From: Daniel Jacobowitz <dan@debian.org>
To: Andrew Griffiths <andrewg@tasmail.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: ptrace allows you to read -r files
Date: Mon, 4 Feb 2002 22:06:28 -0500 [thread overview]
Message-ID: <20020204220628.A2229@nevyn.them.org> (raw)
In-Reply-To: <200202050033.g150XVn17613@picton-ext.nt.tas.gov.au>
In-Reply-To: <200202050033.g150XVn17613@picton-ext.nt.tas.gov.au>
On Tue, Feb 05, 2002 at 11:33:32AM +1100, Andrew Griffiths wrote:
> Hello everyone,
>
> While playing around I noticed that if I fork()ed, then did ptrace(PTRACE_TRACEME,...) then exec'd a non-readable binary, the ptrace interface would let me read the binary.
>
> This was tested on 2.4.17ctx-5 (the security context patch), however I have been told it works on vanilla kernels, also I tested it on 2.4.2-pax on an old machine. (pentium 75...)
>
> For those who want some demo code, you can find it at http://203.39.161.186/readbin.tgz.
>
> For testing it, I used /usr/bin/ssh which was rws--x--x.
>
> Since I'm not subscribed to this list, could any replies be cc'd to me? Thanks.
I think this is just 'known'. Note that it isn't a security problem
otherwise; you'll find that the setuid application does not setuid if
it is ptraced. On 2.4.17 at least.
--
Daniel Jacobowitz Carnegie Mellon University
MontaVista Software Debian GNU/Linux Developer
next prev parent reply other threads:[~2002-02-05 3:07 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-02-05 0:33 ptrace allows you to read -r files Andrew Griffiths
2002-02-05 3:06 ` Daniel Jacobowitz [this message]
-- strict thread matches above, loose matches on Subject: below --
2002-02-05 10:12 Andrew Griffiths
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