From nobody Fri Apr 19 08:36:56 2024 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; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1535037855597307.0426120574606; Thu, 23 Aug 2018 08:24:15 -0700 (PDT) Received: from localhost ([::1]:37202 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fsrT4-00041B-9M for importer@patchew.org; Thu, 23 Aug 2018 11:24:14 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48486) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fsqyZ-00040V-LP for qemu-devel@nongnu.org; Thu, 23 Aug 2018 10:52:44 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fsqyY-0008H0-TZ for qemu-devel@nongnu.org; Thu, 23 Aug 2018 10:52:43 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:60980 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 1fsqyY-0008Gh-OC for qemu-devel@nongnu.org; Thu, 23 Aug 2018 10:52:42 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 6742A7B2B1; Thu, 23 Aug 2018 14:52:42 +0000 (UTC) Received: from vader.redhat.com (ovpn-117-73.ams2.redhat.com [10.36.117.73]) by smtp.corp.redhat.com (Postfix) with ESMTP id 31B102156701; Thu, 23 Aug 2018 14:52:41 +0000 (UTC) From: Eduardo Otubo To: qemu-devel@nongnu.org Date: Thu, 23 Aug 2018 16:52:30 +0200 Message-Id: <20180823145230.13183-5-otubo@redhat.com> In-Reply-To: <20180823145230.13183-1-otubo@redhat.com> References: <20180823145230.13183-1-otubo@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Thu, 23 Aug 2018 14:52:42 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Thu, 23 Aug 2018 14:52:42 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'otubo@redhat.com' RCPT:'' Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 66.187.233.73 Subject: [Qemu-devel] [PULL 4/4] seccomp: set the seccomp filter to all threads 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: , Cc: pmoore@redhat.com, peter.maydell@linaro.org, marcandre.lureau@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RDMRC_1 RSF_0 Z_629925259 SPT_0 Content-Type: text/plain; charset="utf-8" From: Marc-Andr=C3=A9 Lureau 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. This can be verified with for task in /proc/`pidof qemu`/task/*; do cat $task/status | grep Secc ; do= ne Seccomp: 2 Seccomp: 0 Seccomp: 0 Seccomp: 2 Seccomp: 2 Seccomp: 2 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. 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. Signed-off-by: Marc-Andr=C3=A9 Lureau Acked-by: Eduardo Otubo --- qemu-seccomp.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/qemu-seccomp.c b/qemu-seccomp.c index f0c833f3ca..4729eb107f 100644 --- a/qemu-seccomp.c +++ b/qemu-seccomp.c @@ -149,6 +149,11 @@ static int seccomp_start(uint32_t seccomp_opts) goto seccomp_return; } =20 + rc =3D seccomp_attr_set(ctx, SCMP_FLTATR_CTL_TSYNC, 1); + if (rc !=3D 0) { + goto seccomp_return; + } + for (i =3D 0; i < ARRAY_SIZE(blacklist); i++) { if (!(seccomp_opts & blacklist[i].set)) { continue; --=20 2.17.1