From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932184AbeDWRiH (ORCPT ); Mon, 23 Apr 2018 13:38:07 -0400 Received: from gateway22.websitewelcome.com ([192.185.47.144]:17657 "EHLO gateway22.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932093AbeDWRiG (ORCPT ); Mon, 23 Apr 2018 13:38:06 -0400 X-Authority-Reason: nr=8 Date: Mon, 23 Apr 2018 12:38:03 -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 01/11] media: tm6000: fix potential Spectre variant 1 Message-ID: <3d4973141e218fb516422d3d831742d55aaa5c04.1524499368.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: 1fAfPh-004LbA-4O X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.145.48.65]:49542 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 19 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/usb/tm6000/tm6000-video.c:879 vidioc_enum_fmt_vid_cap() warn: potential spectre issue 'format' Fix this by sanitizing f->index before using it to index array _format_ 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/usb/tm6000/tm6000-video.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/media/usb/tm6000/tm6000-video.c b/drivers/media/usb/tm6000/tm6000-video.c index b2399d4..d701027 100644 --- a/drivers/media/usb/tm6000/tm6000-video.c +++ b/drivers/media/usb/tm6000/tm6000-video.c @@ -26,6 +26,7 @@ #include #include #include +#include #include "tm6000-regs.h" #include "tm6000.h" @@ -875,6 +876,7 @@ static int vidioc_enum_fmt_vid_cap(struct file *file, void *priv, if (f->index >= ARRAY_SIZE(format)) return -EINVAL; + f->index = array_index_nospec(f->index, ARRAY_SIZE(format)); strlcpy(f->description, format[f->index].name, sizeof(f->description)); f->pixelformat = format[f->index].fourcc; return 0; -- 2.7.4