[PATCH] integrity: Do not load MOK and MOKx when secure boot be disabled
flat view
STALE1776d
From: Lee, Chun-Yi <hidden>
Date: 2021-12-18 02:09:34
Also in:
lkml
Subsystem:
extended verification module (evm), integrity measurement architecture (ima), security subsystem, the rest · Maintainers:
Mimi Zohar, Roberto Sassu, Dmitry Kasatkin, Paul Moore, James Morris, "Serge E. Hallyn", Linus Torvalds
The security of Machine Owner Key (MOK) relies on secure boot. When
secure boot is disabled, EFI firmware will not verify binary code. Then
arbitrary efi binary code can modify MOK when rebooting.
This patch prevents MOK/MOKx be loaded when secure boot be disabled.
Signed-off-by: "Lee, Chun-Yi" <jlee@suse.com>
---
security/integrity/platform_certs/load_uefi.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/security/integrity/platform_certs/load_uefi.c b/security/integrity/platform_certs/load_uefi.c
index f290f78c3f30..08b6d12f99b4 100644
--- a/security/integrity/platform_certs/load_uefi.c
+++ b/security/integrity/platform_certs/load_uefi.c@@ -6,6 +6,7 @@ #include <linux/err.h> #include <linux/efi.h> #include <linux/slab.h> +#include <linux/ima.h> #include <keys/asymmetric-type.h> #include <keys/system_keyring.h> #include "../integrity.h"
@@ -176,6 +177,10 @@ static int __init load_uefi_certs(void) kfree(dbx); } + /* the MOK/MOKx can not be trusted when secure boot is disabled */ + if (!arch_ima_get_secureboot()) + return 0; + mokx = get_cert_list(L"MokListXRT", &mok_var, &mokxsize, &status); if (!mokx) { if (status == EFI_NOT_FOUND)
--
2.26.2