From: Paul Eggert <eggert@cs.ucla.edu>
To: Eli Zaretskii <eliz@gnu.org>
Cc: romain@orebokech.com, emacs-devel@gnu.org
Subject: Re: set-file-extended-attributes and backups
Date: Fri, 21 Dec 2012 09:48:20 -0800 [thread overview]
Message-ID: <50D4A0E4.3050004@cs.ucla.edu> (raw)
In-Reply-To: <83a9t7qrrw.fsf@gnu.org>
On 12/21/12 08:44, Eli Zaretskii wrote:
> How about if it tried to copy ACLs, and if that failed, attempted to
> copy the file modes? That would DTRT if possible, and fall back on
> the pre-ACL method if not.
That could lead to security issues if the file modes are more
permissive than the ACLs.
Is there an easy way to test whether a file's ACLs could deny
access when the file's modes would allow it? If so, Emacs could
follow your suggestion when that test says "no". If not, Emacs
could fall back on a conservative approximation to that test.
The simplest conservative approximation that I can think of offhand
is to test whether a file has any nontrivial ACLs.
Whatever test Emacs uses, if the test says "yes" Emacs should
be more cautious: create a destination file with a restrictive
mode (e.g., -rw-------), copy the data, then attempt to copy the ACLs,
and if the ACL copy fails then Emacs should not attempt to change
the mode.
next prev parent reply other threads:[~2012-12-21 17:48 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-21 14:53 set-file-extended-attributes and backups Eli Zaretskii
2012-12-21 16:00 ` Paul Eggert
2012-12-21 16:44 ` Eli Zaretskii
2012-12-21 17:48 ` Paul Eggert [this message]
2012-12-21 18:08 ` Eli Zaretskii
2012-12-21 18:31 ` Paul Eggert
2012-12-23 16:59 ` Romain Francoise
2012-12-23 17:35 ` Eli Zaretskii
2012-12-24 0:59 ` Stefan Monnier
2012-12-24 3:44 ` Eli Zaretskii
2012-12-24 5:18 ` Stefan Monnier
2012-12-24 8:25 ` Michael Albinus
2012-12-24 16:24 ` Eli Zaretskii
2012-12-21 18:31 ` Romain Francoise
2012-12-22 23:03 ` Fabrice Popineau
2012-12-23 3:54 ` Eli Zaretskii
2012-12-23 17:17 ` Eli Zaretskii
2012-12-22 16:05 ` Stefan Monnier
2012-12-22 17:03 ` Eli Zaretskii
2012-12-23 13:37 ` Stefan Monnier
2012-12-29 17:20 ` Eli Zaretskii
2012-12-29 17:50 ` Eli Zaretskii
2012-12-29 19:12 ` Michael Albinus
2012-12-30 10:59 ` Michael Albinus
2012-12-30 17:21 ` Eli Zaretskii
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