Re: [PATCH] iio: adc: meson-saradc: fix calibration buffer leak on error

[David Lechner <dlechner@baylibre.com>]

On 4/25/26 1:44 PM, Jonathan Cameron wrote:
> On Sat, 25 Apr 2026 11:17:18 -0500
> David Lechner <dlechner@baylibre.com> wrote:
> 
>> On 4/25/26 11:07 AM, Felix Gu wrote:
>>> meson_sar_adc_temp_sensor_init() allocates a buffer with
>>> nvmem_cell_read(), but the old code leaked it if
>>> syscon_regmap_lookup_by_phandle() failed.
>>>
>>> Switch buf to __free(kfree) so all return paths release it.
>>>
>>> Fixes: d6f2eac64403 ("iio: adc: meson: no devm for nvmem_cell_get")
>>> Signed-off-by: Felix Gu <ustc.gu@gmail.com>
>>> ---
>>>  drivers/iio/adc/meson_saradc.c | 10 +++-------
>>>  1 file changed, 3 insertions(+), 7 deletions(-)
>>>
>>> diff --git a/drivers/iio/adc/meson_saradc.c b/drivers/iio/adc/meson_saradc.c
>>> index 23991a3612bd..9708ddcc4919 100644
>>> --- a/drivers/iio/adc/meson_saradc.c
>>> +++ b/drivers/iio/adc/meson_saradc.c
>>> @@ -786,7 +786,7 @@ static int meson_sar_adc_clk_init(struct iio_dev *indio_dev,
>>>  static int meson_sar_adc_temp_sensor_init(struct iio_dev *indio_dev)
>>>  {  
>>
>> Nice to see one of these cleanup.h patches that is actually fixing a bug.
> 
> It's not fixing anything as far as I can see.
> The syscon_regmap_lookup_by_handle() is earlier in the function and
> nvmem_cell_read() isn't called if that fails.
> 
> So this is just a code simplification and so small benefit if anything.
> 
> Maybe there is an old version that does things in a different order?

I just updated iio/testing today and I see return without kfree().

	priv->tsc_regmap = syscon_regmap_lookup_by_phandle(dev->of_node, "amlogic,hhi-sysctrl");
	if (IS_ERR(priv->tsc_regmap))
		return dev_err_probe(dev, PTR_ERR(priv->tsc_regmap),
				     "failed to get amlogic,hhi-sysctrl regmap\n");


> 
> 
>>
>> Should `#include <linux/cleanup.h>` though rather that relying on it being
>> included through another header.
>>
>> With that fixed...
>>
>> Reviewed-by: David Lechner <dlechner@baylibre.com>
>>
>