#
# This script helps me to check the Linux kernel Kconfig option list
-# against my hardening preferences for x86_64. Let the computers do their job!
+# 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:
-# page_poison=1
-# slub_debug=P
+# slub_debug=FZP
# slab_nomerge
-# pti=on
# kernel.kptr_restrict=1
+# lockdown=1 (is it changed?)
+# page_alloc.shuffle=1
+# iommu=force (does it help against DMA attacks?)
+# page_poison=1 (if enabled)
+#
+# 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
+# ARM64:
+# kpti=on
+# ssbd=force-on
+#
+# N.B. Hardening sysctls:
+# net.core.bpf_jit_harden=2
+# kptr_restrict=2
+# vm.unprivileged_userfaultfd=0
+# kernel.perf_event_paranoid=3
+# kernel.yama.ptrace_scope=1 (or even 3?)
+# kernel.unprivileged_bpf_disabled=1
+# fs.suid_dumpable=0
+# fs.protected_symlinks = 1
+# fs.protected_hardlinks = 1
+# fs.protected_fifos = 2
+# fs.protected_regular = 2
import sys
from argparse import ArgumentParser
from collections import OrderedDict
import re
+import json
debug_mode = False # set it to True to print the unknown options from the config
-error_count = 0
-opt_list = []
+json_mode = False # if True, print results in JSON format
+
+supported_archs = [ 'X86_64', 'X86_32', 'ARM64', 'ARM' ]
-class Opt:
+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):
- global error_count
-
if self.expected == self.state:
- return True, 'OK'
-
- if self.state is None:
+ self.result = 'OK'
+ elif self.state is None:
if self.expected == 'is not set':
- return True, 'OK: not found'
+ self.result = 'OK: not found'
else:
- error_count += 1
- return False, 'FAIL: not found'
+ self.result = 'FAIL: not found'
+ else:
+ self.result = 'FAIL: "' + self.state + '"'
- error_count += 1
- return False, 'FAIL: "' + self.state + '"'
+ if self.result.startswith('OK'):
+ return True, self.result
+ else:
+ return False, self.result
def __repr__(self):
return '{} = {}'.format(self.name, self.state)
-def construct_opt_checks():
- opt_list.append([Opt('BUG', 'y', 'ubuntu18', 'self_protection'), ''])
- opt_list.append([Opt('PAGE_TABLE_ISOLATION', 'y', 'ubuntu18', 'self_protection'), ''])
- opt_list.append([Opt('RETPOLINE', 'y', 'ubuntu18', 'self_protection'), ''])
- opt_list.append([Opt('X86_64', 'y', 'ubuntu18', 'self_protection'), ''])
- opt_list.append([Opt('STRICT_KERNEL_RWX', 'y', 'ubuntu18', 'self_protection'), ''])
- opt_list.append([Opt('STRICT_MODULE_RWX', 'y', 'ubuntu18', 'self_protection'), ''])
- opt_list.append([Opt('DEBUG_WX', 'y', 'ubuntu18', 'self_protection'), ''])
- opt_list.append([Opt('RANDOMIZE_BASE', 'y', 'ubuntu18', 'self_protection'), ''])
- opt_list.append([Opt('RANDOMIZE_MEMORY', 'y', 'ubuntu18', 'self_protection'), ''])
- opt_list.append([Opt('CC_STACKPROTECTOR', 'y', 'ubuntu18', 'self_protection'), ''])
- opt_list.append([Opt('CC_STACKPROTECTOR_STRONG','y', 'ubuntu18', 'self_protection'), ''])
- opt_list.append([Opt('VMAP_STACK', 'y', 'ubuntu18', 'self_protection'), ''])
- opt_list.append([Opt('THREAD_INFO_IN_TASK', 'y', 'ubuntu18', 'self_protection'), ''])
- opt_list.append([Opt('SCHED_STACK_END_CHECK', 'y', 'ubuntu18', 'self_protection'), ''])
- opt_list.append([Opt('SLUB_DEBUG', 'y', 'ubuntu18', 'self_protection'), ''])
- opt_list.append([Opt('SLAB_FREELIST_HARDENED', 'y', 'ubuntu18', 'self_protection'), ''])
- opt_list.append([Opt('SLAB_FREELIST_RANDOM', 'y', 'ubuntu18', 'self_protection'), ''])
- opt_list.append([Opt('HARDENED_USERCOPY', 'y', 'ubuntu18', 'self_protection'), ''])
- opt_list.append([Opt('FORTIFY_SOURCE', 'y', 'ubuntu18', 'self_protection'), ''])
- opt_list.append([Opt('MODULE_SIG', 'y', 'ubuntu18', 'self_protection'), ''])
- opt_list.append([Opt('MODULE_SIG_ALL', 'y', 'ubuntu18', 'self_protection'), ''])
- opt_list.append([Opt('MODULE_SIG_SHA512', 'y', 'ubuntu18', 'self_protection'), ''])
- opt_list.append([Opt('SYN_COOKIES', 'y', 'ubuntu18', 'self_protection'), '']) # another reason?
- opt_list.append([Opt('DEFAULT_MMAP_MIN_ADDR', '65536', 'ubuntu18', 'self_protection'), ''])
-
- opt_list.append([Opt('BUG_ON_DATA_CORRUPTION', 'y', 'kspp', 'self_protection'), ''])
- opt_list.append([Opt('PAGE_POISONING', 'y', 'kspp', 'self_protection'), ''])
- opt_list.append([Opt('GCC_PLUGINS', 'y', 'kspp', 'self_protection'), ''])
- opt_list.append([Opt('GCC_PLUGIN_RANDSTRUCT', 'y', 'kspp', 'self_protection'), ''])
- opt_list.append([Opt('GCC_PLUGIN_STRUCTLEAK', 'y', 'kspp', 'self_protection'), ''])
- opt_list.append([Opt('GCC_PLUGIN_STRUCTLEAK_BYREF_ALL', 'y', 'kspp', 'self_protection'), ''])
- opt_list.append([Opt('GCC_PLUGIN_LATENT_ENTROPY', 'y', 'kspp', 'self_protection'), ''])
- opt_list.append([Opt('REFCOUNT_FULL', 'y', 'kspp', 'self_protection'), ''])
- opt_list.append([Opt('DEBUG_LIST', 'y', 'kspp', 'self_protection'), ''])
- opt_list.append([Opt('DEBUG_SG', 'y', 'kspp', 'self_protection'), ''])
- opt_list.append([Opt('DEBUG_CREDENTIALS', 'y', 'kspp', 'self_protection'), ''])
- opt_list.append([Opt('DEBUG_NOTIFIERS', 'y', 'kspp', 'self_protection'), ''])
- opt_list.append([Opt('MODULE_SIG_FORCE', 'y', 'kspp', 'self_protection'), ''])
- opt_list.append([Opt('HARDENED_USERCOPY_FALLBACK', 'is not set', 'kspp', 'self_protection'), ''])
-
- opt_list.append([Opt('GCC_PLUGIN_STACKLEAK', 'y', 'my', 'self_protection'), ''])
- opt_list.append([Opt('SLUB_DEBUG_ON', 'y', 'my', 'self_protection'), ''])
- opt_list.append([Opt('SECURITY_DMESG_RESTRICT', 'y', 'my', 'self_protection'), ''])
- opt_list.append([Opt('STATIC_USERMODEHELPER', 'y', 'my', 'self_protection'), '']) # breaks systemd?
- opt_list.append([Opt('PAGE_POISONING_NO_SANITY', 'is not set', 'my', 'self_protection'), ''])
- opt_list.append([Opt('PAGE_POISONING_ZERO', 'is not set', 'my', 'self_protection'), ''])
-
- opt_list.append([Opt('SECURITY', 'y', 'ubuntu18', 'security_policy'), ''])
- opt_list.append([Opt('SECURITY_YAMA', 'y', 'ubuntu18', 'security_policy'), ''])
- opt_list.append([Opt('SECURITY_SELINUX_DISABLE', 'is not set', 'ubuntu18', 'security_policy'), ''])
-
- opt_list.append([Opt('SECCOMP', 'y', 'ubuntu18', 'cut_attack_surface'), ''])
- opt_list.append([Opt('SECCOMP_FILTER', 'y', 'ubuntu18', 'cut_attack_surface'), ''])
- opt_list.append([Opt('STRICT_DEVMEM', 'y', 'ubuntu18', 'cut_attack_surface'), ''])
- opt_list.append([Opt('ACPI_CUSTOM_METHOD', 'is not set', 'ubuntu18', 'cut_attack_surface'), ''])
- opt_list.append([Opt('COMPAT_BRK', 'is not set', 'ubuntu18', 'cut_attack_surface'), ''])
- opt_list.append([Opt('DEVKMEM', 'is not set', 'ubuntu18', 'cut_attack_surface'), ''])
- opt_list.append([Opt('COMPAT_VDSO', 'is not set', 'ubuntu18', 'cut_attack_surface'), ''])
- opt_list.append([Opt('X86_PTDUMP', 'is not set', 'ubuntu18', 'cut_attack_surface'), ''])
- opt_list.append([Opt('ZSMALLOC_STAT', 'is not set', 'ubuntu18', 'cut_attack_surface'), ''])
- opt_list.append([Opt('PAGE_OWNER', 'is not set', 'ubuntu18', 'cut_attack_surface'), ''])
- opt_list.append([Opt('DEBUG_KMEMLEAK', 'is not set', 'ubuntu18', 'cut_attack_surface'), ''])
-
- opt_list.append([Opt('IO_STRICT_DEVMEM', 'y', 'kspp', 'cut_attack_surface'), ''])
- opt_list.append([Opt('LEGACY_VSYSCALL_NONE', 'y', 'kspp', 'cut_attack_surface'), '']) # 'vsyscall=none'
- opt_list.append([Opt('BINFMT_MISC', 'is not set', 'kspp', 'cut_attack_surface'), ''])
- opt_list.append([Opt('INET_DIAG', 'is not set', 'kspp', 'cut_attack_surface'), ''])
- opt_list.append([Opt('KEXEC', 'is not set', 'kspp', 'cut_attack_surface'), ''])
- opt_list.append([Opt('PROC_KCORE', 'is not set', 'kspp', 'cut_attack_surface'), ''])
- opt_list.append([Opt('LEGACY_PTYS', 'is not set', 'kspp', 'cut_attack_surface'), ''])
- opt_list.append([Opt('IA32_EMULATION', 'is not set', 'kspp', 'cut_attack_surface'), ''])
- opt_list.append([Opt('X86_X32', 'is not set', 'kspp', 'cut_attack_surface'), ''])
- opt_list.append([Opt('MODIFY_LDT_SYSCALL', 'is not set', 'kspp', 'cut_attack_surface'), ''])
- opt_list.append([Opt('HIBERNATION', 'is not set', 'kspp', 'cut_attack_surface'), ''])
-
- opt_list.append([Opt('KPROBES', 'is not set', 'grsecurity', 'cut_attack_surface'), ''])
- opt_list.append([Opt('UPROBES', 'is not set', 'grsecurity', 'cut_attack_surface'), ''])
- opt_list.append([Opt('GENERIC_TRACER', 'is not set', 'grsecurity', 'cut_attack_surface'), ''])
- opt_list.append([Opt('PROC_VMCORE', 'is not set', 'grsecurity', 'cut_attack_surface'), ''])
- opt_list.append([Opt('PROC_PAGE_MONITOR', 'is not set', 'grsecurity', 'cut_attack_surface'), ''])
- opt_list.append([Opt('USELIB', 'is not set', 'grsecurity', 'cut_attack_surface'), ''])
- opt_list.append([Opt('CHECKPOINT_RESTORE', 'is not set', 'grsecurity', 'cut_attack_surface'), ''])
- opt_list.append([Opt('USERFAULTFD', 'is not set', 'grsecurity', 'cut_attack_surface'), ''])
- opt_list.append([Opt('HWPOISON_INJECT', 'is not set', 'grsecurity', 'cut_attack_surface'), ''])
- opt_list.append([Opt('MEM_SOFT_DIRTY', 'is not set', 'grsecurity', 'cut_attack_surface'), ''])
- opt_list.append([Opt('DEVPORT', 'is not set', 'grsecurity', 'cut_attack_surface'), ''])
- opt_list.append([Opt('DEBUG_FS', 'is not set', 'grsecurity', 'cut_attack_surface'), ''])
- opt_list.append([Opt('NOTIFIER_ERROR_INJECTION','is not set', 'grsecurity', 'cut_attack_surface'), ''])
-
- opt_list.append([Opt('KEXEC_FILE', 'is not set', 'my', 'cut_attack_surface'), ''])
- opt_list.append([Opt('LIVEPATCH', 'is not set', 'my', 'cut_attack_surface'), ''])
- opt_list.append([Opt('USER_NS', 'is not set', 'my', 'cut_attack_surface'), '']) # user.max_user_namespaces=0
- opt_list.append([Opt('IP_DCCP', 'is not set', 'my', 'cut_attack_surface'), ''])
- opt_list.append([Opt('IP_SCTP', 'is not set', 'my', 'cut_attack_surface'), ''])
- opt_list.append([Opt('FTRACE', 'is not set', 'my', 'cut_attack_surface'), ''])
- opt_list.append([Opt('PROFILING', 'is not set', 'my', 'cut_attack_surface'), ''])
- opt_list.append([Opt('BPF_JIT', 'is not set', 'my', 'cut_attack_surface'), ''])
- opt_list.append([Opt('BPF_SYSCALL', 'is not set', 'my', 'cut_attack_surface'), ''])
-
- opt_list.append([Opt('ARCH_MMAP_RND_BITS', '32', 'my', 'userspace_protection'), ''])
-
- opt_list.append([Opt('LKDTM', 'm', 'my', 'feature_test'), ''])
-
-
-def print_opt_checks():
- print('[+] Printing kernel hardening preferences...')
- print(' {:<39}|{:^13}|{:^10}|{:^20}'.format('option name', 'desired val', 'decision', 'reason'))
- print(' ======================================================================================')
- for o in opt_list:
- print(' CONFIG_{:<32}|{:^13}|{:^10}|{:^20}'.format(o[0].name, o[0].expected, o[0].decision, o[0].reason))
- print()
+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 which 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:
+ 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 which 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:
+ self.result = 'FAIL: CONFIG_{} is needed'.format(opt.name)
+ 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
+ msg = 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 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 LOCK_DOWN_KERNEL
+
+ 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'))
+ if debug_mode or 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')))
+ iommu_support_is_set = OptCheck('IOMMU_SUPPORT', 'y', 'defconfig', 'self_protection') # is needed for mitigating DMA attacks
+ checklist.append(iommu_support_is_set)
+ checklist.append(OptCheck('SYN_COOKIES', 'y', 'defconfig', 'self_protection')) # another reason?
+ if debug_mode or 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 debug_mode or 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 debug_mode or arch == 'X86_64' or arch == 'ARM64':
+ checklist.append(OptCheck('VMAP_STACK', 'y', 'defconfig', 'self_protection'))
+ if debug_mode or 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 debug_mode or arch == 'ARM':
+ checklist.append(OptCheck('VMSPLIT_3G', 'y', 'defconfig', 'self_protection'))
+ checklist.append(OptCheck('CPU_SW_DOMAIN_PAN', 'y', 'defconfig', 'self_protection'))
+ checklist.append(OptCheck('STACKPROTECTOR_PER_TASK', 'y', 'defconfig', 'self_protection'))
+ if debug_mode or arch == 'ARM64' or arch == 'ARM':
+ checklist.append(OptCheck('REFCOUNT_FULL', 'y', 'defconfig', 'self_protection'))
+ 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 LOCK_DOWN_KERNEL
+ if debug_mode or arch == 'X86_64' or arch == 'X86_32':
+ checklist.append(OptCheck('DEFAULT_MMAP_MIN_ADDR', '65536', 'kspp', 'self_protection'))
+ checklist.append(OptCheck('REFCOUNT_FULL', 'y', 'kspp', 'self_protection'))
+ if debug_mode or arch == 'X86_32':
+ checklist.append(OptCheck('HIGHMEM64G', 'y', 'kspp', 'self_protection'))
+ checklist.append(OptCheck('X86_PAE', 'y', 'kspp', 'self_protection'))
+ if debug_mode or arch == 'ARM64':
+ checklist.append(OptCheck('ARM64_SW_TTBR0_PAN', 'y', 'kspp', 'self_protection'))
+ if debug_mode or 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(OR(OptCheck('INIT_STACK_ALL', 'y', 'clipos', 'self_protection'), \
+ OptCheck('GCC_PLUGIN_STRUCTLEAK_BYREF_ALL', 'y', 'kspp', 'self_protection')))
+ checklist.append(OptCheck('INIT_ON_ALLOC_DEFAULT_ON', 'y', 'clipos', 'self_protection'))
+ checklist.append(OR(OptCheck('INIT_ON_FREE_DEFAULT_ON', 'y', 'clipos', 'self_protection'), \
+ OptCheck('PAGE_POISONING', 'y', '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))
+ if debug_mode or arch == 'X86_64' or arch == 'ARM64' or arch == 'X86_32':
+ stackleak_is_set = OptCheck('GCC_PLUGIN_STACKLEAK', 'y', 'clipos', '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 debug_mode or arch == 'X86_64' or arch == 'X86_32':
+ checklist.append(OptCheck('RANDOM_TRUST_CPU', 'is not set', 'clipos', 'self_protection'))
+ 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))
+
+ 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 debug_mode or arch == 'X86_64':
+ checklist.append(AND(OptCheck('AMD_IOMMU_V2', 'y', 'my', 'self_protection'), \
+ iommu_support_is_set))
+ if debug_mode or arch == 'X86_32':
+ checklist.append(OptCheck('PAGE_TABLE_ISOLATION', 'y', 'my', 'self_protection'))
+
+ if debug_mode or arch == 'X86_64' or arch == 'ARM64' or arch == 'X86_32':
+ checklist.append(OptCheck('SECURITY', 'y', 'defconfig', 'security_policy')) # and choose your favourite LSM
+ if debug_mode or 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(OptCheck('SECURITY_LOADPIN', 'y', 'my', 'security_policy')) # needs userspace support
+ checklist.append(OptCheck('SECURITY_LOCKDOWN_LSM', 'y', 'my', 'security_policy'))
+ checklist.append(OptCheck('SECURITY_LOCKDOWN_LSM_EARLY', 'y', 'my', 'security_policy'))
+ checklist.append(OptCheck('LOCK_DOWN_KERNEL_FORCE_CONFIDENTIALITY', 'y', 'my', 'security_policy'))
+ checklist.append(OptCheck('SECURITY_SAFESETID', 'y', 'my', 'security_policy'))
+ checklist.append(OptCheck('SECURITY_WRITABLE_HOOKS', 'is not set', 'my', 'security_policy'))
+
+ checklist.append(OptCheck('SECCOMP', 'y', 'defconfig', 'cut_attack_surface'))
+ checklist.append(OptCheck('SECCOMP_FILTER', 'y', 'defconfig', 'cut_attack_surface'))
+ if debug_mode or 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 LOCK_DOWN_KERNEL
+
+ 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 LOCK_DOWN_KERNEL
+ if debug_mode or arch == 'ARM':
+ checklist.append(OR(OptCheck('STRICT_DEVMEM', 'y', 'kspp', 'cut_attack_surface'), \
+ devmem_not_set)) # refers to LOCK_DOWN_KERNEL
+ checklist.append(OptCheck('ACPI_CUSTOM_METHOD', 'is not set', 'kspp', 'cut_attack_surface')) # refers to LOCK_DOWN_KERNEL
+ checklist.append(OptCheck('COMPAT_BRK', 'is not set', 'kspp', 'cut_attack_surface'))
+ checklist.append(OptCheck('DEVKMEM', 'is not set', 'kspp', 'cut_attack_surface'))
+ 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 LOCK_DOWN_KERNEL
+ checklist.append(OptCheck('PROC_KCORE', 'is not set', 'kspp', 'cut_attack_surface')) # refers to LOCK_DOWN_KERNEL
+ 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 LOCK_DOWN_KERNEL
+ if debug_mode or arch == 'X86_64':
+ checklist.append(OptCheck('LEGACY_VSYSCALL_NONE', 'y', 'kspp', 'cut_attack_surface')) # 'vsyscall=none'
+ 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'))
+ if debug_mode or arch == 'ARM':
+ 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 LOCK_DOWN_KERNEL
+ checklist.append(OptCheck('UPROBES', 'is not set', 'grsecurity', 'cut_attack_surface'))
+ checklist.append(OptCheck('GENERIC_TRACER', 'is not set', 'grsecurity', 'cut_attack_surface'))
+ 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 LOCK_DOWN_KERNEL
+ checklist.append(OptCheck('DEBUG_FS', 'is not set', 'grsecurity', 'cut_attack_surface')) # refers to LOCK_DOWN_KERNEL
+ 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 LOCK_DOWN_KERNEL
+ checklist.append(OptCheck('ACPI_APEI_EINJ', 'is not set', 'lockdown', 'cut_attack_surface')) # refers to LOCK_DOWN_KERNEL
+ checklist.append(OptCheck('PROFILING', 'is not set', 'lockdown', 'cut_attack_surface')) # refers to LOCK_DOWN_KERNEL
+ checklist.append(OptCheck('BPF_SYSCALL', 'is not set', 'lockdown', 'cut_attack_surface')) # refers to LOCK_DOWN_KERNEL
+ checklist.append(OptCheck('MMIOTRACE_TEST', 'is not set', 'lockdown', 'cut_attack_surface')) # refers to LOCK_DOWN_KERNEL
+
+ 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 LOCK_DOWN_KERNEL (permissive)
+ checklist.append(OptCheck('USER_NS', 'is not set', 'clipos', 'cut_attack_surface')) # user.max_user_namespaces=0
+ checklist.append(OptCheck('LDISC_AUTOLOAD', 'is not set', 'clipos', 'cut_attack_surface'))
+
+ checklist.append(OptCheck('MMIOTRACE', 'is not set', 'my', 'cut_attack_surface')) # refers to LOCK_DOWN_KERNEL (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'))
+ checklist.append(OptCheck('BPF_JIT', 'is not set', 'my', 'cut_attack_surface'))
+ checklist.append(OptCheck('VIDEO_VIVID', 'is not set', 'my', 'cut_attack_surface'))
+ if debug_mode or arch == 'X86_32':
+ checklist.append(OptCheck('MODIFY_LDT_SYSCALL', 'is not set', 'my', 'cut_attack_surface'))
+
+ if debug_mode or arch == 'ARM64':
+ checklist.append(OptCheck('ARM64_PTR_AUTH', 'y', 'defconfig', 'userspace_hardening'))
+ if debug_mode or arch == 'X86_64' or arch == 'ARM64':
+ checklist.append(OptCheck('ARCH_MMAP_RND_BITS', '32', 'clipos', 'userspace_hardening'))
+ if debug_mode or 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_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
+
+ # header
+ print('{:^45}|{:^13}|{:^10}|{:^20}'.format('option name', 'desired val', 'decision', 'reason'), end='')
+ sep_line_len = 91
+ if with_results:
+ print('| {}'.format('check result'), end='')
+ sep_line_len += 30
+ print()
-def print_check_results():
- global error_count
+ print('=' * sep_line_len)
- print(' {:<39}|{:^13}|{:^10}|{:^20}||{:^20}'.format('option name', 'desired val', 'decision', 'reason', 'check result'))
- print(' ===========================================================================================================')
- for o in opt_list:
- print(' CONFIG_{:<32}|{:^13}|{:^10}|{:^20}||{:^20}'.format(o[0].name, o[0].expected, o[0].decision, o[0].reason, o[1]))
+ for opt in checklist:
+ 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()
print()
def get_option_state(options, name):
- return options[name] if name in options else None
+ return options.get(name, None)
-def check_state(options):
- for o in opt_list:
- opt = o[0]
- opt.state = get_option_state(options, opt.name)
- _, o[1] = opt.check()
+def perform_checks(checklist, parsed_options):
+ for opt in checklist:
+ if hasattr(opt, 'opts'):
+ for o in opt.opts:
+ o.state = get_option_state(parsed_options, o.name)
+ else:
+ opt.state = get_option_state(parsed_options, opt.name)
+ opt.check()
-def check_config_file(fname):
+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")
- print('[+] Checking "{}" against hardening preferences...'.format(fname))
+ if not json_mode:
+ print('[+] Checking "{}" against hardening preferences...'.format(fname))
for line in f.readlines():
line = line.strip()
+ option = None
+ value = None
if opt_is_on.match(line):
- config, value = line[7:].split('=', 1)
- parsed_options[config] = value
+ option, value = line[7:].split('=', 1)
elif opt_is_off.match(line):
- config, value = line[9:].split(' ', 1)
+ option, value = line[9:].split(' ', 1)
if value != 'is not set':
- sys.exit('[!] BUG: bad disabled config option "{}"'.format(line))
+ sys.exit('[!] ERROR: bad disabled config option "{}"'.format(line))
- if config in parsed_options:
- sys.exit('[!] ERROR: config option "{}" exists multiple times'.format(line))
+ if option in parsed_options:
+ sys.exit('[!] ERROR: config option "{}" exists multiple times'.format(line))
- parsed_options[config] = value
+ if option is not None:
+ parsed_options[option] = value
- check_state(parsed_options)
- print_check_results()
+ perform_checks(checklist, parsed_options)
if debug_mode:
- opt_list_names = [opt[0].name for opt in opt_list]
- for option in filter(lambda option: option not in opt_list_names, parsed_options.keys()):
- print("DEBUG: dunno about option {} ".format(option))
+ known_options = [opt.name for opt in checklist]
+ 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__':
+ config_checklist = []
+
parser = ArgumentParser(description='Checks the hardening options in the Linux kernel config')
- parser.add_argument('-p', '--print', action='store_true', help='print hardening preferences')
- parser.add_argument('-c', '--config', help='check the config_file against these preferences')
- parser.add_argument('--debug', action='store_true', help='enable internal debug mode')
+ 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 internal debug mode')
+ parser.add_argument('--json', action='store_true',
+ help='print results in JSON format')
args = parser.parse_args()
- construct_opt_checks()
-
- if args.print:
- print_opt_checks()
- sys.exit(0)
-
if args.debug:
debug_mode = True
+ 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:
- check_config_file(args.config)
- if error_count == 0:
- print('[+] config check is PASSED')
+ arch, msg = detect_arch(args.config)
+ if not arch:
+ sys.exit('[!] ERROR: {}'.format(msg))
+ elif not json_mode:
+ print('[+] Detected architecture: {}'.format(arch))
+
+ 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)
- else:
- sys.exit('[-] config check is NOT PASSED: {} errors'.format(error_count))
+ 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()