diff mbox series

[RFC,v10,01/17] security: add ipe lsm

Message ID 1687986571-16823-2-git-send-email-wufan@linux.microsoft.com (mailing list archive)
State Not Applicable
Headers show
Series Integrity Policy Enforcement LSM (IPE) | expand

Commit Message

Fan Wu June 28, 2023, 9:09 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

v10:
  + Add github url
---
 MAINTAINERS           |  7 +++++++
 security/Kconfig      | 11 ++++++-----
 security/Makefile     |  1 +
 security/ipe/Kconfig  | 17 +++++++++++++++++
 security/ipe/Makefile | 10 ++++++++++
 security/ipe/ipe.c    | 37 +++++++++++++++++++++++++++++++++++++
 security/ipe/ipe.h    | 16 ++++++++++++++++
 7 files changed, 94 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 July 8, 2023, 5:36 a.m. UTC | #1 
On Jun 28, 2023 Fan Wu <wufan@linux.microsoft.com> wrote:
> 
> 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           |  7 +++++++
>  security/Kconfig      | 11 ++++++-----
>  security/Makefile     |  1 +
>  security/ipe/Kconfig  | 17 +++++++++++++++++
>  security/ipe/Makefile | 10 ++++++++++
>  security/ipe/ipe.c    | 37 +++++++++++++++++++++++++++++++++++++
>  security/ipe/ipe.h    | 16 ++++++++++++++++
>  7 files changed, 94 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 a82795114ad4..ad00887d38ea 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -10278,6 +10278,13 @@ T:	git git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity.git
>  F:	security/integrity/
>  F:	security/integrity/ima/
>  
> +INTEGRITY POLICY ENFORCEMENT (IPE)
> +M:	Fan Wu <wufan@linux.microsoft.com>
> +L:	linux-security-module@vger.kernel.org
> +S:	Supported
> +T:	git git://github.com/microsoft/ipe.git

Using the raw git protocol doesn't seem to work with GH, I think you
need to refernce the git/https URL:

 https://github.com/microsoft/ipe.git

> +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 97abeb9b9a19..daa4626ea99c 100644
> --- a/security/Kconfig
> +++ b/security/Kconfig
> @@ -202,6 +202,7 @@ source "security/yama/Kconfig"
>  source "security/safesetid/Kconfig"
>  source "security/lockdown/Kconfig"
>  source "security/landlock/Kconfig"
> +source "security/ipe/Kconfig"
>  
>  source "security/integrity/Kconfig"
>  
> @@ -241,11 +242,11 @@ endchoice
>  
>  config LSM
>  	string "Ordered list of enabled LSMs"
> -	default "landlock,lockdown,yama,loadpin,safesetid,smack,selinux,tomoyo,apparmor,bpf" if DEFAULT_SECURITY_SMACK
> -	default "landlock,lockdown,yama,loadpin,safesetid,apparmor,selinux,smack,tomoyo,bpf" if DEFAULT_SECURITY_APPARMOR
> -	default "landlock,lockdown,yama,loadpin,safesetid,tomoyo,bpf" if DEFAULT_SECURITY_TOMOYO
> -	default "landlock,lockdown,yama,loadpin,safesetid,bpf" if DEFAULT_SECURITY_DAC
> -	default "landlock,lockdown,yama,loadpin,safesetid,selinux,smack,tomoyo,apparmor,bpf"
> +	default "landlock,lockdown,yama,loadpin,safesetid,smack,selinux,tomoyo,apparmor,bpf,ipe" if DEFAULT_SECURITY_SMACK
> +	default "landlock,lockdown,yama,loadpin,safesetid,apparmor,selinux,smack,tomoyo,bpf,ipe" if DEFAULT_SECURITY_APPARMOR
> +	default "landlock,lockdown,yama,loadpin,safesetid,tomoyo,bpf,ipe" if DEFAULT_SECURITY_TOMOYO
> +	default "landlock,lockdown,yama,loadpin,safesetid,bpf,ipe" if DEFAULT_SECURITY_DAC
> +	default "landlock,lockdown,yama,loadpin,safesetid,selinux,smack,tomoyo,apparmor,bpf,ipe"

Generally speaking the BPF LSM should be the last entry in the LSM
list to help prevent issues caused by a BPF LSM returning an improper
error and shortcutting a LSM after it.

>  	help
>  	  A comma-separated list of LSMs, in initialization order.
>  	  Any LSMs left off this list, except for those with order

...

> 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 \

It doesn't look like security/ipe/hook.c is included in this patch.

It is important to ensure that each patch compiles after it is
applied.

--
paul-moore.com
Fan Wu July 13, 2023, 11:31 p.m. UTC | #2 
On Sat, Jul 08, 2023 at 12:22:59AM -0400, Paul Moore wrote:
> On Jun 28, 2023 Fan Wu <wufan@linux.microsoft.com> wrote:
> > 
> > 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           |  7 +++++++
> >  security/Kconfig      | 11 ++++++-----
> >  security/Makefile     |  1 +
> >  security/ipe/Kconfig  | 17 +++++++++++++++++
> >  security/ipe/Makefile | 10 ++++++++++
> >  security/ipe/ipe.c    | 37 +++++++++++++++++++++++++++++++++++++
> >  security/ipe/ipe.h    | 16 ++++++++++++++++
> >  7 files changed, 94 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 a82795114ad4..ad00887d38ea 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -10278,6 +10278,13 @@ T:	git git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity.git
> >  F:	security/integrity/
> >  F:	security/integrity/ima/
> >  
> > +INTEGRITY POLICY ENFORCEMENT (IPE)
> > +M:	Fan Wu <wufan@linux.microsoft.com>
> > +L:	linux-security-module@vger.kernel.org
> > +S:	Supported
> > +T:	git git://github.com/microsoft/ipe.git
> 
> Using the raw git protocol doesn't seem to work with GH, I think you
> need to refernce the git/https URL:
> 
>  https://github.com/microsoft/ipe.git
> 
Sure I can change it.

> > +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 97abeb9b9a19..daa4626ea99c 100644
> > --- a/security/Kconfig
> > +++ b/security/Kconfig
> > @@ -202,6 +202,7 @@ source "security/yama/Kconfig"
> >  source "security/safesetid/Kconfig"
> >  source "security/lockdown/Kconfig"
> >  source "security/landlock/Kconfig"
> > +source "security/ipe/Kconfig"
> >  
> >  source "security/integrity/Kconfig"
> >  
> > @@ -241,11 +242,11 @@ endchoice
> >  
> >  config LSM
> >  	string "Ordered list of enabled LSMs"
> > -	default "landlock,lockdown,yama,loadpin,safesetid,smack,selinux,tomoyo,apparmor,bpf" if DEFAULT_SECURITY_SMACK
> > -	default "landlock,lockdown,yama,loadpin,safesetid,apparmor,selinux,smack,tomoyo,bpf" if DEFAULT_SECURITY_APPARMOR
> > -	default "landlock,lockdown,yama,loadpin,safesetid,tomoyo,bpf" if DEFAULT_SECURITY_TOMOYO
> > -	default "landlock,lockdown,yama,loadpin,safesetid,bpf" if DEFAULT_SECURITY_DAC
> > -	default "landlock,lockdown,yama,loadpin,safesetid,selinux,smack,tomoyo,apparmor,bpf"
> > +	default "landlock,lockdown,yama,loadpin,safesetid,smack,selinux,tomoyo,apparmor,bpf,ipe" if DEFAULT_SECURITY_SMACK
> > +	default "landlock,lockdown,yama,loadpin,safesetid,apparmor,selinux,smack,tomoyo,bpf,ipe" if DEFAULT_SECURITY_APPARMOR
> > +	default "landlock,lockdown,yama,loadpin,safesetid,tomoyo,bpf,ipe" if DEFAULT_SECURITY_TOMOYO
> > +	default "landlock,lockdown,yama,loadpin,safesetid,bpf,ipe" if DEFAULT_SECURITY_DAC
> > +	default "landlock,lockdown,yama,loadpin,safesetid,selinux,smack,tomoyo,apparmor,bpf,ipe"
> 
> Generally speaking the BPF LSM should be the last entry in the LSM
> list to help prevent issues caused by a BPF LSM returning an improper
> error and shortcutting a LSM after it.
> 
Thanks for the insight, I will update this part.

> >  	help
> >  	  A comma-separated list of LSMs, in initialization order.
> >  	  Any LSMs left off this list, except for those with order
> 
> ...
> 
> > 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 \
> 
> It doesn't look like security/ipe/hook.c is included in this patch.
> 
> It is important to ensure that each patch compiles after it is
> applied.
Sorry this was accidentally added during a rebase, I will try to avoid such a mistake in the future.

-Fan

> 
> --
> paul-moore.com
diff mbox series

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index a82795114ad4..ad00887d38ea 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10278,6 +10278,13 @@  T:	git git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity.git
 F:	security/integrity/
 F:	security/integrity/ima/
 
+INTEGRITY POLICY ENFORCEMENT (IPE)
+M:	Fan Wu <wufan@linux.microsoft.com>
+L:	linux-security-module@vger.kernel.org
+S:	Supported
+T:	git git://github.com/microsoft/ipe.git
+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 97abeb9b9a19..daa4626ea99c 100644
--- a/security/Kconfig
+++ b/security/Kconfig
@@ -202,6 +202,7 @@  source "security/yama/Kconfig"
 source "security/safesetid/Kconfig"
 source "security/lockdown/Kconfig"
 source "security/landlock/Kconfig"
+source "security/ipe/Kconfig"
 
 source "security/integrity/Kconfig"
 
@@ -241,11 +242,11 @@  endchoice
 
 config LSM
 	string "Ordered list of enabled LSMs"
-	default "landlock,lockdown,yama,loadpin,safesetid,smack,selinux,tomoyo,apparmor,bpf" if DEFAULT_SECURITY_SMACK
-	default "landlock,lockdown,yama,loadpin,safesetid,apparmor,selinux,smack,tomoyo,bpf" if DEFAULT_SECURITY_APPARMOR
-	default "landlock,lockdown,yama,loadpin,safesetid,tomoyo,bpf" if DEFAULT_SECURITY_TOMOYO
-	default "landlock,lockdown,yama,loadpin,safesetid,bpf" if DEFAULT_SECURITY_DAC
-	default "landlock,lockdown,yama,loadpin,safesetid,selinux,smack,tomoyo,apparmor,bpf"
+	default "landlock,lockdown,yama,loadpin,safesetid,smack,selinux,tomoyo,apparmor,bpf,ipe" if DEFAULT_SECURITY_SMACK
+	default "landlock,lockdown,yama,loadpin,safesetid,apparmor,selinux,smack,tomoyo,bpf,ipe" if DEFAULT_SECURITY_APPARMOR
+	default "landlock,lockdown,yama,loadpin,safesetid,tomoyo,bpf,ipe" if DEFAULT_SECURITY_TOMOYO
+	default "landlock,lockdown,yama,loadpin,safesetid,bpf,ipe" if DEFAULT_SECURITY_DAC
+	default "landlock,lockdown,yama,loadpin,safesetid,selinux,smack,tomoyo,apparmor,bpf,ipe"
 	help
 	  A comma-separated list of LSMs, in initialization order.
 	  Any LSMs left off this list, except for those with order
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..2ee0f5de29d7
--- /dev/null
+++ b/security/ipe/ipe.c
@@ -0,0 +1,37 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) Microsoft Corporation. All rights reserved.
+ */
+
+#include "ipe.h"
+
+static struct lsm_blob_sizes ipe_blobs __ro_after_init = {
+};
+
+static struct security_hook_list ipe_hooks[] __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 registers its hooks and loads the
+ * builtin boot policy.
+ * Return:
+ * * 0		- OK
+ * * -ENOMEM	- Out of memory
+ */
+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..a1c68d0fc2e0
--- /dev/null
+++ b/security/ipe/ipe.h
@@ -0,0 +1,16 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) Microsoft Corporation. All rights reserved.
+ */
+
+#ifndef _IPE_H
+#define _IPE_H
+
+#ifdef pr_fmt
+#undef pr_fmt
+#endif
+#define pr_fmt(fmt) "IPE: " fmt
+
+#include <linux/lsm_hooks.h>
+
+#endif /* _IPE_H */