Re: [PATCH V40 10/29] hibernate: Disable when the kernel is locked down
From: Rafael J. Wysocki <hidden>
Date: 2019-08-20 21:43:13
Also in:
linux-api, linux-pm, lkml
On Tuesday, August 20, 2019 2:17:46 AM CEST Matthew Garrett wrote:
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 Signed-off-by: James Morris <jmorris@namei.org>
Acked-by: Rafael J. Wysocki <redacted>
quoted hunk ↗ jump to hunk
--- 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 b607a8ac97fe..80ac7fb27aa9 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 aaf30ad351f9..3462f7edcaac 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", };