* Re: [PATCH V40 10/29] hibernate: Disable when the kernel is locked down
2019-08-20 0:17 ` [PATCH V40 10/29] hibernate: Disable when the kernel is locked down Matthew Garrett
@ 2019-08-20 21:43 ` Rafael J. Wysocki
2019-08-25 9:51 ` Pavel Machek
1 sibling, 0 replies; 3+ messages in thread
From: Rafael J. Wysocki @ 2019-08-20 21:43 UTC (permalink / raw)
To: Matthew Garrett
Cc: jmorris, linux-security-module, linux-kernel, linux-api,
Josh Boyer, David Howells, Matthew Garrett, Kees Cook, pavel,
linux-pm
On Tuesday, August 20, 2019 2:17:46 AM CEST Matthew Garrett wrote:
> From: Josh Boyer <jwboyer@fedoraproject.org>
>
> 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>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> ---
> 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",
> };
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH V40 10/29] hibernate: Disable when the kernel is locked down
2019-08-20 0:17 ` [PATCH V40 10/29] hibernate: Disable when the kernel is locked down Matthew Garrett
2019-08-20 21:43 ` Rafael J. Wysocki
@ 2019-08-25 9:51 ` Pavel Machek
1 sibling, 0 replies; 3+ messages in thread
From: Pavel Machek @ 2019-08-25 9:51 UTC (permalink / raw)
To: Matthew Garrett
Cc: jmorris, linux-security-module, linux-kernel, linux-api,
Josh Boyer, David Howells, Matthew Garrett, Kees Cook, rjw,
linux-pm
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On Mon 2019-08-19 17:17:46, Matthew Garrett wrote:
> From: Josh Boyer <jwboyer@fedoraproject.org>
>
> 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>
Acked-by: Pavel Machek <pavel@ucw.cz>
Pavel
--
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^ permalink raw reply [flat|nested] 3+ messages in thread