From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47646) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fsWrJ-0004XF-5r for qemu-devel@nongnu.org; Wed, 22 Aug 2018 13:23:54 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fsWrD-0002sd-Ja for qemu-devel@nongnu.org; Wed, 22 Aug 2018 13:23:52 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:51094 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fsWrD-0002sG-Eo for qemu-devel@nongnu.org; Wed, 22 Aug 2018 13:23:47 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 659D640241C0 for ; Wed, 22 Aug 2018 17:23:46 +0000 (UTC) Date: Wed, 22 Aug 2018 18:23:37 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Message-ID: <20180822172337.GY12750@redhat.com> Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= References: <20180822170250.29573-1-marcandre.lureau@redhat.com> <20180822170250.29573-5-marcandre.lureau@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20180822170250.29573-5-marcandre.lureau@redhat.com> Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH v4 4/4] seccomp: set the seccomp filter to all threads List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: =?utf-8?Q?Marc-Andr=C3=A9?= Lureau Cc: qemu-devel@nongnu.org, pmoore@redhat.com, eblake@redhat.com, Eduardo Otubo On Wed, Aug 22, 2018 at 07:02:50PM +0200, Marc-Andr=C3=A9 Lureau wrote: > When using "-seccomp on", the seccomp policy is only applied to the > main thread, the vcpu worker thread and other worker threads created > after seccomp policy is applied; the seccomp policy is not applied to > e.g. the RCU thread because it is created before the seccomp policy is > applied and SECCOMP_FILTER_FLAG_TSYNC isn't used. >=20 > This can be verified with > for task in /proc/`pidof qemu`/task/*; do cat $task/status | grep Secc = ; done > Seccomp: 2 > Seccomp: 0 > Seccomp: 0 > Seccomp: 2 > Seccomp: 2 > Seccomp: 2 >=20 > Starting with libseccomp 2.2.0 and kernel >=3D 3.17, we can use > seccomp_attr_set(ctx, > SCMP_FLTATR_CTL_TSYNC, 1) to update the policy > on all threads. >=20 > libseccomp requirement was bumped to 2.2.0 in previous patch. > libseccomp should fail to set the filter if it can't honour > SCMP_FLTATR_CTL_TSYNC (untested), and thus -sandbox will now fail on > kernel < 3.17. >=20 > Signed-off-by: Marc-Andr=C3=A9 Lureau > --- > qemu-seccomp.c | 5 +++++ > 1 file changed, 5 insertions(+) Reviewed-by: Daniel P. Berrang=C3=A9 Regards, Daniel --=20 |: https://berrange.com -o- https://www.flickr.com/photos/dberran= ge :| |: https://libvirt.org -o- https://fstop138.berrange.c= om :| |: https://entangle-photo.org -o- https://www.instagram.com/dberran= ge :|