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 v4:
- removed the redundant NULL check as put_device() can handle the NULL dev;
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 | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/sound/soc/codecs/wcd934x.c b/sound/soc/codecs/wcd934x.c
index 1bb7e1dc7e6b..e92939068bf7 100644
--- a/sound/soc/codecs/wcd934x.c
+++ b/sound/soc/codecs/wcd934x.c
@@ -5831,6 +5831,13 @@ static const struct snd_soc_component_driver wcd934x_component_drv = {
 	.endianness = 1,
 };
 
+static void wcd934x_put_device_action(void *data)
+{
+	struct device *dev = data;
+
+	put_device(dev);
+}
+
 static int wcd934x_codec_parse_data(struct wcd934x_codec *wcd)
 {
 	struct device *dev = &wcd->sdev->dev;
@@ -5847,11 +5854,13 @@ 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 +5902,10 @@ 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

On Tue, 23 Sep 2025 14:52:12 +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.
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-next

Thanks!

[1/1] ASoC: wcd934x: fix error handling in wcd934x_codec_parse_data()
      commit: 4e65bda8273c938039403144730923e77916a3d7

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

On Tue, Sep 23, 2025 at 02:52:12PM +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 v4:
> - removed the redundant NULL check as put_device() can handle the NULL dev;
> 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 | 17 +++++++++++++++--
>  1 file changed, 15 insertions(+), 2 deletions(-)
> 

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>


-- 
With best wishes
Dmitry