Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932975AbcKILFJ (ORCPT ); Wed, 9 Nov 2016 06:05:09 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:53868 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932778AbcKILFD (ORCPT ); Wed, 9 Nov 2016 06:05:03 -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 4.8 012/138] gpio: GPIOHANDLE_GET_LINE_VALUES_IOCTL: Fix information leak Date: Wed, 9 Nov 2016 11:44:55 +0100 Message-Id: <20161109102845.338949772@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: 1273 Lines: 38 4.8-stable review patch. If anyone has any objections, please let me know. ------------------ From: Lars-Peter Clausen 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 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 @@ -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]);