From nobody Wed Nov 5 02:33:00 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1500641971725655.5100819431177; Fri, 21 Jul 2017 05:59:31 -0700 (PDT) Received: from localhost ([::1]:42989 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dYXWk-00062r-CF for importer@patchew.org; Fri, 21 Jul 2017 08:59:30 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57675) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dYXQE-0000tA-J1 for qemu-devel@nongnu.org; Fri, 21 Jul 2017 08:52:47 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dYXQD-0000eW-PG for qemu-devel@nongnu.org; Fri, 21 Jul 2017 08:52:46 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35290) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dYXQD-0000e9-JC for qemu-devel@nongnu.org; Fri, 21 Jul 2017 08:52:45 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 86F3E655A for ; Fri, 21 Jul 2017 12:52:44 +0000 (UTC) Received: from vader.redhat.com (ovpn-116-236.ams2.redhat.com [10.36.116.236]) by smtp.corp.redhat.com (Postfix) with ESMTP id E80718B30B for ; Fri, 21 Jul 2017 12:52:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 86F3E655A Authentication-Results: ext-mx10.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx10.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=otubo@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 86F3E655A From: Eduardo Otubo To: qemu-devel@nongnu.org Date: Fri, 21 Jul 2017 14:52:35 +0200 Message-Id: <20170721125235.11939-7-otubo@redhat.com> In-Reply-To: <20170721125235.11939-1-otubo@redhat.com> References: <20170721125235.11939-1-otubo@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Fri, 21 Jul 2017 12:52:44 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH 6/6] seccomp: adding documentation to new seccomp model X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Adding new documention under docs/ to describe every one and each new option added by the refactoring patchset. Signed-off-by: Eduardo Otubo --- docs/seccomp.txt | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) create mode 100644 docs/seccomp.txt diff --git a/docs/seccomp.txt b/docs/seccomp.txt new file mode 100644 index 0000000000..4b7edba312 --- /dev/null +++ b/docs/seccomp.txt @@ -0,0 +1,31 @@ +QEMU Seccomp system call filter +=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D + +Starting from Qemu version 2.10, the seccomp filter does not work as a +whitelist but as a blacklist instead. This method allows safer deploys sin= ce +only the strictly forbidden system calls will be black-listed and the +possibility of breaking any workload is close to zero. + +The default option (-sandbox on) has a slightly looser security though and= the +reason is that it shouldn't break any backwards compatibility with previous +deploys and command lines already running. But if the intent is to have a +better security from this version on, one should make use of the following +additional options properly: + +* [,obsolete=3Dallow]: It allows Qemu to run safely on old system that sti= ll + relies on old system calls. + +* [,elevateprivileges=3Ddeny|allow|children]: It allows or denies Qemu pro= cess + to elevate its privileges by blacklisting all set*uid|gid system calls. = The + 'children' option sets the PR_SET_NO_NEW_PRIVS to 1 which allows helpers + (forls and execs) to run unprivileged. + +* [,spawn=3Ddeny]: It blacklists fork and execve syste calls, avoiding Qem= u to + spawn new threads or processes. + +* [,resourcecontrol=3Ddeny]: It blacklists all process affinity and schedu= ler + priority system calls to avoid any bigger of the process. + + +-- +Eduardo Otubo --=20 2.13.3