[RFC PATCH v9 01/16] security: add ipe lsm
From: Fan Wu
Date: Mon Jan 30 2023 - 17:58:52 EST
From: Deven Bowers <deven.desai@xxxxxxxxxxxxxxxxxxx>
Integrity Policy Enforcement (IPE) is an LSM that provides an
complimentary approach to Mandatory Access Control than existing LSMs
today.
Existing LSMs have centered around the concept of access to a resource
should be controlled by the current user's credentials. IPE's approach,
is that access to a resource should be controlled by the system's trust
of a current resource.
The basis of this approach is defining a global policy to specify which
resource can be trusted.
Signed-off-by: Deven Bowers <deven.desai@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Fan Wu <wufan@xxxxxxxxxxxxxxxxxxx>
---
v2:
+ Split evaluation loop, access control hooks,
and evaluation loop from policy parser and userspace
interface to pass mailing list character limit
v3:
+ Move ipe_load_properties to patch 04.
+ Remove useless 0-initializations
+ Prefix extern variables with ipe_
+ Remove kernel module parameters, as these are
exposed through sysctls.
+ Add more prose to the IPE base config option
help text.
+ Use GFP_KERNEL for audit_log_start.
+ Remove unnecessary caching system.
+ Remove comments from headers
+ Use rcu_access_pointer for rcu-pointer null check
+ Remove usage of reqprot; use prot only.
+ Move policy load and activation audit event to 03/12
v4:
+ Remove sysctls in favor of securityfs nodes
+ Re-add kernel module parameters, as these are now
exposed through securityfs.
+ Refactor property audit loop to a separate function.
v5:
+ fix minor grammatical errors
+ do not group rule by curly-brace in audit record,
reconstruct the exact rule.
v6:
+ No changes
v7:
+ Further split lsm creation into a separate commit from the
evaluation loop and audit system, for easier review.
+ Introduce the concept of an ipe_context, a scoped way to
introduce execution policies, used initially for allowing for
kunit tests in isolation.
v8:
+ Follow lsmname_hook_name convention for lsm hooks.
+ Move LSM blob accessors to ipe.c and mark LSM blobs as static.
v9:
+ Remove ipe_context for simplification
---
MAINTAINERS | 5 +++++
security/Kconfig | 11 ++++++-----
security/Makefile | 1 +
security/ipe/Kconfig | 17 +++++++++++++++++
security/ipe/Makefile | 10 ++++++++++
security/ipe/ipe.c | 40 ++++++++++++++++++++++++++++++++++++++++
security/ipe/ipe.h | 13 +++++++++++++
7 files changed, 92 insertions(+), 5 deletions(-)
create mode 100644 security/ipe/Kconfig
create mode 100644 security/ipe/Makefile
create mode 100644 security/ipe/ipe.c
create mode 100644 security/ipe/ipe.h
diff --git a/MAINTAINERS b/MAINTAINERS
index 8a5c25c20d00..5e27e84763cc 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10273,6 +10273,11 @@ T: git git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity.git
F: security/integrity/ima/
F: security/integrity/
+INTEGRITY POLICY ENFORCEMENT (IPE)
+M: Fan Wu <wufan@xxxxxxxxxxxxxxxxxxx>
+S: Supported
+F: security/ipe/
+
INTEL 810/815 FRAMEBUFFER DRIVER
M: Antonino Daplas <adaplas@xxxxxxxxx>
L: linux-fbdev@xxxxxxxxxxxxxxx
diff --git a/security/Kconfig b/security/Kconfig
index e6db09a779b7..9f59add2d16c 100644
--- a/security/Kconfig
+++ b/security/Kconfig
@@ -207,6 +207,7 @@ source "security/yama/Kconfig"
source "security/safesetid/Kconfig"
source "security/lockdown/Kconfig"
source "security/landlock/Kconfig"
+source "security/ipe/Kconfig"
source "security/integrity/Kconfig"
@@ -246,11 +247,11 @@ endchoice
config LSM
string "Ordered list of enabled LSMs"
- default "landlock,lockdown,yama,loadpin,safesetid,integrity,smack,selinux,tomoyo,apparmor,bpf" if DEFAULT_SECURITY_SMACK
- default "landlock,lockdown,yama,loadpin,safesetid,integrity,apparmor,selinux,smack,tomoyo,bpf" if DEFAULT_SECURITY_APPARMOR
- default "landlock,lockdown,yama,loadpin,safesetid,integrity,tomoyo,bpf" if DEFAULT_SECURITY_TOMOYO
- default "landlock,lockdown,yama,loadpin,safesetid,integrity,bpf" if DEFAULT_SECURITY_DAC
- default "landlock,lockdown,yama,loadpin,safesetid,integrity,selinux,smack,tomoyo,apparmor,bpf"
+ default "landlock,lockdown,yama,loadpin,safesetid,integrity,ipe,smack,selinux,tomoyo,apparmor,bpf" if DEFAULT_SECURITY_SMACK
+ default "landlock,lockdown,yama,loadpin,safesetid,integrity,ipe,apparmor,selinux,smack,tomoyo,bpf" if DEFAULT_SECURITY_APPARMOR
+ default "landlock,lockdown,yama,loadpin,safesetid,integrity,ipe,tomoyo,bpf" if DEFAULT_SECURITY_TOMOYO
+ default "landlock,lockdown,yama,loadpin,safesetid,integrity,ipe,bpf" if DEFAULT_SECURITY_DAC
+ default "landlock,lockdown,yama,loadpin,safesetid,integrity,ipe,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 18121f8f85cd..527b1864d96c 100644
--- a/security/Makefile
+++ b/security/Makefile
@@ -24,6 +24,7 @@ obj-$(CONFIG_SECURITY_LOCKDOWN_LSM) += lockdown/
obj-$(CONFIG_CGROUPS) += device_cgroup.o
obj-$(CONFIG_BPF_LSM) += bpf/
obj-$(CONFIG_SECURITY_LANDLOCK) += landlock/
+obj-$(CONFIG_SECURITY_IPE) += ipe/
# Object integrity file lists
obj-$(CONFIG_INTEGRITY) += integrity/
diff --git a/security/ipe/Kconfig b/security/ipe/Kconfig
new file mode 100644
index 000000000000..e4875fb04883
--- /dev/null
+++ b/security/ipe/Kconfig
@@ -0,0 +1,17 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Integrity Policy Enforcement (IPE) configuration
+#
+
+menuconfig SECURITY_IPE
+ bool "Integrity Policy Enforcement (IPE)"
+ depends on SECURITY && SECURITYFS
+ select PKCS7_MESSAGE_PARSER
+ select SYSTEM_DATA_VERIFICATION
+ help
+ This option enables the Integrity Policy Enforcement LSM
+ allowing users to define a policy to enforce a trust-based access
+ control. A key feature of IPE is a customizable policy to allow
+ admins to reconfigure trust requirements on the fly.
+
+ If unsure, answer N.
diff --git a/security/ipe/Makefile b/security/ipe/Makefile
new file mode 100644
index 000000000000..571648579991
--- /dev/null
+++ b/security/ipe/Makefile
@@ -0,0 +1,10 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (C) Microsoft Corporation. All rights reserved.
+#
+# Makefile for building the IPE module as part of the kernel tree.
+#
+
+obj-$(CONFIG_SECURITY_IPE) += \
+ hooks.o \
+ ipe.o \
diff --git a/security/ipe/ipe.c b/security/ipe/ipe.c
new file mode 100644
index 000000000000..9ed3bf4dcc04
--- /dev/null
+++ b/security/ipe/ipe.c
@@ -0,0 +1,40 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) Microsoft Corporation. All rights reserved.
+ */
+
+#include "ipe.h"
+
+static struct lsm_blob_sizes ipe_blobs __lsm_ro_after_init = {
+};
+
+static struct security_hook_list ipe_hooks[] __lsm_ro_after_init = {
+};
+
+/**
+ * ipe_init - Entry point of IPE.
+ *
+ * This is called at LSM init, which happens occurs early during kernel
+ * start up. During this phase, IPE loads the properties compiled into
+ * the kernel, and register's IPE's hooks. The boot policy is loaded
+ * later, during securityfs init, at which point IPE will start
+ * enforcing its policy.
+ *
+ * Return:
+ * * 0 - OK
+ * * -ENOMEM - Context creation failed.
+ */
+static int __init ipe_init(void)
+{
+ int rc = 0;
+
+ security_add_hooks(ipe_hooks, ARRAY_SIZE(ipe_hooks), "ipe");
+
+ return rc;
+}
+
+DEFINE_LSM(ipe) = {
+ .name = "ipe",
+ .init = ipe_init,
+ .blobs = &ipe_blobs,
+};
diff --git a/security/ipe/ipe.h b/security/ipe/ipe.h
new file mode 100644
index 000000000000..ee7ec3f3b55d
--- /dev/null
+++ b/security/ipe/ipe.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) Microsoft Corporation. All rights reserved.
+ */
+
+#ifndef IPE_H
+#define IPE_H
+
+#define pr_fmt(fmt) "IPE " fmt "\n"
+
+#include <linux/lsm_hooks.h>
+
+#endif /* IPE_H */
--
2.39.0