{"id":808630,"url":"http://patchwork.ozlabs.org/api/1.0/patches/808630/?format=json","project":{"id":14,"url":"http://patchwork.ozlabs.org/api/1.0/projects/14/?format=json","name":"QEMU Development","link_name":"qemu-devel","list_id":"qemu-devel.nongnu.org","list_email":"qemu-devel@nongnu.org","web_url":"","scm_url":"","webscm_url":""},"msgid":"<20170901105818.31956-5-otubo@redhat.com>","date":"2017-09-01T10:58:16","name":"[PATCHv4,4/6] seccomp: add spawn argument to command line","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"9b3c5194b01c79cc119e8060f426221088bb99f9","submitter":{"id":71779,"url":"http://patchwork.ozlabs.org/api/1.0/people/71779/?format=json","name":"Eduardo Otubo","email":"otubo@redhat.com"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20170901105818.31956-5-otubo@redhat.com/mbox/","series":[{"id":999,"url":"http://patchwork.ozlabs.org/api/1.0/series/999/?format=json","date":"2017-09-01T10:58:12","name":"seccomp: feature refactoring","version":1,"mbox":"http://patchwork.ozlabs.org/series/999/mbox/"}],"check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/808630/checks/","tags":{},"headers":{"Return-Path":"<qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org>","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@bilbo.ozlabs.org","Authentication-Results":["ozlabs.org;\n\tspf=pass (mailfrom) smtp.mailfrom=nongnu.org\n\t(client-ip=2001:4830:134:3::11; helo=lists.gnu.org;\n\tenvelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org;\n\treceiver=<UNKNOWN>)","ext-mx10.extmail.prod.ext.phx2.redhat.com;\n\tdmarc=none (p=none dis=none) header.from=redhat.com","ext-mx10.extmail.prod.ext.phx2.redhat.com;\n\tspf=fail smtp.mailfrom=otubo@redhat.com"],"Received":["from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11])\n\t(using TLSv1 with cipher AES256-SHA (256/256 bits))\n\t(No client certificate requested)\n\tby ozlabs.org (Postfix) with ESMTPS id 3xkGX92hcJz9s7p\n\tfor <incoming@patchwork.ozlabs.org>;\n\tFri,  1 Sep 2017 21:01:45 +1000 (AEST)","from localhost ([::1]:35186 helo=lists.gnu.org)\n\tby lists.gnu.org with esmtp (Exim 4.71) (envelope-from\n\t<qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org>)\n\tid 1dnjhn-0002HG-Cd\n\tfor incoming@patchwork.ozlabs.org; Fri, 01 Sep 2017 07:01:43 -0400","from eggs.gnu.org ([2001:4830:134:3::10]:51346)\n\tby lists.gnu.org with esmtp (Exim 4.71)\n\t(envelope-from <otubo@redhat.com>) id 1dnjfC-0000Lj-8H\n\tfor qemu-devel@nongnu.org; Fri, 01 Sep 2017 06:59:07 -0400","from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)\n\t(envelope-from <otubo@redhat.com>) id 1dnjf2-0001LG-Pk\n\tfor qemu-devel@nongnu.org; Fri, 01 Sep 2017 06:59:02 -0400","from mx1.redhat.com ([209.132.183.28]:56842)\n\tby eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32)\n\t(Exim 4.71) (envelope-from <otubo@redhat.com>) id 1dnjf2-0001KW-Gm\n\tfor qemu-devel@nongnu.org; Fri, 01 Sep 2017 06:58:52 -0400","from smtp.corp.redhat.com\n\t(int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12])\n\t(using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits))\n\t(No client certificate requested)\n\tby mx1.redhat.com (Postfix) with ESMTPS id 6A91961483\n\tfor <qemu-devel@nongnu.org>; Fri,  1 Sep 2017 10:58:51 +0000 (UTC)","from vader.redhat.com (ovpn-117-156.ams2.redhat.com\n\t[10.36.117.156])\n\tby smtp.corp.redhat.com (Postfix) with ESMTP id DAD2D7EBC7;\n\tFri,  1 Sep 2017 10:58:46 +0000 (UTC)"],"DMARC-Filter":"OpenDMARC Filter v1.3.2 mx1.redhat.com 6A91961483","From":"Eduardo Otubo <otubo@redhat.com>","To":"qemu-devel@nongnu.org","Date":"Fri,  1 Sep 2017 12:58:16 +0200","Message-Id":"<20170901105818.31956-5-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\n\t(mx1.redhat.com [10.5.110.39]);\n\tFri, 01 Sep 2017 10:58:51 +0000 (UTC)","X-detected-operating-system":"by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic]\n\t[fuzzy]","X-Received-From":"209.132.183.28","Subject":"[Qemu-devel] [PATCHv4 4/6] seccomp: add spawn argument to command\n\tline","X-BeenThere":"qemu-devel@nongnu.org","X-Mailman-Version":"2.1.21","Precedence":"list","List-Id":"<qemu-devel.nongnu.org>","List-Unsubscribe":"<https://lists.nongnu.org/mailman/options/qemu-devel>,\n\t<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>","List-Archive":"<http://lists.nongnu.org/archive/html/qemu-devel/>","List-Post":"<mailto:qemu-devel@nongnu.org>","List-Help":"<mailto:qemu-devel-request@nongnu.org?subject=help>","List-Subscribe":"<https://lists.nongnu.org/mailman/listinfo/qemu-devel>,\n\t<mailto:qemu-devel-request@nongnu.org?subject=subscribe>","Cc":"thuth@redhat.com","Errors-To":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org","Sender":"\"Qemu-devel\"\n\t<qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org>"},"content":"This patch adds [,spawn=deny] argument to `-sandbox on' option. It\nblacklists fork and execve system calls, avoiding Qemu to spawn new\nthreads or processes.\n\nSigned-off-by: Eduardo Otubo <otubo@redhat.com>\n---\n include/sysemu/seccomp.h |  1 +\n qemu-options.hx          |  9 +++++++--\n qemu-seccomp.c           | 12 ++++++++++++\n vl.c                     | 16 ++++++++++++++++\n 4 files changed, 36 insertions(+), 2 deletions(-)","diff":"diff --git a/include/sysemu/seccomp.h b/include/sysemu/seccomp.h\nindex 4a9e63c7cd..3ab5fc4f61 100644\n--- a/include/sysemu/seccomp.h\n+++ b/include/sysemu/seccomp.h\n@@ -18,6 +18,7 @@\n #define QEMU_SECCOMP_SET_DEFAULT     (1 << 0)\n #define QEMU_SECCOMP_SET_OBSOLETE    (1 << 1)\n #define QEMU_SECCOMP_SET_PRIVILEGED  (1 << 2)\n+#define QEMU_SECCOMP_SET_SPAWN       (1 << 3)\n \n #include <seccomp.h>\n \ndiff --git a/qemu-options.hx b/qemu-options.hx\nindex 5c1b163fb5..2b04b9f170 100644\n--- a/qemu-options.hx\n+++ b/qemu-options.hx\n@@ -4018,6 +4018,7 @@ ETEXI\n \n DEF(\"sandbox\", HAS_ARG, QEMU_OPTION_sandbox, \\\n     \"-sandbox on[,obsolete=allow|deny][,elevateprivileges=allow|deny|children]\\n\" \\\n+    \"          [,spawn=allow|deny]\\n\" \\\n     \"                Enable seccomp mode 2 system call filter (default 'off').\\n\" \\\n     \"                use 'obsolete' to allow obsolete system calls that are provided\\n\" \\\n     \"                    by the kernel, but typically no longer used by modern\\n\" \\\n@@ -4025,10 +4026,12 @@ DEF(\"sandbox\", HAS_ARG, QEMU_OPTION_sandbox, \\\n     \"                use 'elevateprivileges' to allow or deny QEMU process to elevate\\n\" \\\n     \"                    its privileges by blacklisting all set*uid|gid system calls.\\n\" \\\n     \"                    The value 'children' will deny set*uid|gid system calls for\\n\" \\\n-    \"                    main QEMU process but will allow forks and execves to run unprivileged\\n\",\n+    \"                    main QEMU process but will allow forks and execves to run unprivileged\\n\" \\\n+    \"                use 'spawn' to avoid QEMU to spawn new threads or processes by\\n\" \\\n+    \"                     blacklisting *fork and execve\\n\",\n     QEMU_ARCH_ALL)\n STEXI\n-@item -sandbox @var{arg}[,obsolete=@var{string}][,elevateprivileges=@var{string}]\n+@item -sandbox @var{arg}[,obsolete=@var{string}][,elevateprivileges=@var{string}][,spawn=@var{string}]\n @findex -sandbox\n Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will\n disable it.  The default is 'off'.\n@@ -4037,6 +4040,8 @@ disable it.  The default is 'off'.\n Enable Obsolete system calls\n @item elevateprivileges=@var{string}\n Disable set*uid|gid system calls\n+@item spawn=@var{string}\n+Disable *fork and execve\n @end table\n ETEXI\n \ndiff --git a/qemu-seccomp.c b/qemu-seccomp.c\nindex 16c8c20132..51754ace71 100644\n--- a/qemu-seccomp.c\n+++ b/qemu-seccomp.c\n@@ -67,6 +67,10 @@ static const struct QemuSeccompSyscall blacklist[] = {\n     { SCMP_SYS(setresgid),             4, QEMU_SECCOMP_SET_PRIVILEGED },\n     { SCMP_SYS(setfsuid),              4, QEMU_SECCOMP_SET_PRIVILEGED },\n     { SCMP_SYS(setfsgid),              4, QEMU_SECCOMP_SET_PRIVILEGED },\n+    /* spawn */\n+    { SCMP_SYS(fork),                  8, QEMU_SECCOMP_SET_SPAWN },\n+    { SCMP_SYS(vfork),                 8, QEMU_SECCOMP_SET_SPAWN },\n+    { SCMP_SYS(execve),                8, QEMU_SECCOMP_SET_SPAWN },\n };\n \n \n@@ -100,6 +104,14 @@ int seccomp_start(uint32_t seccomp_opts)\n             }\n \n             break;\n+        case QEMU_SECCOMP_SET_SPAWN:\n+            if (seccomp_opts & QEMU_SECCOMP_SET_SPAWN) {\n+                goto add_syscall;\n+            } else {\n+                continue;\n+            }\n+\n+            break;\n         default:\n             goto add_syscall;\n         }\ndiff --git a/vl.c b/vl.c\nindex 1d44b05772..8e6b252f8f 100644\n--- a/vl.c\n+++ b/vl.c\n@@ -280,6 +280,10 @@ static QemuOptsList qemu_sandbox_opts = {\n             .name = \"elevateprivileges\",\n             .type = QEMU_OPT_STRING,\n         },\n+        {\n+            .name = \"spawn\",\n+            .type = QEMU_OPT_STRING,\n+        },\n         { /* end of list */ }\n     },\n };\n@@ -1079,6 +1083,18 @@ static int parse_sandbox(void *opaque, QemuOpts *opts, Error **errp)\n             }\n         }\n \n+        value = qemu_opt_get(opts, \"spawn\");\n+        if (value) {\n+            if (strcmp(value, \"deny\") == 0) {\n+                seccomp_opts |= QEMU_SECCOMP_SET_SPAWN;\n+            } else if (strcmp(value, \"allow\") == 0) {\n+                /* default value */\n+            } else {\n+                error_report(\"invalid argument for spawn\");\n+                return -1;\n+            }\n+        }\n+\n         if (seccomp_start(seccomp_opts) < 0) {\n             error_report(\"failed to install seccomp syscall filter \"\n                          \"in the kernel\");\n","prefixes":["PATCHv4","4/6"]}