From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:35630 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752802AbeBBRDI (ORCPT ); Fri, 2 Feb 2018 12:03:08 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Arnd Bergmann , Bartosz Golaszewski , Linus Walleij Subject: [PATCH 4.9 06/86] gpio: Fix kernel stack leak to userspace Date: Fri, 2 Feb 2018 17:57:26 +0100 Message-Id: <20180202140823.289348141@linuxfoundation.org> In-Reply-To: <20180202140822.679101338@linuxfoundation.org> References: <20180202140822.679101338@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Linus Walleij 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 Reviewed-by: Bartosz Golaszewski Reviewed-by: Arnd Bergmann Signed-off-by: Linus Walleij Signed-off-by: Greg Kroah-Hartman --- 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);