[{"id":1761591,"web_url":"http://patchwork.ozlabs.org/comment/1761591/","msgid":"<20170901110335.GI31680@redhat.com>","list_archive_url":null,"date":"2017-09-01T11:03:35","subject":"Re: [Qemu-devel] [PATCHv4 6/6] seccomp: adding documentation to new\n\tseccomp model","submitter":{"id":2694,"url":"http://patchwork.ozlabs.org/api/people/2694/","name":"Daniel P. Berrangé","email":"berrange@redhat.com"},"content":"On Fri, Sep 01, 2017 at 12:58:18PM +0200, Eduardo Otubo wrote:\n> Adding new documentation under docs/ to describe every one and each new\n> option added by the refactoring patchset.\n> \n> Signed-off-by: Eduardo Otubo \n> ---\n> docs/seccomp.txt | 31 +++++++++++++++++++++++++++++++\n> 1 file changed, 31 insertions(+)\n> create mode 100644 docs/seccomp.txt\n> \n> diff --git a/docs/seccomp.txt b/docs/seccomp.txt\n> new file mode 100644\n> index 0000000000..a5eca85a9b\n> --- /dev/null\n> +++ b/docs/seccomp.txt\n> @@ -0,0 +1,31 @@\n> +QEMU Seccomp system call filter\n> +===============================\n> +\n> +Starting from QEMU version 2.11, the seccomp filter does not work as a\n> +whitelist but as a blacklist instead. This method allows safer deploys since\n> +only the strictly forbidden system calls will be black-listed and the\n> +possibility of breaking any workload is close to zero.\n> +\n> +The default option (-sandbox on) has a slightly looser security though and the\n> +reason is that it shouldn't break any backwards compatibility with previous\n> +deploys and command lines already running. But if the intent is to have a\n> +better security from this version on, one should make use of the following\n> +additional options properly:\n> +\n> +* obsolete=allow|deny: It allows Qemu to run safely on old system that still\n> + relies on old system calls.\n> +\n> +* elevateprivileges=allow|deny|children: It allows or denies Qemu process\n> + to elevate its privileges by blacklisting all set*uid|gid system calls. The\n> + 'children' option sets the PR_SET_NO_NEW_PRIVS to 1 which allows helpers\n> + (forks and execs) to run unprivileged.\n> +\n> +* spawn=allow|deny: It blacklists fork and execve system calls, avoiding QEMU to\n> + spawn new threads or processes.\n> +\n> +* resourcecontrol=allow|deny: It blacklists all process affinity and scheduler\n> + priority system calls to avoid that the process can increase its amount of\n> + allowed resource consumption.\n> +\n\nThis ought to be part of qemu-options.hx so it makes it into the qemu\ndocs & man page.\n\nRegards,\nDaniel","headers":{"Return-Path":"","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@bilbo.ozlabs.org","Authentication-Results":["ozlabs.org;\n\tspf=pass (mailfrom) smtp.mailfrom=nongnu.org\n\t(client-ip=2001:4830:134:3::11; helo=lists.gnu.org;\n\tenvelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org;\n\treceiver=)","ext-mx09.extmail.prod.ext.phx2.redhat.com;\n\tdmarc=none (p=none dis=none) header.from=redhat.com","ext-mx09.extmail.prod.ext.phx2.redhat.com;\n\tspf=fail smtp.mailfrom=berrange@redhat.com"],"Received":["from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11])\n\t(using TLSv1 with cipher AES256-SHA (256/256 bits))\n\t(No client certificate requested)\n\tby ozlabs.org (Postfix) with ESMTPS id 3xkGbq2YF2z9s7p\n\tfor ;\n\tFri, 1 Sep 2017 21:04:55 +1000 (AEST)","from localhost ([::1]:35244 helo=lists.gnu.org)\n\tby lists.gnu.org with esmtp (Exim 4.71) (envelope-from\n\t)\n\tid 1dnjkr-0004ze-Cr\n\tfor incoming@patchwork.ozlabs.org; Fri, 01 Sep 2017 07:04:53 -0400","from eggs.gnu.org ([2001:4830:134:3::10]:53160)\n\tby lists.gnu.org with esmtp (Exim 4.71)\n\t(envelope-from ) id 1dnjjp-0004j0-1L\n\tfor qemu-devel@nongnu.org; Fri, 01 Sep 2017 07:03:55 -0400","from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)\n\t(envelope-from ) id 1dnjjj-0003LB-00\n\tfor qemu-devel@nongnu.org; Fri, 01 Sep 2017 07:03:49 -0400","from mx1.redhat.com ([209.132.183.28]:57512)\n\tby eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32)\n\t(Exim 4.71) (envelope-from ) id 1dnjji-0003Kx-OM\n\tfor qemu-devel@nongnu.org; Fri, 01 Sep 2017 07:03:42 -0400","from smtp.corp.redhat.com\n\t(int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11])\n\t(using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits))\n\t(No client certificate requested)\n\tby mx1.redhat.com (Postfix) with ESMTPS id ACABC4A6E0\n\tfor ; Fri, 1 Sep 2017 11:03:41 +0000 (UTC)","from redhat.com (unknown [10.42.22.189])\n\tby smtp.corp.redhat.com (Postfix) with ESMTPS id C28DE932F6;\n\tFri, 1 Sep 2017 11:03:38 +0000 (UTC)"],"DMARC-Filter":"OpenDMARC Filter v1.3.2 mx1.redhat.com ACABC4A6E0","Date":"Fri, 1 Sep 2017 12:03:35 +0100","From":"\"Daniel P. Berrange\" ","To":"Eduardo Otubo ","Message-ID":"<20170901110335.GI31680@redhat.com>","References":"<20170901105818.31956-1-otubo@redhat.com>\n\t<20170901105818.31956-7-otubo@redhat.com>","MIME-Version":"1.0","Content-Type":"text/plain; charset=utf-8","Content-Disposition":"inline","In-Reply-To":"<20170901105818.31956-7-otubo@redhat.com>","User-Agent":"Mutt/1.8.3 (2017-05-23)","X-Scanned-By":"MIMEDefang 2.79 on 10.5.11.11","X-Greylist":"Sender IP whitelisted, not delayed by milter-greylist-4.5.16\n\t(mx1.redhat.com [10.5.110.38]);\n\tFri, 01 Sep 2017 11:03:41 +0000 (UTC)","X-detected-operating-system":"by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic]\n\t[fuzzy]","X-Received-From":"209.132.183.28","Subject":"Re: [Qemu-devel] [PATCHv4 6/6] seccomp: adding documentation to new\n\tseccomp model","X-BeenThere":"qemu-devel@nongnu.org","X-Mailman-Version":"2.1.21","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Reply-To":"\"Daniel P. Berrange\" ","Cc":"thuth@redhat.com, qemu-devel@nongnu.org","Errors-To":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org","Sender":"\"Qemu-devel\"\n\t"}}]