linux-kernel - [PATCH v2] leds: netxbig: fix GPIO descriptor leak in error paths

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Message-ID: <20251030025312.1623-1-vulab@iscas.ac.cn>
Date: Thu, 30 Oct 2025 10:53:12 +0800
From: Haotian Zhang <vulab@...as.ac.cn>
To: Lee Jones <lee@...nel.org>,
	Pavel Machek <pavel@...nel.org>,
	Markus.Elfring@....de
Cc: linux-leds@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Haotian Zhang <vulab@...as.ac.cn>
Subject: [PATCH v2] leds: netxbig: fix GPIO descriptor leak in error paths

The function netxbig_gpio_ext_get() acquires GPIO descriptors but
fails to release them when errors occur mid-way through initialization.
The cleanup callback registered by devm_add_action_or_reset() only
runs on success, leaving acquired GPIOs leaked on error paths.

Add goto-based error handling to release all acquired GPIOs before
returning errors.

Fixes: 9af512e81964 ("leds: netxbig: Convert to use GPIO descriptors")
Suggested-by: Markus Elfring <Markus.Elfring@....de>
Signed-off-by: Haotian Zhang <vulab@...as.ac.cn>

---
Changes in v2:
- Consolidate PTR_ERR(gpiod) extraction into err_gpiod_put label
  (suggested by Markus Elfring)
---
 drivers/leds/leds-netxbig.c | 40 +++++++++++++++++++++++++++----------
 1 file changed, 29 insertions(+), 11 deletions(-)

diff --git a/drivers/leds/leds-netxbig.c b/drivers/leds/leds-netxbig.c
index e95287416ef8..55afb03ee933 100644
--- a/drivers/leds/leds-netxbig.c
+++ b/drivers/leds/leds-netxbig.c
@@ -364,6 +364,9 @@ static int netxbig_gpio_ext_get(struct device *dev,
 	if (!addr)
 		return -ENOMEM;
 
+	gpio_ext->addr = addr;
+	gpio_ext->num_addr = 0;
+
 	/*
 	 * We cannot use devm_ managed resources with these GPIO descriptors
 	 * since they are associated with the "GPIO extension device" which
@@ -374,46 +377,61 @@ static int netxbig_gpio_ext_get(struct device *dev,
 	for (i = 0; i < num_addr; i++) {
 		gpiod = gpiod_get_index(gpio_ext_dev, "addr", i,
 					GPIOD_OUT_LOW);
-		if (IS_ERR(gpiod))
-			return PTR_ERR(gpiod);
+		if (IS_ERR(gpiod)) {
+			ret = PTR_ERR(gpiod);
+			goto err_free_addr;
+		}
 		gpiod_set_consumer_name(gpiod, "GPIO extension addr");
 		addr[i] = gpiod;
+		gpio_ext->num_addr++;
 	}
-	gpio_ext->addr = addr;
-	gpio_ext->num_addr = num_addr;
 
 	ret = gpiod_count(gpio_ext_dev, "data");
 	if (ret < 0) {
 		dev_err(dev,
 			"Failed to count GPIOs in DT property data-gpios\n");
-		return ret;
+		goto err_free_addr;
 	}
 	num_data = ret;
 	data = devm_kcalloc(dev, num_data, sizeof(*data), GFP_KERNEL);
-	if (!data)
-		return -ENOMEM;
+	if (!data) {
+		ret = -ENOMEM;
+		goto err_free_addr;
+	}
+
+	gpio_ext->data = data;
+	gpio_ext->num_data = 0;
 
 	for (i = 0; i < num_data; i++) {
 		gpiod = gpiod_get_index(gpio_ext_dev, "data", i,
 					GPIOD_OUT_LOW);
 		if (IS_ERR(gpiod))
-			return PTR_ERR(gpiod);
+			goto err_gpiod_put;
 		gpiod_set_consumer_name(gpiod, "GPIO extension data");
 		data[i] = gpiod;
+		gpio_ext->num_data++;
 	}
-	gpio_ext->data = data;
-	gpio_ext->num_data = num_data;
 
 	gpiod = gpiod_get(gpio_ext_dev, "enable", GPIOD_OUT_LOW);
 	if (IS_ERR(gpiod)) {
 		dev_err(dev,
 			"Failed to get GPIO from DT property enable-gpio\n");
-		return PTR_ERR(gpiod);
+		goto err_gpiod_put;
 	}
 	gpiod_set_consumer_name(gpiod, "GPIO extension enable");
 	gpio_ext->enable = gpiod;
 
 	return devm_add_action_or_reset(dev, netxbig_gpio_ext_remove, gpio_ext);
+
+err_gpiod_put:
+	ret = PTR_ERR(gpiod);
+err_free_data:
+	for (i = 0; i < gpio_ext->num_data; i++)
+		gpiod_put(gpio_ext->data[i]);
+err_free_addr:
+	for (i = 0; i < gpio_ext->num_addr; i++)
+		gpiod_put(gpio_ext->addr[i]);
+	return ret;
 }
 
 static int netxbig_leds_get_of_pdata(struct device *dev,
-- 
2.50.1.windows.1