linux-kernel - Re: [PATCH v3 14/15] exec: Use sane stack rlimit under secureexec

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Message-ID: <alpine.LRH.2.20.1707191942400.10539@namei.org>
Date:   Wed, 19 Jul 2017 19:42:53 +1000 (AEST)
From:   James Morris <jmorris@...ei.org>
To:     Kees Cook <keescook@...omium.org>
cc:     Andrew Morton <akpm@...ux-foundation.org>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        David Howells <dhowells@...hat.com>,
        "Eric W. Biederman" <ebiederm@...ssion.com>,
        John Johansen <john.johansen@...onical.com>,
        "Serge E. Hallyn" <serge@...lyn.com>,
        Paul Moore <paul@...l-moore.com>,
        Stephen Smalley <sds@...ho.nsa.gov>,
        Casey Schaufler <casey@...aufler-ca.com>,
        Tetsuo Handa <penguin-kernel@...ove.SAKURA.ne.jp>,
        James Morris <james.l.morris@...cle.com>,
        Andy Lutomirski <luto@...nel.org>,
        linux-fsdevel@...r.kernel.org,
        linux-security-module@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 14/15] exec: Use sane stack rlimit under secureexec

On Tue, 18 Jul 2017, Kees Cook wrote:

> For a secureexec, before memory layout selection has happened, reset the
> stack rlimit to something sane to avoid the caller having control over
> the resulting layouts.
> 
> $ ulimit -s
> 8192
> $ ulimit -s unlimited
> $ /bin/sh -c 'ulimit -s'
> unlimited
> $ sudo /bin/sh -c 'ulimit -s'
> 8192
> 
> Cc: Linus Torvalds <torvalds@...ux-foundation.org>
> Signed-off-by: Kees Cook <keescook@...omium.org>


Reviewed-by: James Morris <james.l.morris@...cle.com>


-- 
James Morris
<jmorris@...ei.org>