2022-05-19 11:33:58

by Yongzhi Liu

Subject: [PATCH v2] iio: vadc: Fix potential dereference of NULL pointer

The return value of vadc_get_channel() needs to be checked
to avoid use of NULL pointer. Fix this by adding the null
pointer check on prop.

Fixes: 0917de94c ("iio: vadc: Qualcomm SPMI PMIC voltage ADC driver")

Signed-off-by: Yongzhi Liu <[email protected]>
---
drivers/iio/adc/qcom-spmi-vadc.c | 23 ++++++++++++++++++++++-
1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/adc/qcom-spmi-vadc.c b/drivers/iio/adc/qcom-spmi-vadc.c
index 34202ba..9fa61fb 100644
--- a/drivers/iio/adc/qcom-spmi-vadc.c
+++ b/drivers/iio/adc/qcom-spmi-vadc.c
@@ -358,14 +358,25 @@ static int vadc_measure_ref_points(struct vadc_priv *vadc)
vadc->graph[VADC_CALIB_ABSOLUTE].dx = VADC_ABSOLUTE_RANGE_UV;

prop = vadc_get_channel(vadc, VADC_REF_1250MV);
+ if (!prop) {
+ dev_err(vadc->dev, "Please define 1.25V channel\n");
+ ret = -ENODEV;
+ goto err;
+ }
ret = vadc_do_conversion(vadc, prop, &read_1);
if (ret)
goto err;

/* Try with buffered 625mV channel first */
prop = vadc_get_channel(vadc, VADC_SPARE1);
- if (!prop)
+ if (!prop) {
prop = vadc_get_channel(vadc, VADC_REF_625MV);
+ if (!prop) {
+ dev_err(vadc->dev, "Please define 0.625V channel\n");
+ ret = -ENODEV;
+ goto err;
+ }
+ }

ret = vadc_do_conversion(vadc, prop, &read_2);
if (ret)
@@ -381,11 +392,21 @@ static int vadc_measure_ref_points(struct vadc_priv *vadc)

/* Ratiometric calibration */
prop = vadc_get_channel(vadc, VADC_VDD_VADC);
+ if (!prop) {
+ dev_err(vadc->dev, "Please define VDD channel\n");
+ ret = -ENODEV;
+ goto err;
+ }
ret = vadc_do_conversion(vadc, prop, &read_1);
if (ret)
goto err;

prop = vadc_get_channel(vadc, VADC_GND_REF);
+ if (!prop) {
+ dev_err(vadc->dev, "Please define GND channel\n");
+ ret = -ENODEV;
+ goto err;
+ }
ret = vadc_do_conversion(vadc, prop, &read_2);
if (ret)
goto err;
--
2.7.4

2022-05-19 18:25:52

by Yongzhi Liu

Subject: Re: [PATCH v2] iio: vadc: Fix potential dereference of NULL pointer

> -----Original Messages-----
> From: "Kalle Valo" <[email protected]>
> Sent Time: 2022-05-19 23:30:51 (Thursday)
> To: "Yongzhi Liu" <[email protected]>
> Cc: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]
> Subject: Re: [PATCH v2] iio: vadc: Fix potential dereference of NULL pointer
>
> Yongzhi Liu <[email protected]> writes:
>
> > The return value of vadc_get_channel() needs to be checked
> > to avoid use of NULL pointer. Fix this by adding the null
> > pointer check on prop.
> >
> > Fixes: 0917de94c ("iio: vadc: Qualcomm SPMI PMIC voltage ADC driver")
> >
> > Signed-off-by: Yongzhi Liu <[email protected]>
> > ---
> > drivers/iio/adc/qcom-spmi-vadc.c | 23 ++++++++++++++++++++++-
> > 1 file changed, 22 insertions(+), 1 deletion(-)
>

I'm sorry to send this to linux-wireless by mistake. I will cautiously submit patches later.

> Did you sent this to linux-wireless by mistake?
>
> --
> https://patchwork.kernel.org/project/linux-wireless/list/
>
> https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches

2022-05-19 21:53:48

by Kalle Valo

Subject: Re: [PATCH v2] iio: vadc: Fix potential dereference of NULL pointer

Yongzhi Liu <[email protected]> writes:

> The return value of vadc_get_channel() needs to be checked
> to avoid use of NULL pointer. Fix this by adding the null
> pointer check on prop.
>
> Fixes: 0917de94c ("iio: vadc: Qualcomm SPMI PMIC voltage ADC driver")
>
> Signed-off-by: Yongzhi Liu <[email protected]>
> ---
> drivers/iio/adc/qcom-spmi-vadc.c | 23 ++++++++++++++++++++++-
> 1 file changed, 22 insertions(+), 1 deletion(-)

Did you sent this to linux-wireless by mistake?

--
https://patchwork.kernel.org/project/linux-wireless/list/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches