Re: [PATCH v3] ASoC: wcd934x: fix error handling in wcd934x_codec_parse_data()

On Tue, Sep 23, 2025 at 10:38:28AM +0800, Ma Ke wrote:

wcd934x_codec_parse_data() contains a device reference count leak in of_slim_get_device() where device_find_child() increases the reference count of the device but this reference is not properly decreased in the success path. Add put_device() in wcd934x_codec_parse_data() and add devm_add_action_or_reset() in the probe function, which ensures that the reference count of the device is correctly managed.

Memory leak in regmap_init_slimbus() as the allocated regmap is not released when the device is removed. Using devm_regmap_init_slimbus() instead of regmap_init_slimbus() to ensure automatic regmap cleanup on device removal.

Calling path: of_slim_get_device() -> of_find_slim_device() -> device_find_child(). As comment of device_find_child() says, 'NOTE: you will need to drop the reference with put_device() after use.'.

Found by code review.

Cc: stable@vger.kernel.org Fixes: a61f3b4f476e ("ASoC: wcd934x: add support to wcd9340/wcd9341 codec") Signed-off-by: Ma Ke make24@iscas.ac.cn

---

Changes in v3:

• added a wrapper function due to the warning report from kernel test robot;

Changes in v2:

• modified the handling in the success path and fixed the memory leak for regmap as suggestions.

---

sound/soc/codecs/wcd934x.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/sound/soc/codecs/wcd934x.c b/sound/soc/codecs/wcd934x.c index 1bb7e1dc7e6b..d9d8cf64977a 100644 --- a/sound/soc/codecs/wcd934x.c +++ b/sound/soc/codecs/wcd934x.c @@ -5831,6 +5831,15 @@ static const struct snd_soc_component_driver wcd934x_component_drv = { .endianness = 1, }; +static void wcd934x_put_device_action(void *data) +{

• struct device *dev = data;
• if (dev) {

Can it be NULL here? Can put_device() cope with NULL being passed to it?

• put_device(dev);
  

• }

+}

static int wcd934x_codec_parse_data(struct wcd934x_codec *wcd) { struct device *dev = &wcd->sdev->dev; @@ -5847,11 +5856,13 @@ static int wcd934x_codec_parse_data(struct wcd934x_codec *wcd) return dev_err_probe(dev, -EINVAL, "Unable to get SLIM Interface device\n"); slim_get_logical_addr(wcd->sidev);

• wcd->if_regmap = regmap_init_slimbus(wcd->sidev,

• wcd->if_regmap = devm_regmap_init_slimbus(wcd->sidev, &wcd934x_ifc_regmap_config);

• if (IS_ERR(wcd->if_regmap))

• if (IS_ERR(wcd->if_regmap)) {

• put_device(&wcd->sidev->dev);
  

  return dev_err_probe(dev, PTR_ERR(wcd->if_regmap), "Failed to allocate ifc register map\n");
• }

of_property_read_u32(dev->parent->of_node, "qcom,dmic-sample-rate", &wcd->dmic_sample_rate); @@ -5893,6 +5904,10 @@ static int wcd934x_codec_probe(struct platform_device *pdev) if (ret) return ret;

• ret = devm_add_action_or_reset(dev, wcd934x_put_device_action, &wcd->sidev->dev);
• if (ret)

• return ret;
  

• /* set default rate 9P6MHz */ regmap_update_bits(wcd->regmap, WCD934X_CODEC_RPM_CLK_MCLK_CFG, WCD934X_CODEC_RPM_CLK_MCLK_CFG_MCLK_MASK,

-- 2.17.1