linux-kernel - [PATCH] gpiolib: sysfs: Fix improper error handling on failed export

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Date:   Thu, 23 Nov 2023 14:27:49 +0100
From:   Boerge Struempfel <boerge.struempfel@...il.com>
To:     Linus Walleij <linus.walleij@...aro.org>,
        Bartosz Golaszewski <brgl@...ev.pl>,
        Andy Shevchenko <andy@...nel.org>, linux-gpio@...r.kernel.org,
        linux-kernel@...r.kernel.org
Cc:     boerge.struempfel@...il.com, bstruempfel@...ratronik.de
Subject: [PATCH] gpiolib: sysfs: Fix improper error handling on failed export

If gpio_set_transitory fails, we should free the gpio again. Most
notably, the flag FLAG_REQUESTED has previously been set in
gpiod_request_commit, and should be reset on failure.

Signed-off-by: Boerge Struempfel <boerge.struempfel@...il.com>
---
 drivers/gpio/gpiolib-sysfs.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c
index 6f309a3b2d9a..12d853845bb8 100644
--- a/drivers/gpio/gpiolib-sysfs.c
+++ b/drivers/gpio/gpiolib-sysfs.c
@@ -474,14 +474,17 @@ static ssize_t export_store(const struct class *class,
 		goto done;
 
 	status = gpiod_set_transitory(desc, false);
-	if (!status) {
-		status = gpiod_export(desc, true);
-		if (status < 0)
-			gpiod_free(desc);
-		else
-			set_bit(FLAG_SYSFS, &desc->flags);
+	if (status) {
+		gpiod_free(desc);
+		goto done;
 	}
 
+	status = gpiod_export(desc, true);
+	if (status < 0)
+		gpiod_free(desc);
+	else
+		set_bit(FLAG_SYSFS, &desc->flags);
+
 done:
 	if (status)
 		pr_debug("%s: status %d\n", __func__, status);
-- 
2.42.0