Re: [RFC PATCH 1/6] security/fbfam: Add a Kconfig to enable the fbfam feature

From: John Wood <john.wood@gmx.com>
To: Kees Cook <keescook@chromium.org>
Cc: Jann Horn <jannh@google.com>,
	kernel-hardening@lists.openwall.com,
	John Wood <john.wood@gmx.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
Date: Thu, 17 Sep 2020 20:40:06 +0200	[thread overview]
Message-ID: <20200917175146.GB3637@ubuntu> (raw)
In-Reply-To: <202009101615.8566BA3967@keescook>

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.

> --
> Kees Cook

Thanks,
John Wood