From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932456AbeDWRva (ORCPT ); Mon, 23 Apr 2018 13:51:30 -0400 Received: from gateway23.websitewelcome.com ([192.185.49.219]:47143 "EHLO gateway23.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932157AbeDWRv0 (ORCPT ); Mon, 23 Apr 2018 13:51:26 -0400 X-Authority-Reason: nr=8 Date: Mon, 23 Apr 2018 12:51:23 -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: Hans Verkuil Subject: [PATCH 10/11] vivid-sdr-cap: fix potential Spectre variant 1 Message-ID: <586469aa63a9579ecdeb8ffa4fb31d441564c622.1524499368.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: 1fAfcb-0008BT-RO X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.145.48.65]:49622 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 67 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 band->index can be controlled by user-space, hence leading to a potential exploitation of the Spectre variant 1 vulnerability. Smatch warning: drivers/media/platform/vivid/vivid-sdr-cap.c:323 vivid_sdr_enum_freq_bands() warn: potential spectre issue 'bands_adc' Fix this by sanitizing band->index before using it to index bands_adc and bands_fm. 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/vivid/vivid-sdr-cap.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/media/platform/vivid/vivid-sdr-cap.c b/drivers/media/platform/vivid/vivid-sdr-cap.c index cfb7cb4..684d8a2 100644 --- a/drivers/media/platform/vivid/vivid-sdr-cap.c +++ b/drivers/media/platform/vivid/vivid-sdr-cap.c @@ -22,6 +22,8 @@ #include "vivid-ctrls.h" #include "vivid-sdr-cap.h" +#include + /* stream formats */ struct vivid_format { u32 pixelformat; @@ -320,11 +322,15 @@ int vivid_sdr_enum_freq_bands(struct file *file, void *fh, case 0: if (band->index >= ARRAY_SIZE(bands_adc)) return -EINVAL; + band->index = array_index_nospec(band->index, + ARRAY_SIZE(bands_adc)); *band = bands_adc[band->index]; return 0; case 1: if (band->index >= ARRAY_SIZE(bands_fm)) return -EINVAL; + band->index = array_index_nospec(band->index, + ARRAY_SIZE(bands_fm)); *band = bands_fm[band->index]; return 0; default: -- 2.7.4