From nobody Sun Feb 8 21:11:26 2026 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 Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1504263764950542.0931767183906; Fri, 1 Sep 2017 04:02:44 -0700 (PDT) Received: from localhost ([::1]:35197 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dnjil-0003KE-Qz for importer@patchew.org; Fri, 01 Sep 2017 07:02:43 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51251) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dnjey-00008G-Rj for qemu-devel@nongnu.org; Fri, 01 Sep 2017 06:58:53 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dnjet-0001DD-QU for qemu-devel@nongnu.org; Fri, 01 Sep 2017 06:58:48 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37940) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dnjet-0001Cz-IH for qemu-devel@nongnu.org; Fri, 01 Sep 2017 06:58:43 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 854967E456 for ; Fri, 1 Sep 2017 10:58:42 +0000 (UTC) Received: from vader.redhat.com (ovpn-117-156.ams2.redhat.com [10.36.117.156]) by smtp.corp.redhat.com (Postfix) with ESMTP id 347A27E8EB; Fri, 1 Sep 2017 10:58:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 854967E456 Authentication-Results: ext-mx03.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx03.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=otubo@redhat.com From: Eduardo Otubo To: qemu-devel@nongnu.org Date: Fri, 1 Sep 2017 12:58:14 +0200 Message-Id: <20170901105818.31956-3-otubo@redhat.com> In-Reply-To: <20170901105818.31956-1-otubo@redhat.com> References: <20170901105818.31956-1-otubo@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Fri, 01 Sep 2017 10:58:42 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCHv4 2/6] seccomp: add obsolete argument to command line 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: thuth@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" This patch introduces the argument [,obsolete=3Dallow] to the `-sandbox on' option. It allows Qemu to run safely on old system that still relies on old system calls. Signed-off-by: Eduardo Otubo --- include/sysemu/seccomp.h | 3 ++- qemu-options.hx | 12 ++++++++++-- qemu-seccomp.c | 23 ++++++++++++++++++++++- vl.c | 22 +++++++++++++++++++++- 4 files changed, 55 insertions(+), 5 deletions(-) diff --git a/include/sysemu/seccomp.h b/include/sysemu/seccomp.h index 23b9c3c789..215138a372 100644 --- a/include/sysemu/seccomp.h +++ b/include/sysemu/seccomp.h @@ -16,8 +16,9 @@ #define QEMU_SECCOMP_H =20 #define QEMU_SECCOMP_SET_DEFAULT (1 << 0) +#define QEMU_SECCOMP_SET_OBSOLETE (1 << 1) =20 #include =20 -int seccomp_start(void); +int seccomp_start(uint32_t seccomp_opts); #endif diff --git a/qemu-options.hx b/qemu-options.hx index 9f6e2adfff..72150c6b84 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -4017,13 +4017,21 @@ Old param mode (ARM only). ETEXI =20 DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \ - "-sandbox Enable seccomp mode 2 system call filter (default 'of= f').\n", + "-sandbox on[,obsolete=3Dallow|deny]\n" \ + " Enable seccomp mode 2 system call filter (default 'of= f').\n" \ + " use 'obsolete' to allow obsolete system calls that ar= e provided\n" \ + " by the kernel, but typically no longer used by mo= dern\n" \ + " C library implementations.\n", QEMU_ARCH_ALL) STEXI -@item -sandbox @var{arg} +@item -sandbox @var{arg}[,obsolete=3D@var{string}] @findex -sandbox Enable Seccomp mode 2 system call filter. 'on' will enable syscall filteri= ng and 'off' will disable it. The default is 'off'. +@table @option +@item obsolete=3D@var{string} +Enable Obsolete system calls +@end table ETEXI =20 DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig, diff --git a/qemu-seccomp.c b/qemu-seccomp.c index 585de42a97..3e3f15cc08 100644 --- a/qemu-seccomp.c +++ b/qemu-seccomp.c @@ -56,9 +56,22 @@ static const struct QemuSeccompSyscall blacklist[] =3D { { SCMP_SYS(tuxcall), 1, QEMU_SECCOMP_SET_DEFAULT }, { SCMP_SYS(ulimit), 1, QEMU_SECCOMP_SET_DEFAULT }, { SCMP_SYS(vserver), 1, QEMU_SECCOMP_SET_DEFAULT }, + /* obsolete */ + { SCMP_SYS(readdir), 2, QEMU_SECCOMP_SET_OBSOLETE }, + { SCMP_SYS(_sysctl), 2, QEMU_SECCOMP_SET_OBSOLETE }, + { SCMP_SYS(bdflush), 2, QEMU_SECCOMP_SET_OBSOLETE }, + { SCMP_SYS(create_module), 2, QEMU_SECCOMP_SET_OBSOLETE }, + { SCMP_SYS(get_kernel_syms), 2, QEMU_SECCOMP_SET_OBSOLETE }, + { SCMP_SYS(query_module), 2, QEMU_SECCOMP_SET_OBSOLETE }, + { SCMP_SYS(sgetmask), 2, QEMU_SECCOMP_SET_OBSOLETE }, + { SCMP_SYS(ssetmask), 2, QEMU_SECCOMP_SET_OBSOLETE }, + { SCMP_SYS(sysfs), 2, QEMU_SECCOMP_SET_OBSOLETE }, + { SCMP_SYS(uselib), 2, QEMU_SECCOMP_SET_OBSOLETE }, + { SCMP_SYS(ustat), 2, QEMU_SECCOMP_SET_OBSOLETE }, }; =20 -int seccomp_start(void) + +int seccomp_start(uint32_t seccomp_opts) { int rc =3D 0; unsigned int i =3D 0; @@ -72,6 +85,14 @@ int seccomp_start(void) =20 for (i =3D 0; i < ARRAY_SIZE(blacklist); i++) { switch (blacklist[i].set) { + case QEMU_SECCOMP_SET_OBSOLETE: + if (!(seccomp_opts & QEMU_SECCOMP_SET_OBSOLETE)) { + goto add_syscall; + } else { + continue; + } + + break; default: goto add_syscall; } diff --git a/vl.c b/vl.c index 305531aba8..ca267f9918 100644 --- a/vl.c +++ b/vl.c @@ -271,6 +271,10 @@ static QemuOptsList qemu_sandbox_opts =3D { .name =3D "enable", .type =3D QEMU_OPT_BOOL, }, + { + .name =3D "obsolete", + .type =3D QEMU_OPT_STRING, + }, { /* end of list */ } }, }; @@ -1032,7 +1036,23 @@ static int parse_sandbox(void *opaque, QemuOpts *opt= s, Error **errp) { if (qemu_opt_get_bool(opts, "enable", false)) { #ifdef CONFIG_SECCOMP - if (seccomp_start() < 0) { + uint32_t seccomp_opts =3D 0x00000; + const char *value =3D NULL; + + value =3D qemu_opt_get(opts, "obsolete"); + if (value) { + if (strcmp(value, "allow") =3D=3D 0) { + seccomp_opts |=3D QEMU_SECCOMP_SET_OBSOLETE; + } else if (strcmp(value, "deny")) { + /* this is the default option, this if is here + * to provide a little bit of consistency for + * the command line */ + } else { + error_report("invalid argument for obsolete"); + } + } + + if (seccomp_start(seccomp_opts) < 0) { error_report("failed to install seccomp syscall filter " "in the kernel"); return -1; --=20 2.13.5