From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CDB8BC3A59F for ; Thu, 29 Aug 2019 19:12:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A3C9A23403 for ; Thu, 29 Aug 2019 19:12:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727959AbfH2TMB (ORCPT ); Thu, 29 Aug 2019 15:12:01 -0400 Received: from mx1.redhat.com ([209.132.183.28]:42447 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727798AbfH2TMB (ORCPT ); Thu, 29 Aug 2019 15:12:01 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id D94FF307D868; Thu, 29 Aug 2019 19:12:00 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-120-255.rdu2.redhat.com [10.10.120.255]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1123F196B2; Thu, 29 Aug 2019 19:11:57 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: <03eb0974-3996-f356-5fbe-17cf598b0e31@tycho.nsa.gov> References: <03eb0974-3996-f356-5fbe-17cf598b0e31@tycho.nsa.gov> <156710338860.10009.12524626894838499011.stgit@warthog.procyon.org.uk> <156710348066.10009.17986469867635955040.stgit@warthog.procyon.org.uk> To: Stephen Smalley Cc: dhowells@redhat.com, viro@zeniv.linux.org.uk, Casey Schaufler , Greg Kroah-Hartman , nicolas.dichtel@6wind.com, raven@themaw.net, Christian Brauner , keyrings@vger.kernel.org, linux-usb@vger.kernel.org, linux-security-module@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 10/11] selinux: Implement the watch_key security hook [ver #6] MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <14148.1567105917.1@warthog.procyon.org.uk> Date: Thu, 29 Aug 2019 20:11:57 +0100 Message-ID: <14149.1567105917@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.48]); Thu, 29 Aug 2019 19:12:01 +0000 (UTC) Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: Stephen Smalley wrote: > Can watch->cred ever differ from current's cred here? If not, why can't we > just use current_sid() here Um. Not currently. I'm not sure whether its ever likely to be otherwise. Probably we could just use that and fix it up later if we do find otherwise. > and why do we need the watch object at all? It carries more than just the creds for the caller of keyctl_watch_key(), it also carries information about the queue to which notifications will be written, including the creds that were active when that was set up. Note that there's no requirement that the process that opened /dev/watch_queue be the one that sets the watch. In the keyutils testsuite, I 'leak' a file descriptor from the session wrangler into the program that it runs so that tests running inside the test script can add watches to it. David