Patch "gpio: GPIO_GET_CHIPINFO_IOCTL: Fix line offset validation" has been added to the 4.8-stable tree

Patch "gpio: GPIO_GET_CHIPINFO_IOCTL: Fix line offset validation" has been added to the 4.8-stable tree

[gregkh]

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

    gpio: GPIO_GET_CHIPINFO_IOCTL: Fix line offset validation

to the 4.8-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:
     gpio-gpio_get_chipinfo_ioctl-fix-line-offset-validation.patch
and it can be found in the queue-4.8 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 1f1cc4566bd9dd8d3cf19965a4b6392143618536 Mon Sep 17 00:00:00 2001
From: Lars-Peter Clausen <lars@metafoo.de>
Date: Tue, 18 Oct 2016 16:53:59 +0200
Subject: gpio: GPIO_GET_CHIPINFO_IOCTL: Fix line offset validation

From: Lars-Peter Clausen <lars@metafoo.de>

commit 1f1cc4566bd9dd8d3cf19965a4b6392143618536 upstream.

The current line offset validation is off by one. Depending on the data
stored behind the descs array this can either cause undefined behavior or
disclose arbitrary, potentially sensitive, memory to the issuing userspace
application.

Make sure that offset is within the bounds of the desc array.

Fixes: 521a2ad6f862 ("gpio: add userspace ABI for GPIO line information")
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/gpio/gpiolib.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -837,7 +837,7 @@ static long gpio_ioctl(struct file *filp
 
 		if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
 			return -EFAULT;
-		if (lineinfo.line_offset > gdev->ngpio)
+		if (lineinfo.line_offset >= gdev->ngpio)
 			return -EINVAL;
 
 		desc = &gdev->descs[lineinfo.line_offset];


Patches currently in stable-queue which might be from lars@metafoo.de are

queue-4.8/gpio-gpio_get_chipinfo_ioctl-fix-line-offset-validation.patch
queue-4.8/gpio-gpio_get_line-handle-event-_ioctl-fix-file-descriptor-leak.patch
queue-4.8/gpio-gpio_get_chipinfo_ioctl-fix-information-leak.patch
queue-4.8/gpio-gpio_get_lineevent_ioctl-reject-invalid-line-and-event-flags.patch
queue-4.8/gpio-gpiohandle_get_line_values_ioctl-fix-another-information-leak.patch
queue-4.8/gpio-gpio_get_linehandle_ioctl-reject-invalid-line-flags.patch
queue-4.8/gpio-gpio_get_lineevent_ioctl-validate-line-offset.patch
queue-4.8/gpio-gpiohandle_get_line_values_ioctl-fix-information-leak.patch
queue-4.8/gpio-gpio_get_linehandle_ioctl-validate-line-offset.patch