From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753030AbaLGJze (ORCPT ); Sun, 7 Dec 2014 04:55:34 -0500 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:40538 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752928AbaLGJzc (ORCPT ); Sun, 7 Dec 2014 04:55:32 -0500 Date: Sun, 7 Dec 2014 10:55:29 +0100 From: Pavel Machek To: One Thousand Gnomes Cc: Alex Dubov , linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk, corbet@lwn.net, richardcochran@gmail.com Subject: Re: syscall: introduce sendfd() syscall (v.2) Message-ID: <20141207095529.GA18733@amd> References: <1417597255-32530-1-git-send-email-oakad@yahoo.com> <20141205132250.6f2f9ec1@lxorguk.ukuu.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20141205132250.6f2f9ec1@lxorguk.ukuu.org.uk> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri 2014-12-05 13:22:50, One Thousand Gnomes wrote: > > > 2.a. If task A has sufficient capabilities to send signals to task B, then > > task A is already in position to do anything it wants with task B, including > > killing it outright. > > Not entirely true. > > - We have securirty models like SELinux > - We have namespaces and being able to send an fd between namespaces is > not quite as flexible as you would make it > > I suspect therefore it needs security hooks but otherwise looks more sane > than the current AF_UNIX approach. The right test for "can do anything" is "can_ptrace()"... Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html