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

Patch "gpio: GPIOHANDLE_GET_LINE_VALUES_IOCTL: Fix information leak" 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: GPIOHANDLE_GET_LINE_VALUES_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-gpiohandle_get_line_values_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 3eded5d83bf4e36ad78775c7ceb44a45480b0abd Mon Sep 17 00:00:00 2001
From: Lars-Peter Clausen <lars@metafoo.de>
Date: Tue, 18 Oct 2016 16:54:02 +0200
Subject: gpio: GPIOHANDLE_GET_LINE_VALUES_IOCTL: Fix information leak

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

commit 3eded5d83bf4e36ad78775c7ceb44a45480b0abd upstream.

The GPIOHANDLE_GET_LINE_VALUES_IOCTL handler allocates a gpiohandle_data
struct on the stack and then passes it to copy_to_user(). But depending on
the number of requested line handles 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: 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>
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
@@ -342,6 +342,8 @@ static long linehandle_ioctl(struct file
 	if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) {
 		int val;
 
+		memset(&ghd, 0, sizeof(ghd));
+
 		/* TODO: check if descriptors are really input */
 		for (i = 0; i < lh->numdescs; i++) {
 			val = gpiod_get_value_cansleep(lh->descs[i]);


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