linux-kernel - [PATCH v2 05/11] gpio: cdev: Don't check struct gpio_chip in gpio_chrdev

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20260203061059.975605-6-tzungbi@kernel.org>
Date: Tue,  3 Feb 2026 06:10:52 +0000
From: Tzung-Bi Shih <tzungbi@...nel.org>
To: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	"Rafael J. Wysocki" <rafael@...nel.org>,
	Danilo Krummrich <dakr@...nel.org>,
	Bartosz Golaszewski <brgl@...ev.pl>,
	Linus Walleij <linusw@...nel.org>
Cc: Jonathan Corbet <corbet@....net>,
	Shuah Khan <shuah@...nel.org>,
	Laurent Pinchart <laurent.pinchart@...asonboard.com>,
	Wolfram Sang <wsa+renesas@...g-engineering.com>,
	Jason Gunthorpe <jgg@...dia.com>,
	Johan Hovold <johan@...nel.org>,
	linux-kernel@...r.kernel.org,
	linux-kselftest@...r.kernel.org,
	chrome-platform@...ts.linux.dev,
	tzungbi@...nel.org,
	Dan Williams <dan.j.williams@...el.com>,
	linux-gpio@...r.kernel.org
Subject: [PATCH v2 05/11] gpio: cdev: Don't check struct gpio_chip in gpio_chrdev_open()

It's harmless even if: chrdev_open() and cdev_device_del() run at the
same time, and gpio_chrdev_open() gets called after the underlying GPIO
chip has gone.  The subsequent file operations check the availability
of struct gpio_chip anyway.

Don't check struct gpio_chip in gpio_chrdev_open().

Signed-off-by: Tzung-Bi Shih <tzungbi@...nel.org>
---
v2:
- No changes.

v1: https://lore.kernel.org/all/20260116081036.352286-11-tzungbi@kernel.org

 drivers/gpio/gpiolib-cdev.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c
index b89201578516..aaa5de814468 100644
--- a/drivers/gpio/gpiolib-cdev.c
+++ b/drivers/gpio/gpiolib-cdev.c
@@ -2689,12 +2689,6 @@ static int gpio_chrdev_open(struct inode *inode, struct file *file)
 	struct gpio_chardev_data *cdev;
 	int ret = -ENOMEM;
 
-	guard(srcu)(&gdev->srcu);
-
-	/* Fail on open if the backing gpiochip is gone */
-	if (!rcu_access_pointer(gdev->chip))
-		return -ENODEV;
-
 	cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
 	if (!cdev)
 		return -ENOMEM;
-- 
2.53.0.rc2.204.g2597b5adb4-goog