From: Lars-Peter Clausen Date: Tue, 18 Oct 2016 14:54:03 +0000 (+0200) Subject: gpio: GPIO_GET_LINEEVENT_IOCTL: Validate line offset X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=b8b0e3d303654b3bb7b31b0266c513fd6f4132ce;p=linux-beck.git gpio: GPIO_GET_LINEEVENT_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: 61f922db7221 ("gpio: userspace ABI for reading GPIO line events") Signed-off-by: Lars-Peter Clausen Signed-off-by: Linus Walleij --- diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 4ed26bcf054c..db44a7da5eb4 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -733,6 +733,11 @@ static int lineevent_create(struct gpio_device *gdev, void __user *ip) lflags = eventreq.handleflags; eflags = eventreq.eventflags; + if (offset >= gdev->ngpio) { + ret = -EINVAL; + goto out_free_label; + } + /* This is just wrong: we don't look for events on output lines */ if (lflags & GPIOHANDLE_REQUEST_OUTPUT) { ret = -EINVAL;