diff options
Diffstat (limited to '')
-rw-r--r-- | security/integrity/ima/ima_efi.c | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/security/integrity/ima/ima_efi.c b/security/integrity/ima/ima_efi.c new file mode 100644 index 000000000..9db66fe31 --- /dev/null +++ b/security/integrity/ima/ima_efi.c @@ -0,0 +1,75 @@ +/* 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(); + if (IS_ENABLED(CONFIG_KEXEC_SIG)) + set_kexec_sig_enforced(); + return sb_arch_rules; + } + return NULL; +} |