linux-kernel - [PATCH v2] gpio: mpsse: fix reference leak in gpio_mpsse

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Message-ID: <20251226060414.20785-1-nihaal@cse.iitm.ac.in>
Date: Fri, 26 Dec 2025 11:34:10 +0530
From: Abdun Nihaal <nihaal@....iitm.ac.in>
To: linusw@...nel.org
Cc: Abdun Nihaal <nihaal@....iitm.ac.in>,
	brgl@...nel.org,
	linux-gpio@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	stable@...r.kernel.org
Subject: [PATCH v2] gpio: mpsse: fix reference leak in gpio_mpsse_probe() error paths

The reference obtained by calling usb_get_dev() is not released in the
gpio_mpsse_probe() error paths. Fix that by using device managed helper
functions. Also remove the usb_put_dev() call in the disconnect function
since now it will be released automatically.

Cc: stable@...r.kernel.org
Fixes: c46a74ff05c0 ("gpio: add support for FTDI's MPSSE as GPIO")
Signed-off-by: Abdun Nihaal <nihaal@....iitm.ac.in>
---
Compile tested only. Not tested on real hardware.

v1->v2:
- Switched to use devm_add_action_or_reset() to avoid unnecessary gotos,
  as suggested by Bartosz Golaszewski.

Link to v1: https://lore.kernel.org/all/20251223065306.131008-1-nihaal@cse.iitm.ac.in/

 drivers/gpio/gpio-mpsse.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/gpio/gpio-mpsse.c b/drivers/gpio/gpio-mpsse.c
index ace652ba4df1..12191aeb6566 100644
--- a/drivers/gpio/gpio-mpsse.c
+++ b/drivers/gpio/gpio-mpsse.c
@@ -548,6 +548,13 @@ static void gpio_mpsse_ida_remove(void *data)
 	ida_free(&gpio_mpsse_ida, priv->id);
 }
 
+static void gpio_mpsse_usb_put_dev(void *data)
+{
+	struct mpsse_priv *priv = data;
+
+	usb_put_dev(priv->udev);
+}
+
 static int mpsse_init_valid_mask(struct gpio_chip *chip,
 				 unsigned long *valid_mask,
 				 unsigned int ngpios)
@@ -592,6 +599,10 @@ static int gpio_mpsse_probe(struct usb_interface *interface,
 	INIT_LIST_HEAD(&priv->workers);
 
 	priv->udev = usb_get_dev(interface_to_usbdev(interface));
+	err = devm_add_action_or_reset(dev, gpio_mpsse_usb_put_dev, priv);
+	if (err)
+		return err;
+
 	priv->intf = interface;
 	priv->intf_id = interface->cur_altsetting->desc.bInterfaceNumber;
 
@@ -713,7 +724,6 @@ static void gpio_mpsse_disconnect(struct usb_interface *intf)
 
 	priv->intf = NULL;
 	usb_set_intfdata(intf, NULL);
-	usb_put_dev(priv->udev);
 }
 
 static struct usb_driver gpio_mpsse_driver = {
-- 
2.43.0