Linux NFS development
 help / color / mirror / Atom feed
From: Frank van Maarseveen <frankvm@xs4all.nl>
To: nfs@lists.sourceforge.net
Subject: Re: executable but not readable
Date: Sat, 27 Mar 2004 13:17:31 +0100	[thread overview]
Message-ID: <20040327121731.GA27152@janus> (raw)
In-Reply-To: <1080328671.2480.23.camel@lade.trondhjem.org>

On Fri, Mar 26, 2004 at 02:17:51PM -0500, Trond Myklebust wrote:
> 
> In NFSv3, the ACCESS call should then be used to decide whether or not
> the client is allowed to open the file for execution (and for reading if
> that is required). Unfortunately ACCESS is not implemented in the stock
> Linux 2.4.x kernel.

So the kernel does its own permission checking on the client side
for executables _knowing_ that it is going to execute the file but
unfortunately the interpreter has to open the file by itself and that
fails.

But from a different perspective:

Being able to create a (non-setuid) executable which cannot be read
for security reasons looks very weak to me unless of course it is not
possible to let it dump core, strace (ptrace) it, open /proc/... files
etc. But is that all actually the case in 2.6?


-- 
Frank


-------------------------------------------------------
This SF.Net email is sponsored by: IBM Linux Tutorials
Free Linux tutorial presented by Daniel Robbins, President and CEO of
GenToo technologies. Learn everything from fundamentals to system
administration.http://ads.osdn.com/?ad_id=1470&alloc_id=3638&op=click
_______________________________________________
NFS maillist  -  NFS@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/nfs

  reply	other threads:[~2004-03-27 12:18 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-03-25 18:00 executable but not readable Christopher Huhn
2004-03-25 18:37 ` Trond Myklebust
2004-03-26 10:48   ` Christopher Huhn
2004-03-26 19:17     ` Trond Myklebust
2004-03-27 12:17       ` Frank van Maarseveen [this message]
2004-03-28 23:46         ` Trond Myklebust
2004-03-28 23:59           ` Frank van Maarseveen
2004-03-29  1:00             ` Trond Myklebust
2004-03-29 11:35       ` Christopher Huhn

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20040327121731.GA27152@janus \
    --to=frankvm@xs4all.nl \
    --cc=nfs@lists.sourceforge.net \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox