From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934035AbaFCROn (ORCPT ); Tue, 3 Jun 2014 13:14:43 -0400 Received: from mail-vc0-f171.google.com ([209.85.220.171]:61127 "EHLO mail-vc0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932560AbaFCROm (ORCPT ); Tue, 3 Jun 2014 13:14:42 -0400 MIME-Version: 1.0 In-Reply-To: <20140603170244.GA22867@kroah.com> References: <20140603054434.GB2921@kroah.com> <20140603170244.GA22867@kroah.com> Date: Tue, 3 Jun 2014 10:14:41 -0700 X-Google-Sender-Auth: 4oePr0DOhJDSYWrHPY_uyXVEefo Message-ID: Subject: Re: [GIT PULL] char/misc driver patches for 3.16-rc1 From: Linus Torvalds To: Greg KH Cc: Bin Wang , Nobuhiro Iwamatsu , Andrew Morton , Arnd Bergmann , Linux Kernel Mailing List Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jun 3, 2014 at 10:02 AM, Greg KH wrote: > > Hm, I got two different bug reports, and this same patch from two > different people insisting that we broke their drivers with the above > patches, and asked for this patch to be applied. So I do think that we might be able to apply this patch, but I think it needs a *lot* more thought than was obviously spent on it so far. For example, right now it's actively insecure. Do we care? Maybe we don't. The user-space uio side presumably is root-owned, and hopefully trusted. And what about the unaligned mmio case? Are people somehow guaranteeing that the regions is page-aligned, even if it isn't page-sized? What is the actual hardware in question? Basically, it's an obvious security issue, and we shouldn't just say "whatever". But maybe - with lots of commentary about why the security implications aren't actually bad in _practice_, and why things are always page-aligned even if they aren't page-sized, we can say "ok, it's wrong, but we can still do it because xyz". So I'm mostly unhappy because I didn't see that kind of analysis, not because the patch might not eventually be ok. A "this breaks my driver" is nowhere near the kind of thought this needs, I think. Linus