* [PATCH] iio: adc: imx25-gcq: Variable could be uninitialized if regmap_read() fails
@ 2019-09-28 0:28 Yizhuo
2019-09-30 7:44 ` Marco Felsch
0 siblings, 1 reply; 3+ messages in thread
From: Yizhuo @ 2019-09-28 0:28 UTC (permalink / raw)
Cc: csong, Kate Stewart, Lars-Peter Clausen, Pengutronix Kernel Team,
Allison Randal, Greg Kroah-Hartman, Enrico Weigelt,
Fabio Estevam, Sascha Hauer, zhiyunq, linux-kernel, Yizhuo,
linux-iio, NXP Linux Team, Peter Meerwald-Stadler,
Hartmut Knaack, Thomas Gleixner, Shawn Guo, Jonathan Cameron,
linux-arm-kernel
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.
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);
+
+ 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
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^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] iio: adc: imx25-gcq: Variable could be uninitialized if regmap_read() fails
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
0 siblings, 1 reply; 3+ messages in thread
From: Marco Felsch @ 2019-09-30 7:44 UTC (permalink / raw)
To: Yizhuo
Cc: csong, Kate Stewart, Lars-Peter Clausen, Jonathan Cameron,
Peter Meerwald-Stadler, linux-iio, Greg Kroah-Hartman,
Sascha Hauer, zhiyunq, linux-kernel, Fabio Estevam,
NXP Linux Team, Pengutronix Kernel Team, Hartmut Knaack,
Shawn Guo, Thomas Gleixner, Enrico Weigelt, Allison Randal,
linux-arm-kernel
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.
>
> 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
>
>
>
--
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^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] iio: adc: imx25-gcq: Variable could be uninitialized if regmap_read() fails
2019-09-30 7:44 ` Marco Felsch
@ 2019-10-01 8:54 ` Jonathan Cameron
0 siblings, 0 replies; 3+ messages in thread
From: Jonathan Cameron @ 2019-10-01 8:54 UTC (permalink / raw)
To: Marco Felsch
Cc: csong, Kate Stewart, Lars-Peter Clausen, Peter Meerwald-Stadler,
linux-iio, Greg Kroah-Hartman, Sascha Hauer, zhiyunq,
linux-kernel, Fabio Estevam, Yizhuo, NXP Linux Team,
Pengutronix Kernel Team, Hartmut Knaack, Shawn Guo,
Thomas Gleixner, Enrico Weigelt, Allison Randal,
linux-arm-kernel
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
> >
> >
> >
>
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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
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