From patchwork Tue Mar 14 11:32:06 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eduardo Otubo X-Patchwork-Id: 9623067 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 2464D60522 for ; Tue, 14 Mar 2017 11:32:38 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1951828517 for ; Tue, 14 Mar 2017 11:32:38 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0DFC428534; Tue, 14 Mar 2017 11:32:38 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 1F1B628531 for ; Tue, 14 Mar 2017 11:32:37 +0000 (UTC) Received: from localhost ([::1]:57864 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cnkgu-0000iw-2q for patchwork-qemu-devel@patchwork.kernel.org; Tue, 14 Mar 2017 07:32:36 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52941) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cnkgZ-0000i3-8C for qemu-devel@nongnu.org; Tue, 14 Mar 2017 07:32:16 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cnkgX-00084A-QM for qemu-devel@nongnu.org; Tue, 14 Mar 2017 07:32:15 -0400 Received: from mail-wm0-x232.google.com ([2a00:1450:400c:c09::232]:35058) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1cnkgX-00083M-GM for qemu-devel@nongnu.org; Tue, 14 Mar 2017 07:32:13 -0400 Received: by mail-wm0-x232.google.com with SMTP id v186so61502170wmd.0 for ; Tue, 14 Mar 2017 04:32:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=profitbricks-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=L7hUzYQ2hTa72j92Urq3Exs0E+GxWHj60fa1q29TXus=; b=T+IP5BF5vnWOmt7DiXpnlJZhT25NWRcJ0ZvfsuAysloafV+dTIk94WM+uiHM68qJpD OKb3ho0XOmK24w4dwWGtSjDShoGdUxhSJqmGYE8xviUlAuNFdLGJqMU3Hj/M0vAzUUv/ AN3sRtRkGBXo98M9gWZRt1Y/0GsGcG+ri9TpILjHrXCHwwRSILSb/5K/25++ZqF3L+5D 6/8M3nOv1bX30rJf47rZH+G+Be9Dn/mCVQGm8yqYOpfXlcV88o7xOl84ngWAeq/1ccwV lkvMwEnCEJMF7aijWR8fNiPoZ86twDxJklAZG+fg9U/74N9ThUqfmOjgxWZQ+fGbmq0J HBQA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=L7hUzYQ2hTa72j92Urq3Exs0E+GxWHj60fa1q29TXus=; b=hlMvDYZFSVGhKQvACgUYQyVWgklYSCK5DQJA20sZBlgpEblGZ/2kBxaIwkG0Vomih3 sbl4q+fdOWPs1KcECA+HFmK3dsHN3Gfq41bp8TsWsSGghI99GkpuzNsbfr0Rm2YWQit9 y08tNMVIAeiV+h5MiWsnOaJzLdtw9cFoESGGNWNbAXqJXv1K4uTm+EhdnMTAtFPoRxdu dwOEDjZ3nhsVPzzN2jQoC4kGYx4jxBy8Xfv8yz7pdv//enVzKvHw2fo/8G92FXadRg4U lQNio4cgqyd9MF7ZzoRLuKyNbH3hXrnLxxBEX2KtitR5ZoruPI4JyL7+zOw6+yTXFmt3 P5Mw== X-Gm-Message-State: AFeK/H1FxCULiW7dvi5Xev27+dOkMeqyvjVffZtKmPlq93QeeMsciNfLWmdIPXiwvyaQrDEV X-Received: by 10.28.146.12 with SMTP id u12mr14297380wmd.113.1489491132152; Tue, 14 Mar 2017 04:32:12 -0700 (PDT) Received: from vader.pb.local ([62.217.45.26]) by smtp.gmail.com with ESMTPSA id n59sm28846267wrb.54.2017.03.14.04.32.11 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 14 Mar 2017 04:32:11 -0700 (PDT) From: Eduardo Otubo To: qemu-devel@nongnu.org Date: Tue, 14 Mar 2017 12:32:06 +0100 Message-Id: <20170314113209.12025-3-eduardo.otubo@profitbricks.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170314113209.12025-1-eduardo.otubo@profitbricks.com> References: <20170314113209.12025-1-eduardo.otubo@profitbricks.com> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 2a00:1450:400c:c09::232 Subject: [Qemu-devel] [PATCH 2/5] 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+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP This patch introduces the argument [,obsolete=allow] 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 | 4 +++- qemu-options.hx | 9 +++++++-- qemu-seccomp.c | 47 ++++++++++++++++++++++++++++++++++++++++++++++- vl.c | 16 +++++++++++++++- 4 files changed, 71 insertions(+), 5 deletions(-) diff --git a/include/sysemu/seccomp.h b/include/sysemu/seccomp.h index cfc06008cb..7a7bde246b 100644 --- a/include/sysemu/seccomp.h +++ b/include/sysemu/seccomp.h @@ -15,7 +15,9 @@ #ifndef QEMU_SECCOMP_H #define QEMU_SECCOMP_H +#define OBSOLETE 0x0001 + #include -int seccomp_start(void); +int seccomp_start(uint8_t seccomp_opts); #endif diff --git a/qemu-options.hx b/qemu-options.hx index 8dd8ee34a6..1403d0c85f 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -3732,13 +3732,18 @@ Old param mode (ARM only). ETEXI DEF("sandbox", HAS_ARG, QEMU_OPTION_sandbox, \ - "-sandbox Enable seccomp mode 2 system call filter (default 'off').\n", + "-sandbox on[,obsolete=allow] Enable seccomp mode 2 system call filter (default 'off').\n" \ + " obsolete: Allow obsolete system calls", QEMU_ARCH_ALL) STEXI -@item -sandbox @var{arg} +@item -sandbox @var{arg}[,obsolete=@var{string}] @findex -sandbox Enable Seccomp mode 2 system call filter. 'on' will enable syscall filtering and 'off' will disable it. The default is 'off'. +@table @option +@item obsolete=@var{string} +Enable Obsolete system calls +@end table ETEXI DEF("readconfig", HAS_ARG, QEMU_OPTION_readconfig, diff --git a/qemu-seccomp.c b/qemu-seccomp.c index f8877b07b5..5ef36890da 100644 --- a/qemu-seccomp.c +++ b/qemu-seccomp.c @@ -31,6 +31,35 @@ struct QemuSeccompSyscall { uint8_t priority; }; +static const struct QemuSeccompSyscall obsolete[] = { + { SCMP_SYS(readdir), 255 }, + { SCMP_SYS(_sysctl), 255 }, + { SCMP_SYS(afs_syscall), 255 }, + { SCMP_SYS(bdflush), 255 }, + { SCMP_SYS(break), 255 }, + { SCMP_SYS(create_module), 255 }, + { SCMP_SYS(ftime), 255 }, + { SCMP_SYS(get_kernel_syms), 255 }, + { SCMP_SYS(getpmsg), 255 }, + { SCMP_SYS(gtty), 255 }, + { SCMP_SYS(lock), 255 }, + { SCMP_SYS(mpx), 255 }, + { SCMP_SYS(prof), 255 }, + { SCMP_SYS(profil), 255 }, + { SCMP_SYS(putpmsg), 255 }, + { SCMP_SYS(query_module), 255 }, + { SCMP_SYS(security), 255 }, + { SCMP_SYS(sgetmask), 255 }, + { SCMP_SYS(ssetmask), 255 }, + { SCMP_SYS(stty), 255 }, + { SCMP_SYS(sysfs), 255 }, + { SCMP_SYS(tuxcall), 255 }, + { SCMP_SYS(ulimit), 255 }, + { SCMP_SYS(uselib), 255 }, + { SCMP_SYS(ustat), 255 }, + { SCMP_SYS(vserver), 255 }, +}; + static const struct QemuSeccompSyscall blacklist[] = { { SCMP_SYS(reboot), 255 }, { SCMP_SYS(swapon), 255 }, @@ -56,7 +85,20 @@ static const struct QemuSeccompSyscall blacklist[] = { { SCMP_SYS(vserver), 255 }, }; -int seccomp_start(void) +static int is_obsolete(int syscall) +{ + unsigned int i = 0; + + for (i = 0; i < ARRAY_SIZE(obsolete); i++) { + if (syscall == obsolete[i].num) { + return 1; + } + } + + return 0; +} + +int seccomp_start(uint8_t seccomp_opts) { int rc = 0; unsigned int i = 0; @@ -69,6 +111,9 @@ int seccomp_start(void) } for (i = 0; i < ARRAY_SIZE(blacklist); i++) { + if ((seccomp_opts & OBSOLETE) && is_obsolete(blacklist[i].num)) { + continue; + } rc = seccomp_rule_add(ctx, SCMP_ACT_KILL, blacklist[i].num, 0); if (rc < 0) { goto seccomp_return; diff --git a/vl.c b/vl.c index 1a95500ac7..7b08b3383b 100644 --- a/vl.c +++ b/vl.c @@ -269,6 +269,10 @@ static QemuOptsList qemu_sandbox_opts = { .name = "enable", .type = QEMU_OPT_BOOL, }, + { + .name = "obsolete", + .type = QEMU_OPT_STRING, + }, { /* end of list */ } }, }; @@ -1031,7 +1035,17 @@ static int parse_sandbox(void *opaque, QemuOpts *opts, Error **errp) /* FIXME: change this to true for 1.3 */ if (qemu_opt_get_bool(opts, "enable", false)) { #ifdef CONFIG_SECCOMP - if (seccomp_start() < 0) { + uint8_t seccomp_opts = 0x0000; + const char * value = NULL; + + value = qemu_opt_get(opts,"obsolete"); + if (value) { + if (strcmp(value, "allow") == 0) { + seccomp_opts |= OBSOLETE; + } + } + + if (seccomp_start(seccomp_opts) < 0) { error_report("failed to install seccomp syscall filter " "in the kernel"); return -1;