Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753217AbaAZUTe (ORCPT ); Sun, 26 Jan 2014 15:19:34 -0500 Received: from mail-ee0-f43.google.com ([74.125.83.43]:34731 "EHLO mail-ee0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752031AbaAZUTc (ORCPT ); Sun, 26 Jan 2014 15:19:32 -0500 Date: Sun, 26 Jan 2014 21:19:28 +0100 From: Ingo Molnar To: Linus Torvalds Cc: David Howells , Linux Kernel Mailing List , linux-afs@lists.infradead.org, Pali =?iso-8859-1?Q?Roh=E1r?= Subject: Re: [PATCH] afs: proc cells and rootcell are writeable Message-ID: <20140126201928.GA8224@gmail.com> References: <20140126122729.32113.19659.stgit@warthog.procyon.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Linus Torvalds wrote: > On Sun, Jan 26, 2014 at 4:27 AM, David Howells wrote: > > > > - p = proc_create("cells", 0, proc_afs, &afs_proc_cells_fops); > > + p = proc_create("cells", S_IFREG | S_IRUGO | S_IWUSR, proc_afs, &afs_proc_cells_fops); > > - p = proc_create("rootcell", 0, proc_afs, &afs_proc_rootcell_fops); > > + p = proc_create("rootcell", S_IFREG | S_IRUGO | S_IWUSR, proc_afs, &afs_proc_rootcell_fops); > > So the S_IFREG isn't necessary. > > And quite frankly, I personally think S_IRUGO | S_IWUSR is _less_ > readable than 0644. It's damn hard to parse those random letter > combinations, and at least I have to really think about it, in a way > that the octal representation does *not* make me go "I have to think > about that". > > So my personal preference would be to just see that simple 0644 in > proc_create. Hmm? Perhaps we could also generate the most common variants as: #define PERM__rw_r__r__ 0644 #define PERM__r________ 0400 #define PERM__r__r__r__ 0444 #define PERM__r_xr_xr_x 0555 etc. or something similar, more or less matching the output of 'ls -l'? That would also make security bugs in this area apparent at first sight. The number of people who can recognize during review that PERM_rw__w__w is probably unwise is probably two orders of magnitude than those who can interpret octal 0622 at a glance. Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/