From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932414AbeDWRtI (ORCPT ); Mon, 23 Apr 2018 13:49:08 -0400 Received: from gateway22.websitewelcome.com ([192.185.47.144]:47838 "EHLO gateway22.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932324AbeDWRtA (ORCPT ); Mon, 23 Apr 2018 13:49:00 -0400 X-Authority-Reason: nr=8 Date: Mon, 23 Apr 2018 12:48:55 -0500 From: "Gustavo A. R. Silva" To: Mauro Carvalho Chehab , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" , Dan Carpenter Subject: [PATCH 08/11] sh_vou: fix potential Spectre variant 1 Message-ID: <56615d4b6a9557645468873d60f5b0b5fcffcfc7.1524499368.git.gustavo@embeddedor.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - gator4166.hostgator.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - embeddedor.com X-BWhitelist: no X-Source-IP: 189.145.48.65 X-Source-L: No X-Exim-ID: 1fAfaE-00068J-48 X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.145.48.65]:49602 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 58 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org fmt->index can be controlled by user-space, hence leading to a potential exploitation of the Spectre variant 1 vulnerability. Smatch warning: drivers/media/platform/sh_vou.c:407 sh_vou_enum_fmt_vid_out() warn: potential spectre issue 'vou_fmt' Fix this by sanitizing fmt->index before using it to index vou_fmt. Notice that given that speculation windows are large, the policy is to kill the speculation on the first load and not worry if it can be completed with a dependent load/store [1]. [1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2 Cc: stable@vger.kernel.org Reported-by: Dan Carpenter Signed-off-by: Gustavo A. R. Silva --- drivers/media/platform/sh_vou.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/media/platform/sh_vou.c b/drivers/media/platform/sh_vou.c index 4dccf29..58d8645 100644 --- a/drivers/media/platform/sh_vou.c +++ b/drivers/media/platform/sh_vou.c @@ -30,6 +30,8 @@ #include #include +#include + /* Mirror addresses are not available for all registers */ #define VOUER 0 #define VOUCR 4 @@ -398,6 +400,7 @@ static int sh_vou_enum_fmt_vid_out(struct file *file, void *priv, if (fmt->index >= ARRAY_SIZE(vou_fmt)) return -EINVAL; + fmt->index = array_index_nospec(fmt->index, ARRAY_SIZE(vou_fmt)); dev_dbg(vou_dev->v4l2_dev.dev, "%s()\n", __func__); -- 2.7.4