[PATCH V34 10/29] hibernate: Disable when the kernel is locked down
From: Matthew Garrett <hidden>
Date: 2019-06-22 00:04:32
Also in:
linux-api, linux-pm, lkml
Subsystem:
hibernation (aka software suspend, aka swsusp), lockdown security module, security subsystem, suspend to ram, the rest · Maintainers:
"Rafael J. Wysocki", Nicolas Bouchinet, Xiu Jianfeng, Paul Moore, James Morris, "Serge E. Hallyn", Linus Torvalds
From: Josh Boyer <redacted> 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 <redacted> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Matthew Garrett <redacted> Cc: rjw@rjwysocki.net Cc: pavel@ucw.cz cc: linux-pm@vger.kernel.org --- include/linux/security.h | 1 + kernel/power/hibernate.c | 3 ++- security/lockdown/lockdown.c | 1 + 3 files changed, 4 insertions(+), 1 deletion(-)
diff --git a/include/linux/security.h b/include/linux/security.h
index 00a31ab2e5ba..a051f21a1144 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h@@ -85,6 +85,7 @@ 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 abef759de7c8..3a9cb2d3da4a 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c@@ -32,6 +32,7 @@ #include <linux/ctype.h> #include <linux/genhd.h> #include <linux/ktime.h> +#include <linux/security.h> #include <trace/events/power.h> #include "power.h"
@@ -70,7 +71,7 @@ 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 08fcd8116db3..ce5b3da9bd09 100644
--- 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", };
--
2.22.0.410.gd8fdbe21b5-goog