linux-kernel - Re: [PATCH] yama: clarify ptrace

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <be02c1974b028efcc2a0ec49dfedff456a78e156.camel@corsac.net>
Date:   Tue, 02 Oct 2018 23:08:34 +0200
From:   Yves-Alexis Perez <corsac@...sac.net>
To:     Matthew Wilcox <willy@...radead.org>
Cc:     Kees Cook <keescook@...omium.org>,
        Jonathan Corbet <corbet@....net>, linux-doc@...r.kernel.org,
        linux-kernel@...r.kernel.org, trivial@...nel.org
Subject: Re: [PATCH] yama: clarify ptrace_scope=2 in Yama documentation

On Tue, 2018-10-02 at 13:52 -0700, Matthew Wilcox wrote:
> On Tue, Oct 02, 2018 at 10:47:23PM +0200, Yves-Alexis Perez wrote:
> > Current phrasing is ambiguous since it's unclear if attaching to a
> > children through PTRACE_TRACEME requires CAP_SYS_PTRACE. Rephrase the
> > sentence to make that clear.
> 
> I disagree that your sentence makes that clear.  How about:
> 
> >  2 - admin-only attach:
> > -    only processes with ``CAP_SYS_PTRACE`` may use ptrace
> > -    with ``PTRACE_ATTACH``, or through children calling
> > ``PTRACE_TRACEME``.
> > +    only processes with ``CAP_SYS_PTRACE`` may use ptrace, either with
> > +    ``PTRACE_ATTACH`` or through children calling ``PTRACE_TRACEME``.
> 
> +    only processes with ``CAP_SYS_PTRACE`` may use ptrace.  This
> +    restricts both ``PTRACE_ATTACH`` and ``PTRACE_TRACEME``.

Hi Matthew,

I'm no native speaker, both versions are fine by me but I liked keeping the
“children calling” part since the semantics are quite different for
PTRACE_ATTACH and PTRACE_TRACEME.

Regards,
-- 
Yves-Alexis