From e405f9fcb63602d35f7a419ededa3f952a395a72 Mon Sep 17 00:00:00 2001
From: Lars-Peter Clausen <lars@metafoo.de>
Date: Tue, 18 Oct 2016 16:54:01 +0200
Subject: gpio: GPIO_GET_LINEHANDLE_IOCTL: Validate line offset
The line offset that is used as an index into the descs array is provided
by userspace and might go beyond the bounds of the array. If that happens
undefined behavior will occur.
Make sure that the offset is within the bounds of the desc array and reject
any requests that specify a value outside of it.
Cc: stable@vger.kernel.org
Fixes: d7c51b47ac11 ("gpio: userspace ABI for reading/writing GPIO lines")
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
drivers/gpio/gpiolib.c | 5 +++++
1 file changed, 5 insertions(+)
(limited to 'drivers/gpio')
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 7a01969169e8..d287cb4e97c4 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -444,6 +444,11 @@ static int linehandle_create(struct gpio_device *gdev, void __user *ip)
u32 lflags = handlereq.flags;
struct gpio_desc *desc;
+ if (offset >= gdev->ngpio) {
+ ret = -EINVAL;
+ goto out_free_descs;
+ }
+
desc = &gdev->descs[offset];
ret = gpiod_request(desc, lh->label);
if (ret)
--
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