Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Thu, 17 Sep 2020 15:05:18 -0700
From:   Kees Cook <keescook@chromium.org>
To:     John Wood <john.wood@gmx.com>
Cc:     Jann Horn <jannh@google.com>, kernel-hardening@lists.openwall.com,
        Matthew Wilcox <willy@infradead.org>,
        Jonathan Corbet <corbet@lwn.net>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        Ingo Molnar <mingo@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Juri Lelli <juri.lelli@redhat.com>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        Dietmar Eggemann <dietmar.eggemann@arm.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>,
        Luis Chamberlain <mcgrof@kernel.org>,
        Iurii Zaikin <yzaikin@google.com>,
        James Morris <jmorris@namei.org>,
        "Serge E. Hallyn" <serge@hallyn.com>, linux-doc@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
        linux-security-module@vger.kernel.org
Subject: Re: [RFC PATCH 1/6] security/fbfam: Add a Kconfig to enable the
 fbfam feature
Message-ID: <202009171504.841FA53@keescook>
References: <20200910202107.3799376-1-keescook@chromium.org>
 <20200910202107.3799376-2-keescook@chromium.org>
 <202009101615.8566BA3967@keescook>
 <20200917175146.GB3637@ubuntu>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20200917175146.GB3637@ubuntu>
Precedence: bulk

On Thu, Sep 17, 2020 at 08:40:06PM +0200, John Wood wrote:
> Hi,
> 
> On Thu, Sep 10, 2020 at 04:18:08PM -0700, Kees Cook wrote:
> > On Thu, Sep 10, 2020 at 01:21:02PM -0700, Kees Cook wrote:
> > > From: John Wood <john.wood@gmx.com>
> > >
> > > Add a menu entry under "Security options" to enable the "Fork brute
> > > force attack mitigation" feature.
> > >
> > > Signed-off-by: John Wood <john.wood@gmx.com>
> > > ---
> > >  security/Kconfig       |  1 +
> > >  security/fbfam/Kconfig | 10 ++++++++++
> > >  2 files changed, 11 insertions(+)
> > >  create mode 100644 security/fbfam/Kconfig
> > >
> > > diff --git a/security/Kconfig b/security/Kconfig
> > > index 7561f6f99f1d..00a90e25b8d5 100644
> > > --- a/security/Kconfig
> > > +++ b/security/Kconfig
> > > @@ -290,6 +290,7 @@ config LSM
> > >  	  If unsure, leave this as the default.
> > >
> > >  source "security/Kconfig.hardening"
> > > +source "security/fbfam/Kconfig"
> >
> > Given the layout you've chosen and the interface you've got, I think
> > this should just be treated like a regular LSM.
> 
> Yes, throughout the review it seems the most appropiate is treat
> this feature as a regular LSM. Thanks.
> 
> > >
> > >  endmenu
> > >
> > > diff --git a/security/fbfam/Kconfig b/security/fbfam/Kconfig
> > > new file mode 100644
> > > index 000000000000..bbe7f6aad369
> > > --- /dev/null
> > > +++ b/security/fbfam/Kconfig
> > > @@ -0,0 +1,10 @@
> > > +# SPDX-License-Identifier: GPL-2.0
> > > +config FBFAM
> >
> > To jump on the bikeshed: how about just calling this
> > FORK_BRUTE_FORCE_DETECTION or FORK_BRUTE, and the directory could be
> > "brute", etc. "fbfam" doesn't tell anyone anything.
> 
> Understood. But how about use the fbfam abbreviation in the code? Like as
> function name prefix, struct name prefix, ... It would be better to use a
> more descriptive name in this scenario? It is not clear to me.

I don't feel too strongly, but I think having the CONFIG roughly match
the directory name, roughly match the function prefixes should be best.
Maybe call the directory and function prefix "brute"?

-- 
Kees Cook