[PATCH] iio: adc: ti-ads131e08: add missing fwnode_handle_put() in ads131e08_alloc_channels()

[PATCH] iio: adc: ti-ads131e08: add missing fwnode_handle_put() in ads131e08_alloc_channels()

[Jialin Zhang]

fwnode_handle_put() should be used when terminating
device_for_each_child_node() iteration with break or
return to prevent stale device node references from
being left behind.

Fixes: d935eddd2799 ("iio: adc: Add driver for Texas Instruments ADS131E0x ADC family")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Jialin Zhang <zhangjialin11@huawei.com>
---
 drivers/iio/adc/ti-ads131e08.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/adc/ti-ads131e08.c b/drivers/iio/adc/ti-ads131e08.c
index 0c2025a22575..80a09817c119 100644
--- a/drivers/iio/adc/ti-ads131e08.c
+++ b/drivers/iio/adc/ti-ads131e08.c
@@ -739,7 +739,7 @@ static int ads131e08_alloc_channels(struct iio_dev *indio_dev)
 	device_for_each_child_node(dev, node) {
 		ret = fwnode_property_read_u32(node, "reg", &channel);
 		if (ret)
-			return ret;
+			goto err_child_out;
 
 		ret = fwnode_property_read_u32(node, "ti,gain", &tmp);
 		if (ret) {
@@ -747,7 +747,7 @@ static int ads131e08_alloc_channels(struct iio_dev *indio_dev)
 		} else {
 			ret = ads131e08_pga_gain_to_field_value(st, tmp);
 			if (ret < 0)
-				return ret;
+				goto err_child_out;
 
 			channel_config[i].pga_gain = tmp;
 		}
@@ -758,7 +758,7 @@ static int ads131e08_alloc_channels(struct iio_dev *indio_dev)
 		} else {
 			ret = ads131e08_validate_channel_mux(st, tmp);
 			if (ret)
-				return ret;
+				goto err_child_out;
 
 			channel_config[i].mux = tmp;
 		}
@@ -784,6 +784,10 @@ static int ads131e08_alloc_channels(struct iio_dev *indio_dev)
 	st->channel_config = channel_config;
 
 	return 0;
+
+err_child_out:
+	fwnode_handle_put(node);
+	return ret;
 }
 
 static void ads131e08_regulator_disable(void *data)
-- 
2.25.1

Re: [PATCH] iio: adc: ti-ads131e08: add missing fwnode_handle_put() in ads131e08_alloc_channels()

[Jonathan Cameron]

On Tue, 17 May 2022 11:30:20 +0800
Jialin Zhang <zhangjialin11@huawei.com> wrote:

> fwnode_handle_put() should be used when terminating
> device_for_each_child_node() iteration with break or
> return to prevent stale device node references from
> being left behind.
This one seems obviously correct so I'll not wait on anyone else
looking at it - still time though as I won't be sending a pull
request until these have been in next for a day or two.

Applied to the fixes-togreg branch of iio.git.

I rewrapped the description to use longer lines.

Jonathan

> 
> Fixes: d935eddd2799 ("iio: adc: Add driver for Texas Instruments ADS131E0x ADC family")
> Reported-by: Hulk Robot <hulkci@huawei.com>
> Signed-off-by: Jialin Zhang <zhangjialin11@huawei.com>
> ---
>  drivers/iio/adc/ti-ads131e08.c | 10 +++++++---
>  1 file changed, 7 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/iio/adc/ti-ads131e08.c b/drivers/iio/adc/ti-ads131e08.c
> index 0c2025a22575..80a09817c119 100644
> --- a/drivers/iio/adc/ti-ads131e08.c
> +++ b/drivers/iio/adc/ti-ads131e08.c
> @@ -739,7 +739,7 @@ static int ads131e08_alloc_channels(struct iio_dev *indio_dev)
>  	device_for_each_child_node(dev, node) {
>  		ret = fwnode_property_read_u32(node, "reg", &channel);
>  		if (ret)
> -			return ret;
> +			goto err_child_out;
>  
>  		ret = fwnode_property_read_u32(node, "ti,gain", &tmp);
>  		if (ret) {
> @@ -747,7 +747,7 @@ static int ads131e08_alloc_channels(struct iio_dev *indio_dev)
>  		} else {
>  			ret = ads131e08_pga_gain_to_field_value(st, tmp);
>  			if (ret < 0)
> -				return ret;
> +				goto err_child_out;
>  
>  			channel_config[i].pga_gain = tmp;
>  		}
> @@ -758,7 +758,7 @@ static int ads131e08_alloc_channels(struct iio_dev *indio_dev)
>  		} else {
>  			ret = ads131e08_validate_channel_mux(st, tmp);
>  			if (ret)
> -				return ret;
> +				goto err_child_out;
>  
>  			channel_config[i].mux = tmp;
>  		}
> @@ -784,6 +784,10 @@ static int ads131e08_alloc_channels(struct iio_dev *indio_dev)
>  	st->channel_config = channel_config;
>  
>  	return 0;
> +
> +err_child_out:
> +	fwnode_handle_put(node);
> +	return ret;
>  }
>  
>  static void ads131e08_regulator_disable(void *data)