[PATCH v2] leds: pwm-multicolor: Manage the multi-led node reference

[PATCH v2] leds: pwm-multicolor: Manage the multi-led node reference

[Yige Jiang]

led_pwm_mc_probe() leaks the multi-led node reference on successful
probe and if the final PWM update fails. LED registration borrows
the node, so it must remain valid until the LED is unregistered.

Register a managed put action before LED registration. Reverse devres
order then unregisters the LED before releasing the node on unbind
or probe failure. Drop the manual error-path put and return directly
on probe errors, leaving the reference cleanup to devres.

Fixes: 9fa2762110dd ("leds: Add PWM multicolor driver")
Assisted-by: LLM
Signed-off-by: Yige Jiang <yigejiang86@gmail.com>
---
Changes in v2:
- Capitalize the subject description to follow the LED subsystem style.
- Remove the redundant release_mcnode label and return directly from
  the probe error paths.

v1: https://lore.kernel.org/r/rc-review-20261029-ai27-27-2c77ed65cec2@gmail.com

Based on linux-next next-20261016 (2efb7a11f1aa).
Compile-tested: arm64, GCC 14.2.0, W=1, CONFIG_OF_DYNAMIC=y.
COMPILE_TEST=y.
The object was rebuilt from this exact base with v2 applied.
No full kernel or module-link, hardware or runtime test was performed.

 drivers/leds/rgb/leds-pwm-multicolor.c | 31 +++++++++++++-------------
 1 file changed, 16 insertions(+), 15 deletions(-)

diff --git a/drivers/leds/rgb/leds-pwm-multicolor.c b/drivers/leds/rgb/leds-pwm-multicolor.c
index 6365459ec27f17187804153cde6cb1805eca33e9..10527a64d1982733a43b76bd8bc123aba95b6f72 100644
--- a/drivers/leds/rgb/leds-pwm-multicolor.c
+++ b/drivers/leds/rgb/leds-pwm-multicolor.c
@@ -106,6 +106,11 @@ release_fwnode:
 	return ret;
 }
 
+static void led_pwm_mc_put_node(void *data)
+{
+	fwnode_handle_put(data);
+}
+
 static int led_pwm_mc_probe(struct platform_device *pdev)
 {
 	struct fwnode_handle *mcnode;
@@ -121,22 +126,22 @@ static int led_pwm_mc_probe(struct platform_device *pdev)
 		return dev_err_probe(&pdev->dev, -ENODEV,
 				     "expected multi-led node\n");
 
+	ret = devm_add_action_or_reset(&pdev->dev, led_pwm_mc_put_node, mcnode);
+	if (ret)
+		return ret;
+
 	/* count the nodes inside the multi-led node */
 	count = fwnode_get_child_node_count(mcnode);
 
 	priv = devm_kzalloc(&pdev->dev, struct_size(priv, leds, count),
 			    GFP_KERNEL);
-	if (!priv) {
-		ret = -ENOMEM;
-		goto release_mcnode;
-	}
+	if (!priv)
+		return -ENOMEM;
 	mutex_init(&priv->lock);
 
 	subled = devm_kcalloc(&pdev->dev, count, sizeof(*subled), GFP_KERNEL);
-	if (!subled) {
-		ret = -ENOMEM;
-		goto release_mcnode;
-	}
+	if (!subled)
+		return -ENOMEM;
 	priv->mc_cdev.subled_info = subled;
 
 	/* init the multicolor's LED class device */
@@ -144,14 +149,14 @@ static int led_pwm_mc_probe(struct platform_device *pdev)
 	ret = fwnode_property_read_u32(mcnode, "max-brightness",
 				 &cdev->max_brightness);
 	if (ret)
-		goto release_mcnode;
+		return ret;
 
 	cdev->flags = LED_CORE_SUSPENDRESUME;
 	cdev->brightness_set_blocking = led_pwm_mc_set;
 
 	ret = iterate_subleds(&pdev->dev, priv, mcnode);
 	if (ret)
-		goto release_mcnode;
+		return ret;
 
 	init_data.fwnode = mcnode;
 	ret = devm_led_classdev_multicolor_register_ext(&pdev->dev,
@@ -161,7 +166,7 @@ static int led_pwm_mc_probe(struct platform_device *pdev)
 		dev_err(&pdev->dev,
 			"failed to register multicolor PWM led for %s: %d\n",
 			cdev->name, ret);
-		goto release_mcnode;
+		return ret;
 	}
 
 	ret = led_pwm_mc_set(cdev, cdev->brightness);
@@ -172,10 +177,6 @@ static int led_pwm_mc_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, priv);
 	return 0;
-
-release_mcnode:
-	fwnode_handle_put(mcnode);
-	return ret;
 }
 
 static const struct of_device_id of_pwm_leds_mc_match[] = {

base-commit: 2efb7a11f1aa4d2dc285fe2680cca22cb9f72f64

Re: [PATCH v2] leds: pwm-multicolor: Manage the multi-led node reference

[sashiko-bot]

> led_pwm_mc_probe() leaks the multi-led node reference on successful
> probe and if the final PWM update fails. LED registration borrows
> the node, so it must remain valid until the LED is unregistered.
> 
> Register a managed put action before LED registration. Reverse devres
> order then unregisters the LED before releasing the node on unbind
> or probe failure. Drop the manual error-path put and return directly
> on probe errors, leaving the reference cleanup to devres.
> 
> Fixes: 9fa2762110dd ("leds: Add PWM multicolor driver")
> Assisted-by: LLM
> Signed-off-by: Yige Jiang <yigejiang86@gmail.com>

Sashiko has reviewed this patch and found no issues.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261030020521.9399-1-yigejiang86@gmail.com?part=1