This is a note to let you know that I've just added the patch titled
gpio: Fix kernel stack leak to userspace
to the 4.9-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-fix-kernel-stack-leak-to-userspace.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 24bd3efc9d1efb5f756a7c6f807a36ddb6adc671 Mon Sep 17 00:00:00 2001
From: Linus Walleij <linus.walleij@xxxxxxxxxx>
Date: Mon, 22 Jan 2018 13:19:28 +0100
Subject: gpio: Fix kernel stack leak to userspace
From: Linus Walleij <linus.walleij@xxxxxxxxxx>
commit 24bd3efc9d1efb5f756a7c6f807a36ddb6adc671 upstream.
The GPIO event descriptor was leaking kernel stack to
userspace because we don't zero the variable before
use. Ooops. Fix this.
Reported-by: Arnd Bergmann <arnd@xxxxxxxx>
Reviewed-by: Bartosz Golaszewski <brgl@xxxxxxxx>
Reviewed-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpio/gpiolib.c | 3 +++
1 file changed, 3 insertions(+)
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -705,6 +705,9 @@ static irqreturn_t lineevent_irq_thread(
struct gpioevent_data ge;
int ret, level;
+ /* Do not leak kernel stack to userspace */
+ memset(&ge, 0, sizeof(ge));
+
ge.timestamp = ktime_get_real_ns();
level = gpiod_get_value_cansleep(le->desc);
Patches currently in stable-queue which might be from linus.walleij@xxxxxxxxxx are
queue-4.9/gpio-iop-add-missing-module_description-author-license.patch
queue-4.9/tools-gpio-fix-build-error-with-musl-libc.patch
queue-4.9/gpio-fix-kernel-stack-leak-to-userspace.patch
queue-4.9/gpio-ath79-add-missing-module_description-license.patch
queue-4.9/gpio-stmpe-i2c-transfer-are-forbiden-in-atomic-context.patch