From 25519d68344269f9dc58b5bc72f648248a1fafb9 Mon Sep 17 00:00:00 2001 From: Chester Lin Date: Fri, 30 Oct 2020 14:08:39 +0800 Subject: ima: generalize x86/EFI arch glue for other EFI architectures Move the x86 IMA arch code into security/integrity/ima/ima_efi.c, so that we will be able to wire it up for arm64 in a future patch. Co-developed-by: Chester Lin Signed-off-by: Chester Lin Acked-by: Mimi Zohar Signed-off-by: Ard Biesheuvel --- arch/x86/include/asm/efi.h | 3 ++ arch/x86/kernel/Makefile | 2 - arch/x86/kernel/ima_arch.c | 94 ---------------------------------------- security/integrity/ima/Makefile | 4 ++ security/integrity/ima/ima_efi.c | 73 +++++++++++++++++++++++++++++++ 5 files changed, 80 insertions(+), 96 deletions(-) delete mode 100644 arch/x86/kernel/ima_arch.c create mode 100644 security/integrity/ima/ima_efi.c diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h index 7673dc833232..c98f78330b09 100644 --- a/arch/x86/include/asm/efi.h +++ b/arch/x86/include/asm/efi.h @@ -380,4 +380,7 @@ static inline void efi_fake_memmap_early(void) } #endif +#define arch_ima_efi_boot_mode \ + ({ extern struct boot_params boot_params; boot_params.secure_boot; }) + #endif /* _ASM_X86_EFI_H */ diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile index 68608bd892c0..5eeb808eb024 100644 --- a/arch/x86/kernel/Makefile +++ b/arch/x86/kernel/Makefile @@ -161,5 +161,3 @@ ifeq ($(CONFIG_X86_64),y) obj-$(CONFIG_MMCONF_FAM10H) += mmconf-fam10h_64.o obj-y += vsmp_64.o endif - -obj-$(CONFIG_IMA_SECURE_AND_OR_TRUSTED_BOOT) += ima_arch.o diff --git a/arch/x86/kernel/ima_arch.c b/arch/x86/kernel/ima_arch.c deleted file mode 100644 index 7dfb1e808928..000000000000 --- a/arch/x86/kernel/ima_arch.c +++ /dev/null @@ -1,94 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0+ */ -/* - * Copyright (C) 2018 IBM Corporation - */ -#include -#include -#include - -extern struct boot_params boot_params; - -static enum efi_secureboot_mode get_sb_mode(void) -{ - efi_guid_t efi_variable_guid = EFI_GLOBAL_VARIABLE_GUID; - efi_status_t status; - unsigned long size; - u8 secboot, setupmode; - - size = sizeof(secboot); - - if (!efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE)) { - pr_info("ima: secureboot mode unknown, no efi\n"); - return efi_secureboot_mode_unknown; - } - - /* Get variable contents into buffer */ - status = efi.get_variable(L"SecureBoot", &efi_variable_guid, - NULL, &size, &secboot); - if (status == EFI_NOT_FOUND) { - pr_info("ima: secureboot mode disabled\n"); - return efi_secureboot_mode_disabled; - } - - if (status != EFI_SUCCESS) { - pr_info("ima: secureboot mode unknown\n"); - return efi_secureboot_mode_unknown; - } - - size = sizeof(setupmode); - status = efi.get_variable(L"SetupMode", &efi_variable_guid, - NULL, &size, &setupmode); - - if (status != EFI_SUCCESS) /* ignore unknown SetupMode */ - setupmode = 0; - - if (secboot == 0 || setupmode == 1) { - pr_info("ima: secureboot mode disabled\n"); - return efi_secureboot_mode_disabled; - } - - pr_info("ima: secureboot mode enabled\n"); - return efi_secureboot_mode_enabled; -} - -bool arch_ima_get_secureboot(void) -{ - static enum efi_secureboot_mode sb_mode; - static bool initialized; - - if (!initialized && efi_enabled(EFI_BOOT)) { - sb_mode = boot_params.secure_boot; - - 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; -} diff --git a/security/integrity/ima/Makefile b/security/integrity/ima/Makefile index 67dabca670e2..2499f2485c04 100644 --- a/security/integrity/ima/Makefile +++ b/security/integrity/ima/Makefile @@ -14,3 +14,7 @@ ima-$(CONFIG_HAVE_IMA_KEXEC) += ima_kexec.o ima-$(CONFIG_IMA_BLACKLIST_KEYRING) += ima_mok.o ima-$(CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS) += ima_asymmetric_keys.o ima-$(CONFIG_IMA_QUEUE_EARLY_BOOT_KEYS) += ima_queue_keys.o + +ifeq ($(CONFIG_EFI),y) +ima-$(CONFIG_IMA_SECURE_AND_OR_TRUSTED_BOOT) += ima_efi.o +endif diff --git a/security/integrity/ima/ima_efi.c b/security/integrity/ima/ima_efi.c new file mode 100644 index 000000000000..71786d01946f --- /dev/null +++ b/security/integrity/ima/ima_efi.c @@ -0,0 +1,73 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Copyright (C) 2018 IBM Corporation + */ +#include +#include +#include +#include + +#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; +} -- cgit v1.2.3