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=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 E9D3FCA9ECF for ; Fri, 1 Nov 2019 15:09:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BD62E21734 for ; Fri, 1 Nov 2019 15:09:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="PEdE72Sy" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727431AbfKAPJy (ORCPT ); Fri, 1 Nov 2019 11:09:54 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:29304 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727326AbfKAPJy (ORCPT ); Fri, 1 Nov 2019 11:09:54 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1572620992; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=B0+CdOYJOHUYIPhTqYhU6i7fsne7jTye1CGWyYYt7Oo=; b=PEdE72SyrafIuNffIJnCqKwZKifvPCa6bJvmZr8++axQksk4wHInSL8o8aHnoBQXg7z0k0 SEaZI9phGwjWCL5zznGIE1D2F1GVHgmPCNRcrQritCxo06yjfaNhyNHaEZnms91eQOIhjN EUFei3uR7KRh2/L1DvfF4tC/U0+EolE= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-338-5P0N9OwUMBiTSmPWIh5iXQ-1; Fri, 01 Nov 2019 11:09:49 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 6DC6A800D49; Fri, 1 Nov 2019 15:09:46 +0000 (UTC) Received: from madcap2.tricolour.ca (ovpn-112-19.phx2.redhat.com [10.3.112.19]) by smtp.corp.redhat.com (Postfix) with ESMTPS id B445810016E8; Fri, 1 Nov 2019 15:09:30 +0000 (UTC) Date: Fri, 1 Nov 2019 11:09:27 -0400 From: Richard Guy Briggs To: Steve Grubb Cc: nhorman@tuxdriver.com, linux-api@vger.kernel.org, containers@lists.linux-foundation.org, LKML , dhowells@redhat.com, Linux-Audit Mailing List , netfilter-devel@vger.kernel.org, ebiederm@xmission.com, simo@redhat.com, netdev@vger.kernel.org, linux-fsdevel@vger.kernel.org, Eric Paris , mpatel@redhat.com, Serge Hallyn Subject: Re: [PATCH ghak90 V7 20/21] audit: add capcontid to set contid outside init_user_ns Message-ID: <20191101150927.c5sf3n5ezfg2eano@madcap2.tricolour.ca> References: <20191030220320.tnwkaj5gbzchcn7j@madcap2.tricolour.ca> <3677995.NTHC7m0fHc@x2> MIME-Version: 1.0 In-Reply-To: <3677995.NTHC7m0fHc@x2> User-Agent: NeoMutt/20180716 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-MC-Unique: 5P0N9OwUMBiTSmPWIh5iXQ-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=WINDOWS-1252 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On 2019-10-31 10:50, Steve Grubb wrote: > Hello, >=20 > TLDR; I see a lot of benefit to switching away from procfs for setting a= uid &=20 > sessionid. >=20 > On Wednesday, October 30, 2019 6:03:20 PM EDT Richard Guy Briggs wrote: > > > Also, for the record, removing the audit loginuid from procfs is not > > > something to take lightly, if at all; like it or not, it's part of th= e > > > kernel API. >=20 > It can also be used by tools to iterate processes related to one user or= =20 > session. I use this in my Intrusion Prevention System which will land in= =20 > audit user space at some point in the future. >=20 > > Oh, I'm quite aware of how important this change is and it was discusse= d > > with Steve Grubb who saw the concern and value of considering such a > > disruptive change. >=20 > Actually, I advocated for syscall. I think the gist of Eric's idea was th= at / > proc is the intersection of many nasty problems. By relying on it, you ca= n't=20 > simplify the API to reduce the complexity. Almost no program actually nee= ds=20 > access to /proc. ps does. But almost everything else is happy without it.= For=20 > example, when you setup chroot jails, you may have to add /dev/random or = / > dev/null, but almost never /proc. What does force you to add /proc is any= =20 > entry point daemon like sshd because it needs to set the loginuid. If we= =20 > switch away from /proc, then sshd or crond will no longer /require/ procf= s to=20 > be available which again simplifies the system design. >=20 > > Removing proc support for auid/ses would be a > > long-term deprecation if accepted. >=20 > It might need to just be turned into readonly for a while. But then again= ,=20 > perhaps auid and session should be part of /proc//status? Maybe this= can=20 > be done independently and ahead of the container work so there is a migra= tion=20 > path for things that read auid or session. TBH, maybe this should have be= en=20 > done from the beginning. How about making loginuid/contid/capcontid writable only via netlink but still provide the /proc interface for reading? Deprecation of proc can be left as a decision for later. This way sshd/crond/getty don't need /proc, but the info is still there for tools that want to read it. > -Steve - RGB -- Richard Guy Briggs Sr. S/W Engineer, Kernel Security, Base Operating Systems Remote, Ottawa, Red Hat Canada IRC: rgb, SunRaycer Voice: +1.647.777.2635, Internal: (81) 32635