EVM and other LSMs need the ability to query the secure boot status of the system, without directly calling the IMA arch_ima_get_secureboot function. Refactor the secure boot status check into a general, integrity-wide function named arch_integrity_get_secureboot.
Define a new Kconfig option CONFIG_INTEGRITY_SECURE_BOOT, which is automatically configured by the supported architectures. The existing IMA_SECURE_AND_OR_TRUSTED_BOOT Kconfig loads the architecture specific IMA policy based on the refactored secure boot status code. Reported-and-suggested-by: Mimi Zohar <[email protected]> Suggested-by: Roberto Sassu <[email protected]> Signed-off-by: Coiby Xu <[email protected]> --- arch/arm64/Kconfig | 1 + arch/powerpc/Kconfig | 1 + arch/powerpc/kernel/Makefile | 2 +- arch/powerpc/kernel/ima_arch.c | 5 -- arch/powerpc/kernel/integrity_sb_arch.c | 13 +++++ arch/s390/Kconfig | 1 + arch/s390/kernel/Makefile | 1 + arch/s390/kernel/ima_arch.c | 6 -- arch/s390/kernel/integrity_sb_arch.c | 9 +++ arch/x86/Kconfig | 1 + arch/x86/include/asm/efi.h | 4 +- arch/x86/platform/efi/efi.c | 2 +- include/linux/ima.h | 7 +-- include/linux/integrity.h | 8 +++ security/integrity/Kconfig | 6 ++ security/integrity/Makefile | 3 + security/integrity/efi_secureboot.c | 56 +++++++++++++++++++ security/integrity/ima/ima_appraise.c | 2 +- security/integrity/ima/ima_efi.c | 47 +--------------- security/integrity/ima/ima_main.c | 4 +- security/integrity/platform_certs/load_uefi.c | 2 +- 21 files changed, 111 insertions(+), 70 deletions(-) create mode 100644 arch/powerpc/kernel/integrity_sb_arch.c create mode 100644 arch/s390/kernel/integrity_sb_arch.c create mode 100644 security/integrity/efi_secureboot.c diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 93173f0a09c7..4c265b7386bb 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -2427,6 +2427,7 @@ config EFI select EFI_STUB select EFI_GENERIC_STUB imply IMA_SECURE_AND_OR_TRUSTED_BOOT + imply INTEGRITY_SECURE_BOOT default y help This option provides support for runtime services provided diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 9537a61ebae0..878f752c35fb 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -1058,6 +1058,7 @@ config PPC_SECURE_BOOT depends on PPC_POWERNV || PPC_PSERIES depends on IMA_ARCH_POLICY imply IMA_SECURE_AND_OR_TRUSTED_BOOT + imply INTEGRITY_SECURE_BOOT select PSERIES_PLPKS if PPC_PSERIES help Systems with firmware secure boot enabled need to define security diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile index 2f0a2e69c607..3bb1fb9a1e0e 100644 --- a/arch/powerpc/kernel/Makefile +++ b/arch/powerpc/kernel/Makefile @@ -168,7 +168,7 @@ ifneq ($(CONFIG_PPC_POWERNV)$(CONFIG_PPC_SVM),) obj-y += ucall.o endif -obj-$(CONFIG_PPC_SECURE_BOOT) += secure_boot.o ima_arch.o secvar-ops.o +obj-$(CONFIG_PPC_SECURE_BOOT) += secure_boot.o ima_arch.o integrity_sb_arch.o secvar-ops.o obj-$(CONFIG_PPC_SECVAR_SYSFS) += secvar-sysfs.o # Disable GCOV, KCOV & sanitizers in odd or sensitive code diff --git a/arch/powerpc/kernel/ima_arch.c b/arch/powerpc/kernel/ima_arch.c index b7029beed847..0d8892a03526 100644 --- a/arch/powerpc/kernel/ima_arch.c +++ b/arch/powerpc/kernel/ima_arch.c @@ -7,11 +7,6 @@ #include <linux/ima.h> #include <asm/secure_boot.h> -bool arch_ima_get_secureboot(void) -{ - return is_ppc_secureboot_enabled(); -} - /* * The "secure_rules" are enabled only on "secureboot" enabled systems. * These rules verify the file signatures against known good values. diff --git a/arch/powerpc/kernel/integrity_sb_arch.c b/arch/powerpc/kernel/integrity_sb_arch.c new file mode 100644 index 000000000000..29f9494391a3 --- /dev/null +++ b/arch/powerpc/kernel/integrity_sb_arch.c @@ -0,0 +1,13 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2019 IBM Corporation + * Author: Nayna Jain + */ + +#include <linux/integrity.h> +#include <asm/secure_boot.h> + +bool arch_integrity_get_secureboot(void) +{ + return is_ppc_secureboot_enabled(); +} diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index 0e5fad5f06ca..db0383b19493 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -78,6 +78,7 @@ config S390 # Note: keep this list sorted alphabetically # imply IMA_SECURE_AND_OR_TRUSTED_BOOT + imply INTEGRITY_SECURE_BOOT select ALTERNATE_USER_ADDRESS_SPACE select ARCH_32BIT_USTAT_F_TINODE select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile index 42c83d60d6fa..ee976a27e677 100644 --- a/arch/s390/kernel/Makefile +++ b/arch/s390/kernel/Makefile @@ -72,6 +72,7 @@ obj-$(CONFIG_KEXEC_FILE) += machine_kexec_file.o kexec_image.o obj-$(CONFIG_KEXEC_FILE) += kexec_elf.o obj-$(CONFIG_CERT_STORE) += cert_store.o obj-$(CONFIG_IMA_SECURE_AND_OR_TRUSTED_BOOT) += ima_arch.o +obj-$(CONFIG_INTEGRITY_SECURE_BOOT) += integrity_sb_arch.o obj-$(CONFIG_PERF_EVENTS) += perf_event.o obj-$(CONFIG_PERF_EVENTS) += perf_cpum_cf.o perf_cpum_sf.o diff --git a/arch/s390/kernel/ima_arch.c b/arch/s390/kernel/ima_arch.c index f3c3e6e1c5d3..6ccbe34ce408 100644 --- a/arch/s390/kernel/ima_arch.c +++ b/arch/s390/kernel/ima_arch.c @@ -1,12 +1,6 @@ // SPDX-License-Identifier: GPL-2.0 #include <linux/ima.h> -#include <asm/boot_data.h> - -bool arch_ima_get_secureboot(void) -{ - return ipl_secure_flag; -} const char * const *arch_get_ima_policy(void) { diff --git a/arch/s390/kernel/integrity_sb_arch.c b/arch/s390/kernel/integrity_sb_arch.c new file mode 100644 index 000000000000..208a28cb9961 --- /dev/null +++ b/arch/s390/kernel/integrity_sb_arch.c @@ -0,0 +1,9 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/integrity.h> +#include <asm/boot_data.h> + +bool arch_integrity_get_secureboot(void) +{ + return ipl_secure_flag; +} diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 80527299f859..5051cc80309a 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -330,6 +330,7 @@ config X86 select FUNCTION_ALIGNMENT_16B if X86_64 || X86_ALIGNMENT_16 select FUNCTION_ALIGNMENT_4B imply IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI + imply INTEGRITY_SECURE_BOOT if EFI select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE select ARCH_SUPPORTS_PT_RECLAIM if X86_64 select ARCH_SUPPORTS_SCHED_SMT if SMP diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h index f227a70ac91f..d409f11da331 100644 --- a/arch/x86/include/asm/efi.h +++ b/arch/x86/include/asm/efi.h @@ -401,9 +401,9 @@ extern int __init efi_memmap_split_count(efi_memory_desc_t *md, extern void __init efi_memmap_insert(struct efi_memory_map *old_memmap, void *buf, struct efi_mem_range *mem); -extern enum efi_secureboot_mode __x86_ima_efi_boot_mode(void); +enum efi_secureboot_mode __x86_integrity_efi_boot_mode(void); -#define arch_ima_efi_boot_mode __x86_ima_efi_boot_mode() +#define arch_integrity_efi_boot_mode __x86_integrity_efi_boot_mode() #ifdef CONFIG_EFI_RUNTIME_MAP int efi_get_runtime_map_size(void); diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c index 463b784499a8..94704858f17a 100644 --- a/arch/x86/platform/efi/efi.c +++ b/arch/x86/platform/efi/efi.c @@ -921,7 +921,7 @@ umode_t efi_attr_is_visible(struct kobject *kobj, struct attribute *attr, int n) return attr->mode; } -enum efi_secureboot_mode __x86_ima_efi_boot_mode(void) +enum efi_secureboot_mode __x86_integrity_efi_boot_mode(void) { return boot_params.secure_boot; } diff --git a/include/linux/ima.h b/include/linux/ima.h index 8e29cb4e6a01..fc0ce1e27a2f 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h @@ -11,6 +11,7 @@ #include <linux/fs.h> #include <linux/security.h> #include <linux/kexec.h> +#include <linux/integrity.h> #include <crypto/hash_info.h> struct linux_binprm; @@ -72,14 +73,8 @@ int __init ima_get_kexec_buffer(void **addr, size_t *size); #endif #ifdef CONFIG_IMA_SECURE_AND_OR_TRUSTED_BOOT -extern bool arch_ima_get_secureboot(void); extern const char * const *arch_get_ima_policy(void); #else -static inline bool arch_ima_get_secureboot(void) -{ - return false; -} - static inline const char * const *arch_get_ima_policy(void) { return NULL; diff --git a/include/linux/integrity.h b/include/linux/integrity.h index f5842372359b..39e8961b58dd 100644 --- a/include/linux/integrity.h +++ b/include/linux/integrity.h @@ -61,5 +61,13 @@ integrity_inode_attrs_changed(const struct integrity_inode_attributes *attrs, !inode_eq_iversion(inode, attrs->version)); } +#ifdef CONFIG_INTEGRITY_SECURE_BOOT +bool arch_integrity_get_secureboot(void); +#else +static inline bool arch_integrity_get_secureboot(void) +{ + return false; +} +#endif #endif /* _LINUX_INTEGRITY_H */ diff --git a/security/integrity/Kconfig b/security/integrity/Kconfig index 916d4f2bfc44..1c3e54df3b73 100644 --- a/security/integrity/Kconfig +++ b/security/integrity/Kconfig @@ -97,6 +97,12 @@ config INTEGRITY_CA_MACHINE_KEYRING_MAX will not be loaded. The remaining MOK keys are loaded into the .platform keyring. +config INTEGRITY_SECURE_BOOT + bool + help + This option is selected by architectures to provide secure boot + related helper functions. + config LOAD_UEFI_KEYS depends on INTEGRITY_PLATFORM_KEYRING depends on EFI diff --git a/security/integrity/Makefile b/security/integrity/Makefile index 92b63039c654..08622460e6fd 100644 --- a/security/integrity/Makefile +++ b/security/integrity/Makefile @@ -18,6 +18,9 @@ integrity-$(CONFIG_LOAD_IPL_KEYS) += platform_certs/load_ipl_s390.o integrity-$(CONFIG_LOAD_PPC_KEYS) += platform_certs/efi_parser.o \ platform_certs/load_powerpc.o \ platform_certs/keyring_handler.o +ifeq ($(CONFIG_EFI),y) +integrity-$(CONFIG_INTEGRITY_SECURE_BOOT) += efi_secureboot.o +endif # The relative order of the 'ima' and 'evm' LSMs depends on the order below. obj-$(CONFIG_IMA) += ima/ obj-$(CONFIG_EVM) += evm/ diff --git a/security/integrity/efi_secureboot.c b/security/integrity/efi_secureboot.c new file mode 100644 index 000000000000..93d5086217d2 --- /dev/null +++ b/security/integrity/efi_secureboot.c @@ -0,0 +1,56 @@ +// SPDX-License-Identifier: GPL-1.0+ +/* + * Copyright (C) 2018 IBM Corporation + */ +#include <linux/efi.h> +#include <linux/integrity.h> +#include <asm/efi.h> + +#ifndef arch_integrity_efi_boot_mode +#define arch_integrity_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("integrity: 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("integrity: secureboot mode disabled\n"); + else if (mode == efi_secureboot_mode_unknown) + pr_info("integrity: secureboot mode unknown\n"); + else + pr_info("integrity: secureboot mode enabled\n"); + return mode; +} + +/* + * Query secure boot status + * + * Note don't call this function too early e.g. in __setup hook otherwise the + * kernel may hang when calling efi_get_secureboot_mode. + * + */ +bool arch_integrity_get_secureboot(void) +{ + static enum efi_secureboot_mode sb_mode; + static bool initialized; + + if (!initialized && efi_enabled(EFI_BOOT)) { + sb_mode = arch_integrity_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; +} diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index 5149ff4fd50d..f45106cad443 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -27,7 +27,7 @@ core_param(ima_appraise, ima_appraise_cmdline_default, charp, 0); void __init ima_appraise_parse_cmdline(void) { const char *str = ima_appraise_cmdline_default; - bool sb_state = arch_ima_get_secureboot(); + bool sb_state = arch_integrity_get_secureboot(); int appraisal_state = ima_appraise; if (!str) diff --git a/security/integrity/ima/ima_efi.c b/security/integrity/ima/ima_efi.c index 138029bfcce1..d6545ae446c7 100644 --- a/security/integrity/ima/ima_efi.c +++ b/security/integrity/ima/ima_efi.c @@ -2,52 +2,8 @@ /* * 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[] = { @@ -67,7 +23,8 @@ static const char * const sb_arch_rules[] = { const char * const *arch_get_ima_policy(void) { - if (IS_ENABLED(CONFIG_IMA_ARCH_POLICY) && arch_ima_get_secureboot()) { + if (IS_ENABLED(CONFIG_IMA_ARCH_POLICY) && + arch_integrity_get_secureboot()) { if (IS_ENABLED(CONFIG_MODULE_SIG)) set_module_sig_enforced(); if (IS_ENABLED(CONFIG_KEXEC_SIG)) diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 5770cf691912..3f267557dfbe 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -949,8 +949,8 @@ static int ima_load_data(enum kernel_load_data_id id, bool contents) switch (id) { case LOADING_KEXEC_IMAGE: - if (IS_ENABLED(CONFIG_KEXEC_SIG) - && arch_ima_get_secureboot()) { + if (IS_ENABLED(CONFIG_KEXEC_SIG) && + arch_integrity_get_secureboot()) { pr_err("impossible to appraise a kernel image without a file descriptor; try using kexec_file_load syscall.\n"); return -EACCES; } diff --git a/security/integrity/platform_certs/load_uefi.c b/security/integrity/platform_certs/load_uefi.c index d1fdd113450a..3042a0c536d6 100644 --- a/security/integrity/platform_certs/load_uefi.c +++ b/security/integrity/platform_certs/load_uefi.c @@ -212,7 +212,7 @@ static int __init load_uefi_certs(void) } /* the MOK/MOKx can not be trusted when secure boot is disabled */ - if (!arch_ima_get_secureboot()) + if (!arch_integrity_get_secureboot()) return 0; mokx = get_cert_list(L"MokListXRT", &mok_var, &mokxsize, &status); -- 2.52.0
