Re: [kernel-hardening] Re: [PATCH RFC v2 1/3] LSM: Allow per LSM module per "struct task_struct" blob.

From: Kees Cook <keescook-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
To: Djalal Harouni <tixxdz-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Cc: Casey Schaufler <casey-iSGtlc1asvQWG2LlvL+J4A@public.gmane.org>,
	Linux Kernel Mailing List
	<linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
	Andy Lutomirski <luto-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
	Andrew Morton
	<akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>,
	"kernel-hardening-ZwoEplunGu1jrUoiu81ncdBPR1lH4CV8@public.gmane.org"
	<kernel-hardening-ZwoEplunGu1jrUoiu81ncdBPR1lH4CV8@public.gmane.org>,
	LSM List
	<linux-security-module-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
	Linux API <linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
	Dongsu Park <dpark-VwIFZPTo/vqsTnJN9+BGXg@public.gmane.org>,
	James Morris
	<james.l.morris-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>,
	"Serge E. Hallyn" <serge-A9i7LUbDfNHQT0dZR+AlfA@public.gmane.org>,
	Paul Moore <paul-r2n+y4ga6xFZroRs9YW3xA@public.gmane.org>,
	Tetsuo Handa
	<penguin-kernel-1yMVhJb1mP/7nzcFbJAaVXf5DAMn2ifp@public.gmane.org>,
	Greg Kroah-Hartman
	<gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org>
Subject: Re: [kernel-hardening] Re: [PATCH RFC v2 1/3] LSM: Allow per LSM module per "struct task_struct" blob.
Date: Mon, 10 Apr 2017 21:43:45 -0700	[thread overview]
Message-ID: <CAGXu5jL7jLid57UoXCxSqo5JZRLMgZ7X6BSYgWLckp5YpoiAmA@mail.gmail.com> (raw)
In-Reply-To: <CAEiveUd4Obc+YsCiO7dp3-jypbJ4vMmsBOU=Ax8yF7+6dLes0w-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>

On Mon, Apr 10, 2017 at 1:00 PM, Djalal Harouni <tixxdz-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> On Mon, Apr 10, 2017 at 9:26 PM, Casey Schaufler <casey-iSGtlc1asvQWG2LlvL+J4A@public.gmane.org> wrote:
>> I think that would be the prudent approach. There is still
>> the possibility that blob sharing (or full stacking, if you
>> prefer) won't be accepted any time soon.
>
> Ok Casey! I will wait for more feedback, and if other maintainers do
> not object, I will convert it back to rhashtables in next iterations
> making sure that it should be simple to convert later to a blob
> sharing mechanism.

Would it be possible just to add a single field to task_struct if this
LSM is built in? I feel like rhashtables is a huge overhead when a
single field is all that's needed.

-Kees

-- 
Kees Cook
Pixel Security