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From: Eli Zaretskii <eliz@gnu.org>
To: Paul Eggert <eggert@cs.ucla.edu>
Cc: 12632@debbugs.gnu.org
Subject: bug#12632: file permissions checking mishandled when setuid
Date: Tue, 16 Oct 2012 05:46:15 +0200	[thread overview]
Message-ID: <83d30j3wqg.fsf@gnu.org> (raw)
In-Reply-To: <507C823D.40304@cs.ucla.edu>

> Date: Mon, 15 Oct 2012 14:38:05 -0700
> From: Paul Eggert <eggert@cs.ucla.edu>
> CC: 12632@debbugs.gnu.org
> 
> On 10/15/2012 10:31 AM, Eli Zaretskii wrote:
> > Well, actually I thought we should stay with 'stat'.
> 
> We cannot stay with 'stat' everywhere, since 'stat' does not tell us
> whether a file is readable or writeable or executable.  We must use
> faccessat (or something like it, e.g., euidaccess) when we're
> implementing functions like check_writable, check_executable, or
> basically any function that uses R_OK, W_OK, or X_OK.

I was talking about check_existing.

> It's true that we could use 'stat' instead of faccessat(..., F_OK,
> ...), but the question then arises, why bother to make a special
> case for F_OK?

Because it's more universally available, and I believe also more
efficient.

> > So 'stat' is still better, IMO, because it is very efficient
> 
> Why should 'stat' be more efficient than faccessat?

Because it's used a lot.





  reply	other threads:[~2012-10-16  3:46 UTC|newest]

Thread overview: 47+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-10-13  1:58 bug#12632: file permissions checking mishandled when setuid Paul Eggert
2012-10-13  7:23 ` Eli Zaretskii
2012-10-13  8:36   ` Eli Zaretskii
2012-10-14  6:16     ` Paul Eggert
2012-10-14  6:56       ` Eli Zaretskii
2012-10-14 18:14         ` Paul Eggert
2012-10-14 18:39           ` Eli Zaretskii
2012-10-14 19:42             ` Paul Eggert
2012-10-14 20:10               ` Eli Zaretskii
2012-10-14 20:17               ` Eli Zaretskii
2012-10-14 20:40                 ` Paul Eggert
2012-10-14 20:53                   ` Eli Zaretskii
2012-10-15  6:17                     ` Paul Eggert
2012-10-15 17:31                       ` Eli Zaretskii
2012-10-15 21:38                         ` Paul Eggert
2012-10-16  3:46                           ` Eli Zaretskii [this message]
2012-10-16  6:00                             ` Paul Eggert
2012-10-16 16:36                               ` Eli Zaretskii
2012-10-19 17:01                                 ` Paul Eggert
2012-10-19 18:41                                   ` Eli Zaretskii
2012-10-19 18:54                                     ` Paul Eggert
2012-10-19 19:05                                       ` Glenn Morris
2012-10-19 19:36                                         ` Paul Eggert
2012-10-20  2:25                                           ` Richard Stallman
2012-10-20  4:36                                             ` Paul Eggert
2012-10-21  1:44                                           ` Glenn Morris
2012-10-21  2:52                                             ` Paul Eggert
2012-10-21  4:24                                               ` Glenn Morris
2012-10-22  6:03                                                 ` Paul Eggert
2012-10-22 17:19                                                   ` Eli Zaretskii
2012-10-22 20:33                                                     ` Paul Eggert
2012-10-22 21:04                                                       ` Eli Zaretskii
2012-10-22 21:30                                                         ` Paul Eggert
2012-10-23  0:40                                                           ` Stefan Monnier
2012-10-23  1:46                                                             ` Paul Eggert
2012-10-23  3:49                                                               ` Eli Zaretskii
2012-10-23  3:47                                                           ` Eli Zaretskii
2012-10-23  5:07                                                             ` Paul Eggert
2012-10-23 16:44                                                               ` Eli Zaretskii
2012-10-23 19:27                                                                 ` Paul Eggert
2012-10-23 19:50                                                                   ` Eli Zaretskii
2012-10-23 20:01                                                                     ` Paul Eggert
2012-10-23 23:15                                                                   ` Andy Moreton
2012-10-24  3:51                                                                     ` Eli Zaretskii
2012-10-19 19:10                                       ` Eli Zaretskii
2012-11-13  2:19 ` bug#12632: updated version of the patch Paul Eggert
2012-11-14  5:10   ` Paul Eggert

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