From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932444AbeDWRsQ (ORCPT ); Mon, 23 Apr 2018 13:48:16 -0400 Received: from gateway21.websitewelcome.com ([192.185.45.154]:34931 "EHLO gateway21.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932104AbeDWRsN (ORCPT ); Mon, 23 Apr 2018 13:48:13 -0400 X-Authority-Reason: nr=8 Date: Mon, 23 Apr 2018 12:48:11 -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: Ramesh Shanmugasundaram , linux-renesas-soc@vger.kernel.org Subject: [PATCH 07/11] rcar_drif: fix potential Spectre variant 1 Message-ID: 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: 1fAfZU-0005TB-7k X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.145.48.65]:49590 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 52 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 f->index can be controlled by user-space, hence leading to a potential exploitation of the Spectre variant 1 vulnerability. Smatch warning: drivers/media/platform/rcar_drif.c:909 rcar_drif_enum_fmt_sdr_cap() warn: potential spectre issue 'formats' Fix this by sanitizing f->index before using it to index 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/rcar_drif.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/media/platform/rcar_drif.c b/drivers/media/platform/rcar_drif.c index dc7e280..2c21ec2 100644 --- a/drivers/media/platform/rcar_drif.c +++ b/drivers/media/platform/rcar_drif.c @@ -66,6 +66,8 @@ #include #include +#include + /* DRIF register offsets */ #define RCAR_DRIF_SITMDR1 0x00 #define RCAR_DRIF_SITMDR2 0x04 @@ -905,7 +907,7 @@ static int rcar_drif_enum_fmt_sdr_cap(struct file *file, void *priv, { if (f->index >= ARRAY_SIZE(formats)) return -EINVAL; - + f->index = array_index_nospec(f->index, ARRAY_SIZE(formats)); f->pixelformat = formats[f->index].pixelformat; return 0; -- 2.7.4