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From:   Kees Cook <keescook@chromium.org>
Date:   Tue, 2 Oct 2018 13:52:32 -0700
Message-ID: <CAGXu5jKLaYxP81FYp_=Vc8GZWVGs_TAzjw5m2CBm0sNKwohXCg@mail.gmail.com>
Subject: Re: [PATCH] yama: clarify ptrace_scope=2 in Yama documentation
To:     Yves-Alexis Perez <corsac@corsac.net>
Cc:     Jonathan Corbet <corbet@lwn.net>,
        "open list:DOCUMENTATION" <linux-doc@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>, trivial@kernel.org
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On Tue, Oct 2, 2018 at 1:47 PM, Yves-Alexis Perez <corsac@corsac.net> 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.
>
> Signed-off-by: Yves-Alexis Perez <corsac@corsac.net>

Thanks! Yes, this makes things more clear.

Acked-by: Kees Cook <keescook@chromium.org>

Jon, can you take this in your tree?

-Kees

> ---
>  Documentation/admin-guide/LSM/Yama.rst | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/admin-guide/LSM/Yama.rst b/Documentation/admin-guide/LSM/Yama.rst
> index 13468ea696b7..d0a060de3973 100644
> --- a/Documentation/admin-guide/LSM/Yama.rst
> +++ b/Documentation/admin-guide/LSM/Yama.rst
> @@ -64,8 +64,8 @@ The sysctl settings (writable only with ``CAP_SYS_PTRACE``) are:
>      Using ``PTRACE_TRACEME`` is unchanged.
>
>  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``.
>
>  3 - no attach:
>      no processes may use ptrace with ``PTRACE_ATTACH`` nor via
> --
> 2.19.0
>
>
> --
> Yves-Alexis


-- 
Kees Cook
Pixel Security