From: Jonathan Cameron <jic23@kernel.org>
To: Marco Felsch <m.felsch@pengutronix.de>
Cc: Yizhuo <yzhai003@ucr.edu>,
csong@cs.ucr.edu, Kate Stewart <kstewart@linuxfoundation.org>,
Lars-Peter Clausen <lars@metafoo.de>,
Pengutronix Kernel Team <kernel@pengutronix.de>,
Allison Randal <allison@lohutok.net>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Enrico Weigelt <info@metux.net>,
Fabio Estevam <festevam@gmail.com>,
Sascha Hauer <s.hauer@pengutronix.de>,
zhiyunq@cs.ucr.edu, linux-kernel@vger.kernel.org,
linux-iio@vger.kernel.org, NXP Linux Team <linux-imx@nxp.com>,
Peter Meerwald-Stadler <pmeerw@pmeerw.net>,
Hartmut Knaack <knaack.h@gmx.de>,
Thomas Gleixner <tglx@linutronix.de>,
Shawn Guo <shawnguo@kernel.org>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] iio: adc: imx25-gcq: Variable could be uninitialized if regmap_read() fails
Date: Tue, 1 Oct 2019 09:54:46 +0100 [thread overview]
Message-ID: <20191001095446.17bc9cd8@archlinux> (raw)
In-Reply-To: <20190930074412.up4k6zdus4y7u4xb@pengutronix.de>
On Mon, 30 Sep 2019 09:44:12 +0200
Marco Felsch <m.felsch@pengutronix.de> wrote:
> Hi Yizhuo,
>
> thanks for your patch.
>
> On 19-09-27 17:28, Yizhuo wrote:
> > In function mx25_gcq_irq(), local variable "stats" could
> > be uninitialized if function regmap_read() returns -EINVAL.
> > However, this value is used in if statement, which is
> > potentially unsafe. The same case applied to the variable
> > "data" in function mx25_gcq_get_raw_value() in the same file.
>
> IMHO the commit header should be something like: "iio: adc: imx25-gcq:
> fix uninitialized variable usage"...
>
> and please add a fixes tag.
As with the others, before adding a fixes tag, please verify there
is an actual path to trigger this.
In this case it's an mmio regmap with no clock. For those, I'm not sure
if there is a failure path.
Still a worthwhile hardening / cleanup patch, but shouldn't be called
a fix or marked with a fixes tag because we don't want people to think
it is necessary to backport it.
Thanks,
Jonathan
>
> >
> > Signed-off-by: Yizhuo <yzhai003@ucr.edu>
> > ---
> > drivers/iio/adc/fsl-imx25-gcq.c | 10 ++++++++--
> > 1 file changed, 8 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/iio/adc/fsl-imx25-gcq.c b/drivers/iio/adc/fsl-imx25-gcq.c
> > index df19ecae52f7..dbf3e8e85aba 100644
> > --- a/drivers/iio/adc/fsl-imx25-gcq.c
> > +++ b/drivers/iio/adc/fsl-imx25-gcq.c
> > @@ -74,7 +74,10 @@ static irqreturn_t mx25_gcq_irq(int irq, void *data)
> > struct mx25_gcq_priv *priv = data;
> > u32 stats;
> >
> > - regmap_read(priv->regs, MX25_ADCQ_SR, &stats);
> > + int ret = regmap_read(priv->regs, MX25_ADCQ_SR, &stats);
>
> Please don't do this. First declare the variable and then use it.
>
> Regards,
> Marco
>
> > +
> > + if (ret)
> > + return ret;
> >
> > if (stats & MX25_ADCQ_SR_EOQ) {
> > regmap_update_bits(priv->regs, MX25_ADCQ_MR,
> > @@ -121,7 +124,10 @@ static int mx25_gcq_get_raw_value(struct device *dev,
> > return -ETIMEDOUT;
> > }
> >
> > - regmap_read(priv->regs, MX25_ADCQ_FIFO, &data);
> > + int ret = regmap_read(priv->regs, MX25_ADCQ_FIFO, &data);
> > +
> > + if (ret)
> > + return ret;
> >
> > *val = MX25_ADCQ_FIFO_DATA(data);
> >
> > --
> > 2.17.1
> >
> >
> >
>
prev parent reply other threads:[~2019-10-01 8:54 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-28 0:28 [PATCH] iio: adc: imx25-gcq: Variable could be uninitialized if regmap_read() fails Yizhuo
2019-09-30 7:44 ` Marco Felsch
2019-10-01 8:54 ` Jonathan Cameron [this message]
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