Patch "gpiolib: don't dereference a desc before validation" has been added to the 4.15-stable tree

Patch "gpiolib: don't dereference a desc before validation" has been added to the 4.15-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    gpiolib: don't dereference a desc before validation

to the 4.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     gpiolib-don-t-dereference-a-desc-before-validation.patch
and it can be found in the queue-4.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Mon Apr  9 10:16:32 CEST 2018
From: Vladimir Zapolskiy <vz@mleia.com>
Date: Thu, 21 Dec 2017 18:37:24 +0200
Subject: gpiolib: don't dereference a desc before validation

From: Vladimir Zapolskiy <vz@mleia.com>


[ Upstream commit 30322bcf82d74cad0d6e1cf9ba7fa7fa48c7a026 ]

The fix restores a proper validation of an input gpio desc, which
might be needed to deal with optional GPIOs correctly.

Fixes: 02e479808b5d ("gpio: Alter semantics of *raw* operations to actually be raw")
Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/gpio/gpiolib.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -2468,7 +2468,7 @@ EXPORT_SYMBOL_GPL(gpiod_direction_output
  */
 int gpiod_direction_output(struct gpio_desc *desc, int value)
 {
-	struct gpio_chip *gc = desc->gdev->chip;
+	struct gpio_chip *gc;
 	int ret;
 
 	VALIDATE_DESC(desc);
@@ -2485,6 +2485,7 @@ int gpiod_direction_output(struct gpio_d
 		return -EIO;
 	}
 
+	gc = desc->gdev->chip;
 	if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
 		/* First see if we can enable open drain in hardware */
 		ret = gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc),


Patches currently in stable-queue which might be from vz@mleia.com are

queue-4.15/gpiolib-don-t-dereference-a-desc-before-validation.patch