X-Git-Url: https://jxself.org/git/?a=blobdiff_plain;f=kconfig_hardened_check%2F__init__.py;h=9dc59ae633d060dd2b009805659af49540ea6df2;hb=860834d93c56279d0362432032883b6c81ae3ef5;hp=639be27caa457c7612730e21146af0df4adbe9f1;hpb=55690d46d5fa7786c331ec5051672d708cc94f21;p=kconfig-hardened-check.git diff --git a/kconfig_hardened_check/__init__.py b/kconfig_hardened_check/__init__.py index 639be27..9dc59ae 100644 --- a/kconfig_hardened_check/__init__.py +++ b/kconfig_hardened_check/__init__.py @@ -1,8 +1,8 @@ #!/usr/bin/python3 # -# This tool helps me to check the Linux kernel Kconfig option list -# against my security hardening preferences for X86_64, ARM64, X86_32, and ARM. +# This tool helps me to check Linux kernel options against +# my security hardening preferences for X86_64, ARM64, X86_32, and ARM. # Let the computers do their job! # # Author: Alexander Popov @@ -29,9 +29,9 @@ # pti=on # spec_store_bypass_disable=on # l1tf=full,force +# l1d_flush=on (a part of the l1tf option) # mds=full,nosmt # tsx=off -# l1d_flush=on # ARM64: # kpti=on # ssbd=force-on @@ -81,6 +81,7 @@ import re import json from .__about__ import __version__ +TYPES_OF_CHECKS = ('kconfig', 'version') class OptCheck: def __init__(self, reason, decision, name, expected): @@ -106,24 +107,38 @@ class OptCheck: return True return False + def table_print(self, _mode, with_results): + print('{:<40}|{:^7}|{:^12}|{:^10}|{:^18}'.format(self.name, self.type, self.expected, self.decision, self.reason), end='') + if with_results: + print('| {}'.format(self.result), end='') + class KconfigCheck(OptCheck): + def __init__(self, *args, **kwargs): + super().__init__(*args, **kwargs) + self.name = 'CONFIG_' + self.name + @property def type(self): - return "kconfig" + return 'kconfig' - def table_print(self, _mode, with_results): - print('CONFIG_{:<33}|{:^7}|{:^12}|{:^10}|{:^18}'.format(self.name, self.type, self.expected, self.decision, self.reason), end='') + def json_dump(self, with_results): + dump = [self.name, self.type, self.expected, self.decision, self.reason] if with_results: - print('| {}'.format(self.result), end='') + dump.append(self.result) + return dump -class VerCheck: +class VersionCheck: def __init__(self, ver_expected): self.ver_expected = ver_expected self.ver = () self.result = None + @property + def type(self): + return 'version' + def check(self): if self.ver[0] > self.ver_expected[0]: self.result = 'OK: version >= ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1]) @@ -145,8 +160,12 @@ class VerCheck: class PresenceCheck: - def __init__(self, name): - self.name = name + def __init__(self, name, type): + self.type = type + if self.type == 'kconfig': + self.name = 'CONFIG_' + name + else: + sys.exit('[!] ERROR: unsupported type "{}" for {}'.format(type, self.__class__.__name__)) self.state = None self.result = None @@ -158,7 +177,7 @@ class PresenceCheck: return True def table_print(self, _mode, with_results): - print('CONFIG_{:<84}'.format(self.name + ' is present'), end='') + print('{:<91}'.format(self.name + ' is present'), end='') if with_results: print('| {}'.format(self.result), end='') @@ -168,6 +187,8 @@ class ComplexOptCheck: self.opts = opts if not self.opts: sys.exit('[!] ERROR: empty {} check'.format(self.__class__.__name__)) + if len(self.opts) == 1: + sys.exit('[!] ERROR: useless {} check'.format(self.__class__.__name__)) if not isinstance(opts[0], KconfigCheck): sys.exit('[!] ERROR: invalid {} check: {}'.format(self.__class__.__name__, opts)) self.result = None @@ -178,7 +199,7 @@ class ComplexOptCheck: @property def type(self): - return self.opts[0].type + return 'complex' @property def expected(self): @@ -206,6 +227,12 @@ class ComplexOptCheck: if with_results: print('| {}'.format(self.result), end='') + def json_dump(self, with_results): + dump = self.opts[0].json_dump(False) + if with_results: + dump.append(self.result) + return dump + class OR(ComplexOptCheck): # self.opts[0] is the option that this OR-check is about. @@ -220,14 +247,11 @@ class OR(ComplexOptCheck): for i, opt in enumerate(self.opts): ret = opt.check() if ret: - if opt.result != 'OK' or i == 0: - # Preserve additional explanation of this OK result. - # Simple OK is enough only for the main option that - # this OR-check is about. - self.result = opt.result + if opt.result == 'OK' and i != 0: + # Simple OK is not enough for additional checks, add more info: + self.result = 'OK: {} "{}"'.format(opt.name, opt.expected) else: - # Simple OK is not enough for additional checks. - self.result = 'OK: CONFIG_{} "{}"'.format(opt.name, opt.expected) + self.result = opt.result return True self.result = self.opts[0].result return False @@ -251,9 +275,9 @@ class AND(ComplexOptCheck): # and not by the main option that this AND-check is about. # Describe the reason of the FAIL. if opt.result.startswith('FAIL: \"') or opt.result == 'FAIL: not found': - self.result = 'FAIL: CONFIG_{} not "{}"'.format(opt.name, opt.expected) + self.result = 'FAIL: {} not "{}"'.format(opt.name, opt.expected) elif opt.result == 'FAIL: not present': - self.result = 'FAIL: CONFIG_{} not present'.format(opt.name) + self.result = 'FAIL: {} not present'.format(opt.name) else: # This FAIL message is self-explaining. self.result = opt.result @@ -314,7 +338,7 @@ def add_kconfig_checks(l, arch): KconfigCheck('self_protection', 'defconfig', 'DEBUG_SET_MODULE_RONX', 'y'), modules_not_set)] # DEBUG_SET_MODULE_RONX was before v4.11 l += [OR(KconfigCheck('self_protection', 'defconfig', 'REFCOUNT_FULL', 'y'), - VerCheck((5, 5)))] # REFCOUNT_FULL is enabled by default since v5.5 + VersionCheck((5, 5)))] # REFCOUNT_FULL is enabled by default since v5.5 iommu_support_is_set = KconfigCheck('self_protection', 'defconfig', 'IOMMU_SUPPORT', 'y') l += [iommu_support_is_set] # is needed for mitigating DMA attacks if arch in ('X86_64', 'ARM64', 'X86_32'): @@ -344,12 +368,12 @@ def add_kconfig_checks(l, arch): l += [KconfigCheck('self_protection', 'defconfig', 'UNMAP_KERNEL_AT_EL0', 'y')] l += [OR(KconfigCheck('self_protection', 'defconfig', 'HARDEN_EL2_VECTORS', 'y'), AND(KconfigCheck('self_protection', 'defconfig', 'RANDOMIZE_BASE', 'y'), - VerCheck((5, 9))))] # HARDEN_EL2_VECTORS was included in RANDOMIZE_BASE in v5.9 + VersionCheck((5, 9))))] # HARDEN_EL2_VECTORS was included in RANDOMIZE_BASE in v5.9 l += [KconfigCheck('self_protection', 'defconfig', 'RODATA_FULL_DEFAULT_ENABLED', 'y')] l += [KconfigCheck('self_protection', 'defconfig', 'ARM64_PTR_AUTH_KERNEL', 'y')] l += [KconfigCheck('self_protection', 'defconfig', 'ARM64_BTI_KERNEL', 'y')] l += [OR(KconfigCheck('self_protection', 'defconfig', 'HARDEN_BRANCH_PREDICTOR', 'y'), - VerCheck((5, 10)))] # HARDEN_BRANCH_PREDICTOR is enabled by default since v5.10 + VersionCheck((5, 10)))] # HARDEN_BRANCH_PREDICTOR is enabled by default since v5.10 l += [KconfigCheck('self_protection', 'defconfig', 'ARM64_MTE', 'y')] if arch == 'ARM': l += [KconfigCheck('self_protection', 'defconfig', 'CPU_SW_DOMAIN_PAN', 'y')] @@ -446,6 +470,7 @@ def add_kconfig_checks(l, arch): # 'self_protection', 'my' l += [KconfigCheck('self_protection', 'my', 'RESET_ATTACK_MITIGATION', 'y')] # needs userspace support (systemd) if arch == 'X86_64': + l += [KconfigCheck('self_protection', 'my', 'SLS', 'y')] # vs CVE-2021-26341 in Straight-Line-Speculation l += [AND(KconfigCheck('self_protection', 'my', 'AMD_IOMMU_V2', 'y'), iommu_support_is_set)] if arch == 'ARM64': @@ -474,6 +499,7 @@ def add_kconfig_checks(l, arch): loadpin_is_set)] # 'cut_attack_surface', 'defconfig' + l += [KconfigCheck('cut_attack_surface', 'defconfig', 'BPF_UNPRIV_DEFAULT_OFF', 'y')] # see unprivileged_bpf_disabled l += [KconfigCheck('cut_attack_surface', 'defconfig', 'SECCOMP', 'y')] l += [KconfigCheck('cut_attack_surface', 'defconfig', 'SECCOMP_FILTER', 'y')] if arch in ('X86_64', 'ARM64', 'X86_32'): @@ -570,7 +596,7 @@ def add_kconfig_checks(l, arch): l += [KconfigCheck('cut_attack_surface', 'clipos', 'ACPI_TABLE_UPGRADE', 'is not set')] # refers to LOCKDOWN l += [KconfigCheck('cut_attack_surface', 'clipos', 'EFI_CUSTOM_SSDT_OVERLAYS', 'is not set')] l += [AND(KconfigCheck('cut_attack_surface', 'clipos', 'LDISC_AUTOLOAD', 'is not set'), - PresenceCheck('LDISC_AUTOLOAD'))] + PresenceCheck('LDISC_AUTOLOAD', 'kconfig'))] if arch in ('X86_64', 'X86_32'): l += [KconfigCheck('cut_attack_surface', 'clipos', 'X86_INTEL_TSX_MODE_OFF', 'y')] # tsx=off @@ -610,27 +636,33 @@ def add_kconfig_checks(l, arch): def print_unknown_options(checklist, parsed_options): known_options = [] - for opt in checklist: - if hasattr(opt, 'opts'): - for o in opt.opts: - if hasattr(o, 'name'): - known_options.append(o.name) - else: - known_options.append(opt.name) + + for o1 in checklist: + if o1.type != 'complex': + known_options.append(o1.name) + continue + for o2 in o1.opts: + if o2.type != 'complex': + if hasattr(o2, 'name'): + known_options.append(o2.name) + continue + for o3 in o2.opts: + if o3.type == 'complex': + sys.exit('[!] ERROR: unexpected ComplexOptCheck inside {}'.format(o2.name)) + if hasattr(o3, 'name'): + known_options.append(o3.name) + for option, value in parsed_options.items(): if option not in known_options: - print('[?] No rule for option {} ({})'.format(option, value)) + print('[?] No check for option {} ({})'.format(option, value)) def print_checklist(mode, checklist, with_results): if mode == 'json': - opts = [] + output = [] for o in checklist: - opt = ['CONFIG_'+o.name, o.type, o.expected, o.decision, o.reason] - if with_results: - opt.append(o.result) - opts.append(opt) - print(json.dumps(opts)) + output.append(o.json_dump(with_results)) + print(json.dumps(output)) return # table header @@ -673,28 +705,43 @@ def print_checklist(mode, checklist, with_results): print('[+] Config check is finished: \'OK\' - {}{} / \'FAIL\' - {}{}'.format(ok_count, ok_suppressed, fail_count, fail_suppressed)) -def perform_check(opt, parsed_options, kernel_version): - if hasattr(opt, 'opts'): - # prepare ComplexOptCheck +def populate_simple_opt_with_data(opt, data, data_type): + if opt.type == 'complex': + sys.exit('[!] ERROR: unexpected ComplexOptCheck {}: {}'.format(opt.name, vars(opt))) + if data_type not in TYPES_OF_CHECKS: + sys.exit('[!] ERROR: invalid data type "{}"'.format(data_type)) + + if data_type != opt.type: + return + + if data_type == 'kconfig': + opt.state = data.get(opt.name, None) + elif data_type == 'version': + opt.ver = data + + +def populate_opt_with_data(opt, data, data_type): + if opt.type == 'complex': for o in opt.opts: - if hasattr(o, 'opts'): - # Recursion for nested ComplexOptChecks - perform_check(o, parsed_options, kernel_version) - if hasattr(o, 'state'): - o.state = parsed_options.get(o.name, None) - if hasattr(o, 'ver'): - o.ver = kernel_version + if o.type == 'complex': + # Recursion for nested ComplexOptCheck objects + populate_opt_with_data(o, data, data_type) + else: + populate_simple_opt_with_data(o, data, data_type) else: - # prepare simple check, opt.state is mandatory - if not hasattr(opt, 'state'): - sys.exit('[!] ERROR: bad simple check {}'.format(vars(opt))) - opt.state = parsed_options.get(opt.name, None) - opt.check() + if opt.type != 'kconfig': + sys.exit('[!] ERROR: bad type "{}" for a simple check {}'.format(opt.type, opt.name)) + populate_simple_opt_with_data(opt, data, data_type) + + +def populate_with_data(checklist, data, data_type): + for opt in checklist: + populate_opt_with_data(opt, data, data_type) -def perform_checks(checklist, parsed_options, kernel_version): +def perform_checks(checklist): for opt in checklist: - perform_check(opt, parsed_options, kernel_version) + opt.check() def parse_kconfig_file(parsed_options, fname): @@ -708,9 +755,9 @@ def parse_kconfig_file(parsed_options, fname): value = None if opt_is_on.match(line): - option, value = line[7:].split('=', 1) + option, value = line.split('=', 1) elif opt_is_off.match(line): - option, value = line[9:].split(' ', 1) + option, value = line[2:].split(' ', 1) if value != 'is not set': sys.exit('[!] ERROR: bad disabled kconfig option "{}"'.format(line)) @@ -737,7 +784,7 @@ def main(): parser.add_argument('-p', '--print', choices=supported_archs, help='print security hardening preferences for the selected architecture') parser.add_argument('-c', '--config', - help='check the kernel config file against these preferences') + help='check the kernel kconfig file against these preferences') parser.add_argument('-m', '--mode', choices=report_modes, help='choose the report mode') args = parser.parse_args() @@ -746,13 +793,13 @@ def main(): if args.mode: mode = args.mode if mode != 'json': - print("[+] Special report mode: {}".format(mode)) + print('[+] Special report mode: {}'.format(mode)) config_checklist = [] if args.config: if mode != 'json': - print('[+] Config file to check: {}'.format(args.config)) + print('[+] Kconfig file to check: {}'.format(args.config)) arch, msg = detect_arch(args.config, supported_archs) if not arch: @@ -769,11 +816,16 @@ def main(): # add relevant kconfig checks to the checklist add_kconfig_checks(config_checklist, arch) + # populate the checklist with the parsed kconfig data parsed_kconfig_options = OrderedDict() parse_kconfig_file(parsed_kconfig_options, args.config) + populate_with_data(config_checklist, parsed_kconfig_options, 'kconfig') + populate_with_data(config_checklist, kernel_version, 'version') - perform_checks(config_checklist, parsed_kconfig_options, kernel_version) + # now everything is ready for performing the checks + perform_checks(config_checklist) + # finally print the results if mode == 'verbose': print_unknown_options(config_checklist, parsed_kconfig_options) print_checklist(mode, config_checklist, True)