddedor.com>,
	Richard Weinberger <richard@nod.at>,
	linux-kernel@vger.kernel.org, Stephen Boyd <swboyd@chromium.org>,
	Masahiro Yamada <yamada.masahiro@socionext.com>,
	Boris Brezillon <boris.brezillon@collabora.com>,
	linux-mtd@lists.infradead.org,
	Matthias Brugger <matthias.bgg@gmail.com>,
	linux-mediatek@lists.infradead.org,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] mtd: rawnand: mtk: avoid underflow in mtk_nfc_nand_chip_init()
Date: Thu, 17 Sep 2020 18:30:01 +0200	[thread overview]
Message-ID: <20200917183001.393245e8@xps13> (raw)
In-Reply-To: <20200916194045.6378-1-novikov@ispras.ru>

Hi Evgeny,

Evgeny Novikov <novikov@ispras.ru> wrote on Wed, 16 Sep 2020 22:40:45
+0300:

> If of_get_property() will set nsels to negative values the driver may

Is this really a possible case?

Looking at the OF code, I don't think it can ever happen...

> allocate insufficient memory for chip. Moreover, there may be underflow
> for devm_kzalloc(). This can result in various bad consequences later.
> The patch causes mtk_nfc_nand_chip_init() to fail for negative values of
> nsels.
> 
> Found by Linux Driver Verification project (linuxtesting.org).
> 
> Signed-off-by: Evgeny Novikov <novikov@ispras.ru>
> ---
>  drivers/mtd/nand/raw/mtk_nand.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/mtd/nand/raw/mtk_nand.c b/drivers/mtd/nand/raw/mtk_nand.c
> index ad1b55dab211..df98a2eec240 100644
> --- a/drivers/mtd/nand/raw/mtk_nand.c
> +++ b/drivers/mtd/nand/raw/mtk_nand.c
> @@ -1376,7 +1376,7 @@ static int mtk_nfc_nand_chip_init(struct device *dev, struct mtk_nfc *nfc,
>  		return -ENODEV;
>  
>  	nsels /= sizeof(u32);
> -	if (!nsels || nsels > MTK_NAND_MAX_NSELS) {
> +	if (nsels <= 0 || nsels > MTK_NAND_MAX_NSELS) {
>  		dev_err(dev, "invalid reg property size %d\n", nsels);
>  		return -EINVAL;
>  	}

Thanks,
Miquèl

_______________________________________________
Linux-mediatek mailing list
Linux-mediatek@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-mediatek

  reply	other threads:[~2020-09-17 16:30 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-16 19:40 [PATCH] mtd: rawnand: mtk: avoid underflow in mtk_nfc_nand_chip_init() Evgeny Novikov
2020-09-17 16:30 ` Miquel Raynal [this message]
2020-09-18  9:33   ` Evgeny Novikov

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200917183001.393245e8@xps13 \
    --to=miquel.raynal@bootlin.com \
    --cc=boris.brezillon@collabora.com \
    --cc=gustavo@embeddedor.com \
    --cc=ldv-project@linuxtesting.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mediatek@lists.infradead.org \
    --cc=linux-mtd@lists.infradead.org \
    --cc=matthias.bgg@gmail.com \
    --cc=novikov@ispras.ru \
    --cc=richard@nod.at \
    --cc=swboyd@chromium.org \
    --cc=vigneshr@ti.com \
    --cc=yamada.masahiro@socionext.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).