From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932265AbeDWRlK (ORCPT ); Mon, 23 Apr 2018 13:41:10 -0400 Received: from gateway22.websitewelcome.com ([192.185.47.144]:16334 "EHLO gateway22.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932079AbeDWRk6 (ORCPT ); Mon, 23 Apr 2018 13:40:58 -0400 X-Authority-Reason: nr=8 Date: Mon, 23 Apr 2018 12:40:54 -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: Jonathan Corbet Subject: [PATCH 04/11] marvell-ccic: mcam-core: fix potential Spectre variant 1 Message-ID: <64785db2204b1a4446d012e4508c16c523c43345.1524499368.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: 1fAfST-004Nvv-Hx X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.145.48.65]:49558 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 37 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/marvell-ccic/mcam-core.c:1323 mcam_vidioc_enum_fmt_vid_cap() warn: potential spectre issue 'mcam_formats' Fix this by sanitizing fmt->index before using it to index mcam_formats. 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/marvell-ccic/mcam-core.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/media/platform/marvell-ccic/mcam-core.c b/drivers/media/platform/marvell-ccic/mcam-core.c index 80670ee..0a54dba 100644 --- a/drivers/media/platform/marvell-ccic/mcam-core.c +++ b/drivers/media/platform/marvell-ccic/mcam-core.c @@ -33,6 +33,8 @@ #include "mcam-core.h" +#include + #ifdef MCAM_MODE_VMALLOC /* * Internal DMA buffer management. Since the controller cannot do S/G I/O, @@ -1318,6 +1320,7 @@ static int mcam_vidioc_enum_fmt_vid_cap(struct file *filp, { if (fmt->index >= N_MCAM_FMTS) return -EINVAL; + fmt->index = array_index_nospec(fmt->index, N_MCAM_FMTS); strlcpy(fmt->description, mcam_formats[fmt->index].desc, sizeof(fmt->description)); fmt->pixelformat = mcam_formats[fmt->index].pixelformat; -- 2.7.4