From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753169AbbATVBo (ORCPT ); Tue, 20 Jan 2015 16:01:44 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:47347 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751462AbbATVBm (ORCPT ); Tue, 20 Jan 2015 16:01:42 -0500 Date: Wed, 21 Jan 2015 03:51:57 +0800 From: Greg Kroah-Hartman To: Guenter Roeck Cc: Vivien Didelot , linux-kernel@vger.kernel.org, kernel Subject: Re: [PATCH 2/3] sysfs: Only accept read/write permissions for file attributes Message-ID: <20150120195157.GA10864@kroah.com> References: <54BDC087.4010906@roeck-us.net> <1272429736.105015.1421768641283.JavaMail.root@mail> <20150120171312.GA24203@roeck-us.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150120171312.GA24203@roeck-us.net> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 20, 2015 at 09:13:12AM -0800, Guenter Roeck wrote: > On Tue, Jan 20, 2015 at 10:44:01AM -0500, Vivien Didelot wrote: > > Hi Guenter, > > > [ ... ] > > > > > Anyway, my goal was to keep things simple. Taking some bits from the default > > > and others from the return value of the is_visible function isn't simple, > > > even more so since your code would require the is_visible function to mask > > > out SYSFS_PREALLOC to avoid the warning. > > > > While I'm still not sure about the consequences of flipping this SYSFS_PREALLOC > > bit at runtime, I do agree with your goal. > > > > Then to keep it simple, the scope of is_visible could be limited to any bit > > allowed at attribute declaration (using *_ATTR* macros). The compile-time check > > macro VERIFY_OCTAL_PERMISSIONS() allows any bit but S_IWOTH. The scope can be > > SYSFS_PREALLOC | 0775. (or 0664 if we want to avoid executables as well.) > > > > [ This will prevent some follow-up patches "avoid world-writable sysfs files". > > In the future, we may want a runtime equivalent of VERIFY_OCTAL_PERMISSIONS. ] > > > 0775 and 0664 are both fine with me, with a preference for 0664. Before I > resubmit - Greg, any preference from your side ? I don't have the time to look at them this week, so feel free to fix up what you know about and resend and I will get to them as soon as I can. thanks, greg k-h