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%3Ba=su...

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@vger.kernel.org know about it.

From 24bd3efc9d1efb5f756a7c6f807a36ddb6adc671 Mon Sep 17 00:00:00 2001

From: Linus Walleij linus.walleij@linaro.org Date: Mon, 22 Jan 2018 13:19:28 +0100 Subject: gpio: Fix kernel stack leak to userspace

From: Linus Walleij linus.walleij@linaro.org

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@arndb.de Reviewed-by: Bartosz Golaszewski brgl@bgdev.pl Reviewed-by: Arnd Bergmann arnd@arndb.de Signed-off-by: Linus Walleij linus.walleij@linaro.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- 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@linaro.org 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