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From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Kees Cook <keescook@chromium.org>
Cc: linux-kernel@vger.kernel.org, Rob Landley <rob@landley.net>,
	Alexander Viro <viro@zeniv.linux.org.uk>,
	Alan Cox <alan@linux.intel.com>,
	Marcel Holtmann <marcel@holtmann.org>,
	Doug Ledford <dledford@redhat.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Serge Hallyn <serge.hallyn@canonical.com>,
	Joe Korty <joe.korty@ccur.com>,
	linux-doc@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH] fs: make dumpable=2 only write to a pipe
Date: Thu, 21 Jun 2012 22:18:58 +0100	[thread overview]
Message-ID: <20120621221858.25b8be67@pyramind.ukuu.org.uk> (raw)
In-Reply-To: <20120621194319.GA5961@www.outflux.net>

On Thu, 21 Jun 2012 12:43:19 -0700
Kees Cook <keescook@chromium.org> wrote:

> When the suid_dumpable sysctl is set to "2", and there is no
> core dump pipe defined in the core_pattern sysctl, a local user
> can cause core files to be written to root-writable directories,
> potentially with user-controlled content. This means an admin
> can unknowningly reintroduce a variation of CVE-2006-2451 (see
> abf75a5033d4da7b8a7e92321d74021d1fcfb502).

Its intended to work the way it does. It's also ABI. I think pipe-only is
a really good idea. Likewise I accept with the pipe feature nowdays there
is a good case to kill off case 2.

However I don't think magically turning one into the other is sensible,
in fact its *stupid* IMHO because it's asking systems to get unexpected
behaviour.

I would much rather see case 2 either left as is, or set to return
-EINVAL (or similar) and a new case 3 for pipe only.

Alan

  reply	other threads:[~2012-06-21 21:15 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-06-21 19:43 Kees Cook
2012-06-21 21:18 ` Alan Cox [this message]
2012-06-21 22:03   ` Kees Cook

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