4 # This tool helps me to check Linux kernel options against
5 # my security hardening preferences for X86_64, ARM64, X86_32, and ARM.
6 # Let the computers do their job!
8 # Author: Alexander Popov <alex.popov@linux.com>
10 # Please don't cry if my Python code looks like C.
13 # N.B Hardening command line parameters:
14 # iommu=force (does it help against DMA attacks?)
17 # Mitigations of CPU vulnerabilities:
19 # mitigations=auto,nosmt (nosmt is slow)
22 # spec_store_bypass_disable=on
24 # l1d_flush=on (a part of the l1tf option)
33 # sysrq_always_enabled
38 # Hardware tag-based KASAN with arm64 Memory Tagging Extension (MTE):
40 # kasan.stacktrace=off
43 # N.B. Hardening sysctls:
44 # kernel.kptr_restrict=2 (or 1?)
45 # kernel.dmesg_restrict=1 (also see the kconfig option)
46 # kernel.perf_event_paranoid=3
47 # kernel.kexec_load_disabled=1
48 # kernel.yama.ptrace_scope=3
49 # user.max_user_namespaces=0
50 # what about bpf_jit_enable?
51 # kernel.unprivileged_bpf_disabled=1
52 # net.core.bpf_jit_harden=2
53 # vm.unprivileged_userfaultfd=0
54 # (at first, it disabled unprivileged userfaultfd,
55 # and since v5.11 it enables unprivileged userfaultfd for user-mode only)
56 # vm.mmap_min_addr has a good value
57 # dev.tty.ldisc_autoload=0
58 # fs.protected_symlinks=1
59 # fs.protected_hardlinks=1
60 # fs.protected_fifos=2
61 # fs.protected_regular=2
63 # kernel.modules_disabled=1
64 # kernel.randomize_va_space = 2
67 # pylint: disable=missing-module-docstring,missing-class-docstring,missing-function-docstring
68 # pylint: disable=line-too-long,invalid-name,too-many-branches,too-many-statements
72 from argparse import ArgumentParser
73 from collections import OrderedDict
76 from .__about__ import __version__
78 SIMPLE_OPTION_TYPES = ('kconfig', 'version', 'cmdline')
81 # Constructor without the 'expected' parameter is for option presence checks (any value is OK)
82 def __init__(self, reason, decision, name, expected=None):
83 assert(reason and decision and name), \
84 'invalid {} check for "{}"'.format(self.__class__.__name__, name)
86 self.expected = expected
87 self.decision = decision
97 # handle the option presence check
98 if self.expected is None:
99 if self.state is None:
100 self.result = 'FAIL: not present'
102 self.result = 'OK: is present'
105 # handle the option value check
106 if self.expected == self.state:
108 elif self.state is None:
109 if self.expected == 'is not set':
110 self.result = 'OK: not found'
112 self.result = 'FAIL: not found'
114 self.result = 'FAIL: "' + self.state + '"'
116 def table_print(self, _mode, with_results):
117 if self.expected is None:
120 expected = self.expected
121 print('{:<40}|{:^7}|{:^12}|{:^10}|{:^18}'.format(self.name, self.type, expected, self.decision, self.reason), end='')
123 print('| {}'.format(self.result), end='')
125 def json_dump(self, with_results):
126 dump = [self.name, self.type, self.expected, self.decision, self.reason]
128 dump.append(self.result)
132 class KconfigCheck(OptCheck):
133 def __init__(self, *args, **kwargs):
134 super().__init__(*args, **kwargs)
135 self.name = 'CONFIG_' + self.name
142 class CmdlineCheck(OptCheck):
149 def __init__(self, ver_expected):
150 self.ver_expected = ver_expected
159 if self.ver[0] > self.ver_expected[0]:
160 self.result = 'OK: version >= ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
162 if self.ver[0] < self.ver_expected[0]:
163 self.result = 'FAIL: version < ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
165 if self.ver[1] >= self.ver_expected[1]:
166 self.result = 'OK: version >= ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
168 self.result = 'FAIL: version < ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
170 def table_print(self, _mode, with_results):
171 ver_req = 'kernel version >= ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
172 print('{:<91}'.format(ver_req), end='')
174 print('| {}'.format(self.result), end='')
177 class ComplexOptCheck:
178 def __init__(self, *opts):
181 'empty {} check'.format(self.__class__.__name__)
182 assert(len(self.opts) != 1), \
183 'useless {} check: {}'.format(self.__class__.__name__, opts)
184 assert(isinstance(opts[0], (KconfigCheck, CmdlineCheck))), \
185 'invalid {} check: {}'.format(self.__class__.__name__, opts)
194 return self.opts[0].name
198 return self.opts[0].expected
200 def table_print(self, mode, with_results):
201 if mode == 'verbose':
202 print(' {:87}'.format('<<< ' + self.__class__.__name__ + ' >>>'), end='')
204 print('| {}'.format(self.result), end='')
207 o.table_print(mode, with_results)
210 o.table_print(mode, False)
212 print('| {}'.format(self.result), end='')
214 def json_dump(self, with_results):
215 dump = self.opts[0].json_dump(False)
217 dump.append(self.result)
221 class OR(ComplexOptCheck):
222 # self.opts[0] is the option that this OR-check is about.
224 # OR(<X_is_hardened>, <X_is_disabled>)
225 # OR(<X_is_hardened>, <old_X_is_hardened>)
227 for i, opt in enumerate(self.opts):
229 if opt.result.startswith('OK'):
230 self.result = opt.result
231 # Add more info for additional checks:
233 if opt.result == 'OK':
234 self.result = 'OK: {} "{}"'.format(opt.name, opt.expected)
235 elif opt.result == 'OK: not found':
236 self.result = 'OK: {} not found'.format(opt.name)
237 elif opt.result == 'OK: is present':
238 self.result = 'OK: {} is present'.format(opt.name)
240 # VersionCheck provides enough info
241 assert(opt.result.startswith('OK: version')), \
242 'unexpected OK description "{}"'.format(opt.result)
244 self.result = self.opts[0].result
247 class AND(ComplexOptCheck):
248 # self.opts[0] is the option that this AND-check is about.
250 # AND(<suboption>, <main_option>)
251 # Suboption is not checked if checking of the main_option is failed.
252 # AND(<X_is_disabled>, <old_X_is_disabled>)
254 for i, opt in reversed(list(enumerate(self.opts))):
257 self.result = opt.result
259 if not opt.result.startswith('OK'):
260 # This FAIL is caused by additional checks,
261 # and not by the main option that this AND-check is about.
262 # Describe the reason of the FAIL.
263 if opt.result.startswith('FAIL: \"') or opt.result == 'FAIL: not found':
264 self.result = 'FAIL: {} not "{}"'.format(opt.name, opt.expected)
265 elif opt.result == 'FAIL: not present':
266 self.result = 'FAIL: {} not present'.format(opt.name)
268 # VersionCheck provides enough info
269 self.result = opt.result
270 assert(opt.result.startswith('FAIL: version')), \
271 'unexpected FAIL description "{}"'.format(opt.result)
275 def detect_arch(fname, archs):
276 with open(fname, 'r') as f:
277 arch_pattern = re.compile("CONFIG_[a-zA-Z0-9_]*=y")
279 for line in f.readlines():
280 if arch_pattern.match(line):
281 option, _ = line[7:].split('=', 1)
286 return None, 'more than one supported architecture is detected'
288 return None, 'failed to detect architecture'
292 def detect_version(fname):
293 with open(fname, 'r') as f:
294 ver_pattern = re.compile("# Linux/.* Kernel Configuration")
295 for line in f.readlines():
296 if ver_pattern.match(line):
300 ver_numbers = ver_str.split('.')
301 if len(ver_numbers) < 3 or not ver_numbers[0].isdigit() or not ver_numbers[1].isdigit():
302 msg = 'failed to parse the version "' + ver_str + '"'
304 return (int(ver_numbers[0]), int(ver_numbers[1])), None
305 return None, 'no kernel version detected'
308 def add_kconfig_checks(l, arch):
309 # Calling the KconfigCheck class constructor:
310 # KconfigCheck(reason, decision, name, expected)
312 # [!] Don't add CmdlineChecks in add_kconfig_checks() to avoid wrong results
313 # when the tool doesn't check the cmdline.
315 efi_not_set = KconfigCheck('-', '-', 'EFI', 'is not set')
316 cc_is_gcc = KconfigCheck('-', '-', 'CC_IS_GCC', 'y')
317 cc_is_clang = KconfigCheck('-', '-', 'CC_IS_CLANG', 'y')
319 modules_not_set = KconfigCheck('cut_attack_surface', 'kspp', 'MODULES', 'is not set')
320 devmem_not_set = KconfigCheck('cut_attack_surface', 'kspp', 'DEVMEM', 'is not set') # refers to LOCKDOWN
321 bpf_syscall_not_set = KconfigCheck('cut_attack_surface', 'lockdown', 'BPF_SYSCALL', 'is not set') # refers to LOCKDOWN
323 # 'self_protection', 'defconfig'
324 l += [KconfigCheck('self_protection', 'defconfig', 'BUG', 'y')]
325 l += [KconfigCheck('self_protection', 'defconfig', 'SLUB_DEBUG', 'y')]
326 l += [AND(KconfigCheck('self_protection', 'defconfig', 'GCC_PLUGINS', 'y'),
328 l += [OR(KconfigCheck('self_protection', 'defconfig', 'STACKPROTECTOR', 'y'),
329 KconfigCheck('self_protection', 'defconfig', 'CC_STACKPROTECTOR', 'y'),
330 KconfigCheck('self_protection', 'defconfig', 'CC_STACKPROTECTOR_REGULAR', 'y'),
331 KconfigCheck('self_protection', 'defconfig', 'CC_STACKPROTECTOR_AUTO', 'y'),
332 KconfigCheck('self_protection', 'defconfig', 'CC_STACKPROTECTOR_STRONG', 'y'))]
333 l += [OR(KconfigCheck('self_protection', 'defconfig', 'STACKPROTECTOR_STRONG', 'y'),
334 KconfigCheck('self_protection', 'defconfig', 'CC_STACKPROTECTOR_STRONG', 'y'))]
335 l += [OR(KconfigCheck('self_protection', 'defconfig', 'STRICT_KERNEL_RWX', 'y'),
336 KconfigCheck('self_protection', 'defconfig', 'DEBUG_RODATA', 'y'))] # before v4.11
337 l += [OR(KconfigCheck('self_protection', 'defconfig', 'STRICT_MODULE_RWX', 'y'),
338 KconfigCheck('self_protection', 'defconfig', 'DEBUG_SET_MODULE_RONX', 'y'),
339 modules_not_set)] # DEBUG_SET_MODULE_RONX was before v4.11
340 l += [OR(KconfigCheck('self_protection', 'defconfig', 'REFCOUNT_FULL', 'y'),
341 VersionCheck((5, 5)))] # REFCOUNT_FULL is enabled by default since v5.5
342 l += [KconfigCheck('self_protection', 'defconfig', 'THREAD_INFO_IN_TASK', 'y')]
343 iommu_support_is_set = KconfigCheck('self_protection', 'defconfig', 'IOMMU_SUPPORT', 'y')
344 l += [iommu_support_is_set] # is needed for mitigating DMA attacks
345 if arch in ('X86_64', 'ARM64', 'X86_32'):
346 l += [KconfigCheck('self_protection', 'defconfig', 'RANDOMIZE_BASE', 'y')]
347 if arch in ('X86_64', 'ARM64'):
348 l += [KconfigCheck('self_protection', 'defconfig', 'VMAP_STACK', 'y')]
349 if arch in ('X86_64', 'X86_32'):
350 l += [KconfigCheck('self_protection', 'defconfig', 'MICROCODE', 'y')] # is needed for mitigating CPU bugs
351 l += [KconfigCheck('self_protection', 'defconfig', 'RETPOLINE', 'y')]
352 l += [KconfigCheck('self_protection', 'defconfig', 'X86_SMAP', 'y')]
353 l += [KconfigCheck('self_protection', 'defconfig', 'SYN_COOKIES', 'y')] # another reason?
354 l += [OR(KconfigCheck('self_protection', 'defconfig', 'X86_UMIP', 'y'),
355 KconfigCheck('self_protection', 'defconfig', 'X86_INTEL_UMIP', 'y'))]
356 if arch in ('ARM64', 'ARM'):
357 l += [KconfigCheck('self_protection', 'defconfig', 'STACKPROTECTOR_PER_TASK', 'y')]
359 l += [KconfigCheck('self_protection', 'defconfig', 'PAGE_TABLE_ISOLATION', 'y')]
360 l += [KconfigCheck('self_protection', 'defconfig', 'RANDOMIZE_MEMORY', 'y')]
361 l += [AND(KconfigCheck('self_protection', 'defconfig', 'INTEL_IOMMU', 'y'),
362 iommu_support_is_set)]
363 l += [AND(KconfigCheck('self_protection', 'defconfig', 'AMD_IOMMU', 'y'),
364 iommu_support_is_set)]
366 l += [KconfigCheck('self_protection', 'defconfig', 'ARM64_PAN', 'y')]
367 l += [KconfigCheck('self_protection', 'defconfig', 'ARM64_EPAN', 'y')]
368 l += [KconfigCheck('self_protection', 'defconfig', 'UNMAP_KERNEL_AT_EL0', 'y')]
369 l += [OR(KconfigCheck('self_protection', 'defconfig', 'HARDEN_EL2_VECTORS', 'y'),
370 AND(KconfigCheck('self_protection', 'defconfig', 'RANDOMIZE_BASE', 'y'),
371 VersionCheck((5, 9))))] # HARDEN_EL2_VECTORS was included in RANDOMIZE_BASE in v5.9
372 l += [KconfigCheck('self_protection', 'defconfig', 'RODATA_FULL_DEFAULT_ENABLED', 'y')]
373 l += [KconfigCheck('self_protection', 'defconfig', 'ARM64_PTR_AUTH_KERNEL', 'y')]
374 l += [KconfigCheck('self_protection', 'defconfig', 'ARM64_BTI_KERNEL', 'y')]
375 l += [OR(KconfigCheck('self_protection', 'defconfig', 'HARDEN_BRANCH_PREDICTOR', 'y'),
376 VersionCheck((5, 10)))] # HARDEN_BRANCH_PREDICTOR is enabled by default since v5.10
377 l += [KconfigCheck('self_protection', 'defconfig', 'MITIGATE_SPECTRE_BRANCH_HISTORY', 'y')]
378 l += [KconfigCheck('self_protection', 'defconfig', 'ARM64_MTE', 'y')]
379 l += [KconfigCheck('self_protection', 'defconfig', 'RANDOMIZE_MODULE_REGION_FULL', 'y')]
381 l += [KconfigCheck('self_protection', 'defconfig', 'CPU_SW_DOMAIN_PAN', 'y')]
382 l += [KconfigCheck('self_protection', 'defconfig', 'HARDEN_BRANCH_PREDICTOR', 'y')]
383 l += [KconfigCheck('self_protection', 'defconfig', 'HARDEN_BRANCH_HISTORY', 'y')]
385 # 'self_protection', 'kspp'
386 l += [KconfigCheck('self_protection', 'kspp', 'BUG_ON_DATA_CORRUPTION', 'y')]
387 l += [KconfigCheck('self_protection', 'kspp', 'DEBUG_WX', 'y')]
388 l += [KconfigCheck('self_protection', 'kspp', 'SCHED_STACK_END_CHECK', 'y')]
389 l += [KconfigCheck('self_protection', 'kspp', 'SLAB_FREELIST_HARDENED', 'y')]
390 l += [KconfigCheck('self_protection', 'kspp', 'SLAB_FREELIST_RANDOM', 'y')]
391 l += [KconfigCheck('self_protection', 'kspp', 'SHUFFLE_PAGE_ALLOCATOR', 'y')]
392 l += [KconfigCheck('self_protection', 'kspp', 'FORTIFY_SOURCE', 'y')]
393 l += [KconfigCheck('self_protection', 'kspp', 'DEBUG_LIST', 'y')]
394 l += [KconfigCheck('self_protection', 'kspp', 'DEBUG_SG', 'y')]
395 l += [KconfigCheck('self_protection', 'kspp', 'DEBUG_CREDENTIALS', 'y')]
396 l += [KconfigCheck('self_protection', 'kspp', 'DEBUG_NOTIFIERS', 'y')]
397 l += [KconfigCheck('self_protection', 'kspp', 'INIT_ON_ALLOC_DEFAULT_ON', 'y')]
398 l += [AND(KconfigCheck('self_protection', 'kspp', 'GCC_PLUGIN_LATENT_ENTROPY', 'y'),
400 l += [KconfigCheck('self_protection', 'kspp', 'KFENCE', 'y')]
401 l += [KconfigCheck('self_protection', 'kspp', 'WERROR', 'y')]
402 l += [KconfigCheck('self_protection', 'kspp', 'IOMMU_DEFAULT_DMA_STRICT', 'y')]
403 l += [KconfigCheck('self_protection', 'kspp', 'IOMMU_DEFAULT_PASSTHROUGH', 'is not set')] # true if IOMMU_DEFAULT_DMA_STRICT is set
404 l += [KconfigCheck('self_protection', 'kspp', 'ZERO_CALL_USED_REGS', 'y')]
405 randstruct_is_set = KconfigCheck('self_protection', 'kspp', 'GCC_PLUGIN_RANDSTRUCT', 'y')
406 l += [AND(randstruct_is_set, cc_is_gcc)]
407 hardened_usercopy_is_set = KconfigCheck('self_protection', 'kspp', 'HARDENED_USERCOPY', 'y')
408 l += [hardened_usercopy_is_set]
409 l += [AND(KconfigCheck('self_protection', 'kspp', 'HARDENED_USERCOPY_FALLBACK', 'is not set'),
410 hardened_usercopy_is_set)]
411 l += [AND(KconfigCheck('self_protection', 'kspp', 'HARDENED_USERCOPY_PAGESPAN', 'is not set'),
412 hardened_usercopy_is_set)]
413 l += [OR(KconfigCheck('self_protection', 'kspp', 'MODULE_SIG', 'y'),
415 l += [OR(KconfigCheck('self_protection', 'kspp', 'MODULE_SIG_ALL', 'y'),
417 l += [OR(KconfigCheck('self_protection', 'kspp', 'MODULE_SIG_SHA512', 'y'),
419 l += [OR(KconfigCheck('self_protection', 'kspp', 'MODULE_SIG_FORCE', 'y'),
420 modules_not_set)] # refers to LOCKDOWN
421 l += [OR(KconfigCheck('self_protection', 'kspp', 'INIT_STACK_ALL_ZERO', 'y'),
422 KconfigCheck('self_protection', 'kspp', 'GCC_PLUGIN_STRUCTLEAK_BYREF_ALL', 'y'))]
423 l += [OR(KconfigCheck('self_protection', 'kspp', 'INIT_ON_FREE_DEFAULT_ON', 'y'),
424 KconfigCheck('self_protection', 'kspp', 'PAGE_POISONING_ZERO', 'y'))]
425 # CONFIG_INIT_ON_FREE_DEFAULT_ON was added in v5.3.
426 # CONFIG_PAGE_POISONING_ZERO was removed in v5.11.
427 # Starting from v5.11 CONFIG_PAGE_POISONING unconditionally checks
428 # the 0xAA poison pattern on allocation.
429 # That brings higher performance penalty.
430 if arch in ('X86_64', 'ARM64', 'X86_32'):
431 stackleak_is_set = KconfigCheck('self_protection', 'kspp', 'GCC_PLUGIN_STACKLEAK', 'y')
432 l += [AND(stackleak_is_set, cc_is_gcc)]
433 l += [KconfigCheck('self_protection', 'kspp', 'RANDOMIZE_KSTACK_OFFSET_DEFAULT', 'y')]
434 if arch in ('X86_64', 'X86_32'):
435 l += [KconfigCheck('self_protection', 'kspp', 'SCHED_CORE', 'y')]
436 l += [KconfigCheck('self_protection', 'kspp', 'DEFAULT_MMAP_MIN_ADDR', '65536')]
437 if arch in ('ARM64', 'ARM'):
438 l += [KconfigCheck('self_protection', 'kspp', 'DEFAULT_MMAP_MIN_ADDR', '32768')]
439 l += [KconfigCheck('self_protection', 'kspp', 'SYN_COOKIES', 'y')] # another reason?
441 l += [KconfigCheck('self_protection', 'kspp', 'ARM64_SW_TTBR0_PAN', 'y')]
443 l += [KconfigCheck('self_protection', 'kspp', 'PAGE_TABLE_ISOLATION', 'y')]
444 l += [KconfigCheck('self_protection', 'kspp', 'HIGHMEM64G', 'y')]
445 l += [KconfigCheck('self_protection', 'kspp', 'X86_PAE', 'y')]
447 # 'self_protection', 'maintainer'
448 ubsan_bounds_is_set = KconfigCheck('self_protection', 'maintainer', 'UBSAN_BOUNDS', 'y') # only array index bounds checking
449 l += [ubsan_bounds_is_set] # recommended by Kees Cook in /issues/53
450 if arch in ('X86_64', 'ARM64', 'X86_32'): # ARCH_HAS_UBSAN_SANITIZE_ALL is not enabled for ARM
451 l += [AND(KconfigCheck('self_protection', 'maintainer', 'UBSAN_SANITIZE_ALL', 'y'),
452 ubsan_bounds_is_set)] # recommended by Kees Cook in /issues/53
453 l += [AND(KconfigCheck('self_protection', 'maintainer', 'UBSAN_TRAP', 'y'),
454 ubsan_bounds_is_set)] # recommended by Kees Cook in /issues/53
456 # 'self_protection', 'clipos'
457 l += [KconfigCheck('self_protection', 'clipos', 'DEBUG_VIRTUAL', 'y')]
458 l += [KconfigCheck('self_protection', 'clipos', 'STATIC_USERMODEHELPER', 'y')] # needs userspace support
459 l += [OR(KconfigCheck('self_protection', 'clipos', 'EFI_DISABLE_PCI_DMA', 'y'),
461 l += [KconfigCheck('self_protection', 'clipos', 'SLAB_MERGE_DEFAULT', 'is not set')]
462 l += [KconfigCheck('self_protection', 'clipos', 'RANDOM_TRUST_BOOTLOADER', 'is not set')]
463 l += [KconfigCheck('self_protection', 'clipos', 'RANDOM_TRUST_CPU', 'is not set')]
464 l += [AND(KconfigCheck('self_protection', 'clipos', 'GCC_PLUGIN_RANDSTRUCT_PERFORMANCE', 'is not set'),
467 if arch in ('X86_64', 'ARM64', 'X86_32'):
468 l += [AND(KconfigCheck('self_protection', 'clipos', 'STACKLEAK_METRICS', 'is not set'),
471 l += [AND(KconfigCheck('self_protection', 'clipos', 'STACKLEAK_RUNTIME_DISABLE', 'is not set'),
474 if arch in ('X86_64', 'X86_32'):
475 l += [AND(KconfigCheck('self_protection', 'clipos', 'INTEL_IOMMU_DEFAULT_ON', 'y'),
476 iommu_support_is_set)]
478 l += [AND(KconfigCheck('self_protection', 'clipos', 'INTEL_IOMMU_SVM', 'y'),
479 iommu_support_is_set)]
481 l += [AND(KconfigCheck('self_protection', 'clipos', 'INTEL_IOMMU', 'y'),
482 iommu_support_is_set)]
484 # 'self_protection', 'my'
485 l += [OR(KconfigCheck('self_protection', 'my', 'RESET_ATTACK_MITIGATION', 'y'),
486 efi_not_set)] # needs userspace support (systemd)
488 l += [KconfigCheck('self_protection', 'my', 'SLS', 'y')] # vs CVE-2021-26341 in Straight-Line-Speculation
489 l += [AND(KconfigCheck('self_protection', 'my', 'AMD_IOMMU_V2', 'y'),
490 iommu_support_is_set)]
492 l += [KconfigCheck('self_protection', 'my', 'SHADOW_CALL_STACK', 'y')] # depends on clang, maybe it's alternative to STACKPROTECTOR_STRONG
493 l += [KconfigCheck('self_protection', 'my', 'KASAN_HW_TAGS', 'y')]
494 cfi_clang_is_set = KconfigCheck('self_protection', 'my', 'CFI_CLANG', 'y')
495 l += [cfi_clang_is_set]
496 l += [AND(KconfigCheck('self_protection', 'my', 'CFI_PERMISSIVE', 'is not set'),
500 if arch in ('X86_64', 'ARM64', 'X86_32'):
501 l += [KconfigCheck('security_policy', 'defconfig', 'SECURITY', 'y')] # and choose your favourite LSM
503 l += [KconfigCheck('security_policy', 'kspp', 'SECURITY', 'y')] # and choose your favourite LSM
504 l += [KconfigCheck('security_policy', 'kspp', 'SECURITY_YAMA', 'y')]
505 l += [KconfigCheck('security_policy', 'kspp', 'SECURITY_SELINUX_DISABLE', 'is not set')]
506 l += [KconfigCheck('security_policy', 'clipos', 'SECURITY_LOCKDOWN_LSM', 'y')]
507 l += [KconfigCheck('security_policy', 'clipos', 'SECURITY_LOCKDOWN_LSM_EARLY', 'y')]
508 l += [KconfigCheck('security_policy', 'clipos', 'LOCK_DOWN_KERNEL_FORCE_CONFIDENTIALITY', 'y')]
509 l += [KconfigCheck('security_policy', 'my', 'SECURITY_WRITABLE_HOOKS', 'is not set')] # refers to SECURITY_SELINUX_DISABLE
510 l += [KconfigCheck('security_policy', 'my', 'SECURITY_SAFESETID', 'y')]
511 loadpin_is_set = KconfigCheck('security_policy', 'my', 'SECURITY_LOADPIN', 'y')
512 l += [loadpin_is_set] # needs userspace support
513 l += [AND(KconfigCheck('security_policy', 'my', 'SECURITY_LOADPIN_ENFORCE', 'y'),
516 # 'cut_attack_surface', 'defconfig'
517 l += [OR(KconfigCheck('cut_attack_surface', 'defconfig', 'BPF_UNPRIV_DEFAULT_OFF', 'y'),
518 bpf_syscall_not_set)] # see unprivileged_bpf_disabled
519 l += [KconfigCheck('cut_attack_surface', 'defconfig', 'SECCOMP', 'y')]
520 l += [KconfigCheck('cut_attack_surface', 'defconfig', 'SECCOMP_FILTER', 'y')]
521 if arch in ('X86_64', 'ARM64', 'X86_32'):
522 l += [OR(KconfigCheck('cut_attack_surface', 'defconfig', 'STRICT_DEVMEM', 'y'),
523 devmem_not_set)] # refers to LOCKDOWN
525 # 'cut_attack_surface', 'kspp'
526 l += [KconfigCheck('cut_attack_surface', 'kspp', 'SECURITY_DMESG_RESTRICT', 'y')]
527 l += [KconfigCheck('cut_attack_surface', 'kspp', 'ACPI_CUSTOM_METHOD', 'is not set')] # refers to LOCKDOWN
528 l += [KconfigCheck('cut_attack_surface', 'kspp', 'COMPAT_BRK', 'is not set')]
529 l += [KconfigCheck('cut_attack_surface', 'kspp', 'DEVKMEM', 'is not set')] # refers to LOCKDOWN
530 l += [KconfigCheck('cut_attack_surface', 'kspp', 'COMPAT_VDSO', 'is not set')]
531 l += [KconfigCheck('cut_attack_surface', 'kspp', 'BINFMT_MISC', 'is not set')]
532 l += [KconfigCheck('cut_attack_surface', 'kspp', 'INET_DIAG', 'is not set')]
533 l += [KconfigCheck('cut_attack_surface', 'kspp', 'KEXEC', 'is not set')] # refers to LOCKDOWN
534 l += [KconfigCheck('cut_attack_surface', 'kspp', 'PROC_KCORE', 'is not set')] # refers to LOCKDOWN
535 l += [KconfigCheck('cut_attack_surface', 'kspp', 'LEGACY_PTYS', 'is not set')]
536 l += [KconfigCheck('cut_attack_surface', 'kspp', 'HIBERNATION', 'is not set')] # refers to LOCKDOWN
537 l += [KconfigCheck('cut_attack_surface', 'kspp', 'IA32_EMULATION', 'is not set')]
538 l += [KconfigCheck('cut_attack_surface', 'kspp', 'X86_X32', 'is not set')]
539 l += [KconfigCheck('cut_attack_surface', 'kspp', 'MODIFY_LDT_SYSCALL', 'is not set')]
540 l += [KconfigCheck('cut_attack_surface', 'kspp', 'OABI_COMPAT', 'is not set')]
541 l += [KconfigCheck('cut_attack_surface', 'kspp', 'X86_MSR', 'is not set')] # refers to LOCKDOWN
542 l += [modules_not_set]
543 l += [devmem_not_set]
544 l += [OR(KconfigCheck('cut_attack_surface', 'kspp', 'IO_STRICT_DEVMEM', 'y'),
545 devmem_not_set)] # refers to LOCKDOWN
547 l += [OR(KconfigCheck('cut_attack_surface', 'kspp', 'STRICT_DEVMEM', 'y'),
548 devmem_not_set)] # refers to LOCKDOWN
550 l += [KconfigCheck('cut_attack_surface', 'kspp', 'LEGACY_VSYSCALL_NONE', 'y')] # 'vsyscall=none'
552 # 'cut_attack_surface', 'grsec'
553 l += [KconfigCheck('cut_attack_surface', 'grsec', 'ZSMALLOC_STAT', 'is not set')]
554 l += [KconfigCheck('cut_attack_surface', 'grsec', 'PAGE_OWNER', 'is not set')]
555 l += [KconfigCheck('cut_attack_surface', 'grsec', 'DEBUG_KMEMLEAK', 'is not set')]
556 l += [KconfigCheck('cut_attack_surface', 'grsec', 'BINFMT_AOUT', 'is not set')]
557 l += [KconfigCheck('cut_attack_surface', 'grsec', 'KPROBE_EVENTS', 'is not set')]
558 l += [KconfigCheck('cut_attack_surface', 'grsec', 'UPROBE_EVENTS', 'is not set')]
559 l += [KconfigCheck('cut_attack_surface', 'grsec', 'GENERIC_TRACER', 'is not set')] # refers to LOCKDOWN
560 l += [KconfigCheck('cut_attack_surface', 'grsec', 'FUNCTION_TRACER', 'is not set')]
561 l += [KconfigCheck('cut_attack_surface', 'grsec', 'STACK_TRACER', 'is not set')]
562 l += [KconfigCheck('cut_attack_surface', 'grsec', 'HIST_TRIGGERS', 'is not set')]
563 l += [KconfigCheck('cut_attack_surface', 'grsec', 'BLK_DEV_IO_TRACE', 'is not set')]
564 l += [KconfigCheck('cut_attack_surface', 'grsec', 'PROC_VMCORE', 'is not set')]
565 l += [KconfigCheck('cut_attack_surface', 'grsec', 'PROC_PAGE_MONITOR', 'is not set')]
566 l += [KconfigCheck('cut_attack_surface', 'grsec', 'USELIB', 'is not set')]
567 l += [KconfigCheck('cut_attack_surface', 'grsec', 'CHECKPOINT_RESTORE', 'is not set')]
568 l += [KconfigCheck('cut_attack_surface', 'grsec', 'USERFAULTFD', 'is not set')]
569 l += [KconfigCheck('cut_attack_surface', 'grsec', 'HWPOISON_INJECT', 'is not set')]
570 l += [KconfigCheck('cut_attack_surface', 'grsec', 'MEM_SOFT_DIRTY', 'is not set')]
571 l += [KconfigCheck('cut_attack_surface', 'grsec', 'DEVPORT', 'is not set')] # refers to LOCKDOWN
572 l += [KconfigCheck('cut_attack_surface', 'grsec', 'DEBUG_FS', 'is not set')] # refers to LOCKDOWN
573 l += [KconfigCheck('cut_attack_surface', 'grsec', 'NOTIFIER_ERROR_INJECTION', 'is not set')]
574 l += [KconfigCheck('cut_attack_surface', 'grsec', 'FAIL_FUTEX', 'is not set')]
575 l += [KconfigCheck('cut_attack_surface', 'grsec', 'PUNIT_ATOM_DEBUG', 'is not set')]
576 l += [KconfigCheck('cut_attack_surface', 'grsec', 'ACPI_CONFIGFS', 'is not set')]
577 l += [KconfigCheck('cut_attack_surface', 'grsec', 'EDAC_DEBUG', 'is not set')]
578 l += [KconfigCheck('cut_attack_surface', 'grsec', 'DRM_I915_DEBUG', 'is not set')]
579 l += [KconfigCheck('cut_attack_surface', 'grsec', 'BCACHE_CLOSURES_DEBUG', 'is not set')]
580 l += [KconfigCheck('cut_attack_surface', 'grsec', 'DVB_C8SECTPFE', 'is not set')]
581 l += [KconfigCheck('cut_attack_surface', 'grsec', 'MTD_SLRAM', 'is not set')]
582 l += [KconfigCheck('cut_attack_surface', 'grsec', 'MTD_PHRAM', 'is not set')]
583 l += [KconfigCheck('cut_attack_surface', 'grsec', 'IO_URING', 'is not set')]
584 l += [KconfigCheck('cut_attack_surface', 'grsec', 'KCMP', 'is not set')]
585 l += [KconfigCheck('cut_attack_surface', 'grsec', 'RSEQ', 'is not set')]
586 l += [KconfigCheck('cut_attack_surface', 'grsec', 'LATENCYTOP', 'is not set')]
587 l += [KconfigCheck('cut_attack_surface', 'grsec', 'KCOV', 'is not set')]
588 l += [KconfigCheck('cut_attack_surface', 'grsec', 'PROVIDE_OHCI1394_DMA_INIT', 'is not set')]
589 l += [KconfigCheck('cut_attack_surface', 'grsec', 'SUNRPC_DEBUG', 'is not set')]
590 l += [AND(KconfigCheck('cut_attack_surface', 'grsec', 'PTDUMP_DEBUGFS', 'is not set'),
591 KconfigCheck('cut_attack_surface', 'grsec', 'X86_PTDUMP', 'is not set'))]
593 # 'cut_attack_surface', 'maintainer'
594 l += [KconfigCheck('cut_attack_surface', 'maintainer', 'DRM_LEGACY', 'is not set')] # recommended by Daniel Vetter in /issues/38
595 l += [KconfigCheck('cut_attack_surface', 'maintainer', 'FB', 'is not set')] # recommended by Daniel Vetter in /issues/38
596 l += [KconfigCheck('cut_attack_surface', 'maintainer', 'VT', 'is not set')] # recommended by Daniel Vetter in /issues/38
597 l += [KconfigCheck('cut_attack_surface', 'maintainer', 'BLK_DEV_FD', 'is not set')] # recommended by Denis Efremov in /pull/54
598 l += [KconfigCheck('cut_attack_surface', 'maintainer', 'BLK_DEV_FD_RAWCMD', 'is not set')] # recommended by Denis Efremov in /pull/62
600 # 'cut_attack_surface', 'grapheneos'
601 l += [KconfigCheck('cut_attack_surface', 'grapheneos', 'AIO', 'is not set')]
603 # 'cut_attack_surface', 'clipos'
604 l += [KconfigCheck('cut_attack_surface', 'clipos', 'STAGING', 'is not set')]
605 l += [KconfigCheck('cut_attack_surface', 'clipos', 'KSM', 'is not set')] # to prevent FLUSH+RELOAD attack
606 # l += [KconfigCheck('cut_attack_surface', 'clipos', 'IKCONFIG', 'is not set')] # no, IKCONFIG is needed for this check :)
607 l += [KconfigCheck('cut_attack_surface', 'clipos', 'KALLSYMS', 'is not set')]
608 l += [KconfigCheck('cut_attack_surface', 'clipos', 'X86_VSYSCALL_EMULATION', 'is not set')]
609 l += [KconfigCheck('cut_attack_surface', 'clipos', 'MAGIC_SYSRQ', 'is not set')]
610 l += [KconfigCheck('cut_attack_surface', 'clipos', 'KEXEC_FILE', 'is not set')] # refers to LOCKDOWN (permissive)
611 l += [KconfigCheck('cut_attack_surface', 'clipos', 'USER_NS', 'is not set')] # user.max_user_namespaces=0
612 l += [KconfigCheck('cut_attack_surface', 'clipos', 'X86_CPUID', 'is not set')]
613 l += [KconfigCheck('cut_attack_surface', 'clipos', 'X86_IOPL_IOPERM', 'is not set')] # refers to LOCKDOWN
614 l += [KconfigCheck('cut_attack_surface', 'clipos', 'ACPI_TABLE_UPGRADE', 'is not set')] # refers to LOCKDOWN
615 l += [KconfigCheck('cut_attack_surface', 'clipos', 'EFI_CUSTOM_SSDT_OVERLAYS', 'is not set')]
616 l += [AND(KconfigCheck('cut_attack_surface', 'clipos', 'LDISC_AUTOLOAD', 'is not set'),
617 KconfigCheck('cut_attack_surface', 'clipos', 'LDISC_AUTOLOAD'))] # option presence check
618 if arch in ('X86_64', 'X86_32'):
619 l += [KconfigCheck('cut_attack_surface', 'clipos', 'X86_INTEL_TSX_MODE_OFF', 'y')] # tsx=off
621 # 'cut_attack_surface', 'lockdown'
622 l += [bpf_syscall_not_set] # refers to LOCKDOWN
623 l += [KconfigCheck('cut_attack_surface', 'lockdown', 'EFI_TEST', 'is not set')] # refers to LOCKDOWN
624 l += [KconfigCheck('cut_attack_surface', 'lockdown', 'MMIOTRACE_TEST', 'is not set')] # refers to LOCKDOWN
625 l += [KconfigCheck('cut_attack_surface', 'lockdown', 'KPROBES', 'is not set')] # refers to LOCKDOWN
627 # 'cut_attack_surface', 'my'
628 l += [OR(KconfigCheck('cut_attack_surface', 'my', 'TRIM_UNUSED_KSYMS', 'y'),
630 l += [KconfigCheck('cut_attack_surface', 'my', 'MMIOTRACE', 'is not set')] # refers to LOCKDOWN (permissive)
631 l += [KconfigCheck('cut_attack_surface', 'my', 'LIVEPATCH', 'is not set')]
632 l += [KconfigCheck('cut_attack_surface', 'my', 'IP_DCCP', 'is not set')]
633 l += [KconfigCheck('cut_attack_surface', 'my', 'IP_SCTP', 'is not set')]
634 l += [KconfigCheck('cut_attack_surface', 'my', 'FTRACE', 'is not set')] # refers to LOCKDOWN
635 l += [KconfigCheck('cut_attack_surface', 'my', 'VIDEO_VIVID', 'is not set')]
636 l += [KconfigCheck('cut_attack_surface', 'my', 'INPUT_EVBUG', 'is not set')] # Can be used as a keylogger
637 l += [KconfigCheck('cut_attack_surface', 'my', 'KGDB', 'is not set')]
640 if arch in ('X86_64', 'ARM64', 'X86_32'):
641 l += [KconfigCheck('harden_userspace', 'defconfig', 'INTEGRITY', 'y')]
643 l += [KconfigCheck('harden_userspace', 'my', 'INTEGRITY', 'y')]
645 l += [KconfigCheck('harden_userspace', 'defconfig', 'ARM64_PTR_AUTH', 'y')]
646 l += [KconfigCheck('harden_userspace', 'defconfig', 'ARM64_BTI', 'y')]
647 if arch in ('ARM', 'X86_32'):
648 l += [KconfigCheck('harden_userspace', 'defconfig', 'VMSPLIT_3G', 'y')]
649 if arch in ('X86_64', 'ARM64'):
650 l += [KconfigCheck('harden_userspace', 'clipos', 'ARCH_MMAP_RND_BITS', '32')]
651 if arch in ('X86_32', 'ARM'):
652 l += [KconfigCheck('harden_userspace', 'my', 'ARCH_MMAP_RND_BITS', '16')]
655 def add_cmdline_checks(l, arch):
656 # Calling the CmdlineCheck class constructor:
657 # CmdlineCheck(reason, decision, name, expected)
659 # [!] Don't add CmdlineChecks in add_kconfig_checks() to avoid wrong results
660 # when the tool doesn't check the cmdline.
662 # [!] Make sure that values of the options in CmdlineChecks need normalization.
663 # For more info see normalize_cmdline_options().
665 # A common pattern for checking the 'param_x' cmdline parameter
666 # that __overrides__ the 'PARAM_X_DEFAULT' kconfig option:
667 # l += [OR(CmdlineCheck(reason, decision, 'param_x', '1'),
668 # AND(KconfigCheck(reason, decision, 'PARAM_X_DEFAULT_ON', 'y'),
669 # CmdlineCheck(reason, decision, 'param_x, 'is not set')))]
671 # Here we don't check the kconfig options or minimal kernel version
672 # required for the cmdline parameters. That would make the checks
673 # very complex and not give a 100% guarantee anyway.
675 # 'self_protection', 'defconfig'
677 l += [OR(CmdlineCheck('self_protection', 'defconfig', 'rodata', 'full'),
678 AND(KconfigCheck('self_protection', 'defconfig', 'RODATA_FULL_DEFAULT_ENABLED', 'y'),
679 CmdlineCheck('self_protection', 'defconfig', 'rodata', 'is not set')))]
681 l += [OR(CmdlineCheck('self_protection', 'defconfig', 'rodata', '1'),
682 CmdlineCheck('self_protection', 'defconfig', 'rodata', 'is not set'))]
684 # 'self_protection', 'kspp'
685 l += [OR(CmdlineCheck('self_protection', 'kspp', 'init_on_alloc', '1'),
686 AND(KconfigCheck('self_protection', 'kspp', 'INIT_ON_ALLOC_DEFAULT_ON', 'y'),
687 CmdlineCheck('self_protection', 'kspp', 'init_on_alloc', 'is not set')))]
688 l += [OR(CmdlineCheck('self_protection', 'kspp', 'init_on_free', '1'),
689 AND(KconfigCheck('self_protection', 'kspp', 'INIT_ON_FREE_DEFAULT_ON', 'y'),
690 CmdlineCheck('self_protection', 'kspp', 'init_on_free', 'is not set')),
691 AND(CmdlineCheck('self_protection', 'kspp', 'page_poison', '1'),
692 KconfigCheck('self_protection', 'kspp', 'PAGE_POISONING_ZERO', 'y'),
693 CmdlineCheck('self_protection', 'kspp', 'slub_debug', 'P')))]
694 l += [OR(CmdlineCheck('self_protection', 'kspp', 'slab_nomerge'),
695 AND(KconfigCheck('self_protection', 'clipos', 'SLAB_MERGE_DEFAULT', 'is not set'),
696 CmdlineCheck('self_protection', 'kspp', 'slab_merge', 'is not set')))] # option presence check
697 l += [OR(CmdlineCheck('self_protection', 'kspp', 'iommu.strict', '1'),
698 AND(KconfigCheck('self_protection', 'kspp', 'IOMMU_DEFAULT_DMA_STRICT', 'y'),
699 CmdlineCheck('self_protection', 'kspp', 'iommu.strict', 'is not set')))]
700 l += [OR(CmdlineCheck('self_protection', 'kspp', 'iommu.passthrough', '0'),
701 AND(KconfigCheck('self_protection', 'kspp', 'IOMMU_DEFAULT_PASSTHROUGH', 'is not set'),
702 CmdlineCheck('self_protection', 'kspp', 'iommu.passthrough', 'is not set')))]
703 # The cmdline checks compatible with the kconfig recommendations of the KSPP project...
704 l += [OR(CmdlineCheck('self_protection', 'kspp', 'hardened_usercopy', '1'),
705 AND(KconfigCheck('self_protection', 'kspp', 'HARDENED_USERCOPY', 'y'),
706 CmdlineCheck('self_protection', 'kspp', 'hardened_usercopy', 'is not set')))]
707 l += [OR(CmdlineCheck('self_protection', 'kspp', 'slab_common.usercopy_fallback', '0'),
708 AND(KconfigCheck('self_protection', 'kspp', 'HARDENED_USERCOPY_FALLBACK', 'is not set'),
709 CmdlineCheck('self_protection', 'kspp', 'slab_common.usercopy_fallback', 'is not set')))] # ... the end
710 if arch in ('X86_64', 'ARM64', 'X86_32'):
711 l += [OR(CmdlineCheck('self_protection', 'kspp', 'randomize_kstack_offset', '1'),
712 AND(KconfigCheck('self_protection', 'kspp', 'RANDOMIZE_KSTACK_OFFSET_DEFAULT', 'y'),
713 CmdlineCheck('self_protection', 'kspp', 'randomize_kstack_offset', 'is not set')))]
714 if arch in ('X86_64', 'X86_32'):
715 l += [CmdlineCheck('self_protection', 'kspp', 'pti', 'on')]
717 # 'self_protection', 'clipos'
718 l += [CmdlineCheck('self_protection', 'clipos', 'page_alloc.shuffle', '1')]
720 # 'cut_attack_surface', 'kspp'
722 l += [OR(CmdlineCheck('cut_attack_surface', 'kspp', 'vsyscall', 'none'),
723 AND(KconfigCheck('cut_attack_surface', 'kspp', 'LEGACY_VSYSCALL_NONE', 'y'),
724 CmdlineCheck('cut_attack_surface', 'kspp', 'vsyscall', 'is not set')))]
726 # 'cut_attack_surface', 'grsec'
727 # The cmdline checks compatible with the kconfig options disabled by grsecurity...
728 l += [OR(CmdlineCheck('cut_attack_surface', 'grsec', 'debugfs', 'off'),
729 KconfigCheck('cut_attack_surface', 'grsec', 'DEBUG_FS', 'is not set'))] # ... the end
732 def print_unknown_options(checklist, parsed_options):
736 if o1.type != 'complex':
737 known_options.append(o1.name)
740 if o2.type != 'complex':
741 if hasattr(o2, 'name'):
742 known_options.append(o2.name)
745 assert(o3.type != 'complex'), \
746 'unexpected ComplexOptCheck inside {}'.format(o2.name)
747 if hasattr(o3, 'name'):
748 known_options.append(o3.name)
750 for option, value in parsed_options.items():
751 if option not in known_options:
752 print('[?] No check for option {} ({})'.format(option, value))
755 def print_checklist(mode, checklist, with_results):
759 output.append(o.json_dump(with_results))
760 print(json.dumps(output))
767 print('=' * sep_line_len)
768 print('{:^40}|{:^7}|{:^12}|{:^10}|{:^18}'.format('option name', 'type', 'desired val', 'decision', 'reason'), end='')
770 print('| {}'.format('check result'), end='')
772 print('=' * sep_line_len)
775 for opt in checklist:
777 if mode == 'show_ok':
778 if not opt.result.startswith('OK'):
780 if mode == 'show_fail':
781 if not opt.result.startswith('FAIL'):
783 opt.table_print(mode, with_results)
785 if mode == 'verbose':
786 print('-' * sep_line_len)
791 fail_count = len(list(filter(lambda opt: opt.result.startswith('FAIL'), checklist)))
793 ok_count = len(list(filter(lambda opt: opt.result.startswith('OK'), checklist)))
795 if mode == 'show_ok':
796 fail_suppressed = ' (suppressed in output)'
797 if mode == 'show_fail':
798 ok_suppressed = ' (suppressed in output)'
800 print('[+] Config check is finished: \'OK\' - {}{} / \'FAIL\' - {}{}'.format(ok_count, ok_suppressed, fail_count, fail_suppressed))
803 def populate_simple_opt_with_data(opt, data, data_type):
804 assert(opt.type != 'complex'), \
805 'unexpected ComplexOptCheck "{}"'.format(opt.name)
806 assert(opt.type in SIMPLE_OPTION_TYPES), \
807 'invalid opt type "{}"'.format(opt.type)
808 assert(data_type in SIMPLE_OPTION_TYPES), \
809 'invalid data type "{}"'.format(data_type)
811 if data_type != opt.type:
814 if data_type in ('kconfig', 'cmdline'):
815 opt.state = data.get(opt.name, None)
817 assert(data_type == 'version'), \
818 'unexpected data type "{}"'.format(data_type)
822 def populate_opt_with_data(opt, data, data_type):
823 if opt.type == 'complex':
825 if o.type == 'complex':
826 # Recursion for nested ComplexOptCheck objects
827 populate_opt_with_data(o, data, data_type)
829 populate_simple_opt_with_data(o, data, data_type)
831 assert(opt.type in ('kconfig', 'cmdline')), \
832 'bad type "{}" for a simple check'.format(opt.type)
833 populate_simple_opt_with_data(opt, data, data_type)
836 def populate_with_data(checklist, data, data_type):
837 for opt in checklist:
838 populate_opt_with_data(opt, data, data_type)
841 def perform_checks(checklist):
842 for opt in checklist:
846 def parse_kconfig_file(parsed_options, fname):
847 with open(fname, 'r') as f:
848 opt_is_on = re.compile("CONFIG_[a-zA-Z0-9_]*=[a-zA-Z0-9_\"]*")
849 opt_is_off = re.compile("# CONFIG_[a-zA-Z0-9_]* is not set")
851 for line in f.readlines():
856 if opt_is_on.match(line):
857 option, value = line.split('=', 1)
858 if value == 'is not set':
859 sys.exit('[!] ERROR: bad enabled kconfig option "{}"'.format(line))
860 elif opt_is_off.match(line):
861 option, value = line[2:].split(' ', 1)
862 if value != 'is not set':
863 sys.exit('[!] ERROR: bad disabled kconfig option "{}"'.format(line))
865 if option in parsed_options:
866 sys.exit('[!] ERROR: kconfig option "{}" exists multiple times'.format(line))
869 parsed_options[option] = value
872 def normalize_cmdline_options(option, value):
873 # Don't normalize the cmdline option values if
874 # the Linux kernel doesn't use kstrtobool() for them
876 # See pti_check_boottime_disable() in linux/arch/x86/mm/pti.c
878 if option == 'debugfs':
879 # See debugfs_kernel() in fs/debugfs/inode.c
882 # Implement a limited part of the kstrtobool() logic
883 if value in ('1', 'on', 'On', 'ON', 'y', 'Y', 'yes', 'Yes', 'YES'):
885 if value in ('0', 'off', 'Off', 'OFF', 'n', 'N', 'no', 'No', 'NO'):
888 # Preserve unique values
892 def parse_cmdline_file(parsed_options, fname):
893 with open(fname, 'r') as f:
899 sys.exit('[!] ERROR: more than one line in "{}"'.format(fname))
903 name, value = opt.split('=', 1)
906 value = '' # '' is not None
907 value = normalize_cmdline_options(name, value)
908 parsed_options[name] = value
914 # - reporting about unknown kernel options in the kconfig
915 # - verbose printing of ComplexOptCheck items
916 # * json mode for printing the results in JSON format
917 report_modes = ['verbose', 'json', 'show_ok', 'show_fail']
918 supported_archs = ['X86_64', 'X86_32', 'ARM64', 'ARM']
919 parser = ArgumentParser(prog='kconfig-hardened-check',
920 description='A tool for checking the security hardening options of the Linux kernel')
921 parser.add_argument('--version', action='version', version='%(prog)s ' + __version__)
922 parser.add_argument('-p', '--print', choices=supported_archs,
923 help='print security hardening preferences for the selected architecture')
924 parser.add_argument('-c', '--config',
925 help='check the kernel kconfig file against these preferences')
926 parser.add_argument('-l', '--cmdline',
927 help='check the kernel cmdline file against these preferences')
928 parser.add_argument('-m', '--mode', choices=report_modes,
929 help='choose the report mode')
930 args = parser.parse_args()
936 print('[+] Special report mode: {}'.format(mode))
938 config_checklist = []
942 sys.exit('[!] ERROR: --config and --print can\'t be used together')
945 print('[+] Kconfig file to check: {}'.format(args.config))
947 print('[+] Kernel cmdline file to check: {}'.format(args.cmdline))
949 arch, msg = detect_arch(args.config, supported_archs)
951 sys.exit('[!] ERROR: {}'.format(msg))
953 print('[+] Detected architecture: {}'.format(arch))
955 kernel_version, msg = detect_version(args.config)
956 if not kernel_version:
957 sys.exit('[!] ERROR: {}'.format(msg))
959 print('[+] Detected kernel version: {}.{}'.format(kernel_version[0], kernel_version[1]))
961 # add relevant kconfig checks to the checklist
962 add_kconfig_checks(config_checklist, arch)
965 # add relevant cmdline checks to the checklist
966 add_cmdline_checks(config_checklist, arch)
968 # populate the checklist with the parsed kconfig data
969 parsed_kconfig_options = OrderedDict()
970 parse_kconfig_file(parsed_kconfig_options, args.config)
971 populate_with_data(config_checklist, parsed_kconfig_options, 'kconfig')
972 populate_with_data(config_checklist, kernel_version, 'version')
975 # populate the checklist with the parsed kconfig data
976 parsed_cmdline_options = OrderedDict()
977 parse_cmdline_file(parsed_cmdline_options, args.cmdline)
978 populate_with_data(config_checklist, parsed_cmdline_options, 'cmdline')
980 # now everything is ready for performing the checks
981 perform_checks(config_checklist)
983 # finally print the results
984 if mode == 'verbose':
985 print_unknown_options(config_checklist, parsed_kconfig_options)
986 print_checklist(mode, config_checklist, True)
990 sys.exit('[!] ERROR: checking cmdline doesn\'t work without checking kconfig')
993 if mode in ('show_ok', 'show_fail'):
994 sys.exit('[!] ERROR: wrong mode "{}" for --print'.format(mode))
996 add_kconfig_checks(config_checklist, arch)
997 add_cmdline_checks(config_checklist, arch)
999 print('[+] Printing kernel security hardening preferences for {}...'.format(arch))
1000 print_checklist(mode, config_checklist, False)