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 (208.118.235.17 [208.118.235.17]) by mx.zohomail.com with SMTPS id 1534958331850327.00342106776725; Wed, 22 Aug 2018 10:18:51 -0700 (PDT) Received: from localhost ([::1]:60110 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fsWmI-0001Xh-5T for importer@patchew.org; Wed, 22 Aug 2018 13:18:42 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42827) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fsWgA-0004Vy-Of 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 1fsWXD-0005Os-M2 for qemu-devel@nongnu.org; Wed, 22 Aug 2018 13:03:08 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:37454 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 1fsWXD-0005Od-Gu for qemu-devel@nongnu.org; Wed, 22 Aug 2018 13:03:07 -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 37F73401EF02 for ; Wed, 22 Aug 2018 17:03:07 +0000 (UTC) Received: from localhost (ovpn-112-25.ams2.redhat.com [10.36.112.25]) by smtp.corp.redhat.com (Postfix) with ESMTP id B26A82156701; Wed, 22 Aug 2018 17:02:59 +0000 (UTC) From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= To: qemu-devel@nongnu.org Date: Wed, 22 Aug 2018 19:02:48 +0200 Message-Id: <20180822170250.29573-3-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 17:03:07 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.5]); Wed, 22 Aug 2018 17:03:07 +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 2/4] seccomp: prefer SCMP_ACT_KILL_PROCESS if available 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" The upcoming libseccomp release should have SCMP_ACT_KILL_PROCESS action (https://github.com/seccomp/libseccomp/issues/96). SCMP_ACT_KILL_PROCESS is preferable to immediately terminate the offending process, rather than having the SIGSYS handler running. Use SECCOMP_GET_ACTION_AVAIL to check availability of kernel support, as libseccomp will fallback on SCMP_ACT_KILL otherwise, and we still prefer SCMP_ACT_TRAP. Signed-off-by: Marc-Andr=C3=A9 Lureau Reviewed-by: Daniel P. Berrang=C3=A9 Acked-by: Eduardo Otubo --- qemu-seccomp.c | 31 ++++++++++++++++++++++++++++++- 1 file changed, 30 insertions(+), 1 deletion(-) diff --git a/qemu-seccomp.c b/qemu-seccomp.c index b117a92559..f0c833f3ca 100644 --- a/qemu-seccomp.c +++ b/qemu-seccomp.c @@ -20,6 +20,7 @@ #include #include #include "sysemu/seccomp.h" +#include =20 /* For some architectures (notably ARM) cacheflush is not supported until * libseccomp 2.2.3, but configure enforces that we are using a more recent @@ -107,12 +108,40 @@ static const struct QemuSeccompSyscall blacklist[] = =3D { { SCMP_SYS(sched_get_priority_min), QEMU_SECCOMP_SET_RESOURCECTL }, }; =20 +static inline __attribute__((unused)) int +qemu_seccomp(unsigned int operation, unsigned int flags, void *args) +{ +#ifdef __NR_seccomp + return syscall(__NR_seccomp, operation, flags, args); +#else + errno =3D ENOSYS; + return -1; +#endif +} + +static uint32_t qemu_seccomp_get_kill_action(void) +{ +#if defined(SECCOMP_GET_ACTION_AVAIL) && defined(SCMP_ACT_KILL_PROCESS) &&= \ + defined(SECCOMP_RET_KILL_PROCESS) + { + uint32_t action =3D SECCOMP_RET_KILL_PROCESS; + + if (qemu_seccomp(SECCOMP_GET_ACTION_AVAIL, 0, &action) =3D=3D 0) { + return SCMP_ACT_KILL_PROCESS; + } + } +#endif + + return SCMP_ACT_TRAP; +} + =20 static int seccomp_start(uint32_t seccomp_opts) { int rc =3D 0; unsigned int i =3D 0; scmp_filter_ctx ctx; + uint32_t action =3D qemu_seccomp_get_kill_action(); =20 ctx =3D seccomp_init(SCMP_ACT_ALLOW); if (ctx =3D=3D NULL) { @@ -125,7 +154,7 @@ static int seccomp_start(uint32_t seccomp_opts) continue; } =20 - rc =3D seccomp_rule_add_array(ctx, SCMP_ACT_TRAP, blacklist[i].num, + rc =3D seccomp_rule_add_array(ctx, action, blacklist[i].num, blacklist[i].narg, blacklist[i].arg_cm= p); if (rc < 0) { goto seccomp_return; --=20 2.18.0.547.g1d89318c48