linux-kernel - [PATCH v2 23/23] gpio: mark unsafe gpio

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: <20240205093418.39755-24-brgl@bgdev.pl>
Date: Mon,  5 Feb 2024 10:34:18 +0100
From: Bartosz Golaszewski <brgl@...ev.pl>
To: Linus Walleij <linus.walleij@...aro.org>,
	Kent Gibson <warthog618@...il.com>,
	Alex Elder <elder@...aro.org>,
	Geert Uytterhoeven <geert+renesas@...der.be>,
	"Paul E . McKenney" <paulmck@...nel.org>,
	Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
	Wolfram Sang <wsa@...-dreams.de>
Cc: linux-gpio@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
Subject: [PATCH v2 23/23] gpio: mark unsafe gpio_chip manipulators as deprecated

From: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>

We still have some functions that return the address of the GPIO chip
associated with the GPIO device. This is dangerous and the users should
find a better solution. Let's add appropriate comments to the kernel
docs.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
Reviewed-by: Linus Walleij <linus.walleij@...aro.org>
---
 drivers/gpio/gpiolib.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index c7b039398e0d..dc00eeed6253 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -211,6 +211,11 @@ EXPORT_SYMBOL_GPL(desc_to_gpio);
 /**
  * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
  * @desc:	descriptor to return the chip of
+ *
+ * *DEPRECATED*
+ * This function is unsafe and should not be used. Using the chip address
+ * without taking the SRCU read lock may result in dereferencing a dangling
+ * pointer.
  */
 struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
 {
@@ -275,6 +280,7 @@ EXPORT_SYMBOL(gpio_device_get_label);
  * Returns:
  * Address of the GPIO chip backing this device.
  *
+ * *DEPRECATED*
  * Until we can get rid of all non-driver users of struct gpio_chip, we must
  * provide a way of retrieving the pointer to it from struct gpio_device. This
  * is *NOT* safe as the GPIO API is considered to be hot-unpluggable and the
-- 
2.40.1