From nobody Wed Nov 5 15:01:44 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; 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 1534958075147593.4559011910322; Wed, 22 Aug 2018 10:14:35 -0700 (PDT) Received: from localhost ([::1]:60079 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fsWiC-0005ld-FU for importer@patchew.org; Wed, 22 Aug 2018 13:14:28 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42695) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fsWg9-0004Ve-R0 for qemu-devel@nongnu.org; Wed, 22 Aug 2018 13:12:30 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fsWXK-0005Tl-OV for qemu-devel@nongnu.org; Wed, 22 Aug 2018 13:03:17 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:37466 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 1fsWXK-0005TH-Bq for qemu-devel@nongnu.org; Wed, 22 Aug 2018 13:03:14 -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 0DC2B401EF02 for ; Wed, 22 Aug 2018 17:03:14 +0000 (UTC) Received: from localhost (ovpn-112-25.ams2.redhat.com [10.36.112.25]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5CEB42156701; Wed, 22 Aug 2018 17:03:13 +0000 (UTC) From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= To: qemu-devel@nongnu.org Date: Wed, 22 Aug 2018 19:02:50 +0200 Message-Id: <20180822170250.29573-5-marcandre.lureau@redhat.com> In-Reply-To: <20180822170250.29573-1-marcandre.lureau@redhat.com> References: <20180822170250.29573-1-marcandre.lureau@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 [10.11.55.5]); Wed, 22 Aug 2018 17:03:14 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.5]); Wed, 22 Aug 2018 17:03:14 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'marcandre.lureau@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] [PATCH v4 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, Eduardo Otubo , =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= 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" 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 Reviewed-by: Daniel P. Berrang=C3=A9 --- 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 2.18.0.547.g1d89318c48