Subject: Re: Using ftrace/perf as a basis for generic seccomp
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Stefan Fritsch <sf@sfritsch.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>, Eric Paris <eparis@redhat.com>,
        Ingo Molnar <mingo@elte.hu>,
        Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>,
        linux-kernel@vger.kernel.org, agl@google.com, tzanussi@gmail.com,
        Jason Baron <jbaron@redhat.com>,
        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
        2nddept-manager@sdl.hitachi.co.jp,
        Steven Rostedt <rostedt@goodmis.org>,
        Arnaldo Carvalho de Melo <acme@redhat.com>,
        Thomas Gleixner <tglx@linutronix.de>, James Morris <jmorris@namei.org>
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Date: Mon, 07 Feb 2011 13:26:09 +0100
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On Sat, 2011-02-05 at 12:51 +0100, Stefan Fritsch wrote:

> A really major use case is socketcall(2). All socket related syscalls 
> (accept, bind, connect, receivemsg, ...) are implemented as socketcall 
> with an appropriate argument. There will be many cases where you want a 
> sandboxed process to be able to do recvmsg(2) to receive new file 
> descriptors over an already open unix-domain socket from a broker process. 
> But you may want to disallow other socket operations, especially listen, 
> accept, and connect.
> 
> Of course one could also add some special case handling for socketcall 
> in seccomp instead of using the full filtering.

That looks like a perfect use-case for the LSM bits, attach some state
to both the fd object and the task object and if they don't match, don't
allow the action.


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