| 1 | /* SPDX-License-Identifier: GPL-2.0+ */ |
|---|---|
| 2 | /* |
| 3 | * Copyright (C) 2018 IBM Corporation |
| 4 | */ |
| 5 | #include <linux/efi.h> |
| 6 | #include <linux/module.h> |
| 7 | #include <linux/ima.h> |
| 8 | #include <asm/efi.h> |
| 9 | |
| 10 | #ifndef arch_ima_efi_boot_mode |
| 11 | #define arch_ima_efi_boot_mode efi_secureboot_mode_unset |
| 12 | #endif |
| 13 | |
| 14 | static enum efi_secureboot_mode get_sb_mode(void) |
| 15 | { |
| 16 | enum efi_secureboot_mode mode; |
| 17 | |
| 18 | if (!efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE)) { |
| 19 | pr_info("ima: secureboot mode unknown, no efi\n"); |
| 20 | return efi_secureboot_mode_unknown; |
| 21 | } |
| 22 | |
| 23 | mode = efi_get_secureboot_mode(get_var: efi.get_variable); |
| 24 | if (mode == efi_secureboot_mode_disabled) |
| 25 | pr_info("ima: secureboot mode disabled\n"); |
| 26 | else if (mode == efi_secureboot_mode_unknown) |
| 27 | pr_info("ima: secureboot mode unknown\n"); |
| 28 | else |
| 29 | pr_info("ima: secureboot mode enabled\n"); |
| 30 | return mode; |
| 31 | } |
| 32 | |
| 33 | bool arch_ima_get_secureboot(void) |
| 34 | { |
| 35 | static enum efi_secureboot_mode sb_mode; |
| 36 | static bool initialized; |
| 37 | |
| 38 | if (!initialized && efi_enabled(EFI_BOOT)) { |
| 39 | sb_mode = arch_ima_efi_boot_mode; |
| 40 | |
| 41 | if (sb_mode == efi_secureboot_mode_unset) |
| 42 | sb_mode = get_sb_mode(); |
| 43 | initialized = true; |
| 44 | } |
| 45 | |
| 46 | if (sb_mode == efi_secureboot_mode_enabled) |
| 47 | return true; |
| 48 | else |
| 49 | return false; |
| 50 | } |
| 51 | |
| 52 | /* secureboot arch rules */ |
| 53 | static const char * const sb_arch_rules[] = { |
| 54 | #if !IS_ENABLED(CONFIG_KEXEC_SIG) |
| 55 | "appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig", |
| 56 | #endif /* CONFIG_KEXEC_SIG */ |
| 57 | "measure func=KEXEC_KERNEL_CHECK", |
| 58 | #if !IS_ENABLED(CONFIG_MODULE_SIG) |
| 59 | "appraise func=MODULE_CHECK appraise_type=imasig", |
| 60 | #endif |
| 61 | #if IS_ENABLED(CONFIG_INTEGRITY_MACHINE_KEYRING) && IS_ENABLED(CONFIG_IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY) |
| 62 | "appraise func=POLICY_CHECK appraise_type=imasig", |
| 63 | #endif |
| 64 | "measure func=MODULE_CHECK", |
| 65 | NULL |
| 66 | }; |
| 67 | |
| 68 | const char * const *arch_get_ima_policy(void) |
| 69 | { |
| 70 | if (IS_ENABLED(CONFIG_IMA_ARCH_POLICY) && arch_ima_get_secureboot()) { |
| 71 | if (IS_ENABLED(CONFIG_MODULE_SIG)) |
| 72 | set_module_sig_enforced(); |
| 73 | if (IS_ENABLED(CONFIG_KEXEC_SIG)) |
| 74 | set_kexec_sig_enforced(); |
| 75 | return sb_arch_rules; |
| 76 | } |
| 77 | return NULL; |
| 78 | } |
| 79 |