#
#
# N.B Hardening command line parameters:
-# slab_nomerge
# page_alloc.shuffle=1
# iommu=force (does it help against DMA attacks?)
-# iommu.passthrough=0
-# iommu.strict=1
# slub_debug=FZ (slow)
-# init_on_alloc=1 (since v5.3)
-# init_on_free=1 (since v5.3, otherwise slub_debug=P and page_poison=1)
# loadpin.enforce=1
# debugfs=no-mount (or off if possible)
-# randomize_kstack_offset=1
#
# Mitigations of CPU vulnerabilities:
# Аrch-independent:
# mitigations=auto,nosmt (nosmt is slow)
# X86:
# spectre_v2=on
-# pti=on
# spec_store_bypass_disable=on
# l1tf=full,force
# l1d_flush=on (a part of the l1tf option)
#
# Should NOT be set:
# nokaslr
+# sysrq_always_enabled
# arm64.nobti
# arm64.nopauth
+# arm64.nomte
#
# Hardware tag-based KASAN with arm64 Memory Tagging Extension (MTE):
# kasan=on
# what about bpf_jit_enable?
# kernel.unprivileged_bpf_disabled=1
# net.core.bpf_jit_harden=2
-#
# vm.unprivileged_userfaultfd=0
# (at first, it disabled unprivileged userfaultfd,
# and since v5.11 it enables unprivileged userfaultfd for user-mode only)
-#
# dev.tty.ldisc_autoload=0
# fs.protected_symlinks=1
# fs.protected_hardlinks=1
# fs.protected_regular=2
# fs.suid_dumpable=0
# kernel.modules_disabled=1
+# kernel.randomize_va_space = 2
# pylint: disable=missing-module-docstring,missing-class-docstring,missing-function-docstring
import json
from .__about__ import __version__
-TYPES_OF_CHECKS = ('kconfig', 'version')
+SIMPLE_OPTION_TYPES = ('kconfig', 'version', 'cmdline')
class OptCheck:
# Constructor without the 'expected' parameter is for option presence checks (any value is OK)
def __init__(self, reason, decision, name, expected=None):
- if not reason or not decision or not name:
- sys.exit('[!] ERROR: invalid {} check for "{}"'.format(self.__class__.__name__, name))
+ assert(reason and decision and name), \
+ 'invalid {} check for "{}"'.format(self.__class__.__name__, name)
self.name = name
self.expected = expected
self.decision = decision
if with_results:
print('| {}'.format(self.result), end='')
+ def json_dump(self, with_results):
+ dump = [self.name, self.type, self.expected, self.decision, self.reason]
+ if with_results:
+ dump.append(self.result)
+ return dump
+
class KconfigCheck(OptCheck):
def __init__(self, *args, **kwargs):
def type(self):
return 'kconfig'
- def json_dump(self, with_results):
- dump = [self.name, self.type, self.expected, self.decision, self.reason]
- if with_results:
- dump.append(self.result)
- return dump
+
+class CmdlineCheck(OptCheck):
+ @property
+ def type(self):
+ return 'cmdline'
class VersionCheck:
class ComplexOptCheck:
def __init__(self, *opts):
self.opts = opts
- if not self.opts:
- sys.exit('[!] ERROR: empty {} check'.format(self.__class__.__name__))
- if len(self.opts) == 1:
- sys.exit('[!] ERROR: useless {} check'.format(self.__class__.__name__))
- if not isinstance(opts[0], KconfigCheck):
- sys.exit('[!] ERROR: invalid {} check: {}'.format(self.__class__.__name__, opts))
+ assert(self.opts), \
+ 'empty {} check'.format(self.__class__.__name__)
+ assert(len(self.opts) != 1), \
+ 'useless {} check: {}'.format(self.__class__.__name__, opts)
+ assert(isinstance(opts[0], (KconfigCheck, CmdlineCheck))), \
+ 'invalid {} check: {}'.format(self.__class__.__name__, opts)
self.result = None
- @property
- def name(self):
- return self.opts[0].name
-
@property
def type(self):
return 'complex'
@property
- def expected(self):
- return self.opts[0].expected
-
- @property
- def decision(self):
- return self.opts[0].decision
+ def name(self):
+ return self.opts[0].name
@property
- def reason(self):
- return self.opts[0].reason
+ def expected(self):
+ return self.opts[0].expected
def table_print(self, mode, with_results):
if mode == 'verbose':
# OR(<X_is_hardened>, <X_is_disabled>)
# OR(<X_is_hardened>, <old_X_is_hardened>)
def check(self):
- if not self.opts:
- sys.exit('[!] ERROR: invalid OR check')
for i, opt in enumerate(self.opts):
opt.check()
if opt.result.startswith('OK'):
self.result = 'OK: {} not found'.format(opt.name)
elif opt.result == 'OK: is present':
self.result = 'OK: {} is present'.format(opt.name)
- # VersionCheck provides enough info
- elif not opt.result.startswith('OK: version'):
- sys.exit('[!] ERROR: unexpected OK description "{}"'.format(opt.result))
+ else:
+ # VersionCheck provides enough info
+ assert(opt.result.startswith('OK: version')), \
+ 'unexpected OK description "{}"'.format(opt.result)
return
self.result = self.opts[0].result
else:
# VersionCheck provides enough info
self.result = opt.result
- if not opt.result.startswith('FAIL: version'):
- sys.exit('[!] ERROR: unexpected FAIL description "{}"'.format(opt.result))
+ assert(opt.result.startswith('FAIL: version')), \
+ 'unexpected FAIL description "{}"'.format(opt.result)
return
- sys.exit('[!] ERROR: invalid AND check')
def detect_arch(fname, archs):
VersionCheck((5, 10)))] # HARDEN_BRANCH_PREDICTOR is enabled by default since v5.10
l += [KconfigCheck('self_protection', 'defconfig', 'MITIGATE_SPECTRE_BRANCH_HISTORY', 'y')]
l += [KconfigCheck('self_protection', 'defconfig', 'ARM64_MTE', 'y')]
+ l += [KconfigCheck('self_protection', 'defconfig', 'RANDOMIZE_MODULE_REGION_FULL', 'y')]
if arch == 'ARM':
l += [KconfigCheck('self_protection', 'defconfig', 'CPU_SW_DOMAIN_PAN', 'y')]
l += [KconfigCheck('self_protection', 'defconfig', 'HARDEN_BRANCH_PREDICTOR', 'y')]
l += [KconfigCheck('self_protection', 'kspp', 'KFENCE', 'y')]
l += [KconfigCheck('self_protection', 'kspp', 'WERROR', 'y')]
l += [KconfigCheck('self_protection', 'kspp', 'IOMMU_DEFAULT_DMA_STRICT', 'y')]
+ l += [KconfigCheck('self_protection', 'kspp', 'IOMMU_DEFAULT_PASSTHROUGH', 'is not set')] # true if IOMMU_DEFAULT_DMA_STRICT is set
l += [KconfigCheck('self_protection', 'kspp', 'ZERO_CALL_USED_REGS', 'y')]
randstruct_is_set = KconfigCheck('self_protection', 'kspp', 'GCC_PLUGIN_RANDSTRUCT', 'y')
l += [randstruct_is_set]
l += [KconfigCheck('self_protection', 'clipos', 'STATIC_USERMODEHELPER', 'y')] # needs userspace support
l += [OR(KconfigCheck('self_protection', 'clipos', 'EFI_DISABLE_PCI_DMA', 'y'),
efi_not_set)]
- l += [KconfigCheck('self_protection', 'clipos', 'SLAB_MERGE_DEFAULT', 'is not set')] # slab_nomerge
+ l += [KconfigCheck('self_protection', 'clipos', 'SLAB_MERGE_DEFAULT', 'is not set')]
l += [KconfigCheck('self_protection', 'clipos', 'RANDOM_TRUST_BOOTLOADER', 'is not set')]
l += [KconfigCheck('self_protection', 'clipos', 'RANDOM_TRUST_CPU', 'is not set')]
l += [AND(KconfigCheck('self_protection', 'clipos', 'GCC_PLUGIN_RANDSTRUCT_PERFORMANCE', 'is not set'),
l += [KconfigCheck('cut_attack_surface', 'my', 'FTRACE', 'is not set')] # refers to LOCKDOWN
l += [KconfigCheck('cut_attack_surface', 'my', 'VIDEO_VIVID', 'is not set')]
l += [KconfigCheck('cut_attack_surface', 'my', 'INPUT_EVBUG', 'is not set')] # Can be used as a keylogger
+ l += [KconfigCheck('cut_attack_surface', 'my', 'KGDB', 'is not set')]
# 'harden_userspace'
if arch in ('X86_64', 'ARM64', 'X86_32'):
l += [KconfigCheck('harden_userspace', 'defconfig', 'INTEGRITY', 'y')]
if arch == 'ARM':
l += [KconfigCheck('harden_userspace', 'my', 'INTEGRITY', 'y')]
+ if arch == 'ARM64':
+ l += [KconfigCheck('harden_userspace', 'defconfig', 'ARM64_PTR_AUTH', 'y')]
+ l += [KconfigCheck('harden_userspace', 'defconfig', 'ARM64_BTI', 'y')]
if arch in ('ARM', 'X86_32'):
l += [KconfigCheck('harden_userspace', 'defconfig', 'VMSPLIT_3G', 'y')]
if arch in ('X86_64', 'ARM64'):
if arch in ('X86_32', 'ARM'):
l += [KconfigCheck('harden_userspace', 'my', 'ARCH_MMAP_RND_BITS', '16')]
-# l += [KconfigCheck('feature_test', 'my', 'LKDTM', 'm')] # only for debugging!
+
+def add_cmdline_checks(l, arch):
+ # Calling the CmdlineCheck class constructor:
+ # CmdlineCheck(reason, decision, name, expected)
+ # Don't add CmdlineChecks in add_kconfig_checks() to avoid wrong results
+ # when the tool doesn't check the cmdline.
+
+ if arch == 'ARM64':
+ l += [OR(CmdlineCheck('self_protection', 'defconfig', 'rodata', 'full'),
+ AND(KconfigCheck('self_protection', 'defconfig', 'RODATA_FULL_DEFAULT_ENABLED', 'y'),
+ CmdlineCheck('self_protection', 'defconfig', 'rodata', 'is not set')))]
+
+ l += [OR(CmdlineCheck('self_protection', 'kspp', 'init_on_alloc', '1'),
+ AND(KconfigCheck('self_protection', 'kspp', 'INIT_ON_ALLOC_DEFAULT_ON', 'y'),
+ CmdlineCheck('self_protection', 'kspp', 'init_on_alloc', 'is not set')))]
+ l += [OR(CmdlineCheck('self_protection', 'kspp', 'init_on_free', '1'),
+ AND(KconfigCheck('self_protection', 'kspp', 'INIT_ON_FREE_DEFAULT_ON', 'y'),
+ CmdlineCheck('self_protection', 'kspp', 'init_on_free', 'is not set')),
+ AND(CmdlineCheck('self_protection', 'kspp', 'page_poison', '1'),
+ KconfigCheck('self_protection', 'kspp', 'PAGE_POISONING_ZERO', 'y'),
+ CmdlineCheck('self_protection', 'kspp', 'slub_debug', 'P')))]
+ l += [OR(CmdlineCheck('self_protection', 'kspp', 'slab_nomerge'),
+ AND(KconfigCheck('self_protection', 'clipos', 'SLAB_MERGE_DEFAULT', 'is not set'),
+ CmdlineCheck('self_protection', 'kspp', 'slab_merge', 'is not set')))] # option presence check
+ l += [OR(CmdlineCheck('self_protection', 'kspp', 'iommu.strict', '1'),
+ AND(KconfigCheck('self_protection', 'kspp', 'IOMMU_DEFAULT_DMA_STRICT', 'y'),
+ CmdlineCheck('self_protection', 'kspp', 'iommu.strict', 'is not set')))]
+ l += [OR(CmdlineCheck('self_protection', 'kspp', 'iommu.passthrough', '0'),
+ AND(KconfigCheck('self_protection', 'kspp', 'IOMMU_DEFAULT_PASSTHROUGH', 'is not set'),
+ CmdlineCheck('self_protection', 'kspp', 'iommu.passthrough', 'is not set')))]
+ if arch in ('X86_64', 'ARM64', 'X86_32'):
+ l += [OR(CmdlineCheck('self_protection', 'kspp', 'randomize_kstack_offset', '1'),
+ AND(KconfigCheck('self_protection', 'kspp', 'RANDOMIZE_KSTACK_OFFSET_DEFAULT', 'y'),
+ CmdlineCheck('self_protection', 'kspp', 'randomize_kstack_offset', 'is not set')))]
+ if arch in ('X86_64', 'X86_32'):
+ l += [CmdlineCheck('self_protection', 'kspp', 'pti', 'on')]
+
+ if arch == 'X86_64':
+ l += [OR(CmdlineCheck('cut_attack_surface', 'kspp', 'vsyscall', 'none'),
+ AND(KconfigCheck('cut_attack_surface', 'kspp', 'LEGACY_VSYSCALL_NONE', 'y'),
+ CmdlineCheck('cut_attack_surface', 'kspp', 'vsyscall', 'is not set')))]
+
+ # TODO: add other
def print_unknown_options(checklist, parsed_options):
known_options.append(o2.name)
continue
for o3 in o2.opts:
- if o3.type == 'complex':
- sys.exit('[!] ERROR: unexpected ComplexOptCheck inside {}'.format(o2.name))
+ assert(o3.type != 'complex'), \
+ 'unexpected ComplexOptCheck inside {}'.format(o2.name)
if hasattr(o3, 'name'):
known_options.append(o3.name)
def populate_simple_opt_with_data(opt, data, data_type):
- if opt.type == 'complex':
- sys.exit('[!] ERROR: unexpected ComplexOptCheck {}: {}'.format(opt.name, vars(opt)))
- if opt.type not in TYPES_OF_CHECKS:
- sys.exit('[!] ERROR: invalid opt type "{}" for {}'.format(opt.type, opt.name))
- if data_type not in TYPES_OF_CHECKS:
- sys.exit('[!] ERROR: invalid data type "{}"'.format(data_type))
+ assert(opt.type != 'complex'), \
+ 'unexpected ComplexOptCheck "{}"'.format(opt.name)
+ assert(opt.type in SIMPLE_OPTION_TYPES), \
+ 'invalid opt type "{}"'.format(opt.type)
+ assert(data_type in SIMPLE_OPTION_TYPES), \
+ 'invalid data type "{}"'.format(data_type)
if data_type != opt.type:
return
- if data_type == 'kconfig':
+ if data_type in ('kconfig', 'cmdline'):
opt.state = data.get(opt.name, None)
- elif data_type == 'version':
- opt.ver = data
else:
- sys.exit('[!] ERROR: unexpected data type "{}"'.format(data_type))
+ assert(data_type == 'version'), \
+ 'unexpected data type "{}"'.format(data_type)
+ opt.ver = data
def populate_opt_with_data(opt, data, data_type):
else:
populate_simple_opt_with_data(o, data, data_type)
else:
- if opt.type != 'kconfig':
- sys.exit('[!] ERROR: bad type "{}" for a simple check {}'.format(opt.type, opt.name))
+ assert(opt.type in ('kconfig', 'cmdline')), \
+ 'bad type "{}" for a simple check'.format(opt.type)
populate_simple_opt_with_data(opt, data, data_type)
if opt_is_on.match(line):
option, value = line.split('=', 1)
+ if value == 'is not set':
+ sys.exit('[!] ERROR: bad enabled kconfig option "{}"'.format(line))
elif opt_is_off.match(line):
option, value = line[2:].split(' ', 1)
if value != 'is not set':
parsed_options[option] = value
+def parse_cmdline_file(parsed_options, fname):
+ with open(fname, 'r') as f:
+ line = f.readline()
+ opts = line.split()
+
+ line = f.readline()
+ if line:
+ sys.exit('[!] ERROR: more than one line in "{}"'.format(fname))
+
+ for opt in opts:
+ if '=' in opt:
+ name, value = opt.split('=', 1)
+ else:
+ name = opt
+ value = '' # '' is not None
+ parsed_options[name] = value
+
+
def main():
# Report modes:
# * verbose mode for
help='print security hardening preferences for the selected architecture')
parser.add_argument('-c', '--config',
help='check the kernel kconfig file against these preferences')
+ parser.add_argument('-l', '--cmdline',
+ help='check the kernel cmdline file against these preferences')
parser.add_argument('-m', '--mode', choices=report_modes,
help='choose the report mode')
args = parser.parse_args()
config_checklist = []
if args.config:
+ if args.print:
+ sys.exit('[!] ERROR: --config and --print can\'t be used together')
+
if mode != 'json':
print('[+] Kconfig file to check: {}'.format(args.config))
+ if args.cmdline:
+ print('[+] Kernel cmdline file to check: {}'.format(args.cmdline))
arch, msg = detect_arch(args.config, supported_archs)
if not arch:
# add relevant kconfig checks to the checklist
add_kconfig_checks(config_checklist, arch)
+ if args.cmdline:
+ # add relevant cmdline checks to the checklist
+ add_cmdline_checks(config_checklist, arch)
+
# populate the checklist with the parsed kconfig data
parsed_kconfig_options = OrderedDict()
parse_kconfig_file(parsed_kconfig_options, args.config)
populate_with_data(config_checklist, parsed_kconfig_options, 'kconfig')
populate_with_data(config_checklist, kernel_version, 'version')
+ if args.cmdline:
+ # populate the checklist with the parsed kconfig data
+ parsed_cmdline_options = OrderedDict()
+ parse_cmdline_file(parsed_cmdline_options, args.cmdline)
+ populate_with_data(config_checklist, parsed_cmdline_options, 'cmdline')
+
# now everything is ready for performing the checks
perform_checks(config_checklist)
print_checklist(mode, config_checklist, True)
sys.exit(0)
+ elif args.cmdline:
+ sys.exit('[!] ERROR: checking cmdline doesn\'t work without checking kconfig')
if args.print:
if mode in ('show_ok', 'show_fail'):
sys.exit('[!] ERROR: wrong mode "{}" for --print'.format(mode))
arch = args.print
add_kconfig_checks(config_checklist, arch)
+ add_cmdline_checks(config_checklist, arch)
if mode != 'json':
print('[+] Printing kernel security hardening preferences for {}...'.format(arch))
print_checklist(mode, config_checklist, False)
parser.print_help()
sys.exit(0)
-
-if __name__ == '__main__':
- main()
projects / kconfig-hardened-check.git / blobdiff