diff mbox series

[RFC,v9,01/16] security: add ipe lsm

Message ID 1675119451-23180-2-git-send-email-wufan@linux.microsoft.com
State New
Headers
Series Integrity Policy Enforcement LSM (IPE) |

Commit Message

Fan Wu Jan. 30, 2023, 10:57 p.m. UTC 
  From: Deven Bowers <deven.desai@linux.microsoft.com>

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@linux.microsoft.com>
Signed-off-by: Fan Wu <wufan@linux.microsoft.com>
---
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

Comments

Paul Moore March 2, 2023, 7 p.m. UTC | #1 
On Mon, Jan 30, 2023 at 5:58 PM Fan Wu <wufan@linux.microsoft.com> wrote:
>
> From: Deven Bowers <deven.desai@linux.microsoft.com>
>
> 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@linux.microsoft.com>
> Signed-off-by: Fan Wu <wufan@linux.microsoft.com>

...

> ---
>  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@linux.microsoft.com>
> +S:     Supported
> +F:     security/ipe/

You should probably add a mailing list (L:) and source tree URL (T:)
to the IPE entry.  You can use the LSM mailing list to start if you
like, there are several LSMs that do that today, e.g. Smack, Landlock,
etc.  As far as the source tree is concerned, probably the easiest
option is a simple GitHub repo, but there are plenty of other choices
too.

Both the mailing list and the source URLs can always be updated in the
future so don't worry too much about being stuck with either long
term.

--
paul-moore.com
Fan Wu April 6, 2023, 7:20 p.m. UTC | #2 
On Thu, Mar 02, 2023 at 02:00:48PM -0500, Paul Moore wrote:
> On Mon, Jan 30, 2023 at 5:58???PM Fan Wu <wufan@linux.microsoft.com> wrote:
> > 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@linux.microsoft.com>
> > +S:     Supported
> > +F:     security/ipe/
> 
> You should probably add a mailing list (L:) and source tree URL (T:)
> to the IPE entry.  You can use the LSM mailing list to start if you
> like, there are several LSMs that do that today, e.g. Smack, Landlock,
> etc.  As far as the source tree is concerned, probably the easiest
> option is a simple GitHub repo, but there are plenty of other choices
> too.
> 
> Both the mailing list and the source URLs can always be updated in the
> future so don't worry too much about being stuck with either long
> term.
> 
> --
> paul-moore.com

We do have a github repo, I will add that link in the next version.

-Fan
diff mbox series

Patch

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@linux.microsoft.com>
+S:	Supported
+F:	security/ipe/
+
 INTEL 810/815 FRAMEBUFFER DRIVER
 M:	Antonino Daplas <adaplas@gmail.com>
 L:	linux-fbdev@vger.kernel.org
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 */