#!/usr/bin/python3 # # 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 <alex.popov@linux.com> # # Please don't cry if my Python code looks like C. # # # N.B. Hardening sysctls: # kernel.kptr_restrict=2 (or 1?) # kernel.dmesg_restrict=1 (also see the kconfig option) # kernel.perf_event_paranoid=3 # kernel.kexec_load_disabled=1 # kernel.yama.ptrace_scope=3 # user.max_user_namespaces=0 # what about bpf_jit_enable? # kernel.unprivileged_bpf_disabled=1 # net.core.bpf_jit_harden=2 # vm.unprivileged_userfaultfd=0 # (at first, it disabled unprivileged userfaultfd, # and since v5.11 it enables unprivileged userfaultfd for user-mode only) # vm.mmap_min_addr has a good value # dev.tty.ldisc_autoload=0 # fs.protected_symlinks=1 # fs.protected_hardlinks=1 # fs.protected_fifos=2 # fs.protected_regular=2 # fs.suid_dumpable=0 # kernel.modules_disabled=1 # kernel.randomize_va_space = 2 # nosmt sysfs control file # pylint: disable=missing-module-docstring,missing-class-docstring,missing-function-docstring # pylint: disable=line-too-long,invalid-name,too-many-branches,too-many-statements import sys from argparse import ArgumentParser from collections import OrderedDict import re import json from .__about__ import __version__ SIMPLE_OPTION_TYPES = ('kconfig', 'version', 'cmdline') class OptCheck: def __init__(self, reason, decision, name, expected): assert(name and name == name.strip() and len(name.split()) == 1), \ 'invalid name "{}" for {}'.format(name, self.__class__.__name__) self.name = name assert(decision and decision == decision.strip() and len(decision.split()) == 1), \ 'invalid decision "{}" for "{}" check'.format(decision, name) self.decision = decision assert(reason and reason == reason.strip() and len(reason.split()) == 1), \ 'invalid reason "{}" for "{}" check'.format(reason, name) self.reason = reason assert(expected and expected == expected.strip()), \ 'invalid expected value "{}" for "{}" check (1)'.format(expected, name) val_len = len(expected.split()) if val_len == 3: assert(expected in ('is not set', 'is not off')), \ 'invalid expected value "{}" for "{}" check (2)'.format(expected, name) elif val_len == 2: assert(expected == 'is present'), \ 'invalid expected value "{}" for "{}" check (3)'.format(expected, name) else: assert(val_len == 1), \ 'invalid expected value "{}" for "{}" check (4)'.format(expected, name) self.expected = expected self.state = None self.result = None @property def type(self): return None def check(self): # handle the 'is present' check if self.expected == 'is present': if self.state is None: self.result = 'FAIL: is not present' else: self.result = 'OK: is present' return # handle the 'is not off' option check if self.expected == 'is not off': if self.state == 'off': self.result = 'FAIL: is off' if self.state == '0': self.result = 'FAIL: is off, "0"' elif self.state is None: self.result = 'FAIL: is off, not found' else: self.result = 'OK: is not off, "' + self.state + '"' return # handle the option value check if self.expected == self.state: self.result = 'OK' elif self.state is None: if self.expected == 'is not set': self.result = 'OK: is not found' else: self.result = 'FAIL: is not found' else: self.result = 'FAIL: "' + self.state + '"' 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='') def json_dump(self, with_results): dump = [self.name, self.type, self.expected, self.decision, self.reason] if with_results: dump.append(self.result) return dump class KconfigCheck(OptCheck): def __init__(self, *args, **kwargs): super().__init__(*args, **kwargs) self.name = 'CONFIG_' + self.name @property def type(self): return 'kconfig' class CmdlineCheck(OptCheck): @property def type(self): return 'cmdline' class VersionCheck: def __init__(self, ver_expected): assert(ver_expected and isinstance(ver_expected, tuple) and len(ver_expected) == 2), \ 'invalid version "{}" for VersionCheck'.format(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]) return if self.ver[0] < self.ver_expected[0]: self.result = 'FAIL: version < ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1]) return if self.ver[1] >= self.ver_expected[1]: self.result = 'OK: version >= ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1]) return self.result = 'FAIL: version < ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1]) def table_print(self, _mode, with_results): ver_req = 'kernel version >= ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1]) print('{:<91}'.format(ver_req), end='') if with_results: print('| {}'.format(self.result), end='') class ComplexOptCheck: def __init__(self, *opts): self.opts = opts assert(self.opts), \ 'empty {} check'.format(self.__class__.__name__) assert(len(self.opts) != 1), \ 'useless {} check: {}'.format(self.__class__.__name__, opts) assert(isinstance(opts[0], (KconfigCheck, CmdlineCheck))), \ 'invalid {} check: {}'.format(self.__class__.__name__, opts) self.result = None @property def type(self): return 'complex' @property def name(self): return self.opts[0].name @property def expected(self): return self.opts[0].expected def table_print(self, mode, with_results): if mode == 'verbose': print(' {:87}'.format('<<< ' + self.__class__.__name__ + ' >>>'), end='') if with_results: print('| {}'.format(self.result), end='') for o in self.opts: print() o.table_print(mode, with_results) else: o = self.opts[0] o.table_print(mode, False) 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. # Use cases: # OR(<X_is_hardened>, <X_is_disabled>) # OR(<X_is_hardened>, <old_X_is_hardened>) def check(self): for i, opt in enumerate(self.opts): opt.check() if opt.result.startswith('OK'): self.result = opt.result # Add more info for additional checks: if i != 0: if opt.result == 'OK': self.result = 'OK: {} is "{}"'.format(opt.name, opt.expected) elif opt.result == 'OK: is not found': self.result = 'OK: {} is not found'.format(opt.name) elif opt.result == 'OK: is present': self.result = 'OK: {} is present'.format(opt.name) elif opt.result.startswith('OK: is not off'): self.result = 'OK: {} is not off'.format(opt.name) else: # VersionCheck provides enough info assert(opt.result.startswith('OK: version')), \ 'unexpected OK description "{}"'.format(opt.result) return self.result = self.opts[0].result class AND(ComplexOptCheck): # self.opts[0] is the option that this AND-check is about. # Use cases: # AND(<suboption>, <main_option>) # Suboption is not checked if checking of the main_option is failed. # AND(<X_is_disabled>, <old_X_is_disabled>) def check(self): for i, opt in reversed(list(enumerate(self.opts))): opt.check() if i == 0: self.result = opt.result return if not opt.result.startswith('OK'): # This FAIL is caused by additional checks, # 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: is not found': self.result = 'FAIL: {} is not "{}"'.format(opt.name, opt.expected) elif opt.result == 'FAIL: is not present': self.result = 'FAIL: {} is not present'.format(opt.name) elif opt.result in ('FAIL: is off', 'FAIL: is off, "0"'): self.result = 'FAIL: {} is off'.format(opt.name) elif opt.result == 'FAIL: is off, not found': self.result = 'FAIL: {} is off, not found'.format(opt.name) else: # VersionCheck provides enough info self.result = opt.result assert(opt.result.startswith('FAIL: version')), \ 'unexpected FAIL description "{}"'.format(opt.result) return def detect_arch(fname, archs): with open(fname, 'r') as f: arch_pattern = re.compile("CONFIG_[a-zA-Z0-9_]*=y") arch = None for line in f.readlines(): if arch_pattern.match(line): option, _ = line[7:].split('=', 1) if option in archs: if not arch: arch = option else: return None, 'more than one supported architecture is detected' if not arch: return None, 'failed to detect architecture' return arch, 'OK' def detect_kernel_version(fname): with open(fname, 'r') as f: ver_pattern = re.compile("# Linux/.* Kernel Configuration") for line in f.readlines(): if ver_pattern.match(line): line = line.strip() parts = line.split() ver_str = parts[2] ver_numbers = ver_str.split('.') if len(ver_numbers) < 3 or not ver_numbers[0].isdigit() or not ver_numbers[1].isdigit(): msg = 'failed to parse the version "' + ver_str + '"' return None, msg return (int(ver_numbers[0]), int(ver_numbers[1])), None return None, 'no kernel version detected' def detect_compiler(fname): gcc_version = None clang_version = None with open(fname, 'r') as f: gcc_version_pattern = re.compile("CONFIG_GCC_VERSION=[0-9]*") clang_version_pattern = re.compile("CONFIG_CLANG_VERSION=[0-9]*") for line in f.readlines(): if gcc_version_pattern.match(line): gcc_version = line[19:-1] if clang_version_pattern.match(line): clang_version = line[21:-1] if not gcc_version or not clang_version: return None, 'no CONFIG_GCC_VERSION or CONFIG_CLANG_VERSION' if gcc_version == '0' and clang_version != '0': return 'CLANG ' + clang_version, 'OK' if gcc_version != '0' and clang_version == '0': return 'GCC ' + gcc_version, 'OK' sys.exit('[!] ERROR: invalid GCC_VERSION and CLANG_VERSION: {} {}'.format(gcc_version, clang_version)) def add_kconfig_checks(l, arch): # Calling the KconfigCheck class constructor: # KconfigCheck(reason, decision, name, expected) # # [!] Don't add CmdlineChecks in add_kconfig_checks() to avoid wrong results # when the tool doesn't check the cmdline. efi_not_set = KconfigCheck('-', '-', 'EFI', 'is not set') cc_is_gcc = KconfigCheck('-', '-', 'CC_IS_GCC', 'y') # exists since v4.18 cc_is_clang = KconfigCheck('-', '-', 'CC_IS_CLANG', 'y') # exists since v4.18 modules_not_set = KconfigCheck('cut_attack_surface', 'kspp', 'MODULES', 'is not set') devmem_not_set = KconfigCheck('cut_attack_surface', 'kspp', 'DEVMEM', 'is not set') # refers to LOCKDOWN bpf_syscall_not_set = KconfigCheck('cut_attack_surface', 'lockdown', 'BPF_SYSCALL', 'is not set') # refers to LOCKDOWN # 'self_protection', 'defconfig' l += [KconfigCheck('self_protection', 'defconfig', 'BUG', 'y')] l += [KconfigCheck('self_protection', 'defconfig', 'SLUB_DEBUG', 'y')] l += [KconfigCheck('self_protection', 'defconfig', 'THREAD_INFO_IN_TASK', 'y')] gcc_plugins_support_is_set = KconfigCheck('self_protection', 'defconfig', 'GCC_PLUGINS', 'y') l += [gcc_plugins_support_is_set] iommu_support_is_set = KconfigCheck('self_protection', 'defconfig', 'IOMMU_SUPPORT', 'y') l += [iommu_support_is_set] # is needed for mitigating DMA attacks l += [OR(KconfigCheck('self_protection', 'defconfig', 'STACKPROTECTOR', 'y'), KconfigCheck('self_protection', 'defconfig', 'CC_STACKPROTECTOR', 'y'), KconfigCheck('self_protection', 'defconfig', 'CC_STACKPROTECTOR_REGULAR', 'y'), KconfigCheck('self_protection', 'defconfig', 'CC_STACKPROTECTOR_AUTO', 'y'), KconfigCheck('self_protection', 'defconfig', 'CC_STACKPROTECTOR_STRONG', 'y'))] l += [OR(KconfigCheck('self_protection', 'defconfig', 'STACKPROTECTOR_STRONG', 'y'), KconfigCheck('self_protection', 'defconfig', 'CC_STACKPROTECTOR_STRONG', 'y'))] l += [OR(KconfigCheck('self_protection', 'defconfig', 'STRICT_KERNEL_RWX', 'y'), KconfigCheck('self_protection', 'defconfig', 'DEBUG_RODATA', 'y'))] # before v4.11 l += [OR(KconfigCheck('self_protection', 'defconfig', 'STRICT_MODULE_RWX', 'y'), 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'), VersionCheck((5, 5)))] # REFCOUNT_FULL is enabled by default since v5.5 if arch in ('X86_64', 'ARM64', 'X86_32'): l += [KconfigCheck('self_protection', 'defconfig', 'RANDOMIZE_BASE', 'y')] if arch in ('X86_64', 'ARM64', 'ARM'): l += [KconfigCheck('self_protection', 'defconfig', 'VMAP_STACK', 'y')] if arch in ('X86_64', 'X86_32'): l += [KconfigCheck('self_protection', 'defconfig', 'DEBUG_WX', 'y')] l += [KconfigCheck('self_protection', 'defconfig', 'WERROR', 'y')] l += [KconfigCheck('self_protection', 'defconfig', 'X86_MCE', 'y')] l += [KconfigCheck('self_protection', 'defconfig', 'X86_MCE_INTEL', 'y')] l += [KconfigCheck('self_protection', 'defconfig', 'X86_MCE_AMD', 'y')] l += [KconfigCheck('self_protection', 'defconfig', 'MICROCODE', 'y')] # is needed for mitigating CPU bugs l += [KconfigCheck('self_protection', 'defconfig', 'RETPOLINE', 'y')] l += [KconfigCheck('self_protection', 'defconfig', 'SYN_COOKIES', 'y')] # another reason? l += [OR(KconfigCheck('self_protection', 'defconfig', 'X86_SMAP', 'y'), VersionCheck((5, 19)))] # X86_SMAP is enabled by default since v5.19 l += [OR(KconfigCheck('self_protection', 'defconfig', 'X86_UMIP', 'y'), KconfigCheck('self_protection', 'defconfig', 'X86_INTEL_UMIP', 'y'))] if arch in ('ARM64', 'ARM'): l += [KconfigCheck('self_protection', 'defconfig', 'IOMMU_DEFAULT_DMA_STRICT', 'y')] l += [KconfigCheck('self_protection', 'defconfig', 'IOMMU_DEFAULT_PASSTHROUGH', 'is not set')] # true if IOMMU_DEFAULT_DMA_STRICT is set l += [KconfigCheck('self_protection', 'defconfig', 'STACKPROTECTOR_PER_TASK', 'y')] if arch == 'X86_64': l += [KconfigCheck('self_protection', 'defconfig', 'PAGE_TABLE_ISOLATION', 'y')] l += [KconfigCheck('self_protection', 'defconfig', 'RANDOMIZE_MEMORY', 'y')] l += [AND(KconfigCheck('self_protection', 'defconfig', 'INTEL_IOMMU', 'y'), iommu_support_is_set)] l += [AND(KconfigCheck('self_protection', 'defconfig', 'AMD_IOMMU', 'y'), iommu_support_is_set)] if arch == 'ARM64': l += [KconfigCheck('self_protection', 'defconfig', 'ARM64_PAN', 'y')] l += [KconfigCheck('self_protection', 'defconfig', 'ARM64_EPAN', 'y')] l += [KconfigCheck('self_protection', 'defconfig', 'UNMAP_KERNEL_AT_EL0', 'y')] l += [KconfigCheck('self_protection', 'defconfig', 'ARM64_E0PD', 'y')] 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 += [KconfigCheck('self_protection', 'defconfig', 'MITIGATE_SPECTRE_BRANCH_HISTORY', 'y')] l += [KconfigCheck('self_protection', 'defconfig', 'ARM64_MTE', 'y')] l += [KconfigCheck('self_protection', 'defconfig', 'RANDOMIZE_MODULE_REGION_FULL', 'y')] l += [OR(KconfigCheck('self_protection', 'defconfig', 'HARDEN_EL2_VECTORS', 'y'), AND(KconfigCheck('self_protection', 'defconfig', 'RANDOMIZE_BASE', 'y'), VersionCheck((5, 9))))] # HARDEN_EL2_VECTORS was included in RANDOMIZE_BASE in v5.9 l += [OR(KconfigCheck('self_protection', 'defconfig', 'HARDEN_BRANCH_PREDICTOR', 'y'), VersionCheck((5, 10)))] # HARDEN_BRANCH_PREDICTOR is enabled by default since v5.10 if arch == 'ARM': l += [KconfigCheck('self_protection', 'defconfig', 'CPU_SW_DOMAIN_PAN', 'y')] l += [KconfigCheck('self_protection', 'defconfig', 'HARDEN_BRANCH_PREDICTOR', 'y')] l += [KconfigCheck('self_protection', 'defconfig', 'HARDEN_BRANCH_HISTORY', 'y')] # 'self_protection', 'kspp' l += [KconfigCheck('self_protection', 'kspp', 'BUG_ON_DATA_CORRUPTION', 'y')] l += [KconfigCheck('self_protection', 'kspp', 'SCHED_STACK_END_CHECK', 'y')] l += [KconfigCheck('self_protection', 'kspp', 'SLAB_FREELIST_HARDENED', 'y')] l += [KconfigCheck('self_protection', 'kspp', 'SLAB_FREELIST_RANDOM', 'y')] l += [KconfigCheck('self_protection', 'kspp', 'SHUFFLE_PAGE_ALLOCATOR', 'y')] l += [KconfigCheck('self_protection', 'kspp', 'FORTIFY_SOURCE', 'y')] l += [KconfigCheck('self_protection', 'kspp', 'DEBUG_LIST', 'y')] l += [KconfigCheck('self_protection', 'kspp', 'DEBUG_VIRTUAL', 'y')] l += [KconfigCheck('self_protection', 'kspp', 'DEBUG_SG', 'y')] l += [KconfigCheck('self_protection', 'kspp', 'DEBUG_CREDENTIALS', 'y')] l += [KconfigCheck('self_protection', 'kspp', 'DEBUG_NOTIFIERS', 'y')] l += [KconfigCheck('self_protection', 'kspp', 'INIT_ON_ALLOC_DEFAULT_ON', 'y')] l += [KconfigCheck('self_protection', 'kspp', 'KFENCE', 'y')] l += [KconfigCheck('self_protection', 'kspp', 'ZERO_CALL_USED_REGS', 'y')] l += [KconfigCheck('self_protection', 'kspp', 'HW_RANDOM_TPM', 'y')] l += [KconfigCheck('self_protection', 'kspp', 'STATIC_USERMODEHELPER', 'y')] # needs userspace support randstruct_is_set = OR(KconfigCheck('self_protection', 'kspp', 'RANDSTRUCT_FULL', 'y'), KconfigCheck('self_protection', 'kspp', 'GCC_PLUGIN_RANDSTRUCT', 'y')) l += [randstruct_is_set] l += [AND(KconfigCheck('self_protection', 'kspp', 'RANDSTRUCT_PERFORMANCE', 'is not set'), KconfigCheck('self_protection', 'kspp', 'GCC_PLUGIN_RANDSTRUCT_PERFORMANCE', 'is not set'), randstruct_is_set)] hardened_usercopy_is_set = KconfigCheck('self_protection', 'kspp', 'HARDENED_USERCOPY', 'y') l += [hardened_usercopy_is_set] l += [AND(KconfigCheck('self_protection', 'kspp', 'HARDENED_USERCOPY_FALLBACK', 'is not set'), hardened_usercopy_is_set)] l += [AND(KconfigCheck('self_protection', 'kspp', 'HARDENED_USERCOPY_PAGESPAN', 'is not set'), hardened_usercopy_is_set)] l += [AND(KconfigCheck('self_protection', 'kspp', 'GCC_PLUGIN_LATENT_ENTROPY', 'y'), gcc_plugins_support_is_set)] l += [OR(KconfigCheck('self_protection', 'kspp', 'MODULE_SIG', 'y'), modules_not_set)] l += [OR(KconfigCheck('self_protection', 'kspp', 'MODULE_SIG_ALL', 'y'), modules_not_set)] l += [OR(KconfigCheck('self_protection', 'kspp', 'MODULE_SIG_SHA512', 'y'), modules_not_set)] l += [OR(KconfigCheck('self_protection', 'kspp', 'MODULE_SIG_FORCE', 'y'), modules_not_set)] # refers to LOCKDOWN l += [OR(KconfigCheck('self_protection', 'kspp', 'INIT_STACK_ALL_ZERO', 'y'), KconfigCheck('self_protection', 'kspp', 'GCC_PLUGIN_STRUCTLEAK_BYREF_ALL', 'y'))] l += [OR(KconfigCheck('self_protection', 'kspp', 'INIT_ON_FREE_DEFAULT_ON', 'y'), KconfigCheck('self_protection', 'kspp', 'PAGE_POISONING_ZERO', 'y'))] # CONFIG_INIT_ON_FREE_DEFAULT_ON was added in v5.3. # CONFIG_PAGE_POISONING_ZERO was removed in v5.11. # Starting from v5.11 CONFIG_PAGE_POISONING unconditionally checks # the 0xAA poison pattern on allocation. # That brings higher performance penalty. l += [OR(KconfigCheck('self_protection', 'kspp', 'EFI_DISABLE_PCI_DMA', 'y'), efi_not_set)] l += [OR(KconfigCheck('self_protection', 'kspp', 'RESET_ATTACK_MITIGATION', 'y'), efi_not_set)] # needs userspace support (systemd) ubsan_bounds_is_set = KconfigCheck('self_protection', 'kspp', 'UBSAN_BOUNDS', 'y') l += [ubsan_bounds_is_set] l += [OR(KconfigCheck('self_protection', 'kspp', 'UBSAN_LOCAL_BOUNDS', 'y'), AND(ubsan_bounds_is_set, cc_is_gcc))] l += [AND(KconfigCheck('self_protection', 'kspp', 'UBSAN_TRAP', 'y'), ubsan_bounds_is_set, KconfigCheck('self_protection', 'kspp', 'UBSAN_SHIFT', 'is not set'), KconfigCheck('self_protection', 'kspp', 'UBSAN_DIV_ZERO', 'is not set'), KconfigCheck('self_protection', 'kspp', 'UBSAN_UNREACHABLE', 'is not set'), KconfigCheck('self_protection', 'kspp', 'UBSAN_BOOL', 'is not set'), KconfigCheck('self_protection', 'kspp', 'UBSAN_ENUM', 'is not set'), KconfigCheck('self_protection', 'kspp', 'UBSAN_ALIGNMENT', 'is not set'))] # only array index bounds checking with traps if arch in ('X86_64', 'ARM64', 'X86_32'): l += [AND(KconfigCheck('self_protection', 'kspp', 'UBSAN_SANITIZE_ALL', 'y'), ubsan_bounds_is_set)] # ARCH_HAS_UBSAN_SANITIZE_ALL is not enabled for ARM stackleak_is_set = KconfigCheck('self_protection', 'kspp', 'GCC_PLUGIN_STACKLEAK', 'y') l += [AND(stackleak_is_set, gcc_plugins_support_is_set)] l += [AND(KconfigCheck('self_protection', 'kspp', 'STACKLEAK_METRICS', 'is not set'), stackleak_is_set, gcc_plugins_support_is_set)] l += [AND(KconfigCheck('self_protection', 'kspp', 'STACKLEAK_RUNTIME_DISABLE', 'is not set'), stackleak_is_set, gcc_plugins_support_is_set)] l += [KconfigCheck('self_protection', 'kspp', 'RANDOMIZE_KSTACK_OFFSET_DEFAULT', 'y')] if arch in ('X86_64', 'ARM64'): cfi_clang_is_set = KconfigCheck('self_protection', 'kspp', 'CFI_CLANG', 'y') l += [cfi_clang_is_set] l += [AND(KconfigCheck('self_protection', 'kspp', 'CFI_PERMISSIVE', 'is not set'), cfi_clang_is_set)] if arch in ('X86_64', 'X86_32'): l += [KconfigCheck('self_protection', 'kspp', 'SCHED_CORE', 'y')] l += [KconfigCheck('self_protection', 'kspp', 'DEFAULT_MMAP_MIN_ADDR', '65536')] l += [KconfigCheck('self_protection', 'kspp', 'IOMMU_DEFAULT_DMA_STRICT', 'y')] l += [KconfigCheck('self_protection', 'kspp', 'IOMMU_DEFAULT_PASSTHROUGH', 'is not set')] # true if IOMMU_DEFAULT_DMA_STRICT is set l += [AND(KconfigCheck('self_protection', 'kspp', 'INTEL_IOMMU_DEFAULT_ON', 'y'), iommu_support_is_set)] if arch in ('ARM64', 'ARM'): l += [KconfigCheck('self_protection', 'kspp', 'DEBUG_WX', 'y')] l += [KconfigCheck('self_protection', 'kspp', 'WERROR', 'y')] l += [KconfigCheck('self_protection', 'kspp', 'DEFAULT_MMAP_MIN_ADDR', '32768')] l += [KconfigCheck('self_protection', 'kspp', 'SYN_COOKIES', 'y')] # another reason? if arch == 'X86_64': l += [KconfigCheck('self_protection', 'kspp', 'SLS', 'y')] # vs CVE-2021-26341 in Straight-Line-Speculation l += [AND(KconfigCheck('self_protection', 'kspp', 'INTEL_IOMMU_SVM', 'y'), iommu_support_is_set)] l += [AND(KconfigCheck('self_protection', 'kspp', 'AMD_IOMMU_V2', 'y'), iommu_support_is_set)] if arch == 'ARM64': l += [KconfigCheck('self_protection', 'kspp', 'ARM64_SW_TTBR0_PAN', 'y')] l += [KconfigCheck('self_protection', 'kspp', 'SHADOW_CALL_STACK', 'y')] l += [KconfigCheck('self_protection', 'kspp', 'KASAN_HW_TAGS', 'y')] # see also: kasan=on, kasan.stacktrace=off, kasan.fault=panic if arch == 'X86_32': l += [KconfigCheck('self_protection', 'kspp', 'PAGE_TABLE_ISOLATION', 'y')] l += [KconfigCheck('self_protection', 'kspp', 'HIGHMEM64G', 'y')] l += [KconfigCheck('self_protection', 'kspp', 'X86_PAE', 'y')] l += [AND(KconfigCheck('self_protection', 'kspp', 'INTEL_IOMMU', 'y'), iommu_support_is_set)] # 'self_protection', 'clipos' l += [KconfigCheck('self_protection', 'clipos', 'SLAB_MERGE_DEFAULT', 'is not set')] # 'security_policy' if arch in ('X86_64', 'ARM64', 'X86_32'): l += [KconfigCheck('security_policy', 'defconfig', 'SECURITY', 'y')] # and choose your favourite LSM if arch == 'ARM': l += [KconfigCheck('security_policy', 'kspp', 'SECURITY', 'y')] # and choose your favourite LSM l += [KconfigCheck('security_policy', 'kspp', 'SECURITY_YAMA', 'y')] l += [KconfigCheck('security_policy', 'kspp', 'SECURITY_LANDLOCK', 'y')] l += [KconfigCheck('security_policy', 'kspp', 'SECURITY_SELINUX_DISABLE', 'is not set')] l += [KconfigCheck('security_policy', 'kspp', 'SECURITY_SELINUX_BOOTPARAM', 'is not set')] l += [KconfigCheck('security_policy', 'kspp', 'SECURITY_SELINUX_DEVELOP', 'is not set')] l += [KconfigCheck('security_policy', 'kspp', 'SECURITY_LOCKDOWN_LSM', 'y')] l += [KconfigCheck('security_policy', 'kspp', 'SECURITY_LOCKDOWN_LSM_EARLY', 'y')] l += [KconfigCheck('security_policy', 'kspp', 'LOCK_DOWN_KERNEL_FORCE_CONFIDENTIALITY', 'y')] l += [KconfigCheck('security_policy', 'kspp', 'SECURITY_WRITABLE_HOOKS', 'is not set')] # refers to SECURITY_SELINUX_DISABLE # 'cut_attack_surface', 'defconfig' l += [KconfigCheck('cut_attack_surface', 'defconfig', 'SECCOMP', 'y')] l += [KconfigCheck('cut_attack_surface', 'defconfig', 'SECCOMP_FILTER', 'y')] l += [OR(KconfigCheck('cut_attack_surface', 'defconfig', 'BPF_UNPRIV_DEFAULT_OFF', 'y'), bpf_syscall_not_set)] # see unprivileged_bpf_disabled if arch in ('X86_64', 'ARM64', 'X86_32'): l += [OR(KconfigCheck('cut_attack_surface', 'defconfig', 'STRICT_DEVMEM', 'y'), devmem_not_set)] # refers to LOCKDOWN if arch in ('X86_64', 'X86_32'): l += [KconfigCheck('cut_attack_surface', 'defconfig', 'X86_INTEL_TSX_MODE_OFF', 'y')] # tsx=off # 'cut_attack_surface', 'kspp' l += [KconfigCheck('cut_attack_surface', 'kspp', 'SECURITY_DMESG_RESTRICT', 'y')] l += [KconfigCheck('cut_attack_surface', 'kspp', 'ACPI_CUSTOM_METHOD', 'is not set')] # refers to LOCKDOWN l += [KconfigCheck('cut_attack_surface', 'kspp', 'COMPAT_BRK', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'kspp', 'DEVKMEM', 'is not set')] # refers to LOCKDOWN l += [KconfigCheck('cut_attack_surface', 'kspp', 'COMPAT_VDSO', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'kspp', 'BINFMT_MISC', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'kspp', 'INET_DIAG', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'kspp', 'KEXEC', 'is not set')] # refers to LOCKDOWN l += [KconfigCheck('cut_attack_surface', 'kspp', 'PROC_KCORE', 'is not set')] # refers to LOCKDOWN l += [KconfigCheck('cut_attack_surface', 'kspp', 'LEGACY_PTYS', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'kspp', 'HIBERNATION', 'is not set')] # refers to LOCKDOWN l += [KconfigCheck('cut_attack_surface', 'kspp', 'COMPAT', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'kspp', 'IA32_EMULATION', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'kspp', 'X86_X32', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'kspp', 'X86_X32_ABI', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'kspp', 'MODIFY_LDT_SYSCALL', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'kspp', 'OABI_COMPAT', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'kspp', 'X86_MSR', 'is not set')] # refers to LOCKDOWN l += [modules_not_set] l += [devmem_not_set] l += [OR(KconfigCheck('cut_attack_surface', 'kspp', 'IO_STRICT_DEVMEM', 'y'), devmem_not_set)] # refers to LOCKDOWN l += [AND(KconfigCheck('cut_attack_surface', 'kspp', 'LDISC_AUTOLOAD', 'is not set'), KconfigCheck('cut_attack_surface', 'kspp', 'LDISC_AUTOLOAD', 'is present'))] if arch == 'X86_64': l += [KconfigCheck('cut_attack_surface', 'kspp', 'LEGACY_VSYSCALL_NONE', 'y')] # 'vsyscall=none' if arch == 'ARM': l += [OR(KconfigCheck('cut_attack_surface', 'kspp', 'STRICT_DEVMEM', 'y'), devmem_not_set)] # refers to LOCKDOWN # 'cut_attack_surface', 'grsec' l += [KconfigCheck('cut_attack_surface', 'grsec', 'ZSMALLOC_STAT', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'grsec', 'PAGE_OWNER', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'grsec', 'DEBUG_KMEMLEAK', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'grsec', 'BINFMT_AOUT', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'grsec', 'KPROBE_EVENTS', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'grsec', 'UPROBE_EVENTS', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'grsec', 'GENERIC_TRACER', 'is not set')] # refers to LOCKDOWN l += [KconfigCheck('cut_attack_surface', 'grsec', 'FUNCTION_TRACER', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'grsec', 'STACK_TRACER', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'grsec', 'HIST_TRIGGERS', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'grsec', 'BLK_DEV_IO_TRACE', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'grsec', 'PROC_VMCORE', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'grsec', 'PROC_PAGE_MONITOR', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'grsec', 'USELIB', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'grsec', 'CHECKPOINT_RESTORE', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'grsec', 'USERFAULTFD', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'grsec', 'HWPOISON_INJECT', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'grsec', 'MEM_SOFT_DIRTY', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'grsec', 'DEVPORT', 'is not set')] # refers to LOCKDOWN l += [KconfigCheck('cut_attack_surface', 'grsec', 'DEBUG_FS', 'is not set')] # refers to LOCKDOWN l += [KconfigCheck('cut_attack_surface', 'grsec', 'NOTIFIER_ERROR_INJECTION', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'grsec', 'FAIL_FUTEX', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'grsec', 'PUNIT_ATOM_DEBUG', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'grsec', 'ACPI_CONFIGFS', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'grsec', 'EDAC_DEBUG', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'grsec', 'DRM_I915_DEBUG', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'grsec', 'BCACHE_CLOSURES_DEBUG', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'grsec', 'DVB_C8SECTPFE', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'grsec', 'MTD_SLRAM', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'grsec', 'MTD_PHRAM', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'grsec', 'IO_URING', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'grsec', 'KCMP', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'grsec', 'RSEQ', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'grsec', 'LATENCYTOP', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'grsec', 'KCOV', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'grsec', 'PROVIDE_OHCI1394_DMA_INIT', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'grsec', 'SUNRPC_DEBUG', 'is not set')] l += [AND(KconfigCheck('cut_attack_surface', 'grsec', 'PTDUMP_DEBUGFS', 'is not set'), KconfigCheck('cut_attack_surface', 'grsec', 'X86_PTDUMP', 'is not set'))] # 'cut_attack_surface', 'maintainer' l += [KconfigCheck('cut_attack_surface', 'maintainer', 'DRM_LEGACY', 'is not set')] # recommended by Daniel Vetter in /issues/38 l += [KconfigCheck('cut_attack_surface', 'maintainer', 'FB', 'is not set')] # recommended by Daniel Vetter in /issues/38 l += [KconfigCheck('cut_attack_surface', 'maintainer', 'VT', 'is not set')] # recommended by Daniel Vetter in /issues/38 l += [KconfigCheck('cut_attack_surface', 'maintainer', 'BLK_DEV_FD', 'is not set')] # recommended by Denis Efremov in /pull/54 l += [KconfigCheck('cut_attack_surface', 'maintainer', 'BLK_DEV_FD_RAWCMD', 'is not set')] # recommended by Denis Efremov in /pull/62 l += [KconfigCheck('cut_attack_surface', 'maintainer', 'NOUVEAU_LEGACY_CTX_SUPPORT', 'is not set')] # recommended by Dave Airlie in kernel commit b30a43ac7132cdda # 'cut_attack_surface', 'clipos' l += [KconfigCheck('cut_attack_surface', 'clipos', 'STAGING', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'clipos', 'KSM', 'is not set')] # to prevent FLUSH+RELOAD attack l += [KconfigCheck('cut_attack_surface', 'clipos', 'KALLSYMS', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'clipos', 'X86_VSYSCALL_EMULATION', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'clipos', 'MAGIC_SYSRQ', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'clipos', 'KEXEC_FILE', 'is not set')] # refers to LOCKDOWN (permissive) l += [KconfigCheck('cut_attack_surface', 'clipos', 'USER_NS', 'is not set')] # user.max_user_namespaces=0 l += [KconfigCheck('cut_attack_surface', 'clipos', 'X86_CPUID', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'clipos', 'X86_IOPL_IOPERM', 'is not set')] # refers to LOCKDOWN 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 += [KconfigCheck('cut_attack_surface', 'clipos', 'COREDUMP', 'is not set')] # cut userspace attack surface # l += [KconfigCheck('cut_attack_surface', 'clipos', 'IKCONFIG', 'is not set')] # no, IKCONFIG is needed for this check :) # 'cut_attack_surface', 'lockdown' l += [KconfigCheck('cut_attack_surface', 'lockdown', 'EFI_TEST', 'is not set')] # refers to LOCKDOWN l += [KconfigCheck('cut_attack_surface', 'lockdown', 'MMIOTRACE_TEST', 'is not set')] # refers to LOCKDOWN l += [KconfigCheck('cut_attack_surface', 'lockdown', 'KPROBES', 'is not set')] # refers to LOCKDOWN l += [bpf_syscall_not_set] # refers to LOCKDOWN # 'cut_attack_surface', 'my' l += [KconfigCheck('cut_attack_surface', 'my', 'MMIOTRACE', 'is not set')] # refers to LOCKDOWN (permissive) l += [KconfigCheck('cut_attack_surface', 'my', 'LIVEPATCH', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'my', 'IP_DCCP', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'my', 'IP_SCTP', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'my', 'FTRACE', 'is not set')] # refers to LOCKDOWN l += [KconfigCheck('cut_attack_surface', 'my', 'VIDEO_VIVID', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'my', 'INPUT_EVBUG', 'is not set')] # Can be used as a keylogger l += [KconfigCheck('cut_attack_surface', 'my', 'KGDB', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'my', 'AIO', 'is not set')] l += [OR(KconfigCheck('cut_attack_surface', 'my', 'TRIM_UNUSED_KSYMS', 'y'), modules_not_set)] # 'harden_userspace' if arch in ('X86_64', 'ARM64', 'X86_32'): l += [KconfigCheck('harden_userspace', 'defconfig', 'INTEGRITY', 'y')] if arch == 'ARM': l += [KconfigCheck('harden_userspace', 'my', 'INTEGRITY', 'y')] if arch == 'ARM64': l += [KconfigCheck('harden_userspace', 'defconfig', 'ARM64_PTR_AUTH', 'y')] l += [KconfigCheck('harden_userspace', 'defconfig', 'ARM64_BTI', 'y')] if arch in ('ARM', 'X86_32'): l += [KconfigCheck('harden_userspace', 'defconfig', 'VMSPLIT_3G', 'y')] if arch in ('X86_64', 'ARM64'): l += [KconfigCheck('harden_userspace', 'clipos', 'ARCH_MMAP_RND_BITS', '32')] if arch in ('X86_32', 'ARM'): l += [KconfigCheck('harden_userspace', 'my', 'ARCH_MMAP_RND_BITS', '16')] def add_cmdline_checks(l, arch): # Calling the CmdlineCheck class constructor: # CmdlineCheck(reason, decision, name, expected) # # [!] Don't add CmdlineChecks in add_kconfig_checks() to avoid wrong results # when the tool doesn't check the cmdline. # # [!] Make sure that values of the options in CmdlineChecks need normalization. # For more info see normalize_cmdline_options(). # # A common pattern for checking the 'param_x' cmdline parameter # that __overrides__ the 'PARAM_X_DEFAULT' kconfig option: # l += [OR(CmdlineCheck(reason, decision, 'param_x', '1'), # AND(KconfigCheck(reason, decision, 'PARAM_X_DEFAULT_ON', 'y'), # CmdlineCheck(reason, decision, 'param_x, 'is not set')))] # # Here we don't check the kconfig options or minimal kernel version # required for the cmdline parameters. That would make the checks # very complex and not give a 100% guarantee anyway. # 'self_protection', 'defconfig' l += [CmdlineCheck('self_protection', 'defconfig', 'nosmep', 'is not set')] l += [CmdlineCheck('self_protection', 'defconfig', 'nosmap', 'is not set')] l += [CmdlineCheck('self_protection', 'defconfig', 'nokaslr', 'is not set')] l += [CmdlineCheck('self_protection', 'defconfig', 'nopti', 'is not set')] l += [CmdlineCheck('self_protection', 'defconfig', 'nospectre_v1', 'is not set')] l += [CmdlineCheck('self_protection', 'defconfig', 'nospectre_v2', 'is not set')] l += [CmdlineCheck('self_protection', 'defconfig', 'nospectre_bhb', 'is not set')] l += [CmdlineCheck('self_protection', 'defconfig', 'nospec_store_bypass_disable', 'is not set')] l += [CmdlineCheck('self_protection', 'defconfig', 'arm64.nobti', 'is not set')] l += [CmdlineCheck('self_protection', 'defconfig', 'arm64.nopauth', 'is not set')] l += [CmdlineCheck('self_protection', 'defconfig', 'arm64.nomte', 'is not set')] l += [OR(CmdlineCheck('self_protection', 'defconfig', 'mitigations', 'is not off'), CmdlineCheck('self_protection', 'defconfig', 'mitigations', 'is not set'))] l += [OR(CmdlineCheck('self_protection', 'defconfig', 'spectre_v2', 'is not off'), CmdlineCheck('self_protection', 'defconfig', 'spectre_v2', 'is not set'))] l += [OR(CmdlineCheck('self_protection', 'defconfig', 'spectre_v2_user', 'is not off'), CmdlineCheck('self_protection', 'defconfig', 'spectre_v2_user', 'is not set'))] l += [OR(CmdlineCheck('self_protection', 'defconfig', 'spec_store_bypass_disable', 'is not off'), CmdlineCheck('self_protection', 'defconfig', 'spec_store_bypass_disable', 'is not set'))] l += [OR(CmdlineCheck('self_protection', 'defconfig', 'l1tf', 'is not off'), CmdlineCheck('self_protection', 'defconfig', 'l1tf', 'is not set'))] l += [OR(CmdlineCheck('self_protection', 'defconfig', 'mds', 'is not off'), CmdlineCheck('self_protection', 'defconfig', 'mds', 'is not set'))] l += [OR(CmdlineCheck('self_protection', 'defconfig', 'tsx_async_abort', 'is not off'), CmdlineCheck('self_protection', 'defconfig', 'tsx_async_abort', 'is not set'))] l += [OR(CmdlineCheck('self_protection', 'defconfig', 'srbds', 'is not off'), CmdlineCheck('self_protection', 'defconfig', 'srbds', 'is not set'))] l += [OR(CmdlineCheck('self_protection', 'defconfig', 'mmio_stale_data', 'is not off'), CmdlineCheck('self_protection', 'defconfig', 'mmio_stale_data', 'is not set'))] l += [OR(CmdlineCheck('self_protection', 'defconfig', 'retbleed', 'is not off'), CmdlineCheck('self_protection', 'defconfig', 'retbleed', 'is not set'))] l += [OR(CmdlineCheck('self_protection', 'defconfig', 'kpti', 'is not off'), CmdlineCheck('self_protection', 'defconfig', 'kpti', 'is not set'))] l += [OR(CmdlineCheck('self_protection', 'defconfig', 'kvm.nx_huge_pages', 'is not off'), CmdlineCheck('self_protection', 'defconfig', 'kvm.nx_huge_pages', 'is not set'))] if arch == 'ARM64': l += [OR(CmdlineCheck('self_protection', 'defconfig', 'ssbd', 'kernel'), CmdlineCheck('self_protection', 'my', 'ssbd', 'force-on'), CmdlineCheck('self_protection', 'defconfig', 'ssbd', 'is not set'))] l += [OR(CmdlineCheck('self_protection', 'defconfig', 'rodata', 'full'), AND(KconfigCheck('self_protection', 'defconfig', 'RODATA_FULL_DEFAULT_ENABLED', 'y'), CmdlineCheck('self_protection', 'defconfig', 'rodata', 'is not set')))] else: l += [OR(CmdlineCheck('self_protection', 'defconfig', 'rodata', '1'), CmdlineCheck('self_protection', 'defconfig', 'rodata', 'is not set'))] # 'self_protection', 'kspp' l += [CmdlineCheck('self_protection', 'kspp', 'nosmt', 'is present')] l += [OR(CmdlineCheck('self_protection', 'kspp', 'init_on_alloc', '1'), AND(KconfigCheck('self_protection', 'kspp', 'INIT_ON_ALLOC_DEFAULT_ON', 'y'), CmdlineCheck('self_protection', 'kspp', 'init_on_alloc', 'is not set')))] l += [OR(CmdlineCheck('self_protection', 'kspp', 'init_on_free', '1'), AND(KconfigCheck('self_protection', 'kspp', 'INIT_ON_FREE_DEFAULT_ON', 'y'), CmdlineCheck('self_protection', 'kspp', 'init_on_free', 'is not set')), AND(CmdlineCheck('self_protection', 'kspp', 'page_poison', '1'), KconfigCheck('self_protection', 'kspp', 'PAGE_POISONING_ZERO', 'y'), CmdlineCheck('self_protection', 'kspp', 'slub_debug', 'P')))] l += [OR(CmdlineCheck('self_protection', 'kspp', 'slab_nomerge', 'is present'), AND(KconfigCheck('self_protection', 'clipos', 'SLAB_MERGE_DEFAULT', 'is not set'), CmdlineCheck('self_protection', 'kspp', 'slab_merge', 'is not set'), CmdlineCheck('self_protection', 'clipos', 'slub_merge', 'is not set')))] l += [OR(CmdlineCheck('self_protection', 'kspp', 'iommu.strict', '1'), AND(KconfigCheck('self_protection', 'kspp', 'IOMMU_DEFAULT_DMA_STRICT', 'y'), CmdlineCheck('self_protection', 'kspp', 'iommu.strict', 'is not set')))] l += [OR(CmdlineCheck('self_protection', 'kspp', 'iommu.passthrough', '0'), AND(KconfigCheck('self_protection', 'kspp', 'IOMMU_DEFAULT_PASSTHROUGH', 'is not set'), CmdlineCheck('self_protection', 'kspp', 'iommu.passthrough', 'is not set')))] # The cmdline checks compatible with the kconfig recommendations of the KSPP project... l += [OR(CmdlineCheck('self_protection', 'kspp', 'hardened_usercopy', '1'), AND(KconfigCheck('self_protection', 'kspp', 'HARDENED_USERCOPY', 'y'), CmdlineCheck('self_protection', 'kspp', 'hardened_usercopy', 'is not set')))] l += [OR(CmdlineCheck('self_protection', 'kspp', 'slab_common.usercopy_fallback', '0'), AND(KconfigCheck('self_protection', 'kspp', 'HARDENED_USERCOPY_FALLBACK', 'is not set'), CmdlineCheck('self_protection', 'kspp', 'slab_common.usercopy_fallback', 'is not set')))] # ... the end if arch in ('X86_64', 'ARM64', 'X86_32'): l += [OR(CmdlineCheck('self_protection', 'kspp', 'randomize_kstack_offset', '1'), AND(KconfigCheck('self_protection', 'kspp', 'RANDOMIZE_KSTACK_OFFSET_DEFAULT', 'y'), CmdlineCheck('self_protection', 'kspp', 'randomize_kstack_offset', 'is not set')))] if arch in ('X86_64', 'X86_32'): l += [AND(CmdlineCheck('self_protection', 'kspp', 'pti', 'on'), CmdlineCheck('self_protection', 'defconfig', 'nopti', 'is not set'))] # 'self_protection', 'clipos' l += [CmdlineCheck('self_protection', 'clipos', 'page_alloc.shuffle', '1')] if arch in ('X86_64', 'X86_32'): l += [CmdlineCheck('self_protection', 'clipos', 'iommu', 'force')] # 'cut_attack_surface', 'defconfig' if arch in ('X86_64', 'X86_32'): l += [OR(CmdlineCheck('cut_attack_surface', 'defconfig', 'tsx', 'off'), AND(KconfigCheck('cut_attack_surface', 'defconfig', 'X86_INTEL_TSX_MODE_OFF', 'y'), CmdlineCheck('cut_attack_surface', 'defconfig', 'tsx', 'is not set')))] # 'cut_attack_surface', 'kspp' if arch == 'X86_64': l += [OR(CmdlineCheck('cut_attack_surface', 'kspp', 'vsyscall', 'none'), AND(KconfigCheck('cut_attack_surface', 'kspp', 'LEGACY_VSYSCALL_NONE', 'y'), CmdlineCheck('cut_attack_surface', 'kspp', 'vsyscall', 'is not set')))] # 'cut_attack_surface', 'grsec' # The cmdline checks compatible with the kconfig options disabled by grsecurity... l += [OR(CmdlineCheck('cut_attack_surface', 'grsec', 'debugfs', 'off'), KconfigCheck('cut_attack_surface', 'grsec', 'DEBUG_FS', 'is not set'))] # ... the end # 'cut_attack_surface', 'my' l += [CmdlineCheck('cut_attack_surface', 'my', 'sysrq_always_enabled', 'is not set')] def print_unknown_options(checklist, parsed_options): known_options = [] 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: assert(o3.type != 'complex'), \ '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 check for option {} ({})'.format(option, value)) def print_checklist(mode, checklist, with_results): if mode == 'json': output = [] for o in checklist: output.append(o.json_dump(with_results)) print(json.dumps(output)) return # table header sep_line_len = 91 if with_results: sep_line_len += 30 print('=' * sep_line_len) print('{:^40}|{:^7}|{:^12}|{:^10}|{:^18}'.format('option name', 'type', 'desired val', 'decision', 'reason'), end='') if with_results: print('| {}'.format('check result'), end='') print() print('=' * sep_line_len) # table contents for opt in checklist: if with_results: if mode == 'show_ok': if not opt.result.startswith('OK'): continue if mode == 'show_fail': if not opt.result.startswith('FAIL'): continue opt.table_print(mode, with_results) print() if mode == 'verbose': print('-' * sep_line_len) print() # final score if with_results: fail_count = len(list(filter(lambda opt: opt.result.startswith('FAIL'), checklist))) fail_suppressed = '' ok_count = len(list(filter(lambda opt: opt.result.startswith('OK'), checklist))) ok_suppressed = '' if mode == 'show_ok': fail_suppressed = ' (suppressed in output)' if mode == 'show_fail': ok_suppressed = ' (suppressed in output)' if mode != 'json': print('[+] Config check is finished: \'OK\' - {}{} / \'FAIL\' - {}{}'.format(ok_count, ok_suppressed, fail_count, fail_suppressed)) def populate_simple_opt_with_data(opt, data, data_type): assert(opt.type != 'complex'), \ 'unexpected ComplexOptCheck "{}"'.format(opt.name) assert(opt.type in SIMPLE_OPTION_TYPES), \ 'invalid opt type "{}"'.format(opt.type) assert(data_type in SIMPLE_OPTION_TYPES), \ 'invalid data type "{}"'.format(data_type) if data_type != opt.type: return if data_type in ('kconfig', 'cmdline'): opt.state = data.get(opt.name, None) else: assert(data_type == 'version'), \ 'unexpected data type "{}"'.format(data_type) opt.ver = data def populate_opt_with_data(opt, data, data_type): if opt.type == 'complex': for o in opt.opts: 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: assert(opt.type in ('kconfig', 'cmdline')), \ 'bad type "{}" for a simple check'.format(opt.type) 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): for opt in checklist: opt.check() def parse_kconfig_file(parsed_options, fname): with open(fname, 'r') as f: opt_is_on = re.compile("CONFIG_[a-zA-Z0-9_]*=[a-zA-Z0-9_\"]*") opt_is_off = re.compile("# CONFIG_[a-zA-Z0-9_]* is not set") for line in f.readlines(): line = line.strip() option = None value = None if opt_is_on.match(line): option, value = line.split('=', 1) if value == 'is not set': sys.exit('[!] ERROR: bad enabled kconfig option "{}"'.format(line)) elif opt_is_off.match(line): option, value = line[2:].split(' ', 1) if value != 'is not set': sys.exit('[!] ERROR: bad disabled kconfig option "{}"'.format(line)) if option in parsed_options: sys.exit('[!] ERROR: kconfig option "{}" exists multiple times'.format(line)) if option: parsed_options[option] = value def normalize_cmdline_options(option, value): # Don't normalize the cmdline option values if # the Linux kernel doesn't use kstrtobool() for them if option == 'debugfs': # See debugfs_kernel() in fs/debugfs/inode.c return value if option == 'mitigations': # See mitigations_parse_cmdline() in kernel/cpu.c return value if option == 'pti': # See pti_check_boottime_disable() in arch/x86/mm/pti.c return value if option == 'spectre_v2': # See spectre_v2_parse_cmdline() in arch/x86/kernel/cpu/bugs.c return value if option == 'spectre_v2_user': # See spectre_v2_parse_user_cmdline() in arch/x86/kernel/cpu/bugs.c return value if option == 'spec_store_bypass_disable': # See ssb_parse_cmdline() in arch/x86/kernel/cpu/bugs.c return value if option == 'l1tf': # See l1tf_cmdline() in arch/x86/kernel/cpu/bugs.c return value if option == 'mds': # See mds_cmdline() in arch/x86/kernel/cpu/bugs.c return value if option == 'tsx_async_abort': # See tsx_async_abort_parse_cmdline() in arch/x86/kernel/cpu/bugs.c return value if option == 'srbds': # See srbds_parse_cmdline() in arch/x86/kernel/cpu/bugs.c return value if option == 'mmio_stale_data': # See mmio_stale_data_parse_cmdline() in arch/x86/kernel/cpu/bugs.c return value if option == 'retbleed': # See retbleed_parse_cmdline() in arch/x86/kernel/cpu/bugs.c return value if option == 'tsx': # See tsx_init() in arch/x86/kernel/cpu/tsx.c return value # Implement a limited part of the kstrtobool() logic if value in ('1', 'on', 'On', 'ON', 'y', 'Y', 'yes', 'Yes', 'YES'): return '1' if value in ('0', 'off', 'Off', 'OFF', 'n', 'N', 'no', 'No', 'NO'): return '0' # Preserve unique values return value def parse_cmdline_file(parsed_options, fname): with open(fname, 'r') as f: line = f.readline() opts = line.split() line = f.readline() if line: sys.exit('[!] ERROR: more than one line in "{}"'.format(fname)) for opt in opts: if '=' in opt: name, value = opt.split('=', 1) else: name = opt value = '' # '' is not None value = normalize_cmdline_options(name, value) parsed_options[name] = value def main(): # Report modes: # * verbose mode for # - reporting about unknown kernel options in the kconfig # - verbose printing of ComplexOptCheck items # * json mode for printing the results in JSON format report_modes = ['verbose', 'json', 'show_ok', 'show_fail'] supported_archs = ['X86_64', 'X86_32', 'ARM64', 'ARM'] parser = ArgumentParser(prog='kconfig-hardened-check', description='A tool for checking the security hardening options of the Linux kernel') parser.add_argument('--version', action='version', version='%(prog)s ' + __version__) 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 kconfig file against these preferences') parser.add_argument('-l', '--cmdline', help='check the kernel cmdline file against these preferences') parser.add_argument('-m', '--mode', choices=report_modes, help='choose the report mode') args = parser.parse_args() mode = None if args.mode: mode = args.mode if mode != 'json': print('[+] Special report mode: {}'.format(mode)) config_checklist = [] if args.config: if args.print: sys.exit('[!] ERROR: --config and --print can\'t be used together') if mode != 'json': print('[+] Kconfig file to check: {}'.format(args.config)) if args.cmdline: print('[+] Kernel cmdline file to check: {}'.format(args.cmdline)) arch, msg = detect_arch(args.config, supported_archs) if not arch: sys.exit('[!] ERROR: {}'.format(msg)) if mode != 'json': print('[+] Detected architecture: {}'.format(arch)) kernel_version, msg = detect_kernel_version(args.config) if not kernel_version: sys.exit('[!] ERROR: {}'.format(msg)) if mode != 'json': print('[+] Detected kernel version: {}.{}'.format(kernel_version[0], kernel_version[1])) compiler, msg = detect_compiler(args.config) if mode != 'json': if compiler: print('[+] Detected compiler: {}'.format(compiler)) else: print('[-] Can\'t detect the compiler: {}'.format(msg)) # add relevant kconfig checks to the checklist add_kconfig_checks(config_checklist, arch) if args.cmdline: # add relevant cmdline checks to the checklist add_cmdline_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') if args.cmdline: # populate the checklist with the parsed kconfig data parsed_cmdline_options = OrderedDict() parse_cmdline_file(parsed_cmdline_options, args.cmdline) populate_with_data(config_checklist, parsed_cmdline_options, 'cmdline') # now everything is ready, perform the checks perform_checks(config_checklist) if mode == 'verbose': # print the parsed options without the checks (for debugging) all_parsed_options = parsed_kconfig_options # assignment does not copy if args.cmdline: all_parsed_options.update(parsed_cmdline_options) print_unknown_options(config_checklist, all_parsed_options) # finally print the results print_checklist(mode, config_checklist, True) sys.exit(0) elif args.cmdline: sys.exit('[!] ERROR: checking cmdline doesn\'t work without checking kconfig') if args.print: if mode in ('show_ok', 'show_fail'): sys.exit('[!] ERROR: wrong mode "{}" for --print'.format(mode)) arch = args.print add_kconfig_checks(config_checklist, arch) add_cmdline_checks(config_checklist, arch) if mode != 'json': print('[+] Printing kernel security hardening preferences for {}...'.format(arch)) print_checklist(mode, config_checklist, False) sys.exit(0) parser.print_help() sys.exit(0)