kernel-hardening - Re: Re: [PATCH v3 -resend] move RLIMIT_NPROC check from set_user() to do_execve

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Message-ID: <20110811171812.GA17346@albatros>
Date: Thu, 11 Aug 2011 21:18:12 +0400
From: Vasiliy Kulikov <segoon@...nwall.com>
To: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: NeilBrown <neilb@...e.de>, linux-kernel@...r.kernel.org,
	Greg Kroah-Hartman <gregkh@...e.de>,
	Andrew Morton <akpm@...ux-foundation.org>,
	"David S. Miller" <davem@...emloft.net>,
	Jiri Slaby <jslaby@...e.cz>, James Morris <jmorris@...ei.org>,
	kernel-hardening@...ts.openwall.com
Subject: Re: Re: [PATCH v3 -resend] move RLIMIT_NPROC
 check from set_user() to do_execve_common()

Hi Linus,

On Tue, Aug 09, 2011 at 12:16 +1000, NeilBrown wrote:
> On Mon, 8 Aug 2011 19:02:04 +0400 Vasiliy Kulikov <segoon@...nwall.com> wrote:
> 
> > The patch http://lkml.org/lkml/2003/7/13/226 introduced an RLIMIT_NPROC
> > check in set_user() to check for NPROC exceeding via setuid() and
> > similar functions.  Before the check there was a possibility to greatly
> > exceed the allowed number of processes by an unprivileged user if the
> > program relied on rlimit only.  But the check created new security
> > threat: many poorly written programs simply don't check setuid() return
> > code and believe it cannot fail if executed with root privileges.  So,
> > the check is removed in this patch because of too often privilege
> > escalations related to buggy programs.
...
> > Reviewed-by: James Morris <jmorris@...ei.org>
> Acked-by: NeilBrown <neilb@...e.de>

It got 2 positive feedbacks and seems nobody has better solution.
Is it possible to see it in 3.1?

Thanks!

-- 
Vasiliy Kulikov
http://www.openwall.com - bringing security into open computing environments

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