From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54111) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1db46b-0005WA-25 for qemu-devel@nongnu.org; Fri, 28 Jul 2017 08:11:02 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1db46a-0003iu-4n for qemu-devel@nongnu.org; Fri, 28 Jul 2017 08:10:57 -0400 Received: from mx1.redhat.com ([209.132.183.28]:55042) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1db46Z-0003iF-VU for qemu-devel@nongnu.org; Fri, 28 Jul 2017 08:10:56 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 064987CDFE for ; Fri, 28 Jul 2017 12:10:55 +0000 (UTC) From: Eduardo Otubo Date: Fri, 28 Jul 2017 14:10:40 +0200 Message-Id: <20170728121040.631-7-otubo@redhat.com> In-Reply-To: <20170728121040.631-1-otubo@redhat.com> References: <20170728121040.631-1-otubo@redhat.com> Subject: [Qemu-devel] [PATCH v3 6/6] seccomp: adding documentation to new seccomp model List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: thuth@redhat.com, berrange@redhat.com, pbonzini@redhat.com Adding new documention under docs/ to describe every one and each new option added by the seccomp 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 +=============================== + +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 since +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=allow]: It allows Qemu to run safely on old system that still + relies on old system calls. + +* [,elevateprivileges=deny|allow|children]: It allows or denies Qemu process + 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=deny]: It blacklists fork and execve syste calls, avoiding Qemu to + spawn new threads or processes. + +* [,resourcecontrol=deny]: It blacklists all process affinity and scheduler + priority system calls to avoid any bigger of the process. + + +-- +Eduardo Otubo -- 2.13.3