[PATCH V37 10/29] hibernate: Disable when the kernel is locked down
From: Matthew Garrett <hidden>
Date: 2019-07-31 22:16:57
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> Reviewed-by: Kees Cook <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 69c5de539e9a..304a155a5628 100644
--- 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 cd7434e6000d..3c0a5a8170b0 100644
--- 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 6f302c156bc8..a0996f75629f 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", };
--
2.22.0.770.g0f2c4a37fd-goog