[PATCH sb-hibernate 1/1] hibernate: Disable in a signed modules environment

[Josh Boyer <jwboyer@xxxxxxxxxx>]

>From 4fe6d11d21b548d6e8272cc8cad5fcc6150ef081 Mon Sep 17 00:00:00 2001
From: Josh Boyer <jwboyer@xxxxxxxxxxxxxxxxx>
Date: Fri, 26 Oct 2012 14:02:09 -0400
Subject: [PATCH] hibernate: Disable in a signed modules environment

There is currently no way to verify the resume image when returning
from hibernate.  This might compromise the signed modules trust model,
so until we can work with signed hibernate images we disable it in
a secure modules environment.

Signed-off-by: Josh Boyer <jwboyer@xxxxxxxxxxxxxxxxx>
---
 kernel/power/hibernate.c | 16 +++++++++++++++-
 kernel/power/main.c      |  7 ++++++-
 kernel/power/user.c      |  5 +++++
 3 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index b26f5f1..e65228b 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -28,6 +28,8 @@
 #include <linux/syscore_ops.h>
 #include <linux/ctype.h>
 #include <linux/genhd.h>
+#include <linux/efi.h>
+#include <linux/module.h>
 
 #include "power.h"
 
@@ -632,6 +634,10 @@ int hibernate(void)
 {
 	int error;
 
+	if (secure_modules()) {
+		return -EPERM;
+	}
+
 	lock_system_sleep();
 	/* The snapshot device should not be opened while we're running */
 	if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
@@ -723,7 +729,7 @@ static int software_resume(void)
 	/*
 	 * If the user said "noresume".. bail out early.
 	 */
-	if (noresume)
+	if (noresume || secure_modules())
 		return 0;
 
 	/*
@@ -889,6 +895,11 @@ static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
 	int i;
 	char *start = buf;
 
+	if (efi_enabled(EFI_SECURE_BOOT)) {
+		buf += sprintf(buf, "[%s]\n", "disabled");
+		return buf-start;
+	}
+
 	for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
 		if (!hibernation_modes[i])
 			continue;
@@ -923,6 +934,9 @@ static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
 	char *p;
 	int mode = HIBERNATION_INVALID;
 
+	if (secure_modules())
+		return -EPERM;
+
 	p = memchr(buf, '\n', n);
 	len = p ? p - buf : n;
 
diff --git a/kernel/power/main.c b/kernel/power/main.c
index 1d1bf63..300f300 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -15,6 +15,7 @@
 #include <linux/workqueue.h>
 #include <linux/debugfs.h>
 #include <linux/seq_file.h>
+#include <linux/efi.h>
 
 #include "power.h"
 
@@ -301,7 +302,11 @@ static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
 	}
 #endif
 #ifdef CONFIG_HIBERNATION
-	s += sprintf(s, "%s\n", "disk");
+	if (!efi_enabled(EFI_SECURE_BOOT)) {
+		s += sprintf(s, "%s\n", "disk");
+	} else {
+		s += sprintf(s, "\n");
+	}
 #else
 	if (s != buf)
 		/* convert the last space to a newline */
diff --git a/kernel/power/user.c b/kernel/power/user.c
index 4ed81e7..b714ee6 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -24,6 +24,8 @@
 #include <linux/console.h>
 #include <linux/cpu.h>
 #include <linux/freezer.h>
+#include <linux/efi.h>
+#include <linux/module.h>
 
 #include <asm/uaccess.h>
 
@@ -48,6 +50,9 @@ static int snapshot_open(struct inode *inode, struct file *filp)
 	struct snapshot_data *data;
 	int error;
 
+	if (secure_modules())
+		return -EPERM;
+
 	lock_system_sleep();
 
 	if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
-- 
1.8.3.1

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