linux/security/integrity/ima/ima_efi.c

74 lines
1.7 KiB
C

/* SPDX-License-Identifier: GPL-2.0+ */
/*
* Copyright (C) 2018 IBM Corporation
*/
#include <linux/efi.h>
#include <linux/module.h>
#include <linux/ima.h>
#include <asm/efi.h>
#ifndef arch_ima_efi_boot_mode
#define arch_ima_efi_boot_mode efi_secureboot_mode_unset
#endif
static enum efi_secureboot_mode get_sb_mode(void)
{
enum efi_secureboot_mode mode;
if (!efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE)) {
pr_info("ima: secureboot mode unknown, no efi\n");
return efi_secureboot_mode_unknown;
}
mode = efi_get_secureboot_mode(efi.get_variable);
if (mode == efi_secureboot_mode_disabled)
pr_info("ima: secureboot mode disabled\n");
else if (mode == efi_secureboot_mode_unknown)
pr_info("ima: secureboot mode unknown\n");
else
pr_info("ima: secureboot mode enabled\n");
return mode;
}
bool arch_ima_get_secureboot(void)
{
static enum efi_secureboot_mode sb_mode;
static bool initialized;
if (!initialized && efi_enabled(EFI_BOOT)) {
sb_mode = arch_ima_efi_boot_mode;
if (sb_mode == efi_secureboot_mode_unset)
sb_mode = get_sb_mode();
initialized = true;
}
if (sb_mode == efi_secureboot_mode_enabled)
return true;
else
return false;
}
/* secureboot arch rules */
static const char * const sb_arch_rules[] = {
#if !IS_ENABLED(CONFIG_KEXEC_SIG)
"appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig",
#endif /* CONFIG_KEXEC_SIG */
"measure func=KEXEC_KERNEL_CHECK",
#if !IS_ENABLED(CONFIG_MODULE_SIG)
"appraise func=MODULE_CHECK appraise_type=imasig",
#endif
"measure func=MODULE_CHECK",
NULL
};
const char * const *arch_get_ima_policy(void)
{
if (IS_ENABLED(CONFIG_IMA_ARCH_POLICY) && arch_ima_get_secureboot()) {
if (IS_ENABLED(CONFIG_MODULE_SIG))
set_module_sig_enforced();
return sb_arch_rules;
}
return NULL;
}