Patch "gpio: GPIO_GET_CHIPINFO_IOCTL: Fix information leak" has been added to the 4.8-stable tree

[<gregkh@linuxfoundation.org>]

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

    gpio: GPIO_GET_CHIPINFO_IOCTL: Fix information leak

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-information-leak.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 0f4bbb233743bdfd51d47688b0bc2561f310488b Mon Sep 17 00:00:00 2001
From: Lars-Peter Clausen <lars@metafoo.de>
Date: Tue, 18 Oct 2016 16:54:00 +0200
Subject: gpio: GPIO_GET_CHIPINFO_IOCTL: Fix information leak

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

commit 0f4bbb233743bdfd51d47688b0bc2561f310488b upstream.

The GPIO_GET_CHIPINFO_IOCTL handler allocates a gpiochip_info struct on the
stack and then passes it to copy_to_user(). But depending on the length of
the GPIO chip name and label the struct is only partially initialized.

This exposes the previous, potentially sensitive, stack content to the
issuing userspace application. To avoid this make sure that the struct is
fully initialized.

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, 2 insertions(+)

--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -821,6 +821,8 @@ static long gpio_ioctl(struct file *filp
 	if (cmd == GPIO_GET_CHIPINFO_IOCTL) {
 		struct gpiochip_info chipinfo;
 
+		memset(&chipinfo, 0, sizeof(chipinfo));
+
 		strncpy(chipinfo.name, dev_name(&gdev->dev),
 			sizeof(chipinfo.name));
 		chipinfo.name[sizeof(chipinfo.name)-1] = '\0';


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