From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932382AbeDWRuS (ORCPT ); Mon, 23 Apr 2018 13:50:18 -0400 Received: from gateway36.websitewelcome.com ([192.185.198.13]:29803 "EHLO gateway36.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932408AbeDWRuK (ORCPT ); Mon, 23 Apr 2018 13:50:10 -0400 X-Authority-Reason: nr=8 Date: Mon, 23 Apr 2018 12:50:07 -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 Cc: Helen Koike Subject: [PATCH 09/11] vimc-debayer: fix potential Spectre variant 1 Message-ID: <54dea7486d296e39cdbc3e5465fb4f5d3dee92e9.1524499368.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: 1fAfbM-00079I-1f X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.145.48.65]:49610 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 62 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 code->index can be controlled by user-space, hence leading to a potential exploitation of the Spectre variant 1 vulnerability. Smatch warning: drivers/media/platform/vimc/vimc-debayer.c:182 vimc_deb_enum_mbus_code() warn: potential spectre issue 'vimc_deb_pix_map_list' Fix this by sanitizing code->index before using it to index vimc_deb_pix_map_list. 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/vimc/vimc-debayer.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/media/platform/vimc/vimc-debayer.c b/drivers/media/platform/vimc/vimc-debayer.c index 6e10b63..bdd96bb 100644 --- a/drivers/media/platform/vimc/vimc-debayer.c +++ b/drivers/media/platform/vimc/vimc-debayer.c @@ -24,6 +24,8 @@ #include "vimc-common.h" +#include + #define VIMC_DEB_DRV_NAME "vimc-debayer" static unsigned int deb_mean_win_size = 3; @@ -178,7 +180,8 @@ static int vimc_deb_enum_mbus_code(struct v4l2_subdev *sd, } else { if (code->index >= ARRAY_SIZE(vimc_deb_pix_map_list)) return -EINVAL; - + code->index = array_index_nospec(code->index, + ARRAY_SIZE(vimc_deb_pix_map_list)); code->code = vimc_deb_pix_map_list[code->index].code; } -- 2.7.4