[PATCH 5.11 006/122] gpio: sysfs: Obey valid_mask

Greg Kroah-Hartman
2021-04-19T13:09:05Z

From: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>

[ Upstream commit 23cf00ddd2e1aacf1873e43f5e0c519c120daf7a ]

Do not allow exporting GPIOs which are set invalid
by the driver's valid mask.

Fixes: 726cb3ba4969 ("gpiolib: Support 'gpio-reserved-ranges' property")
Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpio/gpiolib-sysfs.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c
index 26c5466b8179..ae49bb23c6ed 100644
--- a/drivers/gpio/gpiolib-sysfs.c
+++ b/drivers/gpio/gpiolib-sysfs.c
@@ -458,6 +458,8 @@ static ssize_t export_store(struct class *class,
long gpio;
struct gpio_desc *desc;
int status;
+ struct gpio_chip *gc;
+ int offset;

status = kstrtol(buf, 0, &gpio);
if (status < 0)
@@ -469,6 +471,12 @@ static ssize_t export_store(struct class *class,
pr_warn("%s: invalid GPIO %ld\n", __func__, gpio);
return -EINVAL;
}
+ gc = desc->gdev->chip;
+ offset = gpio_chip_hwgpio(desc);
+ if (!gpiochip_line_is_valid(gc, offset)) {
+ pr_warn("%s: GPIO %ld masked\n", __func__, gpio);
+ return -EINVAL;
+ }

/* No extra locking here; FLAG_SYSFS just signifies that the
* request and export were done by on behalf of userspace, so
--
2.30.2