[PATCH bpf-next v7 5/8] bpf: lsm: Initialize the BPF LSM hooks

From: KP Singh
Date: Thu Mar 26 2020 - 10:28:48 EST


From: KP Singh <kpsingh@xxxxxxxxxx>

* The hooks are initialized using the definitions in
include/linux/lsm_hook_defs.h.
* The LSM can be enabled / disabled with CONFIG_BPF_LSM.

Signed-off-by: KP Singh <kpsingh@xxxxxxxxxx>
Acked-by: Kees Cook <keescook@xxxxxxxxxxxx>
Reviewed-by: Brendan Jackman <jackmanb@xxxxxxxxxx>
Reviewed-by: Florent Revest <revest@xxxxxxxxxx>
---
security/Kconfig | 10 +++++-----
security/Makefile | 2 ++
security/bpf/Makefile | 5 +++++
security/bpf/hooks.c | 26 ++++++++++++++++++++++++++
4 files changed, 38 insertions(+), 5 deletions(-)
create mode 100644 security/bpf/Makefile
create mode 100644 security/bpf/hooks.c

diff --git a/security/Kconfig b/security/Kconfig
index 2a1a2d396228..cd3cc7da3a55 100644
--- a/security/Kconfig
+++ b/security/Kconfig
@@ -277,11 +277,11 @@ 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 746438499029..22e73a3482bd 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_BPF_LSM) += bpf

# always enable default capabilities
obj-y += commoncap.o
@@ -30,6 +31,7 @@ obj-$(CONFIG_SECURITY_LOADPIN) += loadpin/
obj-$(CONFIG_SECURITY_SAFESETID) += safesetid/
obj-$(CONFIG_SECURITY_LOCKDOWN_LSM) += lockdown/
obj-$(CONFIG_CGROUP_DEVICE) += device_cgroup.o
+obj-$(CONFIG_BPF_LSM) += bpf/

# Object integrity file lists
subdir-$(CONFIG_INTEGRITY) += integrity
diff --git a/security/bpf/Makefile b/security/bpf/Makefile
new file mode 100644
index 000000000000..c7a89a962084
--- /dev/null
+++ b/security/bpf/Makefile
@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (C) 2020 Google LLC.
+
+obj-$(CONFIG_BPF_LSM) := hooks.o
diff --git a/security/bpf/hooks.c b/security/bpf/hooks.c
new file mode 100644
index 000000000000..32d32d485451
--- /dev/null
+++ b/security/bpf/hooks.c
@@ -0,0 +1,26 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Copyright (C) 2020 Google LLC.
+ */
+#include <linux/lsm_hooks.h>
+#include <linux/bpf_lsm.h>
+
+static struct security_hook_list bpf_lsm_hooks[] __lsm_ro_after_init = {
+ #define LSM_HOOK(RET, DEFAULT, NAME, ...) \
+ LSM_HOOK_INIT(NAME, bpf_lsm_##NAME),
+ #include <linux/lsm_hook_defs.h>
+ #undef LSM_HOOK
+};
+
+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,
+};
--
2.20.1