Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933059AbcKILFU (ORCPT ); Wed, 9 Nov 2016 06:05:20 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:53900 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932778AbcKILFP (ORCPT ); Wed, 9 Nov 2016 06:05:15 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lars-Peter Clausen , Linus Walleij Subject: [PATCH 4.8 016/138] gpio: GPIOHANDLE_GET_LINE_VALUES_IOCTL: Fix another information leak Date: Wed, 9 Nov 2016 11:44:59 +0100 Message-Id: <20161109102845.514274931@linuxfoundation.org> X-Mailer: git-send-email 2.10.2 In-Reply-To: <20161109102844.808685475@linuxfoundation.org> References: <20161109102844.808685475@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1251 Lines: 39 4.8-stable review patch. If anyone has any objections, please let me know. ------------------ From: Lars-Peter Clausen commit d82aa4a8f2e8df9673ddb099262355da4c9b99b1 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 only the first element of the values array in the struct is set, which leaves the struct 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. Cc: stable@vger.kernel.org Fixes: 61f922db7221 ("gpio: userspace ABI for reading GPIO line events") Signed-off-by: Lars-Peter Clausen Signed-off-by: Linus Walleij Signed-off-by: Greg Kroah-Hartman --- drivers/gpio/gpiolib.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -645,6 +645,8 @@ static long lineevent_ioctl(struct file if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) { int val; + memset(&ghd, 0, sizeof(ghd)); + val = gpiod_get_value_cansleep(le->desc); if (val < 0) return val;