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?)
16 # Mitigations of CPU vulnerabilities:
18 # mitigations=auto,nosmt (nosmt is slow)
20 # spec_store_bypass_disable=on
22 # l1d_flush=on (a part of the l1tf option)
30 # sysrq_always_enabled
35 # Hardware tag-based KASAN with arm64 Memory Tagging Extension (MTE):
37 # kasan.stacktrace=off
40 # N.B. Hardening sysctls:
41 # kernel.kptr_restrict=2 (or 1?)
42 # kernel.dmesg_restrict=1 (also see the kconfig option)
43 # kernel.perf_event_paranoid=3
44 # kernel.kexec_load_disabled=1
45 # kernel.yama.ptrace_scope=3
46 # user.max_user_namespaces=0
47 # what about bpf_jit_enable?
48 # kernel.unprivileged_bpf_disabled=1
49 # net.core.bpf_jit_harden=2
50 # vm.unprivileged_userfaultfd=0
51 # (at first, it disabled unprivileged userfaultfd,
52 # and since v5.11 it enables unprivileged userfaultfd for user-mode only)
53 # vm.mmap_min_addr has a good value
54 # dev.tty.ldisc_autoload=0
55 # fs.protected_symlinks=1
56 # fs.protected_hardlinks=1
57 # fs.protected_fifos=2
58 # fs.protected_regular=2
60 # kernel.modules_disabled=1
61 # kernel.randomize_va_space = 2
64 # pylint: disable=missing-module-docstring,missing-class-docstring,missing-function-docstring
65 # pylint: disable=line-too-long,invalid-name,too-many-branches,too-many-statements
69 from argparse import ArgumentParser
70 from collections import OrderedDict
73 from .__about__ import __version__
75 SIMPLE_OPTION_TYPES = ('kconfig', 'version', 'cmdline')
78 # Constructor without the 'expected' parameter is for option presence checks (any value is OK)
79 def __init__(self, reason, decision, name, expected=None):
80 assert(name and name == name.strip() and len(name.split()) == 1), \
81 'invalid name "{}" for {}'.format(name, self.__class__.__name__)
84 assert(decision and decision == decision.strip() and len(decision.split()) == 1), \
85 'invalid decision "{}" for "{}" check'.format(decision, name)
86 self.decision = decision
88 assert(reason and reason == reason.strip() and len(reason.split()) == 1), \
89 'invalid reason "{}" for "{}" check'.format(reason, name)
93 assert(expected == expected.strip()), \
94 'invalid expected value "{}" for "{}" check (1)'.format(expected, name)
95 val_len = len(expected.split())
97 assert(expected == 'is not set' or expected == 'is not off'), \
98 'invalid expected value "{}" for "{}" check (2)'.format(expected, name)
100 assert(val_len == 1), \
101 'invalid expected value "{}" for "{}" check (3)'.format(expected, name)
102 self.expected = expected
112 # handle the option presence check
113 if self.expected is None:
114 if self.state is None:
115 self.result = 'FAIL: is not present'
117 self.result = 'OK: is present'
120 # handle the 'is not off' option check
121 if self.expected == 'is not off':
122 if self.state == 'off':
123 self.result = 'FAIL: is off'
124 elif self.state is None:
125 self.result = 'FAIL: is off, not found'
127 self.result = 'OK: is not off, "' + self.state + '"'
130 # handle the option value check
131 if self.expected == self.state:
133 elif self.state is None:
134 if self.expected == 'is not set':
135 self.result = 'OK: is not found'
137 self.result = 'FAIL: is not found'
139 self.result = 'FAIL: "' + self.state + '"'
141 def table_print(self, _mode, with_results):
142 if self.expected is None:
145 expected = self.expected
146 print('{:<40}|{:^7}|{:^12}|{:^10}|{:^18}'.format(self.name, self.type, expected, self.decision, self.reason), end='')
148 print('| {}'.format(self.result), end='')
150 def json_dump(self, with_results):
151 dump = [self.name, self.type, self.expected, self.decision, self.reason]
153 dump.append(self.result)
157 class KconfigCheck(OptCheck):
158 def __init__(self, *args, **kwargs):
159 super().__init__(*args, **kwargs)
160 self.name = 'CONFIG_' + self.name
167 class CmdlineCheck(OptCheck):
174 def __init__(self, ver_expected):
175 assert(ver_expected and isinstance(ver_expected, tuple) and len(ver_expected) == 2), \
176 'invalid version "{}" for VersionCheck'.format(ver_expected)
177 self.ver_expected = ver_expected
186 if self.ver[0] > self.ver_expected[0]:
187 self.result = 'OK: version >= ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
189 if self.ver[0] < self.ver_expected[0]:
190 self.result = 'FAIL: version < ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
192 if self.ver[1] >= self.ver_expected[1]:
193 self.result = 'OK: version >= ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
195 self.result = 'FAIL: version < ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
197 def table_print(self, _mode, with_results):
198 ver_req = 'kernel version >= ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
199 print('{:<91}'.format(ver_req), end='')
201 print('| {}'.format(self.result), end='')
204 class ComplexOptCheck:
205 def __init__(self, *opts):
208 'empty {} check'.format(self.__class__.__name__)
209 assert(len(self.opts) != 1), \
210 'useless {} check: {}'.format(self.__class__.__name__, opts)
211 assert(isinstance(opts[0], (KconfigCheck, CmdlineCheck))), \
212 'invalid {} check: {}'.format(self.__class__.__name__, opts)
221 return self.opts[0].name
225 return self.opts[0].expected
227 def table_print(self, mode, with_results):
228 if mode == 'verbose':
229 print(' {:87}'.format('<<< ' + self.__class__.__name__ + ' >>>'), end='')
231 print('| {}'.format(self.result), end='')
234 o.table_print(mode, with_results)
237 o.table_print(mode, False)
239 print('| {}'.format(self.result), end='')
241 def json_dump(self, with_results):
242 dump = self.opts[0].json_dump(False)
244 dump.append(self.result)
248 class OR(ComplexOptCheck):
249 # self.opts[0] is the option that this OR-check is about.
251 # OR(<X_is_hardened>, <X_is_disabled>)
252 # OR(<X_is_hardened>, <old_X_is_hardened>)
254 for i, opt in enumerate(self.opts):
256 if opt.result.startswith('OK'):
257 self.result = opt.result
258 # Add more info for additional checks:
260 if opt.result == 'OK':
261 self.result = 'OK: {} is "{}"'.format(opt.name, opt.expected)
262 elif opt.result == 'OK: is not found':
263 self.result = 'OK: {} is not found'.format(opt.name)
264 elif opt.result == 'OK: is present':
265 self.result = 'OK: {} is present'.format(opt.name)
266 elif opt.result.startswith('OK: is not off'):
267 self.result = 'OK: {} is not off'.format(opt.name)
269 # VersionCheck provides enough info
270 assert(opt.result.startswith('OK: version')), \
271 'unexpected OK description "{}"'.format(opt.result)
273 self.result = self.opts[0].result
276 class AND(ComplexOptCheck):
277 # self.opts[0] is the option that this AND-check is about.
279 # AND(<suboption>, <main_option>)
280 # Suboption is not checked if checking of the main_option is failed.
281 # AND(<X_is_disabled>, <old_X_is_disabled>)
283 for i, opt in reversed(list(enumerate(self.opts))):
286 self.result = opt.result
288 if not opt.result.startswith('OK'):
289 # This FAIL is caused by additional checks,
290 # and not by the main option that this AND-check is about.
291 # Describe the reason of the FAIL.
292 if opt.result.startswith('FAIL: \"') or opt.result == 'FAIL: is not found':
293 self.result = 'FAIL: {} is not "{}"'.format(opt.name, opt.expected)
294 elif opt.result == 'FAIL: is not present':
295 self.result = 'FAIL: {} is not present'.format(opt.name)
296 elif opt.result == 'FAIL: is off':
297 self.result = 'FAIL: {} is off'.format(opt.name)
298 elif opt.result == 'FAIL: is off, not found':
299 self.result = 'FAIL: {} is off, not found'.format(opt.name)
301 # VersionCheck provides enough info
302 self.result = opt.result
303 assert(opt.result.startswith('FAIL: version')), \
304 'unexpected FAIL description "{}"'.format(opt.result)
308 def detect_arch(fname, archs):
309 with open(fname, 'r') as f:
310 arch_pattern = re.compile("CONFIG_[a-zA-Z0-9_]*=y")
312 for line in f.readlines():
313 if arch_pattern.match(line):
314 option, _ = line[7:].split('=', 1)
319 return None, 'more than one supported architecture is detected'
321 return None, 'failed to detect architecture'
325 def detect_kernel_version(fname):
326 with open(fname, 'r') as f:
327 ver_pattern = re.compile("# Linux/.* Kernel Configuration")
328 for line in f.readlines():
329 if ver_pattern.match(line):
333 ver_numbers = ver_str.split('.')
334 if len(ver_numbers) < 3 or not ver_numbers[0].isdigit() or not ver_numbers[1].isdigit():
335 msg = 'failed to parse the version "' + ver_str + '"'
337 return (int(ver_numbers[0]), int(ver_numbers[1])), None
338 return None, 'no kernel version detected'
341 def detect_compiler(fname):
344 with open(fname, 'r') as f:
345 gcc_version_pattern = re.compile("CONFIG_GCC_VERSION=[0-9]*")
346 clang_version_pattern = re.compile("CONFIG_CLANG_VERSION=[0-9]*")
347 for line in f.readlines():
348 if gcc_version_pattern.match(line):
349 gcc_version = line[19:-1]
350 if clang_version_pattern.match(line):
351 clang_version = line[21:-1]
352 if not gcc_version or not clang_version:
353 return None, 'no CONFIG_GCC_VERSION or CONFIG_CLANG_VERSION'
354 if gcc_version == '0' and clang_version != '0':
355 return 'CLANG ' + clang_version, 'OK'
356 if gcc_version != '0' and clang_version == '0':
357 return 'GCC ' + gcc_version, 'OK'
358 sys.exit('[!] ERROR: invalid GCC_VERSION and CLANG_VERSION: {} {}'.format(gcc_version, clang_version))
361 def add_kconfig_checks(l, arch):
362 # Calling the KconfigCheck class constructor:
363 # KconfigCheck(reason, decision, name, expected)
365 # [!] Don't add CmdlineChecks in add_kconfig_checks() to avoid wrong results
366 # when the tool doesn't check the cmdline.
368 efi_not_set = KconfigCheck('-', '-', 'EFI', 'is not set')
369 cc_is_gcc = KconfigCheck('-', '-', 'CC_IS_GCC', 'y') # exists since v4.18
370 cc_is_clang = KconfigCheck('-', '-', 'CC_IS_CLANG', 'y') # exists since v4.18
372 modules_not_set = KconfigCheck('cut_attack_surface', 'kspp', 'MODULES', 'is not set')
373 devmem_not_set = KconfigCheck('cut_attack_surface', 'kspp', 'DEVMEM', 'is not set') # refers to LOCKDOWN
374 bpf_syscall_not_set = KconfigCheck('cut_attack_surface', 'lockdown', 'BPF_SYSCALL', 'is not set') # refers to LOCKDOWN
376 # 'self_protection', 'defconfig'
377 l += [KconfigCheck('self_protection', 'defconfig', 'BUG', 'y')]
378 l += [KconfigCheck('self_protection', 'defconfig', 'SLUB_DEBUG', 'y')]
379 gcc_plugins_support_is_set = KconfigCheck('self_protection', 'defconfig', 'GCC_PLUGINS', 'y')
380 l += [gcc_plugins_support_is_set]
381 l += [OR(KconfigCheck('self_protection', 'defconfig', 'STACKPROTECTOR', 'y'),
382 KconfigCheck('self_protection', 'defconfig', 'CC_STACKPROTECTOR', 'y'),
383 KconfigCheck('self_protection', 'defconfig', 'CC_STACKPROTECTOR_REGULAR', 'y'),
384 KconfigCheck('self_protection', 'defconfig', 'CC_STACKPROTECTOR_AUTO', 'y'),
385 KconfigCheck('self_protection', 'defconfig', 'CC_STACKPROTECTOR_STRONG', 'y'))]
386 l += [OR(KconfigCheck('self_protection', 'defconfig', 'STACKPROTECTOR_STRONG', 'y'),
387 KconfigCheck('self_protection', 'defconfig', 'CC_STACKPROTECTOR_STRONG', 'y'))]
388 l += [OR(KconfigCheck('self_protection', 'defconfig', 'STRICT_KERNEL_RWX', 'y'),
389 KconfigCheck('self_protection', 'defconfig', 'DEBUG_RODATA', 'y'))] # before v4.11
390 l += [OR(KconfigCheck('self_protection', 'defconfig', 'STRICT_MODULE_RWX', 'y'),
391 KconfigCheck('self_protection', 'defconfig', 'DEBUG_SET_MODULE_RONX', 'y'),
392 modules_not_set)] # DEBUG_SET_MODULE_RONX was before v4.11
393 l += [OR(KconfigCheck('self_protection', 'defconfig', 'REFCOUNT_FULL', 'y'),
394 VersionCheck((5, 5)))] # REFCOUNT_FULL is enabled by default since v5.5
395 l += [KconfigCheck('self_protection', 'defconfig', 'THREAD_INFO_IN_TASK', 'y')]
396 iommu_support_is_set = KconfigCheck('self_protection', 'defconfig', 'IOMMU_SUPPORT', 'y')
397 l += [iommu_support_is_set] # is needed for mitigating DMA attacks
398 if arch in ('X86_64', 'ARM64', 'X86_32'):
399 l += [KconfigCheck('self_protection', 'defconfig', 'RANDOMIZE_BASE', 'y')]
400 if arch in ('X86_64', 'ARM64'):
401 l += [KconfigCheck('self_protection', 'defconfig', 'VMAP_STACK', 'y')]
402 if arch in ('X86_64', 'X86_32'):
403 l += [KconfigCheck('self_protection', 'defconfig', 'X86_MCE', 'y')]
404 l += [KconfigCheck('self_protection', 'defconfig', 'X86_MCE_INTEL', 'y')]
405 l += [KconfigCheck('self_protection', 'defconfig', 'X86_MCE_AMD', 'y')]
406 l += [KconfigCheck('self_protection', 'defconfig', 'MICROCODE', 'y')] # is needed for mitigating CPU bugs
407 l += [KconfigCheck('self_protection', 'defconfig', 'RETPOLINE', 'y')]
408 l += [OR(KconfigCheck('self_protection', 'defconfig', 'X86_SMAP', 'y'),
409 VersionCheck((5, 19)))] # X86_SMAP is enabled by default since v5.19
410 l += [KconfigCheck('self_protection', 'defconfig', 'SYN_COOKIES', 'y')] # another reason?
411 l += [OR(KconfigCheck('self_protection', 'defconfig', 'X86_UMIP', 'y'),
412 KconfigCheck('self_protection', 'defconfig', 'X86_INTEL_UMIP', 'y'))]
413 if arch in ('ARM64', 'ARM'):
414 l += [KconfigCheck('self_protection', 'defconfig', 'STACKPROTECTOR_PER_TASK', 'y')]
416 l += [KconfigCheck('self_protection', 'defconfig', 'PAGE_TABLE_ISOLATION', 'y')]
417 l += [KconfigCheck('self_protection', 'defconfig', 'RANDOMIZE_MEMORY', 'y')]
418 l += [AND(KconfigCheck('self_protection', 'defconfig', 'INTEL_IOMMU', 'y'),
419 iommu_support_is_set)]
420 l += [AND(KconfigCheck('self_protection', 'defconfig', 'AMD_IOMMU', 'y'),
421 iommu_support_is_set)]
423 l += [KconfigCheck('self_protection', 'defconfig', 'ARM64_PAN', 'y')]
424 l += [KconfigCheck('self_protection', 'defconfig', 'ARM64_EPAN', 'y')]
425 l += [KconfigCheck('self_protection', 'defconfig', 'UNMAP_KERNEL_AT_EL0', 'y')]
426 l += [KconfigCheck('self_protection', 'defconfig', 'ARM64_E0PD', 'y')]
427 l += [OR(KconfigCheck('self_protection', 'defconfig', 'HARDEN_EL2_VECTORS', 'y'),
428 AND(KconfigCheck('self_protection', 'defconfig', 'RANDOMIZE_BASE', 'y'),
429 VersionCheck((5, 9))))] # HARDEN_EL2_VECTORS was included in RANDOMIZE_BASE in v5.9
430 l += [KconfigCheck('self_protection', 'defconfig', 'RODATA_FULL_DEFAULT_ENABLED', 'y')]
431 l += [KconfigCheck('self_protection', 'defconfig', 'ARM64_PTR_AUTH_KERNEL', 'y')]
432 l += [KconfigCheck('self_protection', 'defconfig', 'ARM64_BTI_KERNEL', 'y')]
433 l += [OR(KconfigCheck('self_protection', 'defconfig', 'HARDEN_BRANCH_PREDICTOR', 'y'),
434 VersionCheck((5, 10)))] # HARDEN_BRANCH_PREDICTOR is enabled by default since v5.10
435 l += [KconfigCheck('self_protection', 'defconfig', 'MITIGATE_SPECTRE_BRANCH_HISTORY', 'y')]
436 l += [KconfigCheck('self_protection', 'defconfig', 'ARM64_MTE', 'y')]
437 l += [KconfigCheck('self_protection', 'defconfig', 'RANDOMIZE_MODULE_REGION_FULL', 'y')]
439 l += [KconfigCheck('self_protection', 'defconfig', 'CPU_SW_DOMAIN_PAN', 'y')]
440 l += [KconfigCheck('self_protection', 'defconfig', 'HARDEN_BRANCH_PREDICTOR', 'y')]
441 l += [KconfigCheck('self_protection', 'defconfig', 'HARDEN_BRANCH_HISTORY', 'y')]
443 # 'self_protection', 'kspp'
444 l += [KconfigCheck('self_protection', 'kspp', 'BUG_ON_DATA_CORRUPTION', 'y')]
445 l += [KconfigCheck('self_protection', 'kspp', 'DEBUG_WX', 'y')]
446 l += [KconfigCheck('self_protection', 'kspp', 'SCHED_STACK_END_CHECK', 'y')]
447 l += [KconfigCheck('self_protection', 'kspp', 'SLAB_FREELIST_HARDENED', 'y')]
448 l += [KconfigCheck('self_protection', 'kspp', 'SLAB_FREELIST_RANDOM', 'y')]
449 l += [KconfigCheck('self_protection', 'kspp', 'SHUFFLE_PAGE_ALLOCATOR', 'y')]
450 l += [KconfigCheck('self_protection', 'kspp', 'FORTIFY_SOURCE', 'y')]
451 l += [KconfigCheck('self_protection', 'kspp', 'DEBUG_LIST', 'y')]
452 l += [KconfigCheck('self_protection', 'kspp', 'DEBUG_VIRTUAL', 'y')]
453 l += [KconfigCheck('self_protection', 'kspp', 'DEBUG_SG', 'y')]
454 l += [KconfigCheck('self_protection', 'kspp', 'DEBUG_CREDENTIALS', 'y')]
455 l += [KconfigCheck('self_protection', 'kspp', 'DEBUG_NOTIFIERS', 'y')]
456 l += [KconfigCheck('self_protection', 'kspp', 'INIT_ON_ALLOC_DEFAULT_ON', 'y')]
457 l += [AND(KconfigCheck('self_protection', 'kspp', 'GCC_PLUGIN_LATENT_ENTROPY', 'y'),
458 gcc_plugins_support_is_set)]
459 l += [KconfigCheck('self_protection', 'kspp', 'KFENCE', 'y')]
460 l += [KconfigCheck('self_protection', 'kspp', 'WERROR', 'y')]
461 l += [KconfigCheck('self_protection', 'kspp', 'IOMMU_DEFAULT_DMA_STRICT', 'y')]
462 l += [KconfigCheck('self_protection', 'kspp', 'IOMMU_DEFAULT_PASSTHROUGH', 'is not set')] # true if IOMMU_DEFAULT_DMA_STRICT is set
463 l += [KconfigCheck('self_protection', 'kspp', 'ZERO_CALL_USED_REGS', 'y')]
464 l += [KconfigCheck('self_protection', 'kspp', 'HW_RANDOM_TPM', 'y')]
465 l += [KconfigCheck('self_protection', 'kspp', 'STATIC_USERMODEHELPER', 'y')] # needs userspace support
466 l += [KconfigCheck('self_protection', 'kspp', 'SCHED_CORE', 'y')]
467 randstruct_is_set = OR(KconfigCheck('self_protection', 'kspp', 'RANDSTRUCT_FULL', 'y'),
468 KconfigCheck('self_protection', 'kspp', 'GCC_PLUGIN_RANDSTRUCT', 'y'))
469 l += [randstruct_is_set]
470 l += [AND(KconfigCheck('self_protection', 'kspp', 'RANDSTRUCT_PERFORMANCE', 'is not set'),
471 KconfigCheck('self_protection', 'kspp', 'GCC_PLUGIN_RANDSTRUCT_PERFORMANCE', 'is not set'),
473 hardened_usercopy_is_set = KconfigCheck('self_protection', 'kspp', 'HARDENED_USERCOPY', 'y')
474 l += [hardened_usercopy_is_set]
475 l += [AND(KconfigCheck('self_protection', 'kspp', 'HARDENED_USERCOPY_FALLBACK', 'is not set'),
476 hardened_usercopy_is_set)]
477 l += [AND(KconfigCheck('self_protection', 'kspp', 'HARDENED_USERCOPY_PAGESPAN', 'is not set'),
478 hardened_usercopy_is_set)]
479 l += [OR(KconfigCheck('self_protection', 'kspp', 'MODULE_SIG', 'y'),
481 l += [OR(KconfigCheck('self_protection', 'kspp', 'MODULE_SIG_ALL', 'y'),
483 l += [OR(KconfigCheck('self_protection', 'kspp', 'MODULE_SIG_SHA512', 'y'),
485 l += [OR(KconfigCheck('self_protection', 'kspp', 'MODULE_SIG_FORCE', 'y'),
486 modules_not_set)] # refers to LOCKDOWN
487 l += [OR(KconfigCheck('self_protection', 'kspp', 'INIT_STACK_ALL_ZERO', 'y'),
488 KconfigCheck('self_protection', 'kspp', 'GCC_PLUGIN_STRUCTLEAK_BYREF_ALL', 'y'))]
489 l += [OR(KconfigCheck('self_protection', 'kspp', 'INIT_ON_FREE_DEFAULT_ON', 'y'),
490 KconfigCheck('self_protection', 'kspp', 'PAGE_POISONING_ZERO', 'y'))]
491 # CONFIG_INIT_ON_FREE_DEFAULT_ON was added in v5.3.
492 # CONFIG_PAGE_POISONING_ZERO was removed in v5.11.
493 # Starting from v5.11 CONFIG_PAGE_POISONING unconditionally checks
494 # the 0xAA poison pattern on allocation.
495 # That brings higher performance penalty.
496 l += [OR(KconfigCheck('self_protection', 'kspp', 'EFI_DISABLE_PCI_DMA', 'y'),
498 l += [OR(KconfigCheck('self_protection', 'kspp', 'RESET_ATTACK_MITIGATION', 'y'),
499 efi_not_set)] # needs userspace support (systemd)
500 ubsan_bounds_is_set = KconfigCheck('self_protection', 'kspp', 'UBSAN_BOUNDS', 'y')
501 l += [ubsan_bounds_is_set]
502 l += [OR(KconfigCheck('self_protection', 'kspp', 'UBSAN_LOCAL_BOUNDS', 'y'),
503 AND(ubsan_bounds_is_set,
505 l += [AND(KconfigCheck('self_protection', 'kspp', 'UBSAN_TRAP', 'y'),
507 KconfigCheck('self_protection', 'kspp', 'UBSAN_SHIFT', 'is not set'),
508 KconfigCheck('self_protection', 'kspp', 'UBSAN_DIV_ZERO', 'is not set'),
509 KconfigCheck('self_protection', 'kspp', 'UBSAN_UNREACHABLE', 'is not set'),
510 KconfigCheck('self_protection', 'kspp', 'UBSAN_BOOL', 'is not set'),
511 KconfigCheck('self_protection', 'kspp', 'UBSAN_ENUM', 'is not set'),
512 KconfigCheck('self_protection', 'kspp', 'UBSAN_ALIGNMENT', 'is not set'))] # only array index bounds checking with traps
513 if arch in ('X86_64', 'ARM64', 'X86_32'):
514 l += [AND(KconfigCheck('self_protection', 'kspp', 'UBSAN_SANITIZE_ALL', 'y'),
515 ubsan_bounds_is_set)] # ARCH_HAS_UBSAN_SANITIZE_ALL is not enabled for ARM
516 stackleak_is_set = KconfigCheck('self_protection', 'kspp', 'GCC_PLUGIN_STACKLEAK', 'y')
517 l += [AND(stackleak_is_set, gcc_plugins_support_is_set)]
518 l += [AND(KconfigCheck('self_protection', 'kspp', 'STACKLEAK_METRICS', 'is not set'),
520 gcc_plugins_support_is_set)]
521 l += [AND(KconfigCheck('self_protection', 'kspp', 'STACKLEAK_RUNTIME_DISABLE', 'is not set'),
523 gcc_plugins_support_is_set)]
524 l += [KconfigCheck('self_protection', 'kspp', 'RANDOMIZE_KSTACK_OFFSET_DEFAULT', 'y')]
525 if arch in ('X86_64', 'ARM64'):
526 cfi_clang_is_set = KconfigCheck('self_protection', 'kspp', 'CFI_CLANG', 'y')
527 l += [cfi_clang_is_set]
528 l += [AND(KconfigCheck('self_protection', 'kspp', 'CFI_PERMISSIVE', 'is not set'),
530 if arch in ('X86_64', 'X86_32'):
531 l += [KconfigCheck('self_protection', 'kspp', 'DEFAULT_MMAP_MIN_ADDR', '65536')]
532 l += [AND(KconfigCheck('self_protection', 'kspp', 'INTEL_IOMMU_DEFAULT_ON', 'y'),
533 iommu_support_is_set)]
534 if arch in ('ARM64', 'ARM'):
535 l += [KconfigCheck('self_protection', 'kspp', 'DEFAULT_MMAP_MIN_ADDR', '32768')]
536 l += [KconfigCheck('self_protection', 'kspp', 'SYN_COOKIES', 'y')] # another reason?
538 l += [KconfigCheck('self_protection', 'kspp', 'SLS', 'y')] # vs CVE-2021-26341 in Straight-Line-Speculation
539 l += [AND(KconfigCheck('self_protection', 'kspp', 'INTEL_IOMMU_SVM', 'y'),
540 iommu_support_is_set)]
541 l += [AND(KconfigCheck('self_protection', 'kspp', 'AMD_IOMMU_V2', 'y'),
542 iommu_support_is_set)]
544 l += [KconfigCheck('self_protection', 'kspp', 'ARM64_SW_TTBR0_PAN', 'y')]
545 l += [KconfigCheck('self_protection', 'kspp', 'SHADOW_CALL_STACK', 'y')]
546 l += [KconfigCheck('self_protection', 'kspp', 'KASAN_HW_TAGS', 'y')]
548 l += [KconfigCheck('self_protection', 'kspp', 'PAGE_TABLE_ISOLATION', 'y')]
549 l += [KconfigCheck('self_protection', 'kspp', 'HIGHMEM64G', 'y')]
550 l += [KconfigCheck('self_protection', 'kspp', 'X86_PAE', 'y')]
551 l += [AND(KconfigCheck('self_protection', 'kspp', 'INTEL_IOMMU', 'y'),
552 iommu_support_is_set)]
554 # 'self_protection', 'clipos'
555 l += [KconfigCheck('self_protection', 'clipos', 'SLAB_MERGE_DEFAULT', 'is not set')]
558 if arch in ('X86_64', 'ARM64', 'X86_32'):
559 l += [KconfigCheck('security_policy', 'defconfig', 'SECURITY', 'y')] # and choose your favourite LSM
561 l += [KconfigCheck('security_policy', 'kspp', 'SECURITY', 'y')] # and choose your favourite LSM
562 l += [KconfigCheck('security_policy', 'kspp', 'SECURITY_YAMA', 'y')]
563 l += [KconfigCheck('security_policy', 'kspp', 'SECURITY_LANDLOCK', 'y')]
564 l += [KconfigCheck('security_policy', 'kspp', 'SECURITY_SELINUX_DISABLE', 'is not set')]
565 l += [KconfigCheck('security_policy', 'kspp', 'SECURITY_SELINUX_BOOTPARAM', 'is not set')]
566 l += [KconfigCheck('security_policy', 'kspp', 'SECURITY_SELINUX_DEVELOP', 'is not set')]
567 l += [KconfigCheck('security_policy', 'kspp', 'SECURITY_LOCKDOWN_LSM', 'y')]
568 l += [KconfigCheck('security_policy', 'kspp', 'SECURITY_LOCKDOWN_LSM_EARLY', 'y')]
569 l += [KconfigCheck('security_policy', 'kspp', 'LOCK_DOWN_KERNEL_FORCE_CONFIDENTIALITY', 'y')]
570 l += [KconfigCheck('security_policy', 'kspp', 'SECURITY_WRITABLE_HOOKS', 'is not set')] # refers to SECURITY_SELINUX_DISABLE
572 # 'cut_attack_surface', 'defconfig'
573 l += [OR(KconfigCheck('cut_attack_surface', 'defconfig', 'BPF_UNPRIV_DEFAULT_OFF', 'y'),
574 bpf_syscall_not_set)] # see unprivileged_bpf_disabled
575 l += [KconfigCheck('cut_attack_surface', 'defconfig', 'SECCOMP', 'y')]
576 l += [KconfigCheck('cut_attack_surface', 'defconfig', 'SECCOMP_FILTER', 'y')]
577 if arch in ('X86_64', 'ARM64', 'X86_32'):
578 l += [OR(KconfigCheck('cut_attack_surface', 'defconfig', 'STRICT_DEVMEM', 'y'),
579 devmem_not_set)] # refers to LOCKDOWN
581 # 'cut_attack_surface', 'kspp'
582 l += [KconfigCheck('cut_attack_surface', 'kspp', 'SECURITY_DMESG_RESTRICT', 'y')]
583 l += [KconfigCheck('cut_attack_surface', 'kspp', 'ACPI_CUSTOM_METHOD', 'is not set')] # refers to LOCKDOWN
584 l += [KconfigCheck('cut_attack_surface', 'kspp', 'COMPAT_BRK', 'is not set')]
585 l += [KconfigCheck('cut_attack_surface', 'kspp', 'DEVKMEM', 'is not set')] # refers to LOCKDOWN
586 l += [KconfigCheck('cut_attack_surface', 'kspp', 'COMPAT_VDSO', 'is not set')]
587 l += [KconfigCheck('cut_attack_surface', 'kspp', 'BINFMT_MISC', 'is not set')]
588 l += [KconfigCheck('cut_attack_surface', 'kspp', 'INET_DIAG', 'is not set')]
589 l += [KconfigCheck('cut_attack_surface', 'kspp', 'KEXEC', 'is not set')] # refers to LOCKDOWN
590 l += [KconfigCheck('cut_attack_surface', 'kspp', 'PROC_KCORE', 'is not set')] # refers to LOCKDOWN
591 l += [KconfigCheck('cut_attack_surface', 'kspp', 'LEGACY_PTYS', 'is not set')]
592 l += [KconfigCheck('cut_attack_surface', 'kspp', 'HIBERNATION', 'is not set')] # refers to LOCKDOWN
593 l += [KconfigCheck('cut_attack_surface', 'kspp', 'IA32_EMULATION', 'is not set')]
594 l += [KconfigCheck('cut_attack_surface', 'kspp', 'X86_X32', 'is not set')]
595 l += [KconfigCheck('cut_attack_surface', 'kspp', 'MODIFY_LDT_SYSCALL', 'is not set')]
596 l += [KconfigCheck('cut_attack_surface', 'kspp', 'OABI_COMPAT', 'is not set')]
597 l += [KconfigCheck('cut_attack_surface', 'kspp', 'X86_MSR', 'is not set')] # refers to LOCKDOWN
598 l += [modules_not_set]
599 l += [devmem_not_set]
600 l += [OR(KconfigCheck('cut_attack_surface', 'kspp', 'IO_STRICT_DEVMEM', 'y'),
601 devmem_not_set)] # refers to LOCKDOWN
602 l += [AND(KconfigCheck('cut_attack_surface', 'kspp', 'LDISC_AUTOLOAD', 'is not set'),
603 KconfigCheck('cut_attack_surface', 'kspp', 'LDISC_AUTOLOAD'))] # option presence check
605 l += [OR(KconfigCheck('cut_attack_surface', 'kspp', 'STRICT_DEVMEM', 'y'),
606 devmem_not_set)] # refers to LOCKDOWN
608 l += [KconfigCheck('cut_attack_surface', 'kspp', 'LEGACY_VSYSCALL_NONE', 'y')] # 'vsyscall=none'
610 # 'cut_attack_surface', 'grsec'
611 l += [KconfigCheck('cut_attack_surface', 'grsec', 'ZSMALLOC_STAT', 'is not set')]
612 l += [KconfigCheck('cut_attack_surface', 'grsec', 'PAGE_OWNER', 'is not set')]
613 l += [KconfigCheck('cut_attack_surface', 'grsec', 'DEBUG_KMEMLEAK', 'is not set')]
614 l += [KconfigCheck('cut_attack_surface', 'grsec', 'BINFMT_AOUT', 'is not set')]
615 l += [KconfigCheck('cut_attack_surface', 'grsec', 'KPROBE_EVENTS', 'is not set')]
616 l += [KconfigCheck('cut_attack_surface', 'grsec', 'UPROBE_EVENTS', 'is not set')]
617 l += [KconfigCheck('cut_attack_surface', 'grsec', 'GENERIC_TRACER', 'is not set')] # refers to LOCKDOWN
618 l += [KconfigCheck('cut_attack_surface', 'grsec', 'FUNCTION_TRACER', 'is not set')]
619 l += [KconfigCheck('cut_attack_surface', 'grsec', 'STACK_TRACER', 'is not set')]
620 l += [KconfigCheck('cut_attack_surface', 'grsec', 'HIST_TRIGGERS', 'is not set')]
621 l += [KconfigCheck('cut_attack_surface', 'grsec', 'BLK_DEV_IO_TRACE', 'is not set')]
622 l += [KconfigCheck('cut_attack_surface', 'grsec', 'PROC_VMCORE', 'is not set')]
623 l += [KconfigCheck('cut_attack_surface', 'grsec', 'PROC_PAGE_MONITOR', 'is not set')]
624 l += [KconfigCheck('cut_attack_surface', 'grsec', 'USELIB', 'is not set')]
625 l += [KconfigCheck('cut_attack_surface', 'grsec', 'CHECKPOINT_RESTORE', 'is not set')]
626 l += [KconfigCheck('cut_attack_surface', 'grsec', 'USERFAULTFD', 'is not set')]
627 l += [KconfigCheck('cut_attack_surface', 'grsec', 'HWPOISON_INJECT', 'is not set')]
628 l += [KconfigCheck('cut_attack_surface', 'grsec', 'MEM_SOFT_DIRTY', 'is not set')]
629 l += [KconfigCheck('cut_attack_surface', 'grsec', 'DEVPORT', 'is not set')] # refers to LOCKDOWN
630 l += [KconfigCheck('cut_attack_surface', 'grsec', 'DEBUG_FS', 'is not set')] # refers to LOCKDOWN
631 l += [KconfigCheck('cut_attack_surface', 'grsec', 'NOTIFIER_ERROR_INJECTION', 'is not set')]
632 l += [KconfigCheck('cut_attack_surface', 'grsec', 'FAIL_FUTEX', 'is not set')]
633 l += [KconfigCheck('cut_attack_surface', 'grsec', 'PUNIT_ATOM_DEBUG', 'is not set')]
634 l += [KconfigCheck('cut_attack_surface', 'grsec', 'ACPI_CONFIGFS', 'is not set')]
635 l += [KconfigCheck('cut_attack_surface', 'grsec', 'EDAC_DEBUG', 'is not set')]
636 l += [KconfigCheck('cut_attack_surface', 'grsec', 'DRM_I915_DEBUG', 'is not set')]
637 l += [KconfigCheck('cut_attack_surface', 'grsec', 'BCACHE_CLOSURES_DEBUG', 'is not set')]
638 l += [KconfigCheck('cut_attack_surface', 'grsec', 'DVB_C8SECTPFE', 'is not set')]
639 l += [KconfigCheck('cut_attack_surface', 'grsec', 'MTD_SLRAM', 'is not set')]
640 l += [KconfigCheck('cut_attack_surface', 'grsec', 'MTD_PHRAM', 'is not set')]
641 l += [KconfigCheck('cut_attack_surface', 'grsec', 'IO_URING', 'is not set')]
642 l += [KconfigCheck('cut_attack_surface', 'grsec', 'KCMP', 'is not set')]
643 l += [KconfigCheck('cut_attack_surface', 'grsec', 'RSEQ', 'is not set')]
644 l += [KconfigCheck('cut_attack_surface', 'grsec', 'LATENCYTOP', 'is not set')]
645 l += [KconfigCheck('cut_attack_surface', 'grsec', 'KCOV', 'is not set')]
646 l += [KconfigCheck('cut_attack_surface', 'grsec', 'PROVIDE_OHCI1394_DMA_INIT', 'is not set')]
647 l += [KconfigCheck('cut_attack_surface', 'grsec', 'SUNRPC_DEBUG', 'is not set')]
648 l += [AND(KconfigCheck('cut_attack_surface', 'grsec', 'PTDUMP_DEBUGFS', 'is not set'),
649 KconfigCheck('cut_attack_surface', 'grsec', 'X86_PTDUMP', 'is not set'))]
651 # 'cut_attack_surface', 'maintainer'
652 l += [KconfigCheck('cut_attack_surface', 'maintainer', 'DRM_LEGACY', 'is not set')] # recommended by Daniel Vetter in /issues/38
653 l += [KconfigCheck('cut_attack_surface', 'maintainer', 'FB', 'is not set')] # recommended by Daniel Vetter in /issues/38
654 l += [KconfigCheck('cut_attack_surface', 'maintainer', 'VT', 'is not set')] # recommended by Daniel Vetter in /issues/38
655 l += [KconfigCheck('cut_attack_surface', 'maintainer', 'BLK_DEV_FD', 'is not set')] # recommended by Denis Efremov in /pull/54
656 l += [KconfigCheck('cut_attack_surface', 'maintainer', 'BLK_DEV_FD_RAWCMD', 'is not set')] # recommended by Denis Efremov in /pull/62
658 # 'cut_attack_surface', 'grapheneos'
659 l += [KconfigCheck('cut_attack_surface', 'grapheneos', 'AIO', 'is not set')]
661 # 'cut_attack_surface', 'clipos'
662 l += [KconfigCheck('cut_attack_surface', 'clipos', 'STAGING', 'is not set')]
663 l += [KconfigCheck('cut_attack_surface', 'clipos', 'KSM', 'is not set')] # to prevent FLUSH+RELOAD attack
664 # l += [KconfigCheck('cut_attack_surface', 'clipos', 'IKCONFIG', 'is not set')] # no, IKCONFIG is needed for this check :)
665 l += [KconfigCheck('cut_attack_surface', 'clipos', 'KALLSYMS', 'is not set')]
666 l += [KconfigCheck('cut_attack_surface', 'clipos', 'X86_VSYSCALL_EMULATION', 'is not set')]
667 l += [KconfigCheck('cut_attack_surface', 'clipos', 'MAGIC_SYSRQ', 'is not set')]
668 l += [KconfigCheck('cut_attack_surface', 'clipos', 'KEXEC_FILE', 'is not set')] # refers to LOCKDOWN (permissive)
669 l += [KconfigCheck('cut_attack_surface', 'clipos', 'USER_NS', 'is not set')] # user.max_user_namespaces=0
670 l += [KconfigCheck('cut_attack_surface', 'clipos', 'X86_CPUID', 'is not set')]
671 l += [KconfigCheck('cut_attack_surface', 'clipos', 'X86_IOPL_IOPERM', 'is not set')] # refers to LOCKDOWN
672 l += [KconfigCheck('cut_attack_surface', 'clipos', 'ACPI_TABLE_UPGRADE', 'is not set')] # refers to LOCKDOWN
673 l += [KconfigCheck('cut_attack_surface', 'clipos', 'EFI_CUSTOM_SSDT_OVERLAYS', 'is not set')]
674 l += [KconfigCheck('cut_attack_surface', 'clipos', 'COREDUMP', 'is not set')] # cut userspace attack surface
675 if arch in ('X86_64', 'X86_32'):
676 l += [KconfigCheck('cut_attack_surface', 'clipos', 'X86_INTEL_TSX_MODE_OFF', 'y')] # tsx=off
678 # 'cut_attack_surface', 'lockdown'
679 l += [bpf_syscall_not_set] # refers to LOCKDOWN
680 l += [KconfigCheck('cut_attack_surface', 'lockdown', 'EFI_TEST', 'is not set')] # refers to LOCKDOWN
681 l += [KconfigCheck('cut_attack_surface', 'lockdown', 'MMIOTRACE_TEST', 'is not set')] # refers to LOCKDOWN
682 l += [KconfigCheck('cut_attack_surface', 'lockdown', 'KPROBES', 'is not set')] # refers to LOCKDOWN
684 # 'cut_attack_surface', 'my'
685 l += [OR(KconfigCheck('cut_attack_surface', 'my', 'TRIM_UNUSED_KSYMS', 'y'),
687 l += [KconfigCheck('cut_attack_surface', 'my', 'MMIOTRACE', 'is not set')] # refers to LOCKDOWN (permissive)
688 l += [KconfigCheck('cut_attack_surface', 'my', 'LIVEPATCH', 'is not set')]
689 l += [KconfigCheck('cut_attack_surface', 'my', 'IP_DCCP', 'is not set')]
690 l += [KconfigCheck('cut_attack_surface', 'my', 'IP_SCTP', 'is not set')]
691 l += [KconfigCheck('cut_attack_surface', 'my', 'FTRACE', 'is not set')] # refers to LOCKDOWN
692 l += [KconfigCheck('cut_attack_surface', 'my', 'VIDEO_VIVID', 'is not set')]
693 l += [KconfigCheck('cut_attack_surface', 'my', 'INPUT_EVBUG', 'is not set')] # Can be used as a keylogger
694 l += [KconfigCheck('cut_attack_surface', 'my', 'KGDB', 'is not set')]
697 if arch in ('X86_64', 'ARM64', 'X86_32'):
698 l += [KconfigCheck('harden_userspace', 'defconfig', 'INTEGRITY', 'y')]
700 l += [KconfigCheck('harden_userspace', 'my', 'INTEGRITY', 'y')]
702 l += [KconfigCheck('harden_userspace', 'defconfig', 'ARM64_PTR_AUTH', 'y')]
703 l += [KconfigCheck('harden_userspace', 'defconfig', 'ARM64_BTI', 'y')]
704 if arch in ('ARM', 'X86_32'):
705 l += [KconfigCheck('harden_userspace', 'defconfig', 'VMSPLIT_3G', 'y')]
706 if arch in ('X86_64', 'ARM64'):
707 l += [KconfigCheck('harden_userspace', 'clipos', 'ARCH_MMAP_RND_BITS', '32')]
708 if arch in ('X86_32', 'ARM'):
709 l += [KconfigCheck('harden_userspace', 'my', 'ARCH_MMAP_RND_BITS', '16')]
712 def add_cmdline_checks(l, arch):
713 # Calling the CmdlineCheck class constructor:
714 # CmdlineCheck(reason, decision, name, expected)
716 # [!] Don't add CmdlineChecks in add_kconfig_checks() to avoid wrong results
717 # when the tool doesn't check the cmdline.
719 # [!] Make sure that values of the options in CmdlineChecks need normalization.
720 # For more info see normalize_cmdline_options().
722 # A common pattern for checking the 'param_x' cmdline parameter
723 # that __overrides__ the 'PARAM_X_DEFAULT' kconfig option:
724 # l += [OR(CmdlineCheck(reason, decision, 'param_x', '1'),
725 # AND(KconfigCheck(reason, decision, 'PARAM_X_DEFAULT_ON', 'y'),
726 # CmdlineCheck(reason, decision, 'param_x, 'is not set')))]
728 # Here we don't check the kconfig options or minimal kernel version
729 # required for the cmdline parameters. That would make the checks
730 # very complex and not give a 100% guarantee anyway.
732 # 'self_protection', 'defconfig'
733 l += [CmdlineCheck('self_protection', 'defconfig', 'nosmep', 'is not set')]
734 l += [CmdlineCheck('self_protection', 'defconfig', 'nosmap', 'is not set')]
735 l += [CmdlineCheck('self_protection', 'defconfig', 'nokaslr', 'is not set')]
736 l += [CmdlineCheck('self_protection', 'defconfig', 'nopti', 'is not set')]
737 l += [CmdlineCheck('self_protection', 'defconfig', 'nospectre_v1', 'is not set')]
738 l += [CmdlineCheck('self_protection', 'defconfig', 'nospectre_v2', 'is not set')]
740 l += [OR(CmdlineCheck('self_protection', 'defconfig', 'rodata', 'full'),
741 AND(KconfigCheck('self_protection', 'defconfig', 'RODATA_FULL_DEFAULT_ENABLED', 'y'),
742 CmdlineCheck('self_protection', 'defconfig', 'rodata', 'is not set')))]
744 l += [OR(CmdlineCheck('self_protection', 'defconfig', 'rodata', '1'),
745 CmdlineCheck('self_protection', 'defconfig', 'rodata', 'is not set'))]
747 # 'self_protection', 'kspp'
748 l += [OR(CmdlineCheck('self_protection', 'kspp', 'init_on_alloc', '1'),
749 AND(KconfigCheck('self_protection', 'kspp', 'INIT_ON_ALLOC_DEFAULT_ON', 'y'),
750 CmdlineCheck('self_protection', 'kspp', 'init_on_alloc', 'is not set')))]
751 l += [OR(CmdlineCheck('self_protection', 'kspp', 'init_on_free', '1'),
752 AND(KconfigCheck('self_protection', 'kspp', 'INIT_ON_FREE_DEFAULT_ON', 'y'),
753 CmdlineCheck('self_protection', 'kspp', 'init_on_free', 'is not set')),
754 AND(CmdlineCheck('self_protection', 'kspp', 'page_poison', '1'),
755 KconfigCheck('self_protection', 'kspp', 'PAGE_POISONING_ZERO', 'y'),
756 CmdlineCheck('self_protection', 'kspp', 'slub_debug', 'P')))]
757 l += [OR(CmdlineCheck('self_protection', 'kspp', 'slab_nomerge'),
758 AND(KconfigCheck('self_protection', 'clipos', 'SLAB_MERGE_DEFAULT', 'is not set'),
759 CmdlineCheck('self_protection', 'kspp', 'slab_merge', 'is not set')))] # option presence check
760 l += [OR(CmdlineCheck('self_protection', 'kspp', 'iommu.strict', '1'),
761 AND(KconfigCheck('self_protection', 'kspp', 'IOMMU_DEFAULT_DMA_STRICT', 'y'),
762 CmdlineCheck('self_protection', 'kspp', 'iommu.strict', 'is not set')))]
763 l += [OR(CmdlineCheck('self_protection', 'kspp', 'iommu.passthrough', '0'),
764 AND(KconfigCheck('self_protection', 'kspp', 'IOMMU_DEFAULT_PASSTHROUGH', 'is not set'),
765 CmdlineCheck('self_protection', 'kspp', 'iommu.passthrough', 'is not set')))]
766 # The cmdline checks compatible with the kconfig recommendations of the KSPP project...
767 l += [OR(CmdlineCheck('self_protection', 'kspp', 'hardened_usercopy', '1'),
768 AND(KconfigCheck('self_protection', 'kspp', 'HARDENED_USERCOPY', 'y'),
769 CmdlineCheck('self_protection', 'kspp', 'hardened_usercopy', 'is not set')))]
770 l += [OR(CmdlineCheck('self_protection', 'kspp', 'slab_common.usercopy_fallback', '0'),
771 AND(KconfigCheck('self_protection', 'kspp', 'HARDENED_USERCOPY_FALLBACK', 'is not set'),
772 CmdlineCheck('self_protection', 'kspp', 'slab_common.usercopy_fallback', 'is not set')))]
774 if arch in ('X86_64', 'ARM64', 'X86_32'):
775 l += [OR(CmdlineCheck('self_protection', 'kspp', 'randomize_kstack_offset', '1'),
776 AND(KconfigCheck('self_protection', 'kspp', 'RANDOMIZE_KSTACK_OFFSET_DEFAULT', 'y'),
777 CmdlineCheck('self_protection', 'kspp', 'randomize_kstack_offset', 'is not set')))]
778 if arch in ('X86_64', 'X86_32'):
779 l += [AND(CmdlineCheck('self_protection', 'kspp', 'pti', 'on'),
780 CmdlineCheck('self_protection', 'defconfig', 'nopti', 'is not set'))]
782 # 'self_protection', 'clipos'
783 l += [CmdlineCheck('self_protection', 'clipos', 'page_alloc.shuffle', '1')]
784 if arch in ('X86_64', 'X86_32'):
785 l += [AND(CmdlineCheck('self_protection', 'clipos', 'spectre_v2', 'on'),
786 CmdlineCheck('self_protection', 'defconfig', 'nospectre_v2', 'is not set'))]
788 # 'cut_attack_surface', 'kspp'
790 l += [OR(CmdlineCheck('cut_attack_surface', 'kspp', 'vsyscall', 'none'),
791 AND(KconfigCheck('cut_attack_surface', 'kspp', 'LEGACY_VSYSCALL_NONE', 'y'),
792 CmdlineCheck('cut_attack_surface', 'kspp', 'vsyscall', 'is not set')))]
794 # 'cut_attack_surface', 'grsec'
795 # The cmdline checks compatible with the kconfig options disabled by grsecurity...
796 l += [OR(CmdlineCheck('cut_attack_surface', 'grsec', 'debugfs', 'off'),
797 KconfigCheck('cut_attack_surface', 'grsec', 'DEBUG_FS', 'is not set'))] # ... the end
800 def print_unknown_options(checklist, parsed_options):
804 if o1.type != 'complex':
805 known_options.append(o1.name)
808 if o2.type != 'complex':
809 if hasattr(o2, 'name'):
810 known_options.append(o2.name)
813 assert(o3.type != 'complex'), \
814 'unexpected ComplexOptCheck inside {}'.format(o2.name)
815 if hasattr(o3, 'name'):
816 known_options.append(o3.name)
818 for option, value in parsed_options.items():
819 if option not in known_options:
820 print('[?] No check for option {} ({})'.format(option, value))
823 def print_checklist(mode, checklist, with_results):
827 output.append(o.json_dump(with_results))
828 print(json.dumps(output))
835 print('=' * sep_line_len)
836 print('{:^40}|{:^7}|{:^12}|{:^10}|{:^18}'.format('option name', 'type', 'desired val', 'decision', 'reason'), end='')
838 print('| {}'.format('check result'), end='')
840 print('=' * sep_line_len)
843 for opt in checklist:
845 if mode == 'show_ok':
846 if not opt.result.startswith('OK'):
848 if mode == 'show_fail':
849 if not opt.result.startswith('FAIL'):
851 opt.table_print(mode, with_results)
853 if mode == 'verbose':
854 print('-' * sep_line_len)
859 fail_count = len(list(filter(lambda opt: opt.result.startswith('FAIL'), checklist)))
861 ok_count = len(list(filter(lambda opt: opt.result.startswith('OK'), checklist)))
863 if mode == 'show_ok':
864 fail_suppressed = ' (suppressed in output)'
865 if mode == 'show_fail':
866 ok_suppressed = ' (suppressed in output)'
868 print('[+] Config check is finished: \'OK\' - {}{} / \'FAIL\' - {}{}'.format(ok_count, ok_suppressed, fail_count, fail_suppressed))
871 def populate_simple_opt_with_data(opt, data, data_type):
872 assert(opt.type != 'complex'), \
873 'unexpected ComplexOptCheck "{}"'.format(opt.name)
874 assert(opt.type in SIMPLE_OPTION_TYPES), \
875 'invalid opt type "{}"'.format(opt.type)
876 assert(data_type in SIMPLE_OPTION_TYPES), \
877 'invalid data type "{}"'.format(data_type)
879 if data_type != opt.type:
882 if data_type in ('kconfig', 'cmdline'):
883 opt.state = data.get(opt.name, None)
885 assert(data_type == 'version'), \
886 'unexpected data type "{}"'.format(data_type)
890 def populate_opt_with_data(opt, data, data_type):
891 if opt.type == 'complex':
893 if o.type == 'complex':
894 # Recursion for nested ComplexOptCheck objects
895 populate_opt_with_data(o, data, data_type)
897 populate_simple_opt_with_data(o, data, data_type)
899 assert(opt.type in ('kconfig', 'cmdline')), \
900 'bad type "{}" for a simple check'.format(opt.type)
901 populate_simple_opt_with_data(opt, data, data_type)
904 def populate_with_data(checklist, data, data_type):
905 for opt in checklist:
906 populate_opt_with_data(opt, data, data_type)
909 def perform_checks(checklist):
910 for opt in checklist:
914 def parse_kconfig_file(parsed_options, fname):
915 with open(fname, 'r') as f:
916 opt_is_on = re.compile("CONFIG_[a-zA-Z0-9_]*=[a-zA-Z0-9_\"]*")
917 opt_is_off = re.compile("# CONFIG_[a-zA-Z0-9_]* is not set")
919 for line in f.readlines():
924 if opt_is_on.match(line):
925 option, value = line.split('=', 1)
926 if value == 'is not set':
927 sys.exit('[!] ERROR: bad enabled kconfig option "{}"'.format(line))
928 elif opt_is_off.match(line):
929 option, value = line[2:].split(' ', 1)
930 if value != 'is not set':
931 sys.exit('[!] ERROR: bad disabled kconfig option "{}"'.format(line))
933 if option in parsed_options:
934 sys.exit('[!] ERROR: kconfig option "{}" exists multiple times'.format(line))
937 parsed_options[option] = value
940 def normalize_cmdline_options(option, value):
941 # Don't normalize the cmdline option values if
942 # the Linux kernel doesn't use kstrtobool() for them
944 # See pti_check_boottime_disable() in linux/arch/x86/mm/pti.c
946 if option == 'spectre_v2':
947 # See spectre_v2_parse_cmdline() in linux/arch/x86/kernel/cpu/bugs.c
949 if option == 'debugfs':
950 # See debugfs_kernel() in fs/debugfs/inode.c
953 # Implement a limited part of the kstrtobool() logic
954 if value in ('1', 'on', 'On', 'ON', 'y', 'Y', 'yes', 'Yes', 'YES'):
956 if value in ('0', 'off', 'Off', 'OFF', 'n', 'N', 'no', 'No', 'NO'):
959 # Preserve unique values
963 def parse_cmdline_file(parsed_options, fname):
964 with open(fname, 'r') as f:
970 sys.exit('[!] ERROR: more than one line in "{}"'.format(fname))
974 name, value = opt.split('=', 1)
977 value = '' # '' is not None
978 value = normalize_cmdline_options(name, value)
979 parsed_options[name] = value
985 # - reporting about unknown kernel options in the kconfig
986 # - verbose printing of ComplexOptCheck items
987 # * json mode for printing the results in JSON format
988 report_modes = ['verbose', 'json', 'show_ok', 'show_fail']
989 supported_archs = ['X86_64', 'X86_32', 'ARM64', 'ARM']
990 parser = ArgumentParser(prog='kconfig-hardened-check',
991 description='A tool for checking the security hardening options of the Linux kernel')
992 parser.add_argument('--version', action='version', version='%(prog)s ' + __version__)
993 parser.add_argument('-p', '--print', choices=supported_archs,
994 help='print security hardening preferences for the selected architecture')
995 parser.add_argument('-c', '--config',
996 help='check the kernel kconfig file against these preferences')
997 parser.add_argument('-l', '--cmdline',
998 help='check the kernel cmdline file against these preferences')
999 parser.add_argument('-m', '--mode', choices=report_modes,
1000 help='choose the report mode')
1001 args = parser.parse_args()
1007 print('[+] Special report mode: {}'.format(mode))
1009 config_checklist = []
1013 sys.exit('[!] ERROR: --config and --print can\'t be used together')
1016 print('[+] Kconfig file to check: {}'.format(args.config))
1018 print('[+] Kernel cmdline file to check: {}'.format(args.cmdline))
1020 arch, msg = detect_arch(args.config, supported_archs)
1022 sys.exit('[!] ERROR: {}'.format(msg))
1024 print('[+] Detected architecture: {}'.format(arch))
1026 kernel_version, msg = detect_kernel_version(args.config)
1027 if not kernel_version:
1028 sys.exit('[!] ERROR: {}'.format(msg))
1030 print('[+] Detected kernel version: {}.{}'.format(kernel_version[0], kernel_version[1]))
1032 compiler, msg = detect_compiler(args.config)
1035 print('[+] Detected compiler: {}'.format(compiler))
1037 print('[-] Can\'t detect the compiler: {}'.format(msg))
1039 # add relevant kconfig checks to the checklist
1040 add_kconfig_checks(config_checklist, arch)
1043 # add relevant cmdline checks to the checklist
1044 add_cmdline_checks(config_checklist, arch)
1046 # populate the checklist with the parsed kconfig data
1047 parsed_kconfig_options = OrderedDict()
1048 parse_kconfig_file(parsed_kconfig_options, args.config)
1049 populate_with_data(config_checklist, parsed_kconfig_options, 'kconfig')
1050 populate_with_data(config_checklist, kernel_version, 'version')
1053 # populate the checklist with the parsed kconfig data
1054 parsed_cmdline_options = OrderedDict()
1055 parse_cmdline_file(parsed_cmdline_options, args.cmdline)
1056 populate_with_data(config_checklist, parsed_cmdline_options, 'cmdline')
1058 # now everything is ready for performing the checks
1059 perform_checks(config_checklist)
1061 # finally print the results
1062 if mode == 'verbose':
1063 print_unknown_options(config_checklist, parsed_kconfig_options)
1064 print_checklist(mode, config_checklist, True)
1068 sys.exit('[!] ERROR: checking cmdline doesn\'t work without checking kconfig')
1071 if mode in ('show_ok', 'show_fail'):
1072 sys.exit('[!] ERROR: wrong mode "{}" for --print'.format(mode))
1074 add_kconfig_checks(config_checklist, arch)
1075 add_cmdline_checks(config_checklist, arch)
1077 print('[+] Printing kernel security hardening preferences for {}...'.format(arch))
1078 print_checklist(mode, config_checklist, False)