From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_NEOMUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 58A70C282D8 for ; Fri, 1 Feb 2019 12:11:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 24180218AC for ; Fri, 1 Feb 2019 12:11:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727450AbfBAMLt (ORCPT ); Fri, 1 Feb 2019 07:11:49 -0500 Received: from mga01.intel.com ([192.55.52.88]:51326 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725857AbfBAMLt (ORCPT ); Fri, 1 Feb 2019 07:11:49 -0500 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 01 Feb 2019 04:11:48 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,548,1539673200"; d="scan'208";a="316803213" Received: from paasikivi.fi.intel.com ([10.237.72.42]) by fmsmga005.fm.intel.com with ESMTP; 01 Feb 2019 04:11:47 -0800 Received: by paasikivi.fi.intel.com (Postfix, from userid 1000) id 1A43E203D9; Fri, 1 Feb 2019 14:11:46 +0200 (EET) Date: Fri, 1 Feb 2019 14:11:45 +0200 From: Sakari Ailus To: Hans Verkuil Cc: Linux Media Mailing List , Thierry Reding Subject: Re: [GIT FIXES FOR v5.0] v4l2-ioctl: Clear only per-plane reserved fields Message-ID: <20190201121145.fjznkpuwxuqme2yk@paasikivi.fi.intel.com> References: <7b7507b5-f4d1-d95b-b77b-bd7a8044a5ef@xs4all.nl> <20190111211010.volneg4ew4omg6ff@mara.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org On Sat, Jan 12, 2019 at 10:17:47AM +0100, Hans Verkuil wrote: > On 1/11/19 10:10 PM, Sakari Ailus wrote: > > Hi Hans, > > > > On Fri, Jan 11, 2019 at 09:31:25AM +0100, Hans Verkuil wrote: > >> Three fixes for a bug introduced in 5.0. > >> > >> The last patch (Validate num_planes for debug messages) is also backported > >> to kernels >= 4.12 (the oldest kernel for which it applies cleanly). > > > > The surrounding lines of code have changed slightly over the years. The > > older kernels still suffer from the same problem as far as I see, so the > > backport is relevant down to 3.16 at least (but older kernels aren't > > supported anyway so I didn't check further). The problem was likely > > introduced by the big IOCTL handling patches long, long time ago. Huh. > > > > I didn't plan on backporting this to older kernels. You have to be root > to enable this debugging, so it is not security bug. It is a security problem, even if root would have to enable the feature. In practice it is not that severe as few would end up doing that. But we don't know. I think it'd be easier to fix it than informing potential users about its dangers. I can submit a patch for the older kernels, too. -- Sakari Ailus sakari.ailus@linux.intel.com