--- /dev/null
+#!/usr/bin/python3
+
+#
+# This script helps me to check the Linux kernel Kconfig option list
+# against my 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 command line parameters:
+# slub_debug=FZP
+# slab_nomerge
+# page_alloc.shuffle=1
+# iommu=force (does it help against DMA attacks?)
+# page_poison=1 (if enabled)
+# init_on_alloc=1
+# init_on_free=1
+# loadpin.enforce=1
+#
+# Mitigations of CPU vulnerabilities:
+# Аrch-independent:
+# mitigations=auto,nosmt
+# X86:
+# spectre_v2=on
+# pti=on
+# spec_store_bypass_disable=on
+# l1tf=full,force
+# mds=full,nosmt
+# tsx=off
+# ARM64:
+# kpti=on
+# ssbd=force-on
+#
+# N.B. Hardening sysctls:
+# kernel.kptr_restrict=2
+# kernel.dmesg_restrict=1
+# kernel.perf_event_paranoid=3
+# kernel.kexec_load_disabled=1
+# kernel.yama.ptrace_scope=3
+# user.max_user_namespaces=0
+# kernel.unprivileged_bpf_disabled=1
+# net.core.bpf_jit_harden=2
+#
+# vm.unprivileged_userfaultfd=0
+#
+# 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
+
+import sys
+from argparse import ArgumentParser
+from collections import OrderedDict
+import re
+import json
+
+# debug_mode enables:
+# - reporting about unknown kernel options in the config,
+# - verbose printing of ComplexOptChecks (OR, AND).
+debug_mode = False
+
+# json_mode is for printing results in JSON format
+json_mode = False
+
+supported_archs = [ 'X86_64', 'X86_32', 'ARM64', 'ARM' ]
+config_checklist = []
+kernel_version = None
+
+
+class OptCheck:
+ def __init__(self, name, expected, decision, reason):
+ self.name = name
+ self.expected = expected
+ self.decision = decision
+ self.reason = reason
+ self.state = None
+ self.result = None
+
+ def check(self):
+ if self.expected == self.state:
+ self.result = 'OK'
+ elif self.state is None:
+ if self.expected == 'is not set':
+ self.result = 'OK: not found'
+ else:
+ self.result = 'FAIL: not found'
+ else:
+ self.result = 'FAIL: "' + self.state + '"'
+
+ if self.result.startswith('OK'):
+ return True, self.result
+ else:
+ return False, self.result
+
+
+class VerCheck:
+ def __init__(self, ver_expected):
+ self.ver_expected = ver_expected
+ self.result = None
+
+ def check(self):
+ if kernel_version[0] > self.ver_expected[0]:
+ self.result = 'OK: version >= ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
+ return True, self.result
+ if kernel_version[0] < self.ver_expected[0]:
+ self.result = 'FAIL: version < ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
+ return False, self.result
+ if kernel_version[1] >= self.ver_expected[1]:
+ self.result = 'OK: version >= ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
+ return True, self.result
+ else:
+ self.result = 'FAIL: version < ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
+ return False, self.result
+
+
+class ComplexOptCheck:
+ def __init__(self, *opts):
+ self.opts = opts
+ self.result = None
+
+ @property
+ def name(self):
+ return self.opts[0].name
+
+ @property
+ def expected(self):
+ return self.opts[0].expected
+
+ @property
+ def state(self):
+ return self.opts[0].state
+
+ @property
+ def decision(self):
+ return self.opts[0].decision
+
+ @property
+ def reason(self):
+ return self.opts[0].reason
+
+
+class OR(ComplexOptCheck):
+ # self.opts[0] is the option that this OR-check is about.
+ # Use case:
+ # OR(<X_is_hardened>, <X_is_disabled>)
+ # OR(<X_is_hardened>, <X_is_hardened_old>)
+
+ def check(self):
+ if not self.opts:
+ sys.exit('[!] ERROR: invalid OR check')
+
+ for i, opt in enumerate(self.opts):
+ ret, msg = opt.check()
+ if ret:
+ if i == 0 or not hasattr(opt, 'name'):
+ self.result = opt.result
+ else:
+ self.result = 'OK: CONFIG_{} "{}"'.format(opt.name, opt.expected)
+ return True, self.result
+ self.result = self.opts[0].result
+ return False, self.result
+
+
+class AND(ComplexOptCheck):
+ # self.opts[0] is the option that this AND-check is about.
+ # Use case: AND(<suboption>, <main_option>)
+ # Suboption is not checked if checking of the main_option is failed.
+
+ def check(self):
+ for i, opt in reversed(list(enumerate(self.opts))):
+ ret, msg = opt.check()
+ if i == 0:
+ self.result = opt.result
+ return ret, self.result
+ elif not ret:
+ if hasattr(opt, 'name'):
+ self.result = 'FAIL: CONFIG_{} is needed'.format(opt.name)
+ else:
+ self.result = opt.result
+ return False, self.result
+
+ sys.exit('[!] ERROR: invalid AND check')
+
+
+def detect_arch(fname):
+ with open(fname, 'r') as f:
+ arch_pattern = re.compile("CONFIG_[a-zA-Z0-9_]*=y")
+ arch = None
+ if not json_mode:
+ print('[+] Trying to detect architecture in "{}"...'.format(fname))
+ for line in f.readlines():
+ if arch_pattern.match(line):
+ option, value = line[7:].split('=', 1)
+ if option in supported_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'
+ else:
+ return arch, 'OK'
+
+
+def detect_version(fname):
+ with open(fname, 'r') as f:
+ ver_pattern = re.compile("# Linux/.* Kernel Configuration")
+ if not json_mode:
+ print('[+] Trying to detect kernel version in "{}"...'.format(fname))
+ for line in f.readlines():
+ if ver_pattern.match(line):
+ line = line.strip()
+ if not json_mode:
+ print('[+] Found version line: "{}"'.format(line))
+ 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
+ else:
+ return (int(ver_numbers[0]), int(ver_numbers[1])), None
+ return None, 'no kernel version detected'
+
+
+def construct_checklist(checklist, arch):
+ modules_not_set = OptCheck('MODULES', 'is not set', 'kspp', 'cut_attack_surface')
+ devmem_not_set = OptCheck('DEVMEM', 'is not set', 'kspp', 'cut_attack_surface') # refers to LOCKDOWN
+
+ checklist.append(OptCheck('BUG', 'y', 'defconfig', 'self_protection'))
+ checklist.append(OR(OptCheck('STRICT_KERNEL_RWX', 'y', 'defconfig', 'self_protection'), \
+ OptCheck('DEBUG_RODATA', 'y', 'defconfig', 'self_protection'))) # before v4.11
+ checklist.append(OR(OptCheck('STACKPROTECTOR_STRONG', 'y', 'defconfig', 'self_protection'), \
+ OptCheck('CC_STACKPROTECTOR_STRONG', 'y', 'defconfig', 'self_protection')))
+ checklist.append(OptCheck('SLUB_DEBUG', 'y', 'defconfig', 'self_protection'))
+ checklist.append(OR(OptCheck('STRICT_MODULE_RWX', 'y', 'defconfig', 'self_protection'), \
+ OptCheck('DEBUG_SET_MODULE_RONX', 'y', 'defconfig', 'self_protection'), \
+ modules_not_set)) # DEBUG_SET_MODULE_RONX was before v4.11
+ checklist.append(OptCheck('GCC_PLUGINS', 'y', 'defconfig', 'self_protection'))
+ checklist.append(OR(OptCheck('REFCOUNT_FULL', 'y', 'defconfig', 'self_protection'), \
+ VerCheck((5, 5)))) # REFCOUNT_FULL is enabled by default since v5.5
+ iommu_support_is_set = OptCheck('IOMMU_SUPPORT', 'y', 'defconfig', 'self_protection') # is needed for mitigating DMA attacks
+ checklist.append(iommu_support_is_set)
+ if arch == 'X86_64' or arch == 'X86_32':
+ checklist.append(OptCheck('MICROCODE', 'y', 'defconfig', 'self_protection')) # is needed for mitigating CPU bugs
+ checklist.append(OptCheck('RETPOLINE', 'y', 'defconfig', 'self_protection'))
+ checklist.append(OptCheck('X86_SMAP', 'y', 'defconfig', 'self_protection'))
+ checklist.append(OR(OptCheck('X86_UMIP', 'y', 'defconfig', 'self_protection'), \
+ OptCheck('X86_INTEL_UMIP', 'y', 'defconfig', 'self_protection')))
+ checklist.append(OptCheck('SYN_COOKIES', 'y', 'defconfig', 'self_protection')) # another reason?
+ if arch == 'X86_64':
+ checklist.append(OptCheck('PAGE_TABLE_ISOLATION', 'y', 'defconfig', 'self_protection'))
+ checklist.append(OptCheck('RANDOMIZE_MEMORY', 'y', 'defconfig', 'self_protection'))
+ checklist.append(AND(OptCheck('INTEL_IOMMU', 'y', 'defconfig', 'self_protection'), \
+ iommu_support_is_set))
+ checklist.append(AND(OptCheck('AMD_IOMMU', 'y', 'defconfig', 'self_protection'), \
+ iommu_support_is_set))
+ if arch == 'ARM64':
+ checklist.append(OptCheck('UNMAP_KERNEL_AT_EL0', 'y', 'defconfig', 'self_protection'))
+ checklist.append(OptCheck('HARDEN_EL2_VECTORS', 'y', 'defconfig', 'self_protection'))
+ checklist.append(OptCheck('RODATA_FULL_DEFAULT_ENABLED', 'y', 'defconfig', 'self_protection'))
+ if arch == 'X86_64' or arch == 'ARM64':
+ checklist.append(OptCheck('VMAP_STACK', 'y', 'defconfig', 'self_protection'))
+ if arch == 'X86_64' or arch == 'ARM64' or arch == 'X86_32':
+ checklist.append(OptCheck('RANDOMIZE_BASE', 'y', 'defconfig', 'self_protection'))
+ checklist.append(OptCheck('THREAD_INFO_IN_TASK', 'y', 'defconfig', 'self_protection'))
+ if arch == 'ARM':
+ checklist.append(OptCheck('CPU_SW_DOMAIN_PAN', 'y', 'defconfig', 'self_protection'))
+ checklist.append(OptCheck('STACKPROTECTOR_PER_TASK', 'y', 'defconfig', 'self_protection'))
+ if arch == 'ARM64' or arch == 'ARM':
+ checklist.append(OptCheck('HARDEN_BRANCH_PREDICTOR', 'y', 'defconfig', 'self_protection'))
+
+ checklist.append(OptCheck('BUG_ON_DATA_CORRUPTION', 'y', 'kspp', 'self_protection'))
+ checklist.append(OptCheck('DEBUG_WX', 'y', 'kspp', 'self_protection'))
+ checklist.append(OptCheck('SCHED_STACK_END_CHECK', 'y', 'kspp', 'self_protection'))
+ checklist.append(OptCheck('SLAB_FREELIST_HARDENED', 'y', 'kspp', 'self_protection'))
+ checklist.append(OptCheck('SLAB_FREELIST_RANDOM', 'y', 'kspp', 'self_protection'))
+ checklist.append(OptCheck('SHUFFLE_PAGE_ALLOCATOR', 'y', 'kspp', 'self_protection'))
+ checklist.append(OptCheck('FORTIFY_SOURCE', 'y', 'kspp', 'self_protection'))
+ randstruct_is_set = OptCheck('GCC_PLUGIN_RANDSTRUCT', 'y', 'kspp', 'self_protection')
+ checklist.append(randstruct_is_set)
+ checklist.append(OptCheck('GCC_PLUGIN_LATENT_ENTROPY', 'y', 'kspp', 'self_protection'))
+ checklist.append(OptCheck('DEBUG_LIST', 'y', 'kspp', 'self_protection'))
+ checklist.append(OptCheck('DEBUG_SG', 'y', 'kspp', 'self_protection'))
+ checklist.append(OptCheck('DEBUG_CREDENTIALS', 'y', 'kspp', 'self_protection'))
+ checklist.append(OptCheck('DEBUG_NOTIFIERS', 'y', 'kspp', 'self_protection'))
+ hardened_usercopy_is_set = OptCheck('HARDENED_USERCOPY', 'y', 'kspp', 'self_protection')
+ checklist.append(hardened_usercopy_is_set)
+ checklist.append(AND(OptCheck('HARDENED_USERCOPY_FALLBACK', 'is not set', 'kspp', 'self_protection'), \
+ hardened_usercopy_is_set))
+ checklist.append(OR(OptCheck('MODULE_SIG', 'y', 'kspp', 'self_protection'), \
+ modules_not_set))
+ checklist.append(OR(OptCheck('MODULE_SIG_ALL', 'y', 'kspp', 'self_protection'), \
+ modules_not_set))
+ checklist.append(OR(OptCheck('MODULE_SIG_SHA512', 'y', 'kspp', 'self_protection'), \
+ modules_not_set))
+ checklist.append(OR(OptCheck('MODULE_SIG_FORCE', 'y', 'kspp', 'self_protection'), \
+ modules_not_set)) # refers to LOCKDOWN
+ checklist.append(OR(OptCheck('INIT_STACK_ALL', 'y', 'kspp', 'self_protection'), \
+ OptCheck('GCC_PLUGIN_STRUCTLEAK_BYREF_ALL', 'y', 'kspp', 'self_protection')))
+ checklist.append(OptCheck('INIT_ON_ALLOC_DEFAULT_ON', 'y', 'kspp', 'self_protection'))
+ checklist.append(OR(OptCheck('INIT_ON_FREE_DEFAULT_ON', 'y', 'kspp', 'self_protection'), \
+ OptCheck('PAGE_POISONING', 'y', 'kspp', 'self_protection'))) # before v5.3
+ if arch == 'X86_64' or arch == 'ARM64' or arch == 'X86_32':
+ stackleak_is_set = OptCheck('GCC_PLUGIN_STACKLEAK', 'y', 'kspp', 'self_protection')
+ checklist.append(stackleak_is_set)
+ checklist.append(AND(OptCheck('STACKLEAK_METRICS', 'is not set', 'clipos', 'self_protection'), \
+ stackleak_is_set))
+ checklist.append(AND(OptCheck('STACKLEAK_RUNTIME_DISABLE', 'is not set', 'clipos', 'self_protection'), \
+ stackleak_is_set))
+ if arch == 'X86_64' or arch == 'X86_32':
+ checklist.append(OptCheck('DEFAULT_MMAP_MIN_ADDR', '65536', 'kspp', 'self_protection'))
+ if arch == 'X86_32':
+ checklist.append(OptCheck('PAGE_TABLE_ISOLATION', 'y', 'kspp', 'self_protection'))
+ checklist.append(OptCheck('HIGHMEM64G', 'y', 'kspp', 'self_protection'))
+ checklist.append(OptCheck('X86_PAE', 'y', 'kspp', 'self_protection'))
+ if arch == 'ARM64':
+ checklist.append(OptCheck('ARM64_SW_TTBR0_PAN', 'y', 'kspp', 'self_protection'))
+ if arch == 'ARM64' or arch == 'ARM':
+ checklist.append(OptCheck('SYN_COOKIES', 'y', 'kspp', 'self_protection')) # another reason?
+ checklist.append(OptCheck('DEFAULT_MMAP_MIN_ADDR', '32768', 'kspp', 'self_protection'))
+
+ checklist.append(OptCheck('SECURITY_DMESG_RESTRICT', 'y', 'clipos', 'self_protection'))
+ checklist.append(OptCheck('DEBUG_VIRTUAL', 'y', 'clipos', 'self_protection'))
+ checklist.append(OptCheck('STATIC_USERMODEHELPER', 'y', 'clipos', 'self_protection')) # needs userspace support (systemd)
+ checklist.append(OptCheck('SLAB_MERGE_DEFAULT', 'is not set', 'clipos', 'self_protection')) # slab_nomerge
+ checklist.append(AND(OptCheck('GCC_PLUGIN_RANDSTRUCT_PERFORMANCE', 'is not set', 'clipos', 'self_protection'), \
+ randstruct_is_set))
+ checklist.append(OptCheck('RANDOM_TRUST_BOOTLOADER', 'is not set', 'clipos', 'self_protection'))
+ checklist.append(OptCheck('RANDOM_TRUST_CPU', 'is not set', 'clipos', 'self_protection'))
+ if arch == 'X86_64' or arch == 'X86_32':
+ checklist.append(AND(OptCheck('INTEL_IOMMU_SVM', 'y', 'clipos', 'self_protection'), \
+ iommu_support_is_set))
+ checklist.append(AND(OptCheck('INTEL_IOMMU_DEFAULT_ON', 'y', 'clipos', 'self_protection'), \
+ iommu_support_is_set))
+ if arch == 'X86_32':
+ checklist.append(AND(OptCheck('INTEL_IOMMU', 'y', 'clipos', 'self_protection'), \
+ iommu_support_is_set))
+
+ checklist.append(OptCheck('SLUB_DEBUG_ON', 'y', 'my', 'self_protection'))
+ checklist.append(OptCheck('RESET_ATTACK_MITIGATION', 'y', 'my', 'self_protection')) # needs userspace support (systemd)
+ if arch == 'X86_64':
+ checklist.append(AND(OptCheck('AMD_IOMMU_V2', 'y', 'my', 'self_protection'), \
+ iommu_support_is_set))
+
+ if arch == 'X86_64' or arch == 'ARM64' or arch == 'X86_32':
+ checklist.append(OptCheck('SECURITY', 'y', 'defconfig', 'security_policy')) # and choose your favourite LSM
+ if arch == 'ARM':
+ checklist.append(OptCheck('SECURITY', 'y', 'kspp', 'security_policy')) # and choose your favourite LSM
+ checklist.append(OptCheck('SECURITY_YAMA', 'y', 'kspp', 'security_policy'))
+ checklist.append(OR(OptCheck('SECURITY_WRITABLE_HOOKS', 'is not set', 'my', 'security_policy'), \
+ OptCheck('SECURITY_SELINUX_DISABLE', 'is not set', 'kspp', 'security_policy')))
+ checklist.append(OptCheck('SECURITY_LOCKDOWN_LSM', 'y', 'clipos', 'security_policy'))
+ checklist.append(OptCheck('SECURITY_LOCKDOWN_LSM_EARLY', 'y', 'clipos', 'security_policy'))
+ checklist.append(OptCheck('LOCK_DOWN_KERNEL_FORCE_CONFIDENTIALITY', 'y', 'clipos', 'security_policy'))
+ loadpin_is_set = OptCheck('SECURITY_LOADPIN', 'y', 'my', 'security_policy') # needs userspace support
+ checklist.append(loadpin_is_set)
+ checklist.append(AND(OptCheck('SECURITY_LOADPIN_ENFORCE', 'y', 'my', 'security_policy'), \
+ loadpin_is_set))
+ checklist.append(OptCheck('SECURITY_SAFESETID', 'y', 'my', 'security_policy'))
+
+ checklist.append(OptCheck('SECCOMP', 'y', 'defconfig', 'cut_attack_surface'))
+ checklist.append(OptCheck('SECCOMP_FILTER', 'y', 'defconfig', 'cut_attack_surface'))
+ if arch == 'X86_64' or arch == 'ARM64' or arch == 'X86_32':
+ checklist.append(OR(OptCheck('STRICT_DEVMEM', 'y', 'defconfig', 'cut_attack_surface'), \
+ devmem_not_set)) # refers to LOCKDOWN
+
+ checklist.append(modules_not_set)
+ checklist.append(devmem_not_set)
+ checklist.append(OR(OptCheck('IO_STRICT_DEVMEM', 'y', 'kspp', 'cut_attack_surface'), \
+ devmem_not_set)) # refers to LOCKDOWN
+ if arch == 'ARM':
+ checklist.append(OR(OptCheck('STRICT_DEVMEM', 'y', 'kspp', 'cut_attack_surface'), \
+ devmem_not_set)) # refers to LOCKDOWN
+ if arch == 'X86_64':
+ checklist.append(OptCheck('LEGACY_VSYSCALL_NONE', 'y', 'kspp', 'cut_attack_surface')) # 'vsyscall=none'
+ checklist.append(OptCheck('ACPI_CUSTOM_METHOD', 'is not set', 'kspp', 'cut_attack_surface')) # refers to LOCKDOWN
+ checklist.append(OptCheck('COMPAT_BRK', 'is not set', 'kspp', 'cut_attack_surface'))
+ checklist.append(OptCheck('DEVKMEM', 'is not set', 'kspp', 'cut_attack_surface')) # refers to LOCKDOWN
+ checklist.append(OptCheck('COMPAT_VDSO', 'is not set', 'kspp', 'cut_attack_surface'))
+ checklist.append(OptCheck('BINFMT_MISC', 'is not set', 'kspp', 'cut_attack_surface'))
+ checklist.append(OptCheck('INET_DIAG', 'is not set', 'kspp', 'cut_attack_surface'))
+ checklist.append(OptCheck('KEXEC', 'is not set', 'kspp', 'cut_attack_surface')) # refers to LOCKDOWN
+ checklist.append(OptCheck('PROC_KCORE', 'is not set', 'kspp', 'cut_attack_surface')) # refers to LOCKDOWN
+ checklist.append(OptCheck('LEGACY_PTYS', 'is not set', 'kspp', 'cut_attack_surface'))
+ checklist.append(OptCheck('HIBERNATION', 'is not set', 'kspp', 'cut_attack_surface')) # refers to LOCKDOWN
+ checklist.append(OptCheck('IA32_EMULATION', 'is not set', 'kspp', 'cut_attack_surface'))
+ checklist.append(OptCheck('X86_X32', 'is not set', 'kspp', 'cut_attack_surface'))
+ checklist.append(OptCheck('MODIFY_LDT_SYSCALL', 'is not set', 'kspp', 'cut_attack_surface'))
+ checklist.append(OptCheck('OABI_COMPAT', 'is not set', 'kspp', 'cut_attack_surface'))
+
+ checklist.append(OptCheck('X86_PTDUMP', 'is not set', 'grsecurity', 'cut_attack_surface'))
+ checklist.append(OptCheck('ZSMALLOC_STAT', 'is not set', 'grsecurity', 'cut_attack_surface'))
+ checklist.append(OptCheck('PAGE_OWNER', 'is not set', 'grsecurity', 'cut_attack_surface'))
+ checklist.append(OptCheck('DEBUG_KMEMLEAK', 'is not set', 'grsecurity', 'cut_attack_surface'))
+ checklist.append(OptCheck('BINFMT_AOUT', 'is not set', 'grsecurity', 'cut_attack_surface'))
+ checklist.append(OptCheck('KPROBES', 'is not set', 'grsecurity', 'cut_attack_surface')) # refers to LOCKDOWN
+ checklist.append(OptCheck('UPROBES', 'is not set', 'grsecurity', 'cut_attack_surface'))
+ checklist.append(OptCheck('GENERIC_TRACER', 'is not set', 'grsecurity', 'cut_attack_surface')) # refers to LOCKDOWN
+ checklist.append(OptCheck('PROC_VMCORE', 'is not set', 'grsecurity', 'cut_attack_surface'))
+ checklist.append(OptCheck('PROC_PAGE_MONITOR', 'is not set', 'grsecurity', 'cut_attack_surface'))
+ checklist.append(OptCheck('USELIB', 'is not set', 'grsecurity', 'cut_attack_surface'))
+ checklist.append(OptCheck('CHECKPOINT_RESTORE', 'is not set', 'grsecurity', 'cut_attack_surface'))
+ checklist.append(OptCheck('USERFAULTFD', 'is not set', 'grsecurity', 'cut_attack_surface'))
+ checklist.append(OptCheck('HWPOISON_INJECT', 'is not set', 'grsecurity', 'cut_attack_surface'))
+ checklist.append(OptCheck('MEM_SOFT_DIRTY', 'is not set', 'grsecurity', 'cut_attack_surface'))
+ checklist.append(OptCheck('DEVPORT', 'is not set', 'grsecurity', 'cut_attack_surface')) # refers to LOCKDOWN
+ checklist.append(OptCheck('DEBUG_FS', 'is not set', 'grsecurity', 'cut_attack_surface')) # refers to LOCKDOWN
+ checklist.append(OptCheck('NOTIFIER_ERROR_INJECTION','is not set', 'grsecurity', 'cut_attack_surface'))
+
+ checklist.append(OptCheck('ACPI_TABLE_UPGRADE', 'is not set', 'lockdown', 'cut_attack_surface')) # refers to LOCKDOWN
+ checklist.append(OptCheck('X86_IOPL_IOPERM', 'is not set', 'lockdown', 'cut_attack_surface')) # refers to LOCKDOWN
+ checklist.append(OptCheck('EFI_TEST', 'is not set', 'lockdown', 'cut_attack_surface')) # refers to LOCKDOWN
+ checklist.append(OptCheck('BPF_SYSCALL', 'is not set', 'lockdown', 'cut_attack_surface')) # refers to LOCKDOWN
+ checklist.append(OptCheck('MMIOTRACE_TEST', 'is not set', 'lockdown', 'cut_attack_surface')) # refers to LOCKDOWN
+
+ if arch == 'X86_64' or arch == 'X86_32':
+ checklist.append(OptCheck('X86_INTEL_TSX_MODE_OFF', 'y', 'clipos', 'cut_attack_surface')) # tsx=off
+ checklist.append(OptCheck('STAGING', 'is not set', 'clipos', 'cut_attack_surface'))
+ checklist.append(OptCheck('KSM', 'is not set', 'clipos', 'cut_attack_surface')) # to prevent FLUSH+RELOAD attack
+# checklist.append(OptCheck('IKCONFIG', 'is not set', 'clipos', 'cut_attack_surface')) # no, this info is needed for this check :)
+ checklist.append(OptCheck('KALLSYMS', 'is not set', 'clipos', 'cut_attack_surface'))
+ checklist.append(OptCheck('X86_VSYSCALL_EMULATION', 'is not set', 'clipos', 'cut_attack_surface'))
+ checklist.append(OptCheck('MAGIC_SYSRQ', 'is not set', 'clipos', 'cut_attack_surface'))
+ checklist.append(OptCheck('KEXEC_FILE', 'is not set', 'clipos', 'cut_attack_surface')) # refers to LOCKDOWN (permissive)
+ checklist.append(OptCheck('USER_NS', 'is not set', 'clipos', 'cut_attack_surface')) # user.max_user_namespaces=0
+ checklist.append(OptCheck('X86_MSR', 'is not set', 'clipos', 'cut_attack_surface')) # refers to LOCKDOWN
+ checklist.append(OptCheck('X86_CPUID', 'is not set', 'clipos', 'cut_attack_surface'))
+ checklist.append(AND(OptCheck('LDISC_AUTOLOAD', 'is not set', 'clipos', 'cut_attack_surface'), \
+ VerCheck((5, 1)))) # LDISC_AUTOLOAD can be disabled since v5.1
+
+ checklist.append(OptCheck('AIO', 'is not set', 'grapheneos', 'cut_attack_surface'))
+
+ checklist.append(OptCheck('MMIOTRACE', 'is not set', 'my', 'cut_attack_surface')) # refers to LOCKDOWN (permissive)
+ checklist.append(OptCheck('LIVEPATCH', 'is not set', 'my', 'cut_attack_surface'))
+ checklist.append(OptCheck('IP_DCCP', 'is not set', 'my', 'cut_attack_surface'))
+ checklist.append(OptCheck('IP_SCTP', 'is not set', 'my', 'cut_attack_surface'))
+ checklist.append(OptCheck('FTRACE', 'is not set', 'my', 'cut_attack_surface')) # refers to LOCKDOWN
+ checklist.append(OptCheck('BPF_JIT', 'is not set', 'my', 'cut_attack_surface'))
+ checklist.append(OptCheck('VIDEO_VIVID', 'is not set', 'my', 'cut_attack_surface'))
+
+ checklist.append(OptCheck('INTEGRITY', 'y', 'defconfig', 'userspace_hardening'))
+ if arch == 'ARM64':
+ checklist.append(OptCheck('ARM64_PTR_AUTH', 'y', 'defconfig', 'userspace_hardening'))
+ if arch == 'ARM' or arch == 'X86_32':
+ checklist.append(OptCheck('VMSPLIT_3G', 'y', 'defconfig', 'userspace_hardening'))
+ if arch == 'X86_64' or arch == 'ARM64':
+ checklist.append(OptCheck('ARCH_MMAP_RND_BITS', '32', 'clipos', 'userspace_hardening'))
+ if arch == 'X86_32' or arch == 'ARM':
+ checklist.append(OptCheck('ARCH_MMAP_RND_BITS', '16', 'my', 'userspace_hardening'))
+
+# checklist.append(OptCheck('LKDTM', 'm', 'my', 'feature_test'))
+
+
+def print_opt(opt, with_results):
+ print('CONFIG_{:<38}|{:^13}|{:^10}|{:^20}'.format(opt.name, opt.expected, opt.decision, opt.reason), end='')
+ if with_results:
+ print('| {}'.format(opt.result), end='')
+ print()
+
+
+def print_checklist(checklist, with_results):
+ if json_mode:
+ opts = []
+ for o in checklist:
+ opt = ['CONFIG_'+o.name, o.expected, o.decision, o.reason]
+ if with_results:
+ opt.append(o.result)
+ opts.append(opt)
+ print(json.dumps(opts))
+ return
+
+ # table header
+ sep_line_len = 91
+ if with_results:
+ sep_line_len += 30
+ print('=' * sep_line_len)
+ print('{:^45}|{:^13}|{:^10}|{:^20}'.format('option name', '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 debug_mode and hasattr(opt, 'opts'):
+ print(' {:87}'.format('<<< ' + opt.__class__.__name__ + ' >>>'), end='')
+ if with_results:
+ print('| {}'.format(opt.result), end='')
+ print()
+ for o in opt.opts:
+ if hasattr(o, 'ver_expected'):
+ ver_req = 'kernel version >= ' + str(o.ver_expected[0]) + '.' + str(o.ver_expected[1])
+ print('{:<91}'.format(ver_req), end='')
+ if with_results:
+ print('| {}'.format(o.result), end='')
+ print()
+ else:
+ print_opt(o, with_results)
+ else:
+ print_opt(opt, with_results)
+ if debug_mode:
+ print('-' * sep_line_len)
+ print()
+
+
+def perform_checks(checklist, parsed_options):
+ for opt in checklist:
+ if hasattr(opt, 'opts'):
+ # prepare ComplexOptCheck
+ for o in opt.opts:
+ if hasattr(o, 'name'):
+ o.state = parsed_options.get(o.name, None)
+ else:
+ # prepare simple OptCheck
+ if not hasattr(opt, 'name'):
+ sys.exit('[!] ERROR: bad OptCheck {}'.format(vars(opt)))
+ opt.state = parsed_options.get(opt.name, None)
+ opt.check()
+
+
+def check_config_file(checklist, fname):
+ with open(fname, 'r') as f:
+ parsed_options = OrderedDict()
+ 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")
+
+ if not json_mode:
+ print('[+] Checking "{}" against {} hardening preferences...'.format(fname, arch))
+ for line in f.readlines():
+ line = line.strip()
+ option = None
+ value = None
+
+ if opt_is_on.match(line):
+ option, value = line[7:].split('=', 1)
+ elif opt_is_off.match(line):
+ option, value = line[9:].split(' ', 1)
+ if value != 'is not set':
+ sys.exit('[!] ERROR: bad disabled config option "{}"'.format(line))
+
+ if option in parsed_options:
+ sys.exit('[!] ERROR: config option "{}" exists multiple times'.format(line))
+
+ if option is not None:
+ parsed_options[option] = value
+
+ perform_checks(checklist, parsed_options)
+
+ if debug_mode:
+ 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 option, value in parsed_options.items():
+ if option not in known_options:
+ print('DEBUG: dunno about option {} ({})'.format(option, value))
+
+ print_checklist(checklist, True)
+
+
+if __name__ == '__main__':
+ parser = ArgumentParser(description='Checks the hardening options in the Linux kernel config')
+ parser.add_argument('-p', '--print', choices=supported_archs,
+ help='print hardening preferences for selected architecture')
+ parser.add_argument('-c', '--config',
+ help='check the config_file against these preferences')
+ parser.add_argument('--debug', action='store_true',
+ help='enable verbose debug mode')
+ parser.add_argument('--json', action='store_true',
+ help='print results in JSON format')
+ args = parser.parse_args()
+
+ if args.debug:
+ debug_mode = True
+ print('[!] WARNING: debug mode is enabled')
+ if args.json:
+ json_mode = True
+ if debug_mode and json_mode:
+ sys.exit('[!] ERROR: options --debug and --json cannot be used simultaneously')
+
+ if args.config:
+ arch, msg = detect_arch(args.config)
+ if not arch:
+ sys.exit('[!] ERROR: {}'.format(msg))
+ elif not json_mode:
+ print('[+] Detected architecture: {}'.format(arch))
+
+ kernel_version, msg = detect_version(args.config)
+ if not kernel_version:
+ sys.exit('[!] ERROR: {}'.format(msg))
+ elif not json_mode:
+ print('[+] Detected kernel version: {}.{}'.format(kernel_version[0], kernel_version[1]))
+
+ construct_checklist(config_checklist, arch)
+ check_config_file(config_checklist, args.config)
+ error_count = len(list(filter(lambda opt: opt.result.startswith('FAIL'), config_checklist)))
+ ok_count = len(list(filter(lambda opt: opt.result.startswith('OK'), config_checklist)))
+ if debug_mode:
+ sys.exit(0)
+ if not json_mode:
+ print('[+] config check is finished: \'OK\' - {} / \'FAIL\' - {}'.format(ok_count, error_count))
+ sys.exit(0)
+
+ if args.print:
+ arch = args.print
+ construct_checklist(config_checklist, arch)
+ if not json_mode:
+ print('[+] Printing kernel hardening preferences for {}...'.format(arch))
+ print_checklist(config_checklist, False)
+ sys.exit(0)
+
+ parser.print_help()
+++ /dev/null
-#!/usr/bin/python3
-
-#
-# This script helps me to check the Linux kernel Kconfig option list
-# against my 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 command line parameters:
-# slub_debug=FZP
-# slab_nomerge
-# page_alloc.shuffle=1
-# iommu=force (does it help against DMA attacks?)
-# page_poison=1 (if enabled)
-# init_on_alloc=1
-# init_on_free=1
-# loadpin.enforce=1
-#
-# Mitigations of CPU vulnerabilities:
-# Аrch-independent:
-# mitigations=auto,nosmt
-# X86:
-# spectre_v2=on
-# pti=on
-# spec_store_bypass_disable=on
-# l1tf=full,force
-# mds=full,nosmt
-# tsx=off
-# ARM64:
-# kpti=on
-# ssbd=force-on
-#
-# N.B. Hardening sysctls:
-# kernel.kptr_restrict=2
-# kernel.dmesg_restrict=1
-# kernel.perf_event_paranoid=3
-# kernel.kexec_load_disabled=1
-# kernel.yama.ptrace_scope=3
-# user.max_user_namespaces=0
-# kernel.unprivileged_bpf_disabled=1
-# net.core.bpf_jit_harden=2
-#
-# vm.unprivileged_userfaultfd=0
-#
-# 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
-
-import sys
-from argparse import ArgumentParser
-from collections import OrderedDict
-import re
-import json
-
-# debug_mode enables:
-# - reporting about unknown kernel options in the config,
-# - verbose printing of ComplexOptChecks (OR, AND).
-debug_mode = False
-
-# json_mode is for printing results in JSON format
-json_mode = False
-
-supported_archs = [ 'X86_64', 'X86_32', 'ARM64', 'ARM' ]
-config_checklist = []
-kernel_version = None
-
-
-class OptCheck:
- def __init__(self, name, expected, decision, reason):
- self.name = name
- self.expected = expected
- self.decision = decision
- self.reason = reason
- self.state = None
- self.result = None
-
- def check(self):
- if self.expected == self.state:
- self.result = 'OK'
- elif self.state is None:
- if self.expected == 'is not set':
- self.result = 'OK: not found'
- else:
- self.result = 'FAIL: not found'
- else:
- self.result = 'FAIL: "' + self.state + '"'
-
- if self.result.startswith('OK'):
- return True, self.result
- else:
- return False, self.result
-
-
-class VerCheck:
- def __init__(self, ver_expected):
- self.ver_expected = ver_expected
- self.result = None
-
- def check(self):
- if kernel_version[0] > self.ver_expected[0]:
- self.result = 'OK: version >= ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
- return True, self.result
- if kernel_version[0] < self.ver_expected[0]:
- self.result = 'FAIL: version < ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
- return False, self.result
- if kernel_version[1] >= self.ver_expected[1]:
- self.result = 'OK: version >= ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
- return True, self.result
- else:
- self.result = 'FAIL: version < ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
- return False, self.result
-
-
-class ComplexOptCheck:
- def __init__(self, *opts):
- self.opts = opts
- self.result = None
-
- @property
- def name(self):
- return self.opts[0].name
-
- @property
- def expected(self):
- return self.opts[0].expected
-
- @property
- def state(self):
- return self.opts[0].state
-
- @property
- def decision(self):
- return self.opts[0].decision
-
- @property
- def reason(self):
- return self.opts[0].reason
-
-
-class OR(ComplexOptCheck):
- # self.opts[0] is the option that this OR-check is about.
- # Use case:
- # OR(<X_is_hardened>, <X_is_disabled>)
- # OR(<X_is_hardened>, <X_is_hardened_old>)
-
- def check(self):
- if not self.opts:
- sys.exit('[!] ERROR: invalid OR check')
-
- for i, opt in enumerate(self.opts):
- ret, msg = opt.check()
- if ret:
- if i == 0 or not hasattr(opt, 'name'):
- self.result = opt.result
- else:
- self.result = 'OK: CONFIG_{} "{}"'.format(opt.name, opt.expected)
- return True, self.result
- self.result = self.opts[0].result
- return False, self.result
-
-
-class AND(ComplexOptCheck):
- # self.opts[0] is the option that this AND-check is about.
- # Use case: AND(<suboption>, <main_option>)
- # Suboption is not checked if checking of the main_option is failed.
-
- def check(self):
- for i, opt in reversed(list(enumerate(self.opts))):
- ret, msg = opt.check()
- if i == 0:
- self.result = opt.result
- return ret, self.result
- elif not ret:
- if hasattr(opt, 'name'):
- self.result = 'FAIL: CONFIG_{} is needed'.format(opt.name)
- else:
- self.result = opt.result
- return False, self.result
-
- sys.exit('[!] ERROR: invalid AND check')
-
-
-def detect_arch(fname):
- with open(fname, 'r') as f:
- arch_pattern = re.compile("CONFIG_[a-zA-Z0-9_]*=y")
- arch = None
- if not json_mode:
- print('[+] Trying to detect architecture in "{}"...'.format(fname))
- for line in f.readlines():
- if arch_pattern.match(line):
- option, value = line[7:].split('=', 1)
- if option in supported_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'
- else:
- return arch, 'OK'
-
-
-def detect_version(fname):
- with open(fname, 'r') as f:
- ver_pattern = re.compile("# Linux/.* Kernel Configuration")
- if not json_mode:
- print('[+] Trying to detect kernel version in "{}"...'.format(fname))
- for line in f.readlines():
- if ver_pattern.match(line):
- line = line.strip()
- if not json_mode:
- print('[+] Found version line: "{}"'.format(line))
- 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
- else:
- return (int(ver_numbers[0]), int(ver_numbers[1])), None
- return None, 'no kernel version detected'
-
-
-def construct_checklist(checklist, arch):
- modules_not_set = OptCheck('MODULES', 'is not set', 'kspp', 'cut_attack_surface')
- devmem_not_set = OptCheck('DEVMEM', 'is not set', 'kspp', 'cut_attack_surface') # refers to LOCKDOWN
-
- checklist.append(OptCheck('BUG', 'y', 'defconfig', 'self_protection'))
- checklist.append(OR(OptCheck('STRICT_KERNEL_RWX', 'y', 'defconfig', 'self_protection'), \
- OptCheck('DEBUG_RODATA', 'y', 'defconfig', 'self_protection'))) # before v4.11
- checklist.append(OR(OptCheck('STACKPROTECTOR_STRONG', 'y', 'defconfig', 'self_protection'), \
- OptCheck('CC_STACKPROTECTOR_STRONG', 'y', 'defconfig', 'self_protection')))
- checklist.append(OptCheck('SLUB_DEBUG', 'y', 'defconfig', 'self_protection'))
- checklist.append(OR(OptCheck('STRICT_MODULE_RWX', 'y', 'defconfig', 'self_protection'), \
- OptCheck('DEBUG_SET_MODULE_RONX', 'y', 'defconfig', 'self_protection'), \
- modules_not_set)) # DEBUG_SET_MODULE_RONX was before v4.11
- checklist.append(OptCheck('GCC_PLUGINS', 'y', 'defconfig', 'self_protection'))
- checklist.append(OR(OptCheck('REFCOUNT_FULL', 'y', 'defconfig', 'self_protection'), \
- VerCheck((5, 5)))) # REFCOUNT_FULL is enabled by default since v5.5
- iommu_support_is_set = OptCheck('IOMMU_SUPPORT', 'y', 'defconfig', 'self_protection') # is needed for mitigating DMA attacks
- checklist.append(iommu_support_is_set)
- if arch == 'X86_64' or arch == 'X86_32':
- checklist.append(OptCheck('MICROCODE', 'y', 'defconfig', 'self_protection')) # is needed for mitigating CPU bugs
- checklist.append(OptCheck('RETPOLINE', 'y', 'defconfig', 'self_protection'))
- checklist.append(OptCheck('X86_SMAP', 'y', 'defconfig', 'self_protection'))
- checklist.append(OR(OptCheck('X86_UMIP', 'y', 'defconfig', 'self_protection'), \
- OptCheck('X86_INTEL_UMIP', 'y', 'defconfig', 'self_protection')))
- checklist.append(OptCheck('SYN_COOKIES', 'y', 'defconfig', 'self_protection')) # another reason?
- if arch == 'X86_64':
- checklist.append(OptCheck('PAGE_TABLE_ISOLATION', 'y', 'defconfig', 'self_protection'))
- checklist.append(OptCheck('RANDOMIZE_MEMORY', 'y', 'defconfig', 'self_protection'))
- checklist.append(AND(OptCheck('INTEL_IOMMU', 'y', 'defconfig', 'self_protection'), \
- iommu_support_is_set))
- checklist.append(AND(OptCheck('AMD_IOMMU', 'y', 'defconfig', 'self_protection'), \
- iommu_support_is_set))
- if arch == 'ARM64':
- checklist.append(OptCheck('UNMAP_KERNEL_AT_EL0', 'y', 'defconfig', 'self_protection'))
- checklist.append(OptCheck('HARDEN_EL2_VECTORS', 'y', 'defconfig', 'self_protection'))
- checklist.append(OptCheck('RODATA_FULL_DEFAULT_ENABLED', 'y', 'defconfig', 'self_protection'))
- if arch == 'X86_64' or arch == 'ARM64':
- checklist.append(OptCheck('VMAP_STACK', 'y', 'defconfig', 'self_protection'))
- if arch == 'X86_64' or arch == 'ARM64' or arch == 'X86_32':
- checklist.append(OptCheck('RANDOMIZE_BASE', 'y', 'defconfig', 'self_protection'))
- checklist.append(OptCheck('THREAD_INFO_IN_TASK', 'y', 'defconfig', 'self_protection'))
- if arch == 'ARM':
- checklist.append(OptCheck('CPU_SW_DOMAIN_PAN', 'y', 'defconfig', 'self_protection'))
- checklist.append(OptCheck('STACKPROTECTOR_PER_TASK', 'y', 'defconfig', 'self_protection'))
- if arch == 'ARM64' or arch == 'ARM':
- checklist.append(OptCheck('HARDEN_BRANCH_PREDICTOR', 'y', 'defconfig', 'self_protection'))
-
- checklist.append(OptCheck('BUG_ON_DATA_CORRUPTION', 'y', 'kspp', 'self_protection'))
- checklist.append(OptCheck('DEBUG_WX', 'y', 'kspp', 'self_protection'))
- checklist.append(OptCheck('SCHED_STACK_END_CHECK', 'y', 'kspp', 'self_protection'))
- checklist.append(OptCheck('SLAB_FREELIST_HARDENED', 'y', 'kspp', 'self_protection'))
- checklist.append(OptCheck('SLAB_FREELIST_RANDOM', 'y', 'kspp', 'self_protection'))
- checklist.append(OptCheck('SHUFFLE_PAGE_ALLOCATOR', 'y', 'kspp', 'self_protection'))
- checklist.append(OptCheck('FORTIFY_SOURCE', 'y', 'kspp', 'self_protection'))
- randstruct_is_set = OptCheck('GCC_PLUGIN_RANDSTRUCT', 'y', 'kspp', 'self_protection')
- checklist.append(randstruct_is_set)
- checklist.append(OptCheck('GCC_PLUGIN_LATENT_ENTROPY', 'y', 'kspp', 'self_protection'))
- checklist.append(OptCheck('DEBUG_LIST', 'y', 'kspp', 'self_protection'))
- checklist.append(OptCheck('DEBUG_SG', 'y', 'kspp', 'self_protection'))
- checklist.append(OptCheck('DEBUG_CREDENTIALS', 'y', 'kspp', 'self_protection'))
- checklist.append(OptCheck('DEBUG_NOTIFIERS', 'y', 'kspp', 'self_protection'))
- hardened_usercopy_is_set = OptCheck('HARDENED_USERCOPY', 'y', 'kspp', 'self_protection')
- checklist.append(hardened_usercopy_is_set)
- checklist.append(AND(OptCheck('HARDENED_USERCOPY_FALLBACK', 'is not set', 'kspp', 'self_protection'), \
- hardened_usercopy_is_set))
- checklist.append(OR(OptCheck('MODULE_SIG', 'y', 'kspp', 'self_protection'), \
- modules_not_set))
- checklist.append(OR(OptCheck('MODULE_SIG_ALL', 'y', 'kspp', 'self_protection'), \
- modules_not_set))
- checklist.append(OR(OptCheck('MODULE_SIG_SHA512', 'y', 'kspp', 'self_protection'), \
- modules_not_set))
- checklist.append(OR(OptCheck('MODULE_SIG_FORCE', 'y', 'kspp', 'self_protection'), \
- modules_not_set)) # refers to LOCKDOWN
- checklist.append(OR(OptCheck('INIT_STACK_ALL', 'y', 'kspp', 'self_protection'), \
- OptCheck('GCC_PLUGIN_STRUCTLEAK_BYREF_ALL', 'y', 'kspp', 'self_protection')))
- checklist.append(OptCheck('INIT_ON_ALLOC_DEFAULT_ON', 'y', 'kspp', 'self_protection'))
- checklist.append(OR(OptCheck('INIT_ON_FREE_DEFAULT_ON', 'y', 'kspp', 'self_protection'), \
- OptCheck('PAGE_POISONING', 'y', 'kspp', 'self_protection'))) # before v5.3
- if arch == 'X86_64' or arch == 'ARM64' or arch == 'X86_32':
- stackleak_is_set = OptCheck('GCC_PLUGIN_STACKLEAK', 'y', 'kspp', 'self_protection')
- checklist.append(stackleak_is_set)
- checklist.append(AND(OptCheck('STACKLEAK_METRICS', 'is not set', 'clipos', 'self_protection'), \
- stackleak_is_set))
- checklist.append(AND(OptCheck('STACKLEAK_RUNTIME_DISABLE', 'is not set', 'clipos', 'self_protection'), \
- stackleak_is_set))
- if arch == 'X86_64' or arch == 'X86_32':
- checklist.append(OptCheck('DEFAULT_MMAP_MIN_ADDR', '65536', 'kspp', 'self_protection'))
- if arch == 'X86_32':
- checklist.append(OptCheck('PAGE_TABLE_ISOLATION', 'y', 'kspp', 'self_protection'))
- checklist.append(OptCheck('HIGHMEM64G', 'y', 'kspp', 'self_protection'))
- checklist.append(OptCheck('X86_PAE', 'y', 'kspp', 'self_protection'))
- if arch == 'ARM64':
- checklist.append(OptCheck('ARM64_SW_TTBR0_PAN', 'y', 'kspp', 'self_protection'))
- if arch == 'ARM64' or arch == 'ARM':
- checklist.append(OptCheck('SYN_COOKIES', 'y', 'kspp', 'self_protection')) # another reason?
- checklist.append(OptCheck('DEFAULT_MMAP_MIN_ADDR', '32768', 'kspp', 'self_protection'))
-
- checklist.append(OptCheck('SECURITY_DMESG_RESTRICT', 'y', 'clipos', 'self_protection'))
- checklist.append(OptCheck('DEBUG_VIRTUAL', 'y', 'clipos', 'self_protection'))
- checklist.append(OptCheck('STATIC_USERMODEHELPER', 'y', 'clipos', 'self_protection')) # needs userspace support (systemd)
- checklist.append(OptCheck('SLAB_MERGE_DEFAULT', 'is not set', 'clipos', 'self_protection')) # slab_nomerge
- checklist.append(AND(OptCheck('GCC_PLUGIN_RANDSTRUCT_PERFORMANCE', 'is not set', 'clipos', 'self_protection'), \
- randstruct_is_set))
- checklist.append(OptCheck('RANDOM_TRUST_BOOTLOADER', 'is not set', 'clipos', 'self_protection'))
- checklist.append(OptCheck('RANDOM_TRUST_CPU', 'is not set', 'clipos', 'self_protection'))
- if arch == 'X86_64' or arch == 'X86_32':
- checklist.append(AND(OptCheck('INTEL_IOMMU_SVM', 'y', 'clipos', 'self_protection'), \
- iommu_support_is_set))
- checklist.append(AND(OptCheck('INTEL_IOMMU_DEFAULT_ON', 'y', 'clipos', 'self_protection'), \
- iommu_support_is_set))
- if arch == 'X86_32':
- checklist.append(AND(OptCheck('INTEL_IOMMU', 'y', 'clipos', 'self_protection'), \
- iommu_support_is_set))
-
- checklist.append(OptCheck('SLUB_DEBUG_ON', 'y', 'my', 'self_protection'))
- checklist.append(OptCheck('RESET_ATTACK_MITIGATION', 'y', 'my', 'self_protection')) # needs userspace support (systemd)
- if arch == 'X86_64':
- checklist.append(AND(OptCheck('AMD_IOMMU_V2', 'y', 'my', 'self_protection'), \
- iommu_support_is_set))
-
- if arch == 'X86_64' or arch == 'ARM64' or arch == 'X86_32':
- checklist.append(OptCheck('SECURITY', 'y', 'defconfig', 'security_policy')) # and choose your favourite LSM
- if arch == 'ARM':
- checklist.append(OptCheck('SECURITY', 'y', 'kspp', 'security_policy')) # and choose your favourite LSM
- checklist.append(OptCheck('SECURITY_YAMA', 'y', 'kspp', 'security_policy'))
- checklist.append(OR(OptCheck('SECURITY_WRITABLE_HOOKS', 'is not set', 'my', 'security_policy'), \
- OptCheck('SECURITY_SELINUX_DISABLE', 'is not set', 'kspp', 'security_policy')))
- checklist.append(OptCheck('SECURITY_LOCKDOWN_LSM', 'y', 'clipos', 'security_policy'))
- checklist.append(OptCheck('SECURITY_LOCKDOWN_LSM_EARLY', 'y', 'clipos', 'security_policy'))
- checklist.append(OptCheck('LOCK_DOWN_KERNEL_FORCE_CONFIDENTIALITY', 'y', 'clipos', 'security_policy'))
- loadpin_is_set = OptCheck('SECURITY_LOADPIN', 'y', 'my', 'security_policy') # needs userspace support
- checklist.append(loadpin_is_set)
- checklist.append(AND(OptCheck('SECURITY_LOADPIN_ENFORCE', 'y', 'my', 'security_policy'), \
- loadpin_is_set))
- checklist.append(OptCheck('SECURITY_SAFESETID', 'y', 'my', 'security_policy'))
-
- checklist.append(OptCheck('SECCOMP', 'y', 'defconfig', 'cut_attack_surface'))
- checklist.append(OptCheck('SECCOMP_FILTER', 'y', 'defconfig', 'cut_attack_surface'))
- if arch == 'X86_64' or arch == 'ARM64' or arch == 'X86_32':
- checklist.append(OR(OptCheck('STRICT_DEVMEM', 'y', 'defconfig', 'cut_attack_surface'), \
- devmem_not_set)) # refers to LOCKDOWN
-
- checklist.append(modules_not_set)
- checklist.append(devmem_not_set)
- checklist.append(OR(OptCheck('IO_STRICT_DEVMEM', 'y', 'kspp', 'cut_attack_surface'), \
- devmem_not_set)) # refers to LOCKDOWN
- if arch == 'ARM':
- checklist.append(OR(OptCheck('STRICT_DEVMEM', 'y', 'kspp', 'cut_attack_surface'), \
- devmem_not_set)) # refers to LOCKDOWN
- if arch == 'X86_64':
- checklist.append(OptCheck('LEGACY_VSYSCALL_NONE', 'y', 'kspp', 'cut_attack_surface')) # 'vsyscall=none'
- checklist.append(OptCheck('ACPI_CUSTOM_METHOD', 'is not set', 'kspp', 'cut_attack_surface')) # refers to LOCKDOWN
- checklist.append(OptCheck('COMPAT_BRK', 'is not set', 'kspp', 'cut_attack_surface'))
- checklist.append(OptCheck('DEVKMEM', 'is not set', 'kspp', 'cut_attack_surface')) # refers to LOCKDOWN
- checklist.append(OptCheck('COMPAT_VDSO', 'is not set', 'kspp', 'cut_attack_surface'))
- checklist.append(OptCheck('BINFMT_MISC', 'is not set', 'kspp', 'cut_attack_surface'))
- checklist.append(OptCheck('INET_DIAG', 'is not set', 'kspp', 'cut_attack_surface'))
- checklist.append(OptCheck('KEXEC', 'is not set', 'kspp', 'cut_attack_surface')) # refers to LOCKDOWN
- checklist.append(OptCheck('PROC_KCORE', 'is not set', 'kspp', 'cut_attack_surface')) # refers to LOCKDOWN
- checklist.append(OptCheck('LEGACY_PTYS', 'is not set', 'kspp', 'cut_attack_surface'))
- checklist.append(OptCheck('HIBERNATION', 'is not set', 'kspp', 'cut_attack_surface')) # refers to LOCKDOWN
- checklist.append(OptCheck('IA32_EMULATION', 'is not set', 'kspp', 'cut_attack_surface'))
- checklist.append(OptCheck('X86_X32', 'is not set', 'kspp', 'cut_attack_surface'))
- checklist.append(OptCheck('MODIFY_LDT_SYSCALL', 'is not set', 'kspp', 'cut_attack_surface'))
- checklist.append(OptCheck('OABI_COMPAT', 'is not set', 'kspp', 'cut_attack_surface'))
-
- checklist.append(OptCheck('X86_PTDUMP', 'is not set', 'grsecurity', 'cut_attack_surface'))
- checklist.append(OptCheck('ZSMALLOC_STAT', 'is not set', 'grsecurity', 'cut_attack_surface'))
- checklist.append(OptCheck('PAGE_OWNER', 'is not set', 'grsecurity', 'cut_attack_surface'))
- checklist.append(OptCheck('DEBUG_KMEMLEAK', 'is not set', 'grsecurity', 'cut_attack_surface'))
- checklist.append(OptCheck('BINFMT_AOUT', 'is not set', 'grsecurity', 'cut_attack_surface'))
- checklist.append(OptCheck('KPROBES', 'is not set', 'grsecurity', 'cut_attack_surface')) # refers to LOCKDOWN
- checklist.append(OptCheck('UPROBES', 'is not set', 'grsecurity', 'cut_attack_surface'))
- checklist.append(OptCheck('GENERIC_TRACER', 'is not set', 'grsecurity', 'cut_attack_surface')) # refers to LOCKDOWN
- checklist.append(OptCheck('PROC_VMCORE', 'is not set', 'grsecurity', 'cut_attack_surface'))
- checklist.append(OptCheck('PROC_PAGE_MONITOR', 'is not set', 'grsecurity', 'cut_attack_surface'))
- checklist.append(OptCheck('USELIB', 'is not set', 'grsecurity', 'cut_attack_surface'))
- checklist.append(OptCheck('CHECKPOINT_RESTORE', 'is not set', 'grsecurity', 'cut_attack_surface'))
- checklist.append(OptCheck('USERFAULTFD', 'is not set', 'grsecurity', 'cut_attack_surface'))
- checklist.append(OptCheck('HWPOISON_INJECT', 'is not set', 'grsecurity', 'cut_attack_surface'))
- checklist.append(OptCheck('MEM_SOFT_DIRTY', 'is not set', 'grsecurity', 'cut_attack_surface'))
- checklist.append(OptCheck('DEVPORT', 'is not set', 'grsecurity', 'cut_attack_surface')) # refers to LOCKDOWN
- checklist.append(OptCheck('DEBUG_FS', 'is not set', 'grsecurity', 'cut_attack_surface')) # refers to LOCKDOWN
- checklist.append(OptCheck('NOTIFIER_ERROR_INJECTION','is not set', 'grsecurity', 'cut_attack_surface'))
-
- checklist.append(OptCheck('ACPI_TABLE_UPGRADE', 'is not set', 'lockdown', 'cut_attack_surface')) # refers to LOCKDOWN
- checklist.append(OptCheck('X86_IOPL_IOPERM', 'is not set', 'lockdown', 'cut_attack_surface')) # refers to LOCKDOWN
- checklist.append(OptCheck('EFI_TEST', 'is not set', 'lockdown', 'cut_attack_surface')) # refers to LOCKDOWN
- checklist.append(OptCheck('BPF_SYSCALL', 'is not set', 'lockdown', 'cut_attack_surface')) # refers to LOCKDOWN
- checklist.append(OptCheck('MMIOTRACE_TEST', 'is not set', 'lockdown', 'cut_attack_surface')) # refers to LOCKDOWN
-
- if arch == 'X86_64' or arch == 'X86_32':
- checklist.append(OptCheck('X86_INTEL_TSX_MODE_OFF', 'y', 'clipos', 'cut_attack_surface')) # tsx=off
- checklist.append(OptCheck('STAGING', 'is not set', 'clipos', 'cut_attack_surface'))
- checklist.append(OptCheck('KSM', 'is not set', 'clipos', 'cut_attack_surface')) # to prevent FLUSH+RELOAD attack
-# checklist.append(OptCheck('IKCONFIG', 'is not set', 'clipos', 'cut_attack_surface')) # no, this info is needed for this check :)
- checklist.append(OptCheck('KALLSYMS', 'is not set', 'clipos', 'cut_attack_surface'))
- checklist.append(OptCheck('X86_VSYSCALL_EMULATION', 'is not set', 'clipos', 'cut_attack_surface'))
- checklist.append(OptCheck('MAGIC_SYSRQ', 'is not set', 'clipos', 'cut_attack_surface'))
- checklist.append(OptCheck('KEXEC_FILE', 'is not set', 'clipos', 'cut_attack_surface')) # refers to LOCKDOWN (permissive)
- checklist.append(OptCheck('USER_NS', 'is not set', 'clipos', 'cut_attack_surface')) # user.max_user_namespaces=0
- checklist.append(OptCheck('X86_MSR', 'is not set', 'clipos', 'cut_attack_surface')) # refers to LOCKDOWN
- checklist.append(OptCheck('X86_CPUID', 'is not set', 'clipos', 'cut_attack_surface'))
- checklist.append(AND(OptCheck('LDISC_AUTOLOAD', 'is not set', 'clipos', 'cut_attack_surface'), \
- VerCheck((5, 1)))) # LDISC_AUTOLOAD can be disabled since v5.1
-
- checklist.append(OptCheck('AIO', 'is not set', 'grapheneos', 'cut_attack_surface'))
-
- checklist.append(OptCheck('MMIOTRACE', 'is not set', 'my', 'cut_attack_surface')) # refers to LOCKDOWN (permissive)
- checklist.append(OptCheck('LIVEPATCH', 'is not set', 'my', 'cut_attack_surface'))
- checklist.append(OptCheck('IP_DCCP', 'is not set', 'my', 'cut_attack_surface'))
- checklist.append(OptCheck('IP_SCTP', 'is not set', 'my', 'cut_attack_surface'))
- checklist.append(OptCheck('FTRACE', 'is not set', 'my', 'cut_attack_surface')) # refers to LOCKDOWN
- checklist.append(OptCheck('BPF_JIT', 'is not set', 'my', 'cut_attack_surface'))
- checklist.append(OptCheck('VIDEO_VIVID', 'is not set', 'my', 'cut_attack_surface'))
-
- checklist.append(OptCheck('INTEGRITY', 'y', 'defconfig', 'userspace_hardening'))
- if arch == 'ARM64':
- checklist.append(OptCheck('ARM64_PTR_AUTH', 'y', 'defconfig', 'userspace_hardening'))
- if arch == 'ARM' or arch == 'X86_32':
- checklist.append(OptCheck('VMSPLIT_3G', 'y', 'defconfig', 'userspace_hardening'))
- if arch == 'X86_64' or arch == 'ARM64':
- checklist.append(OptCheck('ARCH_MMAP_RND_BITS', '32', 'clipos', 'userspace_hardening'))
- if arch == 'X86_32' or arch == 'ARM':
- checklist.append(OptCheck('ARCH_MMAP_RND_BITS', '16', 'my', 'userspace_hardening'))
-
-# checklist.append(OptCheck('LKDTM', 'm', 'my', 'feature_test'))
-
-
-def print_opt(opt, with_results):
- print('CONFIG_{:<38}|{:^13}|{:^10}|{:^20}'.format(opt.name, opt.expected, opt.decision, opt.reason), end='')
- if with_results:
- print('| {}'.format(opt.result), end='')
- print()
-
-
-def print_checklist(checklist, with_results):
- if json_mode:
- opts = []
- for o in checklist:
- opt = ['CONFIG_'+o.name, o.expected, o.decision, o.reason]
- if with_results:
- opt.append(o.result)
- opts.append(opt)
- print(json.dumps(opts))
- return
-
- # table header
- sep_line_len = 91
- if with_results:
- sep_line_len += 30
- print('=' * sep_line_len)
- print('{:^45}|{:^13}|{:^10}|{:^20}'.format('option name', '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 debug_mode and hasattr(opt, 'opts'):
- print(' {:87}'.format('<<< ' + opt.__class__.__name__ + ' >>>'), end='')
- if with_results:
- print('| {}'.format(opt.result), end='')
- print()
- for o in opt.opts:
- if hasattr(o, 'ver_expected'):
- ver_req = 'kernel version >= ' + str(o.ver_expected[0]) + '.' + str(o.ver_expected[1])
- print('{:<91}'.format(ver_req), end='')
- if with_results:
- print('| {}'.format(o.result), end='')
- print()
- else:
- print_opt(o, with_results)
- else:
- print_opt(opt, with_results)
- if debug_mode:
- print('-' * sep_line_len)
- print()
-
-
-def perform_checks(checklist, parsed_options):
- for opt in checklist:
- if hasattr(opt, 'opts'):
- # prepare ComplexOptCheck
- for o in opt.opts:
- if hasattr(o, 'name'):
- o.state = parsed_options.get(o.name, None)
- else:
- # prepare simple OptCheck
- if not hasattr(opt, 'name'):
- sys.exit('[!] ERROR: bad OptCheck {}'.format(vars(opt)))
- opt.state = parsed_options.get(opt.name, None)
- opt.check()
-
-
-def check_config_file(checklist, fname):
- with open(fname, 'r') as f:
- parsed_options = OrderedDict()
- 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")
-
- if not json_mode:
- print('[+] Checking "{}" against {} hardening preferences...'.format(fname, arch))
- for line in f.readlines():
- line = line.strip()
- option = None
- value = None
-
- if opt_is_on.match(line):
- option, value = line[7:].split('=', 1)
- elif opt_is_off.match(line):
- option, value = line[9:].split(' ', 1)
- if value != 'is not set':
- sys.exit('[!] ERROR: bad disabled config option "{}"'.format(line))
-
- if option in parsed_options:
- sys.exit('[!] ERROR: config option "{}" exists multiple times'.format(line))
-
- if option is not None:
- parsed_options[option] = value
-
- perform_checks(checklist, parsed_options)
-
- if debug_mode:
- 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 option, value in parsed_options.items():
- if option not in known_options:
- print('DEBUG: dunno about option {} ({})'.format(option, value))
-
- print_checklist(checklist, True)
-
-
-if __name__ == '__main__':
- parser = ArgumentParser(description='Checks the hardening options in the Linux kernel config')
- parser.add_argument('-p', '--print', choices=supported_archs,
- help='print hardening preferences for selected architecture')
- parser.add_argument('-c', '--config',
- help='check the config_file against these preferences')
- parser.add_argument('--debug', action='store_true',
- help='enable verbose debug mode')
- parser.add_argument('--json', action='store_true',
- help='print results in JSON format')
- args = parser.parse_args()
-
- if args.debug:
- debug_mode = True
- print('[!] WARNING: debug mode is enabled')
- if args.json:
- json_mode = True
- if debug_mode and json_mode:
- sys.exit('[!] ERROR: options --debug and --json cannot be used simultaneously')
-
- if args.config:
- arch, msg = detect_arch(args.config)
- if not arch:
- sys.exit('[!] ERROR: {}'.format(msg))
- elif not json_mode:
- print('[+] Detected architecture: {}'.format(arch))
-
- kernel_version, msg = detect_version(args.config)
- if not kernel_version:
- sys.exit('[!] ERROR: {}'.format(msg))
- elif not json_mode:
- print('[+] Detected kernel version: {}.{}'.format(kernel_version[0], kernel_version[1]))
-
- construct_checklist(config_checklist, arch)
- check_config_file(config_checklist, args.config)
- error_count = len(list(filter(lambda opt: opt.result.startswith('FAIL'), config_checklist)))
- ok_count = len(list(filter(lambda opt: opt.result.startswith('OK'), config_checklist)))
- if debug_mode:
- sys.exit(0)
- if not json_mode:
- print('[+] config check is finished: \'OK\' - {} / \'FAIL\' - {}'.format(ok_count, error_count))
- sys.exit(0)
-
- if args.print:
- arch = args.print
- construct_checklist(config_checklist, arch)
- if not json_mode:
- print('[+] Printing kernel hardening preferences for {}...'.format(arch))
- print_checklist(config_checklist, False)
- sys.exit(0)
-
- parser.print_help()
projects / kconfig-hardened-check.git / commitdiff