# 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
#
# fs.suid_dumpable=0
# kernel.modules_disabled=1
+
+# 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 json
from .__about__ import __version__
-# pylint: disable=line-too-long,bad-whitespace,too-many-branches
-# pylint: disable=too-many-statements,global-statement
-
-# Report modes:
-# * verbose mode for
-# - reporting about unknown kernel options in the config
-# - verbose printing of ComplexOptCheck items
-# * json mode for printing the results in JSON format
-report_modes = ['verbose', 'json']
-
-supported_archs = ['X86_64', 'X86_32', 'ARM64', 'ARM']
-
-kernel_version = None
-
class OptCheck:
def __init__(self, reason, decision, name, expected):
return True
return False
- def table_print(self, mode, with_results):
+ def table_print(self, _mode, with_results):
print('CONFIG_{:<38}|{:^13}|{:^10}|{:^20}'.format(self.name, self.expected, self.decision, self.reason), end='')
if with_results:
print('| {}'.format(self.result), end='')
class VerCheck:
def __init__(self, ver_expected):
self.ver_expected = ver_expected
+ self.ver = ()
self.result = None
def check(self):
- if kernel_version[0] > self.ver_expected[0]:
+ if self.ver[0] > self.ver_expected[0]:
self.result = 'OK: version >= ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
return True
- if kernel_version[0] < self.ver_expected[0]:
+ if self.ver[0] < self.ver_expected[0]:
self.result = 'FAIL: version < ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
return False
- if kernel_version[1] >= self.ver_expected[1]:
+ if self.ver[1] >= self.ver_expected[1]:
self.result = 'OK: version >= ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
return True
self.result = 'FAIL: version < ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
return False
- def table_print(self, mode, with_results):
+ 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:
self.result = 'OK: is present'
return True
- def table_print(self, mode, with_results):
+ def table_print(self, _mode, with_results):
print('CONFIG_{:<84}'.format(self.name + ' is present'), end='')
if with_results:
print('| {}'.format(self.result), end='')
class ComplexOptCheck:
def __init__(self, *opts):
self.opts = opts
+ if not self.opts:
+ sys.exit('[!] ERROR: empty {} check'.format(self.__class__.__name__))
+ if not isinstance(opts[0], OptCheck):
+ sys.exit('[!] ERROR: invalid {} check: {}'.format(self.__class__.__name__, opts))
self.result = None
@property
class OR(ComplexOptCheck):
# self.opts[0] is the option that this OR-check is about.
- # Use case:
+ # Use cases:
# OR(<X_is_hardened>, <X_is_disabled>)
- # OR(<X_is_hardened>, <X_is_hardened_old>)
+ # OR(<X_is_hardened>, <old_X_is_hardened>)
def check(self):
if not self.opts:
for i, opt in enumerate(self.opts):
ret = opt.check()
if ret:
- if i == 0 or not hasattr(opt, 'expected'):
+ if opt.result != 'OK' or i == 0:
+ # Preserve additional explanation of this OK result.
+ # Simple OK is enough only for the main option that
+ # this OR-check is about.
self.result = opt.result
else:
+ # Simple OK is not enough for additional checks.
self.result = 'OK: CONFIG_{} "{}"'.format(opt.name, opt.expected)
return True
self.result = self.opts[0].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.
+ # 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))):
self.result = opt.result
return ret
if not ret:
- if hasattr(opt, 'expected'):
- self.result = 'FAIL: CONFIG_{} is needed'.format(opt.name)
+ # 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: not found':
+ self.result = 'FAIL: CONFIG_{} not "{}"'.format(opt.name, opt.expected)
+ elif opt.result == 'FAIL: not present':
+ self.result = 'FAIL: CONFIG_{} not present'.format(opt.name)
else:
+ # This FAIL message is self-explaining.
self.result = opt.result
return False
sys.exit('[!] ERROR: invalid AND check')
-def detect_arch(fname):
+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 supported_archs:
+ if option in archs:
if not arch:
arch = option
else:
if arch == 'ARM64':
l += [OptCheck('self_protection', 'defconfig', 'ARM64_PAN', 'y')]
l += [OptCheck('self_protection', 'defconfig', 'UNMAP_KERNEL_AT_EL0', 'y')]
- l += [OptCheck('self_protection', 'defconfig', 'HARDEN_EL2_VECTORS', 'y')]
+ l += [OR(OptCheck('self_protection', 'defconfig', 'HARDEN_EL2_VECTORS', 'y'),
+ AND(OptCheck('self_protection', 'defconfig', 'RANDOMIZE_BASE', 'y'),
+ VerCheck((5, 9))))] # HARDEN_EL2_VECTORS was included in RANDOMIZE_BASE in v5.9
l += [OptCheck('self_protection', 'defconfig', 'RODATA_FULL_DEFAULT_ENABLED', 'y')]
l += [OptCheck('self_protection', 'defconfig', 'ARM64_PTR_AUTH', 'y')]
+ l += [OptCheck('self_protection', 'defconfig', 'ARM64_BTI_KERNEL', 'y')]
if arch in ('X86_64', 'ARM64'):
l += [OptCheck('self_protection', 'defconfig', 'VMAP_STACK', 'y')]
if arch in ('X86_64', 'ARM64', 'X86_32'):
modules_not_set)]
l += [OR(OptCheck('self_protection', 'kspp', 'MODULE_SIG_FORCE', 'y'),
modules_not_set)] # refers to LOCKDOWN
- l += [OR(OptCheck('self_protection', 'kspp', 'INIT_STACK_ALL', 'y'),
+ l += [OR(OptCheck('self_protection', 'kspp', 'INIT_STACK_ALL_ZERO', 'y'),
OptCheck('self_protection', 'kspp', 'GCC_PLUGIN_STRUCTLEAK_BYREF_ALL', 'y'))]
l += [OR(OptCheck('self_protection', 'kspp', 'INIT_ON_FREE_DEFAULT_ON', 'y'),
- OptCheck('self_protection', 'kspp', 'PAGE_POISONING', 'y'))] # before v5.3
+ OptCheck('self_protection', 'kspp', 'PAGE_POISONING_ZERO', 'y'))] # before v5.3
if arch in ('X86_64', 'ARM64', 'X86_32'):
stackleak_is_set = OptCheck('self_protection', 'kspp', 'GCC_PLUGIN_STACKLEAK', 'y')
l += [stackleak_is_set]
l += [OptCheck('self_protection', 'clipos', 'SECURITY_DMESG_RESTRICT', 'y')]
l += [OptCheck('self_protection', 'clipos', 'DEBUG_VIRTUAL', 'y')]
l += [OptCheck('self_protection', 'clipos', 'STATIC_USERMODEHELPER', 'y')] # needs userspace support
+ l += [OptCheck('self_protection', 'clipos', 'EFI_DISABLE_PCI_DMA', 'y')]
l += [OptCheck('self_protection', 'clipos', 'SLAB_MERGE_DEFAULT', 'is not set')] # slab_nomerge
l += [OptCheck('self_protection', 'clipos', 'RANDOM_TRUST_BOOTLOADER', 'is not set')]
l += [OptCheck('self_protection', 'clipos', 'RANDOM_TRUST_CPU', 'is not set')]
iommu_support_is_set)]
# 'self_protection', 'my'
- l += [OptCheck('self_protection', 'my', 'SLUB_DEBUG_ON', 'y')]
+ l += [AND(OptCheck('self_protection', 'my', 'UBSAN_BOUNDS', 'y'),
+ OptCheck('self_protection', 'my', 'UBSAN_MISC', 'is not set'),
+ OptCheck('self_protection', 'my', 'UBSAN_TRAP', 'y'))]
+ l += [OptCheck('self_protection', 'my', 'SLUB_DEBUG_ON', 'y')] # TODO: is it better to set that via kernel cmd?
l += [OptCheck('self_protection', 'my', 'RESET_ATTACK_MITIGATION', 'y')] # needs userspace support (systemd)
if arch == 'X86_64':
l += [AND(OptCheck('self_protection', 'my', 'AMD_IOMMU_V2', 'y'),
iommu_support_is_set)]
+ if arch == 'ARM64':
+ l += [OptCheck('self_protection', 'my', 'SHADOW_CALL_STACK', 'y')]
# 'security_policy'
if arch in ('X86_64', 'ARM64', 'X86_32'):
l += [OptCheck('cut_attack_surface', 'kspp', 'LEGACY_VSYSCALL_NONE', 'y')] # 'vsyscall=none'
# 'cut_attack_surface', 'grsecurity'
- l += [OptCheck('cut_attack_surface', 'grsecurity', 'X86_PTDUMP', 'is not set')]
l += [OptCheck('cut_attack_surface', 'grsecurity', 'ZSMALLOC_STAT', 'is not set')]
l += [OptCheck('cut_attack_surface', 'grsecurity', 'PAGE_OWNER', 'is not set')]
l += [OptCheck('cut_attack_surface', 'grsecurity', 'DEBUG_KMEMLEAK', 'is not set')]
l += [OptCheck('cut_attack_surface', 'grsecurity', 'MEM_SOFT_DIRTY', 'is not set')]
l += [OptCheck('cut_attack_surface', 'grsecurity', 'DEVPORT', 'is not set')] # refers to LOCKDOWN
l += [OptCheck('cut_attack_surface', 'grsecurity', 'DEBUG_FS', 'is not set')] # refers to LOCKDOWN
- l += [OptCheck('cut_attack_surface', 'grsecurity', 'NOTIFIER_ERROR_INJECTION','is not set')]
+ l += [OptCheck('cut_attack_surface', 'grsecurity', 'NOTIFIER_ERROR_INJECTION', 'is not set')]
+ l += [AND(OptCheck('cut_attack_surface', 'grsecurity', 'X86_PTDUMP', 'is not set'),
+ OptCheck('cut_attack_surface', 'my', 'PTDUMP_DEBUGFS', 'is not set'))]
# 'cut_attack_surface', 'maintainer'
l += [OptCheck('cut_attack_surface', 'maintainer', 'DRM_LEGACY', 'is not set')]
l += [OptCheck('cut_attack_surface', 'maintainer', 'FB', 'is not set')]
l += [OptCheck('cut_attack_surface', 'maintainer', 'VT', 'is not set')]
- # 'cut_attack_surface', 'lockdown'
- l += [OptCheck('cut_attack_surface', 'lockdown', 'ACPI_TABLE_UPGRADE', 'is not set')] # refers to LOCKDOWN
- l += [OptCheck('cut_attack_surface', 'lockdown', 'X86_IOPL_IOPERM', 'is not set')] # refers to LOCKDOWN
- l += [OptCheck('cut_attack_surface', 'lockdown', 'EFI_TEST', 'is not set')] # refers to LOCKDOWN
- l += [OptCheck('cut_attack_surface', 'lockdown', 'BPF_SYSCALL', 'is not set')] # refers to LOCKDOWN
- l += [OptCheck('cut_attack_surface', 'lockdown', 'MMIOTRACE_TEST', 'is not set')] # refers to LOCKDOWN
+ # 'cut_attack_surface', 'grapheneos'
+ l += [OptCheck('cut_attack_surface', 'grapheneos', 'AIO', 'is not set')]
# 'cut_attack_surface', 'clipos'
l += [OptCheck('cut_attack_surface', 'clipos', 'STAGING', 'is not set')]
l += [OptCheck('cut_attack_surface', 'clipos', 'USER_NS', 'is not set')] # user.max_user_namespaces=0
l += [OptCheck('cut_attack_surface', 'clipos', 'X86_MSR', 'is not set')] # refers to LOCKDOWN
l += [OptCheck('cut_attack_surface', 'clipos', 'X86_CPUID', 'is not set')]
+ l += [OptCheck('cut_attack_surface', 'clipos', 'IO_URING', 'is not set')]
+ l += [OptCheck('cut_attack_surface', 'clipos', 'X86_IOPL_IOPERM', 'is not set')] # refers to LOCKDOWN
+ l += [OptCheck('cut_attack_surface', 'clipos', 'ACPI_TABLE_UPGRADE', 'is not set')] # refers to LOCKDOWN
+ l += [OptCheck('cut_attack_surface', 'clipos', 'EFI_CUSTOM_SSDT_OVERLAYS', 'is not set')]
l += [AND(OptCheck('cut_attack_surface', 'clipos', 'LDISC_AUTOLOAD', 'is not set'),
PresenceCheck('LDISC_AUTOLOAD'))]
if arch in ('X86_64', 'X86_32'):
l += [OptCheck('cut_attack_surface', 'clipos', 'X86_INTEL_TSX_MODE_OFF', 'y')] # tsx=off
- # 'cut_attack_surface', 'grapheneos'
- l += [OptCheck('cut_attack_surface', 'grapheneos', 'AIO', 'is not set')]
+ # 'cut_attack_surface', 'lockdown'
+ l += [OptCheck('cut_attack_surface', 'lockdown', 'EFI_TEST', 'is not set')] # refers to LOCKDOWN
+ l += [OptCheck('cut_attack_surface', 'lockdown', 'BPF_SYSCALL', 'is not set')] # refers to LOCKDOWN
+ l += [OptCheck('cut_attack_surface', 'lockdown', 'MMIOTRACE_TEST', 'is not set')] # refers to LOCKDOWN
# 'cut_attack_surface', 'my'
+ l += [OptCheck('cut_attack_surface', 'my', 'TRIM_UNUSED_KSYMS', 'y')]
l += [OptCheck('cut_attack_surface', 'my', 'MMIOTRACE', 'is not set')] # refers to LOCKDOWN (permissive)
l += [OptCheck('cut_attack_surface', 'my', 'LIVEPATCH', 'is not set')]
l += [OptCheck('cut_attack_surface', 'my', 'IP_DCCP', 'is not set')]
l += [OptCheck('cut_attack_surface', 'my', 'IP_SCTP', 'is not set')]
l += [OptCheck('cut_attack_surface', 'my', 'FTRACE', 'is not set')] # refers to LOCKDOWN
- l += [OptCheck('cut_attack_surface', 'my', 'BPF_JIT', 'is not set')]
l += [OptCheck('cut_attack_surface', 'my', 'VIDEO_VIVID', 'is not set')]
l += [OptCheck('cut_attack_surface', 'my', 'INPUT_EVBUG', 'is not set')] # Can be used as a keylogger
# 'userspace_hardening'
- l += [OptCheck('userspace_hardening', 'defconfig', 'INTEGRITY', 'y')]
+ if arch in ('X86_64', 'ARM64', 'X86_32'):
+ l += [OptCheck('userspace_hardening', 'defconfig', 'INTEGRITY', 'y')]
+ if arch == 'ARM':
+ l += [OptCheck('userspace_hardening', 'my', 'INTEGRITY', 'y')]
if arch in ('ARM', 'X86_32'):
l += [OptCheck('userspace_hardening', 'defconfig', 'VMSPLIT_3G', 'y')]
if arch in ('X86_64', 'ARM64'):
# 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':
# final score
if with_results:
- error_count = len(list(filter(lambda opt: opt.result.startswith('FAIL'), checklist)))
+ 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, error_count))
-
-
-def perform_checks(checklist, parsed_options):
+ print('[+] Config check is finished: \'OK\' - {}{} / \'FAIL\' - {}{}'.format(ok_count, ok_suppressed, fail_count, fail_suppressed))
+
+
+def perform_check(opt, parsed_options, kernel_version):
+ if hasattr(opt, 'opts'):
+ # prepare ComplexOptCheck
+ for o in opt.opts:
+ if hasattr(o, 'opts'):
+ # Recursion for nested ComplexOptChecks
+ perform_check(o, parsed_options, kernel_version)
+ if hasattr(o, 'state'):
+ o.state = parsed_options.get(o.name, None)
+ if hasattr(o, 'ver'):
+ o.ver = kernel_version
+ else:
+ # prepare simple check, opt.state is mandatory
+ if not hasattr(opt, 'state'):
+ sys.exit('[!] ERROR: bad simple check {}'.format(vars(opt)))
+ opt.state = parsed_options.get(opt.name, None)
+ opt.check()
+
+
+def perform_checks(checklist, parsed_options, kernel_version):
for opt in checklist:
- if hasattr(opt, 'opts'):
- # prepare ComplexOptCheck
- for o in opt.opts:
- if hasattr(o, 'state'):
- o.state = parsed_options.get(o.name, None)
- else:
- # prepare simple check
- if not hasattr(opt, 'state'):
- sys.exit('[!] ERROR: bad simple check {}'.format(vars(opt)))
- opt.state = parsed_options.get(opt.name, None)
- opt.check()
+ perform_check(opt, parsed_options, kernel_version)
def parse_config_file(parsed_options, fname):
def main():
- global kernel_version
-
- mode = None
- config_checklist = []
- parsed_options = OrderedDict()
-
+ # Report modes:
+ # * verbose mode for
+ # - reporting about unknown kernel options in the config
+ # - 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='Checks the hardening options in the Linux kernel config')
parser.add_argument('--version', action='version', version='%(prog)s ' + __version__)
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')
+ help='check the kernel config 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 mode != 'json':
print('[+] Config file to check: {}'.format(args.config))
- arch, msg = detect_arch(args.config)
+ arch, msg = detect_arch(args.config, supported_archs)
if not arch:
sys.exit('[!] ERROR: {}'.format(msg))
if mode != 'json':
print('[+] Detected kernel version: {}.{}'.format(kernel_version[0], kernel_version[1]))
construct_checklist(config_checklist, arch)
+ parsed_options = OrderedDict()
parse_config_file(parsed_options, args.config)
- perform_checks(config_checklist, parsed_options)
+ perform_checks(config_checklist, parsed_options, kernel_version)
if mode == 'verbose':
print_unknown_options(config_checklist, parsed_options)
sys.exit(0)
if args.print:
+ if mode in ('show_ok', 'show_fail'):
+ sys.exit('[!] ERROR: please use "{}" mode for checking the kernel config'.format(mode))
arch = args.print
construct_checklist(config_checklist, arch)
if mode != 'json':
projects / kconfig-hardened-check.git / blobdiff