kernel/0001-security-lockdown-expose-a-hook-to-lock-the-kernel-d.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Jeremy Cline <jcline@redhat.com>
Date: Mon, 30 Sep 2019 21:22:47 +0000
Subject: [PATCH] security: lockdown: expose a hook to lock the kernel down

In order to automatically lock down kernels running on UEFI machines
booted in Secure Boot mode, expose the lock_kernel_down() hook.

Upstream Status: RHEL only
Signed-off-by: Jeremy Cline <jcline@redhat.com>
---
 include/linux/lsm_hook_defs.h | 2 ++
 include/linux/lsm_hooks.h     | 6 ++++++
 include/linux/security.h      | 5 +++++
 security/lockdown/lockdown.c  | 1 +
 security/security.c           | 6 ++++++
 5 files changed, 20 insertions(+)

diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
index 5616b2567aa7..bc5caab1413b 100644
--- a/include/linux/lsm_hook_defs.h
+++ b/include/linux/lsm_hook_defs.h
@@ -371,6 +371,8 @@ LSM_HOOK(void, LSM_RET_VOID, bpf_prog_free_security, struct bpf_prog_aux *aux)
 #endif /* CONFIG_BPF_SYSCALL */

 LSM_HOOK(int, 0, locked_down, enum lockdown_reason what)
+LSM_HOOK(int, 0, lock_kernel_down, const char *where, enum lockdown_reason level)
+

 #ifdef CONFIG_PERF_EVENTS
 LSM_HOOK(int, 0, perf_event_open, struct perf_event_attr *attr, int type)
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index 44d5422c18e4..e8c9797994df 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -1476,6 +1476,12 @@
  *
  *     @what: kernel feature being accessed
  *
+ * @lock_kernel_down
+ * 	Put the kernel into lock-down mode.
+ *
+ * 	@where: Where the lock-down is originating from (e.g. command line option)
+ * 	@level: The lock-down level (can only increase)
+ *
  * Security hooks for perf events
  *
  * @perf_event_open:
diff --git a/include/linux/security.h b/include/linux/security.h
index a8d9310472df..381305889d89 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -446,6 +446,7 @@ int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen);
 int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen);
 int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen);
 int security_locked_down(enum lockdown_reason what);
+int security_lock_kernel_down(const char *where, enum lockdown_reason level);
 #else /* CONFIG_SECURITY */

 static inline int call_blocking_lsm_notifier(enum lsm_event event, void *data)
@@ -1273,6 +1274,10 @@ static inline int security_locked_down(enum lockdown_reason what)
 {
 	return 0;
 }
+static inline int security_lock_kernel_down(const char *where, enum lockdown_reason level)
+{
+	return 0;
+}
 #endif	/* CONFIG_SECURITY */

 #ifdef CONFIG_SECURITY_NETWORK
diff --git a/security/lockdown/lockdown.c b/security/lockdown/lockdown.c
index 5a952617a0eb..61cc3cdc4d25 100644
--- a/security/lockdown/lockdown.c
+++ b/security/lockdown/lockdown.c
@@ -73,6 +73,7 @@ static int lockdown_is_locked_down(enum lockdown_reason what)

 static struct security_hook_list lockdown_hooks[] __lsm_ro_after_init = {
 	LSM_HOOK_INIT(locked_down, lockdown_is_locked_down),
+	LSM_HOOK_INIT(lock_kernel_down, lock_kernel_down),
 };

 static int __init lockdown_lsm_init(void)
diff --git a/security/security.c b/security/security.c
index 51de970fbb1e..48d05f8067f2 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2468,6 +2468,12 @@ int security_locked_down(enum lockdown_reason what)
 }
 EXPORT_SYMBOL(security_locked_down);

+int security_lock_kernel_down(const char *where, enum lockdown_reason level)
+{
+	return call_int_hook(lock_kernel_down, 0, where, level);
+}
+EXPORT_SYMBOL(security_lock_kernel_down);
+
 #ifdef CONFIG_PERF_EVENTS
 int security_perf_event_open(struct perf_event_attr *attr, int type)
 {
-- 
2.26.2