hibernate: Disable when the kernel is locked down

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 when the
kernel is locked down.

Signed-off-by: Josh Boyer <jwboyer@fedoraproject.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Matthew Garrett <mjg59@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: rjw@rjwysocki.net
Cc: pavel@ucw.cz
cc: linux-pm@vger.kernel.org
Signed-off-by: James Morris <jmorris@namei.org>

diff --git a/include/linux/security.h b/include/linux/security.h
index b607a8a..80ac7fb 100644 (file)
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -106,6 +106,7 @@ enum lockdown_reason {
        LOCKDOWN_MODULE_SIGNATURE,
        LOCKDOWN_DEV_MEM,
        LOCKDOWN_KEXEC,
+       LOCKDOWN_HIBERNATION,
        LOCKDOWN_INTEGRITY_MAX,
        LOCKDOWN_CONFIDENTIALITY_MAX,
 };

diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index cd7434e..3c0a5a8 100644 (file)
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -30,6 +30,7 @@
 #include <linux/ctype.h>
 #include <linux/genhd.h>
 #include <linux/ktime.h>
+#include <linux/security.h>
 #include <trace/events/power.h>
 
 #include "power.h"
@@ -68,7 +69,7 @@ static const struct platform_hibernation_ops *hibernation_ops;
 
 bool hibernation_available(void)
 {
-       return (nohibernate == 0);
+       return nohibernate == 0 && !security_locked_down(LOCKDOWN_HIBERNATION);
 }
 
 /**

diff --git a/security/lockdown/lockdown.c b/security/lockdown/lockdown.c
index aaf30ad..3462f7e 100644 (file)
--- a/security/lockdown/lockdown.c
+++ b/security/lockdown/lockdown.c
@@ -21,6 +21,7 @@ static char *lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX+1] = {
        [LOCKDOWN_MODULE_SIGNATURE] = "unsigned module loading",
        [LOCKDOWN_DEV_MEM] = "/dev/mem,kmem,port",
        [LOCKDOWN_KEXEC] = "kexec of unsigned images",
+       [LOCKDOWN_HIBERNATION] = "hibernation",
        [LOCKDOWN_INTEGRITY_MAX] = "integrity",
        [LOCKDOWN_CONFIDENTIALITY_MAX] = "confidentiality",
 };