From ffc544a91a0f9040a79fda8c2cb051fefa43212b Mon Sep 17 00:00:00 2001 From: Vladimir Zapolskiy Date: Thu, 21 Dec 2017 18:37:24 +0200 Subject: [PATCH] gpiolib: don't dereference a desc before validation [ 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 Signed-off-by: Linus Walleij Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/gpio/gpiolib.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 7a5cf5b08c54f..00d0060435856 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -2468,7 +2468,7 @@ EXPORT_SYMBOL_GPL(gpiod_direction_output_raw); */ 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_desc *desc, int value) 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), -- 2.47.2