From patchwork Thu Jan 23 15:24:32 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: KP Singh X-Patchwork-Id: 11348421 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0C0BA1580 for ; Thu, 23 Jan 2020 15:25:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CAAC624125 for ; Thu, 23 Jan 2020 15:25:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="PhO4IWnS" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729143AbgAWPZN (ORCPT ); Thu, 23 Jan 2020 10:25:13 -0500 Received: from mail-pf1-f195.google.com ([209.85.210.195]:34413 "EHLO mail-pf1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729107AbgAWPZM (ORCPT ); Thu, 23 Jan 2020 10:25:12 -0500 Received: by mail-pf1-f195.google.com with SMTP id i6so1702735pfc.1 for ; Thu, 23 Jan 2020 07:25:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=P5LBJaFDLztjq1pA7rdewN/YeJDD/aqWt25XqpUQugg=; b=PhO4IWnS7UTGNIhjsCNuAQ+vXoBbxnfY+FxDg5skR81zbdnTTrSt0u+XLNYUy6JfR5 u1Z1SX8nflhnoYrAkWD7dAa2ImWhYnfxdG9acvMYHRvDCPlRxXwY8JCdfIk6kzayhhyS 6iCh4YUlv9F5YJ1hWAhw23Z8ixI8P88gcoLUk= 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:mime-version:content-transfer-encoding; bh=P5LBJaFDLztjq1pA7rdewN/YeJDD/aqWt25XqpUQugg=; b=azoeixFXLm/YgOM3C39tBxRAjCiVmeL0IleWZJ1AlEEae6WgBUjaBNnwUTFanErHnw Exbv3Ge1EQhv/TauoE2wtnH5oipBgeiqeLL+0zhUKxxnZ28ApYutMhNv5FE9q7zxQ3QR ZoGKLAfS604Bk6hLaFh3m3slF2n6PB3BjaeOoN2mp42K2H51MLLhUM4Y7q1J5aTJ2gFx zu1Uq+WGsbUkTsmLIMrZVOm5aMnR4WNy+Ji0nXBTMxhT+OLdrG7pwPCLGGv3X2PnvZFt 6rYbxDZN6yQSmDVZTujT1FrFQdrbBvRs41Ek/C5Tju4h1g233TSf9fu4GDLhqxxFNCHV Nb3A== X-Gm-Message-State: APjAAAVpf70Q4nEvXDves6cYbWKuvJ0Obva4bYsS7JHCsB/+Ke+51wJy NHycw5d8urNnuRH4NTGdY3+3tA== X-Google-Smtp-Source: APXvYqw0QVN0qvLEwTUy1TPANc2VCcjPVms57fAzqOQQLRM+xZ3uizYZNqMjSjC+H4QVb9gquyo5ZA== X-Received: by 2002:a62:6805:: with SMTP id d5mr7923883pfc.125.1579793111792; Thu, 23 Jan 2020 07:25:11 -0800 (PST) Received: from kpsingh-kernel.localdomain ([2a00:79e1:abc:122:bd8d:3f7b:87f7:16d1]) by smtp.gmail.com with ESMTPSA id v5sm3108118pfn.122.2020.01.23.07.25.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 23 Jan 2020 07:25:11 -0800 (PST) From: KP Singh To: linux-kernel@vger.kernel.org, bpf@vger.kernel.org, linux-security-module@vger.kernel.org Cc: Brendan Jackman , Florent Revest , Thomas Garnier , Alexei Starovoitov , Daniel Borkmann , James Morris , Kees Cook , Thomas Garnier , Michael Halcrow , Paul Turner , Brendan Gregg , Jann Horn , Matthew Garrett , Christian Brauner , =?utf-8?q?Micka=C3=ABl_Sala=C3=BCn?= , Florent Revest , Brendan Jackman , Martin KaFai Lau , Song Liu , Yonghong Song , "Serge E. Hallyn" , Mauro Carvalho Chehab , "David S. Miller" , Greg Kroah-Hartman , Nicolas Ferre , Stanislav Fomichev , Quentin Monnet , Andrey Ignatov , Joe Stringer Subject: [PATCH bpf-next v3 02/10] bpf: lsm: Add a skeleton and config options Date: Thu, 23 Jan 2020 07:24:32 -0800 Message-Id: <20200123152440.28956-3-kpsingh@chromium.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200123152440.28956-1-kpsingh@chromium.org> References: <20200123152440.28956-1-kpsingh@chromium.org> MIME-Version: 1.0 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: From: KP Singh The LSM can be enabled by CONFIG_SECURITY_BPF. Without CONFIG_SECURITY_BPF_ENFORCE, the LSM will run the attached eBPF programs but not enforce MAC policy based on the return value of the attached programs. The BPF LSM has two kinds of hooks: - Statically defined hooks defined at init with __lsm_ro_after_init which are attached to the security_hook_heads defined in security/security.c similar to other LSMs. - Mutable hooks that are attached to a separate security_hook_heads maintained by the BPF LSM (introduced in a subsequent patch). The mutable hooks are always executed after all the static hooks (irrespective of the position of "bpf" in the list of LSMs). Therefore, the newly introduced LSM_ORDER_LAST represents the behaviour of this LSM correctly Signed-off-by: KP Singh Reviewed-by: Brendan Jackman Reviewed-by: Florent Revest Reviewed-by: Thomas Garnier --- MAINTAINERS | 7 +++++++ include/linux/lsm_hooks.h | 1 + security/Kconfig | 11 ++++++----- security/Makefile | 2 ++ security/bpf/Kconfig | 22 ++++++++++++++++++++++ security/bpf/Makefile | 5 +++++ security/bpf/lsm.c | 26 ++++++++++++++++++++++++++ security/security.c | 5 +++++ 8 files changed, 74 insertions(+), 5 deletions(-) create mode 100644 security/bpf/Kconfig create mode 100644 security/bpf/Makefile create mode 100644 security/bpf/lsm.c diff --git a/MAINTAINERS b/MAINTAINERS index 702382b89c37..e2b7f76a1a70 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -3203,6 +3203,13 @@ S: Supported F: arch/x86/net/ X: arch/x86/net/bpf_jit_comp32.c +BPF SECURITY MODULE +M: KP Singh +L: linux-security-module@vger.kernel.org +L: bpf@vger.kernel.org +S: Maintained +F: security/bpf/ + BROADCOM B44 10/100 ETHERNET DRIVER M: Michael Chan L: netdev@vger.kernel.org diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index 20d8cf194fb7..5f744fcb2275 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -2121,6 +2121,7 @@ extern void security_add_hooks(struct security_hook_list *hooks, int count, enum lsm_order { LSM_ORDER_FIRST = -1, /* This is only for capabilities. */ LSM_ORDER_MUTABLE = 0, + LSM_ORDER_LAST = 1, }; struct lsm_info { diff --git a/security/Kconfig b/security/Kconfig index 2a1a2d396228..6f1aab195e7d 100644 --- a/security/Kconfig +++ b/security/Kconfig @@ -236,6 +236,7 @@ source "security/tomoyo/Kconfig" source "security/apparmor/Kconfig" source "security/loadpin/Kconfig" source "security/yama/Kconfig" +source "security/bpf/Kconfig" source "security/safesetid/Kconfig" source "security/lockdown/Kconfig" @@ -277,11 +278,11 @@ endchoice config LSM string "Ordered list of enabled LSMs" - default "lockdown,yama,loadpin,safesetid,integrity,smack,selinux,tomoyo,apparmor" if DEFAULT_SECURITY_SMACK - default "lockdown,yama,loadpin,safesetid,integrity,apparmor,selinux,smack,tomoyo" if DEFAULT_SECURITY_APPARMOR - default "lockdown,yama,loadpin,safesetid,integrity,tomoyo" if DEFAULT_SECURITY_TOMOYO - default "lockdown,yama,loadpin,safesetid,integrity" if DEFAULT_SECURITY_DAC - default "lockdown,yama,loadpin,safesetid,integrity,selinux,smack,tomoyo,apparmor" + default "lockdown,yama,loadpin,safesetid,integrity,smack,selinux,tomoyo,apparmor,bpf" if DEFAULT_SECURITY_SMACK + default "lockdown,yama,loadpin,safesetid,integrity,apparmor,selinux,smack,tomoyo,bpf" if DEFAULT_SECURITY_APPARMOR + default "lockdown,yama,loadpin,safesetid,integrity,tomoyo,bpf" if DEFAULT_SECURITY_TOMOYO + default "lockdown,yama,loadpin,safesetid,integrity,bpf" if DEFAULT_SECURITY_DAC + default "lockdown,yama,loadpin,safesetid,integrity,selinux,smack,tomoyo,apparmor,bpf" help A comma-separated list of LSMs, in initialization order. Any LSMs left off this list will be ignored. This can be diff --git a/security/Makefile b/security/Makefile index be1dd9d2cb2f..50e6821dd7b7 100644 --- a/security/Makefile +++ b/security/Makefile @@ -12,6 +12,7 @@ subdir-$(CONFIG_SECURITY_YAMA) += yama subdir-$(CONFIG_SECURITY_LOADPIN) += loadpin subdir-$(CONFIG_SECURITY_SAFESETID) += safesetid subdir-$(CONFIG_SECURITY_LOCKDOWN_LSM) += lockdown +subdir-$(CONFIG_SECURITY_BPF) += bpf # always enable default capabilities obj-y += commoncap.o @@ -29,6 +30,7 @@ obj-$(CONFIG_SECURITY_YAMA) += yama/ obj-$(CONFIG_SECURITY_LOADPIN) += loadpin/ obj-$(CONFIG_SECURITY_SAFESETID) += safesetid/ obj-$(CONFIG_SECURITY_LOCKDOWN_LSM) += lockdown/ +obj-$(CONFIG_SECURITY_BPF) += bpf/ obj-$(CONFIG_CGROUP_DEVICE) += device_cgroup.o # Object integrity file lists diff --git a/security/bpf/Kconfig b/security/bpf/Kconfig new file mode 100644 index 000000000000..a5f6c67ae526 --- /dev/null +++ b/security/bpf/Kconfig @@ -0,0 +1,22 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Copyright 2019 Google LLC. + +config SECURITY_BPF + bool "BPF-based MAC and audit policy" + depends on SECURITY + depends on BPF_SYSCALL + help + This enables instrumentation of the security hooks with + eBPF programs. + + If you are unsure how to answer this question, answer N. + +config SECURITY_BPF_ENFORCE + bool "Deny operations based on the evaluation of the attached programs" + depends on SECURITY_BPF + help + eBPF programs attached to hooks can be used for both auditing and + enforcement. Enabling enforcement implies that the evaluation result + from the attached eBPF programs will allow or deny the operation + guarded by the security hook. diff --git a/security/bpf/Makefile b/security/bpf/Makefile new file mode 100644 index 000000000000..26a0ab6f99b7 --- /dev/null +++ b/security/bpf/Makefile @@ -0,0 +1,5 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Copyright 2019 Google LLC. + +obj-$(CONFIG_SECURITY_BPF) := lsm.o diff --git a/security/bpf/lsm.c b/security/bpf/lsm.c new file mode 100644 index 000000000000..dc9ac03c7aa0 --- /dev/null +++ b/security/bpf/lsm.c @@ -0,0 +1,26 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * Copyright 2019 Google LLC. + */ + +#include + +/* This is only for internal hooks, always statically shipped as part of the + * BPF LSM. Statically defined hooks are appended to the security_hook_heads + * which is common for LSMs and R/O after init. + */ +static struct security_hook_list bpf_lsm_hooks[] __lsm_ro_after_init = {}; + +static int __init bpf_lsm_init(void) +{ + security_add_hooks(bpf_lsm_hooks, ARRAY_SIZE(bpf_lsm_hooks), "bpf"); + pr_info("LSM support for eBPF active\n"); + return 0; +} + +DEFINE_LSM(bpf) = { + .name = "bpf", + .init = bpf_lsm_init, + .order = LSM_ORDER_LAST, +}; diff --git a/security/security.c b/security/security.c index cd2d18d2d279..30a8aa700557 100644 --- a/security/security.c +++ b/security/security.c @@ -264,6 +264,11 @@ static void __init ordered_lsm_parse(const char *order, const char *origin) } } + for (lsm = __start_lsm_info; lsm < __end_lsm_info; lsm++) { + if (lsm->order == LSM_ORDER_LAST) + append_ordered_lsm(lsm, "last"); + } + /* Disable all LSMs not in the ordered list. */ for (lsm = __start_lsm_info; lsm < __end_lsm_info; lsm++) { if (exists_ordered_lsm(lsm))