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:
19 # l1d_flush=on (a part of the l1tf option)
27 # sysrq_always_enabled
32 # Hardware tag-based KASAN with arm64 Memory Tagging Extension (MTE):
34 # kasan.stacktrace=off
37 # N.B. Hardening sysctls:
38 # kernel.kptr_restrict=2 (or 1?)
39 # kernel.dmesg_restrict=1 (also see the kconfig option)
40 # kernel.perf_event_paranoid=3
41 # kernel.kexec_load_disabled=1
42 # kernel.yama.ptrace_scope=3
43 # user.max_user_namespaces=0
44 # what about bpf_jit_enable?
45 # kernel.unprivileged_bpf_disabled=1
46 # net.core.bpf_jit_harden=2
47 # vm.unprivileged_userfaultfd=0
48 # (at first, it disabled unprivileged userfaultfd,
49 # and since v5.11 it enables unprivileged userfaultfd for user-mode only)
50 # vm.mmap_min_addr has a good value
51 # dev.tty.ldisc_autoload=0
52 # fs.protected_symlinks=1
53 # fs.protected_hardlinks=1
54 # fs.protected_fifos=2
55 # fs.protected_regular=2
57 # kernel.modules_disabled=1
58 # kernel.randomize_va_space = 2
61 # pylint: disable=missing-module-docstring,missing-class-docstring,missing-function-docstring
62 # pylint: disable=line-too-long,invalid-name,too-many-branches,too-many-statements
66 from argparse import ArgumentParser
67 from collections import OrderedDict
70 from .__about__ import __version__
72 SIMPLE_OPTION_TYPES = ('kconfig', 'version', 'cmdline')
75 def __init__(self, reason, decision, name, expected):
76 assert(name and name == name.strip() and len(name.split()) == 1), \
77 'invalid name "{}" for {}'.format(name, self.__class__.__name__)
80 assert(decision and decision == decision.strip() and len(decision.split()) == 1), \
81 'invalid decision "{}" for "{}" check'.format(decision, name)
82 self.decision = decision
84 assert(reason and reason == reason.strip() and len(reason.split()) == 1), \
85 'invalid reason "{}" for "{}" check'.format(reason, name)
88 assert(expected and expected == expected.strip()), \
89 'invalid expected value "{}" for "{}" check (1)'.format(expected, name)
90 val_len = len(expected.split())
92 assert(expected == 'is not set' or expected == 'is not off'), \
93 'invalid expected value "{}" for "{}" check (2)'.format(expected, name)
95 assert(expected == 'is present'), \
96 'invalid expected value "{}" for "{}" check (3)'.format(expected, name)
98 assert(val_len == 1), \
99 'invalid expected value "{}" for "{}" check (4)'.format(expected, name)
100 self.expected = expected
110 # handle the 'is present' check
111 if self.expected == 'is present':
112 if self.state is None:
113 self.result = 'FAIL: is not present'
115 self.result = 'OK: is present'
118 # handle the 'is not off' option check
119 if self.expected == 'is not off':
120 if self.state == 'off':
121 self.result = 'FAIL: is off'
122 elif self.state is None:
123 self.result = 'FAIL: is off, not found'
125 self.result = 'OK: is not off, "' + self.state + '"'
128 # handle the option value check
129 if self.expected == self.state:
131 elif self.state is None:
132 if self.expected == 'is not set':
133 self.result = 'OK: is not found'
135 self.result = 'FAIL: is not found'
137 self.result = 'FAIL: "' + self.state + '"'
139 def table_print(self, _mode, with_results):
140 print('{:<40}|{:^7}|{:^12}|{:^10}|{:^18}'.format(self.name, self.type, self.expected, self.decision, self.reason), end='')
142 print('| {}'.format(self.result), end='')
144 def json_dump(self, with_results):
145 dump = [self.name, self.type, self.expected, self.decision, self.reason]
147 dump.append(self.result)
151 class KconfigCheck(OptCheck):
152 def __init__(self, *args, **kwargs):
153 super().__init__(*args, **kwargs)
154 self.name = 'CONFIG_' + self.name
161 class CmdlineCheck(OptCheck):
168 def __init__(self, ver_expected):
169 assert(ver_expected and isinstance(ver_expected, tuple) and len(ver_expected) == 2), \
170 'invalid version "{}" for VersionCheck'.format(ver_expected)
171 self.ver_expected = ver_expected
180 if self.ver[0] > self.ver_expected[0]:
181 self.result = 'OK: version >= ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
183 if self.ver[0] < self.ver_expected[0]:
184 self.result = 'FAIL: version < ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
186 if self.ver[1] >= self.ver_expected[1]:
187 self.result = 'OK: version >= ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
189 self.result = 'FAIL: version < ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
191 def table_print(self, _mode, with_results):
192 ver_req = 'kernel version >= ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
193 print('{:<91}'.format(ver_req), end='')
195 print('| {}'.format(self.result), end='')
198 class ComplexOptCheck:
199 def __init__(self, *opts):
202 'empty {} check'.format(self.__class__.__name__)
203 assert(len(self.opts) != 1), \
204 'useless {} check: {}'.format(self.__class__.__name__, opts)
205 assert(isinstance(opts[0], (KconfigCheck, CmdlineCheck))), \
206 'invalid {} check: {}'.format(self.__class__.__name__, opts)
215 return self.opts[0].name
219 return self.opts[0].expected
221 def table_print(self, mode, with_results):
222 if mode == 'verbose':
223 print(' {:87}'.format('<<< ' + self.__class__.__name__ + ' >>>'), end='')
225 print('| {}'.format(self.result), end='')
228 o.table_print(mode, with_results)
231 o.table_print(mode, False)
233 print('| {}'.format(self.result), end='')
235 def json_dump(self, with_results):
236 dump = self.opts[0].json_dump(False)
238 dump.append(self.result)
242 class OR(ComplexOptCheck):
243 # self.opts[0] is the option that this OR-check is about.
245 # OR(<X_is_hardened>, <X_is_disabled>)
246 # OR(<X_is_hardened>, <old_X_is_hardened>)
248 for i, opt in enumerate(self.opts):
250 if opt.result.startswith('OK'):
251 self.result = opt.result
252 # Add more info for additional checks:
254 if opt.result == 'OK':
255 self.result = 'OK: {} is "{}"'.format(opt.name, opt.expected)
256 elif opt.result == 'OK: is not found':
257 self.result = 'OK: {} is not found'.format(opt.name)
258 elif opt.result == 'OK: is present':
259 self.result = 'OK: {} is present'.format(opt.name)
260 elif opt.result.startswith('OK: is not off'):
261 self.result = 'OK: {} is not off'.format(opt.name)
263 # VersionCheck provides enough info
264 assert(opt.result.startswith('OK: version')), \
265 'unexpected OK description "{}"'.format(opt.result)
267 self.result = self.opts[0].result
270 class AND(ComplexOptCheck):
271 # self.opts[0] is the option that this AND-check is about.
273 # AND(<suboption>, <main_option>)
274 # Suboption is not checked if checking of the main_option is failed.
275 # AND(<X_is_disabled>, <old_X_is_disabled>)
277 for i, opt in reversed(list(enumerate(self.opts))):
280 self.result = opt.result
282 if not opt.result.startswith('OK'):
283 # This FAIL is caused by additional checks,
284 # and not by the main option that this AND-check is about.
285 # Describe the reason of the FAIL.
286 if opt.result.startswith('FAIL: \"') or opt.result == 'FAIL: is not found':
287 self.result = 'FAIL: {} is not "{}"'.format(opt.name, opt.expected)
288 elif opt.result == 'FAIL: is not present':
289 self.result = 'FAIL: {} is not present'.format(opt.name)
290 elif opt.result == 'FAIL: is off':
291 self.result = 'FAIL: {} is off'.format(opt.name)
292 elif opt.result == 'FAIL: is off, not found':
293 self.result = 'FAIL: {} is off, not found'.format(opt.name)
295 # VersionCheck provides enough info
296 self.result = opt.result
297 assert(opt.result.startswith('FAIL: version')), \
298 'unexpected FAIL description "{}"'.format(opt.result)
302 def detect_arch(fname, archs):
303 with open(fname, 'r') as f:
304 arch_pattern = re.compile("CONFIG_[a-zA-Z0-9_]*=y")
306 for line in f.readlines():
307 if arch_pattern.match(line):
308 option, _ = line[7:].split('=', 1)
313 return None, 'more than one supported architecture is detected'
315 return None, 'failed to detect architecture'
319 def detect_kernel_version(fname):
320 with open(fname, 'r') as f:
321 ver_pattern = re.compile("# Linux/.* Kernel Configuration")
322 for line in f.readlines():
323 if ver_pattern.match(line):
327 ver_numbers = ver_str.split('.')
328 if len(ver_numbers) < 3 or not ver_numbers[0].isdigit() or not ver_numbers[1].isdigit():
329 msg = 'failed to parse the version "' + ver_str + '"'
331 return (int(ver_numbers[0]), int(ver_numbers[1])), None
332 return None, 'no kernel version detected'
335 def detect_compiler(fname):
338 with open(fname, 'r') as f:
339 gcc_version_pattern = re.compile("CONFIG_GCC_VERSION=[0-9]*")
340 clang_version_pattern = re.compile("CONFIG_CLANG_VERSION=[0-9]*")
341 for line in f.readlines():
342 if gcc_version_pattern.match(line):
343 gcc_version = line[19:-1]
344 if clang_version_pattern.match(line):
345 clang_version = line[21:-1]
346 if not gcc_version or not clang_version:
347 return None, 'no CONFIG_GCC_VERSION or CONFIG_CLANG_VERSION'
348 if gcc_version == '0' and clang_version != '0':
349 return 'CLANG ' + clang_version, 'OK'
350 if gcc_version != '0' and clang_version == '0':
351 return 'GCC ' + gcc_version, 'OK'
352 sys.exit('[!] ERROR: invalid GCC_VERSION and CLANG_VERSION: {} {}'.format(gcc_version, clang_version))
355 def add_kconfig_checks(l, arch):
356 # Calling the KconfigCheck class constructor:
357 # KconfigCheck(reason, decision, name, expected)
359 # [!] Don't add CmdlineChecks in add_kconfig_checks() to avoid wrong results
360 # when the tool doesn't check the cmdline.
362 efi_not_set = KconfigCheck('-', '-', 'EFI', 'is not set')
363 cc_is_gcc = KconfigCheck('-', '-', 'CC_IS_GCC', 'y') # exists since v4.18
364 cc_is_clang = KconfigCheck('-', '-', 'CC_IS_CLANG', 'y') # exists since v4.18
366 modules_not_set = KconfigCheck('cut_attack_surface', 'kspp', 'MODULES', 'is not set')
367 devmem_not_set = KconfigCheck('cut_attack_surface', 'kspp', 'DEVMEM', 'is not set') # refers to LOCKDOWN
368 bpf_syscall_not_set = KconfigCheck('cut_attack_surface', 'lockdown', 'BPF_SYSCALL', 'is not set') # refers to LOCKDOWN
370 # 'self_protection', 'defconfig'
371 l += [KconfigCheck('self_protection', 'defconfig', 'BUG', 'y')]
372 l += [KconfigCheck('self_protection', 'defconfig', 'SLUB_DEBUG', 'y')]
373 gcc_plugins_support_is_set = KconfigCheck('self_protection', 'defconfig', 'GCC_PLUGINS', 'y')
374 l += [gcc_plugins_support_is_set]
375 l += [OR(KconfigCheck('self_protection', 'defconfig', 'STACKPROTECTOR', 'y'),
376 KconfigCheck('self_protection', 'defconfig', 'CC_STACKPROTECTOR', 'y'),
377 KconfigCheck('self_protection', 'defconfig', 'CC_STACKPROTECTOR_REGULAR', 'y'),
378 KconfigCheck('self_protection', 'defconfig', 'CC_STACKPROTECTOR_AUTO', 'y'),
379 KconfigCheck('self_protection', 'defconfig', 'CC_STACKPROTECTOR_STRONG', 'y'))]
380 l += [OR(KconfigCheck('self_protection', 'defconfig', 'STACKPROTECTOR_STRONG', 'y'),
381 KconfigCheck('self_protection', 'defconfig', 'CC_STACKPROTECTOR_STRONG', 'y'))]
382 l += [OR(KconfigCheck('self_protection', 'defconfig', 'STRICT_KERNEL_RWX', 'y'),
383 KconfigCheck('self_protection', 'defconfig', 'DEBUG_RODATA', 'y'))] # before v4.11
384 l += [OR(KconfigCheck('self_protection', 'defconfig', 'STRICT_MODULE_RWX', 'y'),
385 KconfigCheck('self_protection', 'defconfig', 'DEBUG_SET_MODULE_RONX', 'y'),
386 modules_not_set)] # DEBUG_SET_MODULE_RONX was before v4.11
387 l += [OR(KconfigCheck('self_protection', 'defconfig', 'REFCOUNT_FULL', 'y'),
388 VersionCheck((5, 5)))] # REFCOUNT_FULL is enabled by default since v5.5
389 l += [KconfigCheck('self_protection', 'defconfig', 'THREAD_INFO_IN_TASK', 'y')]
390 iommu_support_is_set = KconfigCheck('self_protection', 'defconfig', 'IOMMU_SUPPORT', 'y')
391 l += [iommu_support_is_set] # is needed for mitigating DMA attacks
392 if arch in ('X86_64', 'ARM64', 'X86_32'):
393 l += [KconfigCheck('self_protection', 'defconfig', 'RANDOMIZE_BASE', 'y')]
394 if arch in ('X86_64', 'ARM64'):
395 l += [KconfigCheck('self_protection', 'defconfig', 'VMAP_STACK', 'y')]
396 if arch in ('X86_64', 'X86_32'):
397 l += [KconfigCheck('self_protection', 'defconfig', 'X86_MCE', 'y')]
398 l += [KconfigCheck('self_protection', 'defconfig', 'X86_MCE_INTEL', 'y')]
399 l += [KconfigCheck('self_protection', 'defconfig', 'X86_MCE_AMD', 'y')]
400 l += [KconfigCheck('self_protection', 'defconfig', 'MICROCODE', 'y')] # is needed for mitigating CPU bugs
401 l += [KconfigCheck('self_protection', 'defconfig', 'RETPOLINE', 'y')]
402 l += [OR(KconfigCheck('self_protection', 'defconfig', 'X86_SMAP', 'y'),
403 VersionCheck((5, 19)))] # X86_SMAP is enabled by default since v5.19
404 l += [KconfigCheck('self_protection', 'defconfig', 'SYN_COOKIES', 'y')] # another reason?
405 l += [OR(KconfigCheck('self_protection', 'defconfig', 'X86_UMIP', 'y'),
406 KconfigCheck('self_protection', 'defconfig', 'X86_INTEL_UMIP', 'y'))]
407 if arch in ('ARM64', 'ARM'):
408 l += [KconfigCheck('self_protection', 'defconfig', 'STACKPROTECTOR_PER_TASK', 'y')]
410 l += [KconfigCheck('self_protection', 'defconfig', 'PAGE_TABLE_ISOLATION', 'y')]
411 l += [KconfigCheck('self_protection', 'defconfig', 'RANDOMIZE_MEMORY', 'y')]
412 l += [AND(KconfigCheck('self_protection', 'defconfig', 'INTEL_IOMMU', 'y'),
413 iommu_support_is_set)]
414 l += [AND(KconfigCheck('self_protection', 'defconfig', 'AMD_IOMMU', 'y'),
415 iommu_support_is_set)]
417 l += [KconfigCheck('self_protection', 'defconfig', 'ARM64_PAN', 'y')]
418 l += [KconfigCheck('self_protection', 'defconfig', 'ARM64_EPAN', 'y')]
419 l += [KconfigCheck('self_protection', 'defconfig', 'UNMAP_KERNEL_AT_EL0', 'y')]
420 l += [KconfigCheck('self_protection', 'defconfig', 'ARM64_E0PD', 'y')]
421 l += [OR(KconfigCheck('self_protection', 'defconfig', 'HARDEN_EL2_VECTORS', 'y'),
422 AND(KconfigCheck('self_protection', 'defconfig', 'RANDOMIZE_BASE', 'y'),
423 VersionCheck((5, 9))))] # HARDEN_EL2_VECTORS was included in RANDOMIZE_BASE in v5.9
424 l += [KconfigCheck('self_protection', 'defconfig', 'RODATA_FULL_DEFAULT_ENABLED', 'y')]
425 l += [KconfigCheck('self_protection', 'defconfig', 'ARM64_PTR_AUTH_KERNEL', 'y')]
426 l += [KconfigCheck('self_protection', 'defconfig', 'ARM64_BTI_KERNEL', 'y')]
427 l += [OR(KconfigCheck('self_protection', 'defconfig', 'HARDEN_BRANCH_PREDICTOR', 'y'),
428 VersionCheck((5, 10)))] # HARDEN_BRANCH_PREDICTOR is enabled by default since v5.10
429 l += [KconfigCheck('self_protection', 'defconfig', 'MITIGATE_SPECTRE_BRANCH_HISTORY', 'y')]
430 l += [KconfigCheck('self_protection', 'defconfig', 'ARM64_MTE', 'y')]
431 l += [KconfigCheck('self_protection', 'defconfig', 'RANDOMIZE_MODULE_REGION_FULL', 'y')]
433 l += [KconfigCheck('self_protection', 'defconfig', 'CPU_SW_DOMAIN_PAN', 'y')]
434 l += [KconfigCheck('self_protection', 'defconfig', 'HARDEN_BRANCH_PREDICTOR', 'y')]
435 l += [KconfigCheck('self_protection', 'defconfig', 'HARDEN_BRANCH_HISTORY', 'y')]
437 # 'self_protection', 'kspp'
438 l += [KconfigCheck('self_protection', 'kspp', 'BUG_ON_DATA_CORRUPTION', 'y')]
439 l += [KconfigCheck('self_protection', 'kspp', 'DEBUG_WX', 'y')]
440 l += [KconfigCheck('self_protection', 'kspp', 'SCHED_STACK_END_CHECK', 'y')]
441 l += [KconfigCheck('self_protection', 'kspp', 'SLAB_FREELIST_HARDENED', 'y')]
442 l += [KconfigCheck('self_protection', 'kspp', 'SLAB_FREELIST_RANDOM', 'y')]
443 l += [KconfigCheck('self_protection', 'kspp', 'SHUFFLE_PAGE_ALLOCATOR', 'y')]
444 l += [KconfigCheck('self_protection', 'kspp', 'FORTIFY_SOURCE', 'y')]
445 l += [KconfigCheck('self_protection', 'kspp', 'DEBUG_LIST', 'y')]
446 l += [KconfigCheck('self_protection', 'kspp', 'DEBUG_VIRTUAL', 'y')]
447 l += [KconfigCheck('self_protection', 'kspp', 'DEBUG_SG', 'y')]
448 l += [KconfigCheck('self_protection', 'kspp', 'DEBUG_CREDENTIALS', 'y')]
449 l += [KconfigCheck('self_protection', 'kspp', 'DEBUG_NOTIFIERS', 'y')]
450 l += [KconfigCheck('self_protection', 'kspp', 'INIT_ON_ALLOC_DEFAULT_ON', 'y')]
451 l += [AND(KconfigCheck('self_protection', 'kspp', 'GCC_PLUGIN_LATENT_ENTROPY', 'y'),
452 gcc_plugins_support_is_set)]
453 l += [KconfigCheck('self_protection', 'kspp', 'KFENCE', 'y')]
454 l += [KconfigCheck('self_protection', 'kspp', 'WERROR', 'y')]
455 l += [KconfigCheck('self_protection', 'kspp', 'IOMMU_DEFAULT_DMA_STRICT', 'y')]
456 l += [KconfigCheck('self_protection', 'kspp', 'IOMMU_DEFAULT_PASSTHROUGH', 'is not set')] # true if IOMMU_DEFAULT_DMA_STRICT is set
457 l += [KconfigCheck('self_protection', 'kspp', 'ZERO_CALL_USED_REGS', 'y')]
458 l += [KconfigCheck('self_protection', 'kspp', 'HW_RANDOM_TPM', 'y')]
459 l += [KconfigCheck('self_protection', 'kspp', 'STATIC_USERMODEHELPER', 'y')] # needs userspace support
460 l += [KconfigCheck('self_protection', 'kspp', 'SCHED_CORE', 'y')]
461 randstruct_is_set = OR(KconfigCheck('self_protection', 'kspp', 'RANDSTRUCT_FULL', 'y'),
462 KconfigCheck('self_protection', 'kspp', 'GCC_PLUGIN_RANDSTRUCT', 'y'))
463 l += [randstruct_is_set]
464 l += [AND(KconfigCheck('self_protection', 'kspp', 'RANDSTRUCT_PERFORMANCE', 'is not set'),
465 KconfigCheck('self_protection', 'kspp', 'GCC_PLUGIN_RANDSTRUCT_PERFORMANCE', 'is not set'),
467 hardened_usercopy_is_set = KconfigCheck('self_protection', 'kspp', 'HARDENED_USERCOPY', 'y')
468 l += [hardened_usercopy_is_set]
469 l += [AND(KconfigCheck('self_protection', 'kspp', 'HARDENED_USERCOPY_FALLBACK', 'is not set'),
470 hardened_usercopy_is_set)]
471 l += [AND(KconfigCheck('self_protection', 'kspp', 'HARDENED_USERCOPY_PAGESPAN', 'is not set'),
472 hardened_usercopy_is_set)]
473 l += [OR(KconfigCheck('self_protection', 'kspp', 'MODULE_SIG', 'y'),
475 l += [OR(KconfigCheck('self_protection', 'kspp', 'MODULE_SIG_ALL', 'y'),
477 l += [OR(KconfigCheck('self_protection', 'kspp', 'MODULE_SIG_SHA512', 'y'),
479 l += [OR(KconfigCheck('self_protection', 'kspp', 'MODULE_SIG_FORCE', 'y'),
480 modules_not_set)] # refers to LOCKDOWN
481 l += [OR(KconfigCheck('self_protection', 'kspp', 'INIT_STACK_ALL_ZERO', 'y'),
482 KconfigCheck('self_protection', 'kspp', 'GCC_PLUGIN_STRUCTLEAK_BYREF_ALL', 'y'))]
483 l += [OR(KconfigCheck('self_protection', 'kspp', 'INIT_ON_FREE_DEFAULT_ON', 'y'),
484 KconfigCheck('self_protection', 'kspp', 'PAGE_POISONING_ZERO', 'y'))]
485 # CONFIG_INIT_ON_FREE_DEFAULT_ON was added in v5.3.
486 # CONFIG_PAGE_POISONING_ZERO was removed in v5.11.
487 # Starting from v5.11 CONFIG_PAGE_POISONING unconditionally checks
488 # the 0xAA poison pattern on allocation.
489 # That brings higher performance penalty.
490 l += [OR(KconfigCheck('self_protection', 'kspp', 'EFI_DISABLE_PCI_DMA', 'y'),
492 l += [OR(KconfigCheck('self_protection', 'kspp', 'RESET_ATTACK_MITIGATION', 'y'),
493 efi_not_set)] # needs userspace support (systemd)
494 ubsan_bounds_is_set = KconfigCheck('self_protection', 'kspp', 'UBSAN_BOUNDS', 'y')
495 l += [ubsan_bounds_is_set]
496 l += [OR(KconfigCheck('self_protection', 'kspp', 'UBSAN_LOCAL_BOUNDS', 'y'),
497 AND(ubsan_bounds_is_set,
499 l += [AND(KconfigCheck('self_protection', 'kspp', 'UBSAN_TRAP', 'y'),
501 KconfigCheck('self_protection', 'kspp', 'UBSAN_SHIFT', 'is not set'),
502 KconfigCheck('self_protection', 'kspp', 'UBSAN_DIV_ZERO', 'is not set'),
503 KconfigCheck('self_protection', 'kspp', 'UBSAN_UNREACHABLE', 'is not set'),
504 KconfigCheck('self_protection', 'kspp', 'UBSAN_BOOL', 'is not set'),
505 KconfigCheck('self_protection', 'kspp', 'UBSAN_ENUM', 'is not set'),
506 KconfigCheck('self_protection', 'kspp', 'UBSAN_ALIGNMENT', 'is not set'))] # only array index bounds checking with traps
507 if arch in ('X86_64', 'ARM64', 'X86_32'):
508 l += [AND(KconfigCheck('self_protection', 'kspp', 'UBSAN_SANITIZE_ALL', 'y'),
509 ubsan_bounds_is_set)] # ARCH_HAS_UBSAN_SANITIZE_ALL is not enabled for ARM
510 stackleak_is_set = KconfigCheck('self_protection', 'kspp', 'GCC_PLUGIN_STACKLEAK', 'y')
511 l += [AND(stackleak_is_set, gcc_plugins_support_is_set)]
512 l += [AND(KconfigCheck('self_protection', 'kspp', 'STACKLEAK_METRICS', 'is not set'),
514 gcc_plugins_support_is_set)]
515 l += [AND(KconfigCheck('self_protection', 'kspp', 'STACKLEAK_RUNTIME_DISABLE', 'is not set'),
517 gcc_plugins_support_is_set)]
518 l += [KconfigCheck('self_protection', 'kspp', 'RANDOMIZE_KSTACK_OFFSET_DEFAULT', 'y')]
519 if arch in ('X86_64', 'ARM64'):
520 cfi_clang_is_set = KconfigCheck('self_protection', 'kspp', 'CFI_CLANG', 'y')
521 l += [cfi_clang_is_set]
522 l += [AND(KconfigCheck('self_protection', 'kspp', 'CFI_PERMISSIVE', 'is not set'),
524 if arch in ('X86_64', 'X86_32'):
525 l += [KconfigCheck('self_protection', 'kspp', 'DEFAULT_MMAP_MIN_ADDR', '65536')]
526 l += [AND(KconfigCheck('self_protection', 'kspp', 'INTEL_IOMMU_DEFAULT_ON', 'y'),
527 iommu_support_is_set)]
528 if arch in ('ARM64', 'ARM'):
529 l += [KconfigCheck('self_protection', 'kspp', 'DEFAULT_MMAP_MIN_ADDR', '32768')]
530 l += [KconfigCheck('self_protection', 'kspp', 'SYN_COOKIES', 'y')] # another reason?
532 l += [KconfigCheck('self_protection', 'kspp', 'SLS', 'y')] # vs CVE-2021-26341 in Straight-Line-Speculation
533 l += [AND(KconfigCheck('self_protection', 'kspp', 'INTEL_IOMMU_SVM', 'y'),
534 iommu_support_is_set)]
535 l += [AND(KconfigCheck('self_protection', 'kspp', 'AMD_IOMMU_V2', 'y'),
536 iommu_support_is_set)]
538 l += [KconfigCheck('self_protection', 'kspp', 'ARM64_SW_TTBR0_PAN', 'y')]
539 l += [KconfigCheck('self_protection', 'kspp', 'SHADOW_CALL_STACK', 'y')]
540 l += [KconfigCheck('self_protection', 'kspp', 'KASAN_HW_TAGS', 'y')]
542 l += [KconfigCheck('self_protection', 'kspp', 'PAGE_TABLE_ISOLATION', 'y')]
543 l += [KconfigCheck('self_protection', 'kspp', 'HIGHMEM64G', 'y')]
544 l += [KconfigCheck('self_protection', 'kspp', 'X86_PAE', 'y')]
545 l += [AND(KconfigCheck('self_protection', 'kspp', 'INTEL_IOMMU', 'y'),
546 iommu_support_is_set)]
548 # 'self_protection', 'clipos'
549 l += [KconfigCheck('self_protection', 'clipos', 'SLAB_MERGE_DEFAULT', 'is not set')]
552 if arch in ('X86_64', 'ARM64', 'X86_32'):
553 l += [KconfigCheck('security_policy', 'defconfig', 'SECURITY', 'y')] # and choose your favourite LSM
555 l += [KconfigCheck('security_policy', 'kspp', 'SECURITY', 'y')] # and choose your favourite LSM
556 l += [KconfigCheck('security_policy', 'kspp', 'SECURITY_YAMA', 'y')]
557 l += [KconfigCheck('security_policy', 'kspp', 'SECURITY_LANDLOCK', 'y')]
558 l += [KconfigCheck('security_policy', 'kspp', 'SECURITY_SELINUX_DISABLE', 'is not set')]
559 l += [KconfigCheck('security_policy', 'kspp', 'SECURITY_SELINUX_BOOTPARAM', 'is not set')]
560 l += [KconfigCheck('security_policy', 'kspp', 'SECURITY_SELINUX_DEVELOP', 'is not set')]
561 l += [KconfigCheck('security_policy', 'kspp', 'SECURITY_LOCKDOWN_LSM', 'y')]
562 l += [KconfigCheck('security_policy', 'kspp', 'SECURITY_LOCKDOWN_LSM_EARLY', 'y')]
563 l += [KconfigCheck('security_policy', 'kspp', 'LOCK_DOWN_KERNEL_FORCE_CONFIDENTIALITY', 'y')]
564 l += [KconfigCheck('security_policy', 'kspp', 'SECURITY_WRITABLE_HOOKS', 'is not set')] # refers to SECURITY_SELINUX_DISABLE
566 # 'cut_attack_surface', 'defconfig'
567 l += [OR(KconfigCheck('cut_attack_surface', 'defconfig', 'BPF_UNPRIV_DEFAULT_OFF', 'y'),
568 bpf_syscall_not_set)] # see unprivileged_bpf_disabled
569 l += [KconfigCheck('cut_attack_surface', 'defconfig', 'SECCOMP', 'y')]
570 l += [KconfigCheck('cut_attack_surface', 'defconfig', 'SECCOMP_FILTER', 'y')]
571 if arch in ('X86_64', 'ARM64', 'X86_32'):
572 l += [OR(KconfigCheck('cut_attack_surface', 'defconfig', 'STRICT_DEVMEM', 'y'),
573 devmem_not_set)] # refers to LOCKDOWN
575 # 'cut_attack_surface', 'kspp'
576 l += [KconfigCheck('cut_attack_surface', 'kspp', 'SECURITY_DMESG_RESTRICT', 'y')]
577 l += [KconfigCheck('cut_attack_surface', 'kspp', 'ACPI_CUSTOM_METHOD', 'is not set')] # refers to LOCKDOWN
578 l += [KconfigCheck('cut_attack_surface', 'kspp', 'COMPAT_BRK', 'is not set')]
579 l += [KconfigCheck('cut_attack_surface', 'kspp', 'DEVKMEM', 'is not set')] # refers to LOCKDOWN
580 l += [KconfigCheck('cut_attack_surface', 'kspp', 'COMPAT_VDSO', 'is not set')]
581 l += [KconfigCheck('cut_attack_surface', 'kspp', 'BINFMT_MISC', 'is not set')]
582 l += [KconfigCheck('cut_attack_surface', 'kspp', 'INET_DIAG', 'is not set')]
583 l += [KconfigCheck('cut_attack_surface', 'kspp', 'KEXEC', 'is not set')] # refers to LOCKDOWN
584 l += [KconfigCheck('cut_attack_surface', 'kspp', 'PROC_KCORE', 'is not set')] # refers to LOCKDOWN
585 l += [KconfigCheck('cut_attack_surface', 'kspp', 'LEGACY_PTYS', 'is not set')]
586 l += [KconfigCheck('cut_attack_surface', 'kspp', 'HIBERNATION', 'is not set')] # refers to LOCKDOWN
587 l += [KconfigCheck('cut_attack_surface', 'kspp', 'IA32_EMULATION', 'is not set')]
588 l += [KconfigCheck('cut_attack_surface', 'kspp', 'X86_X32', 'is not set')]
589 l += [KconfigCheck('cut_attack_surface', 'kspp', 'MODIFY_LDT_SYSCALL', 'is not set')]
590 l += [KconfigCheck('cut_attack_surface', 'kspp', 'OABI_COMPAT', 'is not set')]
591 l += [KconfigCheck('cut_attack_surface', 'kspp', 'X86_MSR', 'is not set')] # refers to LOCKDOWN
592 l += [modules_not_set]
593 l += [devmem_not_set]
594 l += [OR(KconfigCheck('cut_attack_surface', 'kspp', 'IO_STRICT_DEVMEM', 'y'),
595 devmem_not_set)] # refers to LOCKDOWN
596 l += [AND(KconfigCheck('cut_attack_surface', 'kspp', 'LDISC_AUTOLOAD', 'is not set'),
597 KconfigCheck('cut_attack_surface', 'kspp', 'LDISC_AUTOLOAD', 'is present'))]
599 l += [OR(KconfigCheck('cut_attack_surface', 'kspp', 'STRICT_DEVMEM', 'y'),
600 devmem_not_set)] # refers to LOCKDOWN
602 l += [KconfigCheck('cut_attack_surface', 'kspp', 'LEGACY_VSYSCALL_NONE', 'y')] # 'vsyscall=none'
604 # 'cut_attack_surface', 'grsec'
605 l += [KconfigCheck('cut_attack_surface', 'grsec', 'ZSMALLOC_STAT', 'is not set')]
606 l += [KconfigCheck('cut_attack_surface', 'grsec', 'PAGE_OWNER', 'is not set')]
607 l += [KconfigCheck('cut_attack_surface', 'grsec', 'DEBUG_KMEMLEAK', 'is not set')]
608 l += [KconfigCheck('cut_attack_surface', 'grsec', 'BINFMT_AOUT', 'is not set')]
609 l += [KconfigCheck('cut_attack_surface', 'grsec', 'KPROBE_EVENTS', 'is not set')]
610 l += [KconfigCheck('cut_attack_surface', 'grsec', 'UPROBE_EVENTS', 'is not set')]
611 l += [KconfigCheck('cut_attack_surface', 'grsec', 'GENERIC_TRACER', 'is not set')] # refers to LOCKDOWN
612 l += [KconfigCheck('cut_attack_surface', 'grsec', 'FUNCTION_TRACER', 'is not set')]
613 l += [KconfigCheck('cut_attack_surface', 'grsec', 'STACK_TRACER', 'is not set')]
614 l += [KconfigCheck('cut_attack_surface', 'grsec', 'HIST_TRIGGERS', 'is not set')]
615 l += [KconfigCheck('cut_attack_surface', 'grsec', 'BLK_DEV_IO_TRACE', 'is not set')]
616 l += [KconfigCheck('cut_attack_surface', 'grsec', 'PROC_VMCORE', 'is not set')]
617 l += [KconfigCheck('cut_attack_surface', 'grsec', 'PROC_PAGE_MONITOR', 'is not set')]
618 l += [KconfigCheck('cut_attack_surface', 'grsec', 'USELIB', 'is not set')]
619 l += [KconfigCheck('cut_attack_surface', 'grsec', 'CHECKPOINT_RESTORE', 'is not set')]
620 l += [KconfigCheck('cut_attack_surface', 'grsec', 'USERFAULTFD', 'is not set')]
621 l += [KconfigCheck('cut_attack_surface', 'grsec', 'HWPOISON_INJECT', 'is not set')]
622 l += [KconfigCheck('cut_attack_surface', 'grsec', 'MEM_SOFT_DIRTY', 'is not set')]
623 l += [KconfigCheck('cut_attack_surface', 'grsec', 'DEVPORT', 'is not set')] # refers to LOCKDOWN
624 l += [KconfigCheck('cut_attack_surface', 'grsec', 'DEBUG_FS', 'is not set')] # refers to LOCKDOWN
625 l += [KconfigCheck('cut_attack_surface', 'grsec', 'NOTIFIER_ERROR_INJECTION', 'is not set')]
626 l += [KconfigCheck('cut_attack_surface', 'grsec', 'FAIL_FUTEX', 'is not set')]
627 l += [KconfigCheck('cut_attack_surface', 'grsec', 'PUNIT_ATOM_DEBUG', 'is not set')]
628 l += [KconfigCheck('cut_attack_surface', 'grsec', 'ACPI_CONFIGFS', 'is not set')]
629 l += [KconfigCheck('cut_attack_surface', 'grsec', 'EDAC_DEBUG', 'is not set')]
630 l += [KconfigCheck('cut_attack_surface', 'grsec', 'DRM_I915_DEBUG', 'is not set')]
631 l += [KconfigCheck('cut_attack_surface', 'grsec', 'BCACHE_CLOSURES_DEBUG', 'is not set')]
632 l += [KconfigCheck('cut_attack_surface', 'grsec', 'DVB_C8SECTPFE', 'is not set')]
633 l += [KconfigCheck('cut_attack_surface', 'grsec', 'MTD_SLRAM', 'is not set')]
634 l += [KconfigCheck('cut_attack_surface', 'grsec', 'MTD_PHRAM', 'is not set')]
635 l += [KconfigCheck('cut_attack_surface', 'grsec', 'IO_URING', 'is not set')]
636 l += [KconfigCheck('cut_attack_surface', 'grsec', 'KCMP', 'is not set')]
637 l += [KconfigCheck('cut_attack_surface', 'grsec', 'RSEQ', 'is not set')]
638 l += [KconfigCheck('cut_attack_surface', 'grsec', 'LATENCYTOP', 'is not set')]
639 l += [KconfigCheck('cut_attack_surface', 'grsec', 'KCOV', 'is not set')]
640 l += [KconfigCheck('cut_attack_surface', 'grsec', 'PROVIDE_OHCI1394_DMA_INIT', 'is not set')]
641 l += [KconfigCheck('cut_attack_surface', 'grsec', 'SUNRPC_DEBUG', 'is not set')]
642 l += [AND(KconfigCheck('cut_attack_surface', 'grsec', 'PTDUMP_DEBUGFS', 'is not set'),
643 KconfigCheck('cut_attack_surface', 'grsec', 'X86_PTDUMP', 'is not set'))]
645 # 'cut_attack_surface', 'maintainer'
646 l += [KconfigCheck('cut_attack_surface', 'maintainer', 'DRM_LEGACY', 'is not set')] # recommended by Daniel Vetter in /issues/38
647 l += [KconfigCheck('cut_attack_surface', 'maintainer', 'FB', 'is not set')] # recommended by Daniel Vetter in /issues/38
648 l += [KconfigCheck('cut_attack_surface', 'maintainer', 'VT', 'is not set')] # recommended by Daniel Vetter in /issues/38
649 l += [KconfigCheck('cut_attack_surface', 'maintainer', 'BLK_DEV_FD', 'is not set')] # recommended by Denis Efremov in /pull/54
650 l += [KconfigCheck('cut_attack_surface', 'maintainer', 'BLK_DEV_FD_RAWCMD', 'is not set')] # recommended by Denis Efremov in /pull/62
652 # 'cut_attack_surface', 'grapheneos'
653 l += [KconfigCheck('cut_attack_surface', 'grapheneos', 'AIO', 'is not set')]
655 # 'cut_attack_surface', 'clipos'
656 l += [KconfigCheck('cut_attack_surface', 'clipos', 'STAGING', 'is not set')]
657 l += [KconfigCheck('cut_attack_surface', 'clipos', 'KSM', 'is not set')] # to prevent FLUSH+RELOAD attack
658 # l += [KconfigCheck('cut_attack_surface', 'clipos', 'IKCONFIG', 'is not set')] # no, IKCONFIG is needed for this check :)
659 l += [KconfigCheck('cut_attack_surface', 'clipos', 'KALLSYMS', 'is not set')]
660 l += [KconfigCheck('cut_attack_surface', 'clipos', 'X86_VSYSCALL_EMULATION', 'is not set')]
661 l += [KconfigCheck('cut_attack_surface', 'clipos', 'MAGIC_SYSRQ', 'is not set')]
662 l += [KconfigCheck('cut_attack_surface', 'clipos', 'KEXEC_FILE', 'is not set')] # refers to LOCKDOWN (permissive)
663 l += [KconfigCheck('cut_attack_surface', 'clipos', 'USER_NS', 'is not set')] # user.max_user_namespaces=0
664 l += [KconfigCheck('cut_attack_surface', 'clipos', 'X86_CPUID', 'is not set')]
665 l += [KconfigCheck('cut_attack_surface', 'clipos', 'X86_IOPL_IOPERM', 'is not set')] # refers to LOCKDOWN
666 l += [KconfigCheck('cut_attack_surface', 'clipos', 'ACPI_TABLE_UPGRADE', 'is not set')] # refers to LOCKDOWN
667 l += [KconfigCheck('cut_attack_surface', 'clipos', 'EFI_CUSTOM_SSDT_OVERLAYS', 'is not set')]
668 l += [KconfigCheck('cut_attack_surface', 'clipos', 'COREDUMP', 'is not set')] # cut userspace attack surface
669 if arch in ('X86_64', 'X86_32'):
670 l += [KconfigCheck('cut_attack_surface', 'clipos', 'X86_INTEL_TSX_MODE_OFF', 'y')] # tsx=off
672 # 'cut_attack_surface', 'lockdown'
673 l += [bpf_syscall_not_set] # refers to LOCKDOWN
674 l += [KconfigCheck('cut_attack_surface', 'lockdown', 'EFI_TEST', 'is not set')] # refers to LOCKDOWN
675 l += [KconfigCheck('cut_attack_surface', 'lockdown', 'MMIOTRACE_TEST', 'is not set')] # refers to LOCKDOWN
676 l += [KconfigCheck('cut_attack_surface', 'lockdown', 'KPROBES', 'is not set')] # refers to LOCKDOWN
678 # 'cut_attack_surface', 'my'
679 l += [OR(KconfigCheck('cut_attack_surface', 'my', 'TRIM_UNUSED_KSYMS', 'y'),
681 l += [KconfigCheck('cut_attack_surface', 'my', 'MMIOTRACE', 'is not set')] # refers to LOCKDOWN (permissive)
682 l += [KconfigCheck('cut_attack_surface', 'my', 'LIVEPATCH', 'is not set')]
683 l += [KconfigCheck('cut_attack_surface', 'my', 'IP_DCCP', 'is not set')]
684 l += [KconfigCheck('cut_attack_surface', 'my', 'IP_SCTP', 'is not set')]
685 l += [KconfigCheck('cut_attack_surface', 'my', 'FTRACE', 'is not set')] # refers to LOCKDOWN
686 l += [KconfigCheck('cut_attack_surface', 'my', 'VIDEO_VIVID', 'is not set')]
687 l += [KconfigCheck('cut_attack_surface', 'my', 'INPUT_EVBUG', 'is not set')] # Can be used as a keylogger
688 l += [KconfigCheck('cut_attack_surface', 'my', 'KGDB', 'is not set')]
691 if arch in ('X86_64', 'ARM64', 'X86_32'):
692 l += [KconfigCheck('harden_userspace', 'defconfig', 'INTEGRITY', 'y')]
694 l += [KconfigCheck('harden_userspace', 'my', 'INTEGRITY', 'y')]
696 l += [KconfigCheck('harden_userspace', 'defconfig', 'ARM64_PTR_AUTH', 'y')]
697 l += [KconfigCheck('harden_userspace', 'defconfig', 'ARM64_BTI', 'y')]
698 if arch in ('ARM', 'X86_32'):
699 l += [KconfigCheck('harden_userspace', 'defconfig', 'VMSPLIT_3G', 'y')]
700 if arch in ('X86_64', 'ARM64'):
701 l += [KconfigCheck('harden_userspace', 'clipos', 'ARCH_MMAP_RND_BITS', '32')]
702 if arch in ('X86_32', 'ARM'):
703 l += [KconfigCheck('harden_userspace', 'my', 'ARCH_MMAP_RND_BITS', '16')]
706 def add_cmdline_checks(l, arch):
707 # Calling the CmdlineCheck class constructor:
708 # CmdlineCheck(reason, decision, name, expected)
710 # [!] Don't add CmdlineChecks in add_kconfig_checks() to avoid wrong results
711 # when the tool doesn't check the cmdline.
713 # [!] Make sure that values of the options in CmdlineChecks need normalization.
714 # For more info see normalize_cmdline_options().
716 # A common pattern for checking the 'param_x' cmdline parameter
717 # that __overrides__ the 'PARAM_X_DEFAULT' kconfig option:
718 # l += [OR(CmdlineCheck(reason, decision, 'param_x', '1'),
719 # AND(KconfigCheck(reason, decision, 'PARAM_X_DEFAULT_ON', 'y'),
720 # CmdlineCheck(reason, decision, 'param_x, 'is not set')))]
722 # Here we don't check the kconfig options or minimal kernel version
723 # required for the cmdline parameters. That would make the checks
724 # very complex and not give a 100% guarantee anyway.
726 # 'self_protection', 'defconfig'
727 l += [CmdlineCheck('self_protection', 'defconfig', 'nosmep', 'is not set')]
728 l += [CmdlineCheck('self_protection', 'defconfig', 'nosmap', 'is not set')]
729 l += [CmdlineCheck('self_protection', 'defconfig', 'nokaslr', 'is not set')]
730 l += [CmdlineCheck('self_protection', 'defconfig', 'nopti', 'is not set')]
731 l += [CmdlineCheck('self_protection', 'defconfig', 'nospectre_v1', 'is not set')]
732 l += [CmdlineCheck('self_protection', 'defconfig', 'nospectre_v2', 'is not set')]
733 l += [CmdlineCheck('self_protection', 'defconfig', 'nospec_store_bypass_disable', 'is not set')]
734 l += [OR(CmdlineCheck('self_protection', 'defconfig', 'mitigations', 'is not off'),
735 CmdlineCheck('self_protection', 'defconfig', 'mitigations', 'is not set'))]
736 l += [OR(CmdlineCheck('self_protection', 'defconfig', 'spectre_v2', 'is not off'),
737 CmdlineCheck('self_protection', 'defconfig', 'spectre_v2', 'is not set'))]
738 l += [OR(CmdlineCheck('self_protection', 'defconfig', 'spectre_v2_user', 'is not off'),
739 CmdlineCheck('self_protection', 'defconfig', 'spectre_v2_user', 'is not set'))]
740 l += [OR(CmdlineCheck('self_protection', 'defconfig', 'spec_store_bypass_disable', 'is not off'),
741 CmdlineCheck('self_protection', 'defconfig', 'spec_store_bypass_disable', 'is not set'))]
742 l += [OR(CmdlineCheck('self_protection', 'defconfig', 'l1tf', 'is not off'),
743 CmdlineCheck('self_protection', 'defconfig', 'l1tf', 'is not set'))]
745 l += [OR(CmdlineCheck('self_protection', 'defconfig', 'rodata', 'full'),
746 AND(KconfigCheck('self_protection', 'defconfig', 'RODATA_FULL_DEFAULT_ENABLED', 'y'),
747 CmdlineCheck('self_protection', 'defconfig', 'rodata', 'is not set')))]
749 l += [OR(CmdlineCheck('self_protection', 'defconfig', 'rodata', '1'),
750 CmdlineCheck('self_protection', 'defconfig', 'rodata', 'is not set'))]
752 # 'self_protection', 'kspp'
753 l += [CmdlineCheck('self_protection', 'kspp', 'nosmt', 'is present')]
754 l += [OR(CmdlineCheck('self_protection', 'kspp', 'init_on_alloc', '1'),
755 AND(KconfigCheck('self_protection', 'kspp', 'INIT_ON_ALLOC_DEFAULT_ON', 'y'),
756 CmdlineCheck('self_protection', 'kspp', 'init_on_alloc', 'is not set')))]
757 l += [OR(CmdlineCheck('self_protection', 'kspp', 'init_on_free', '1'),
758 AND(KconfigCheck('self_protection', 'kspp', 'INIT_ON_FREE_DEFAULT_ON', 'y'),
759 CmdlineCheck('self_protection', 'kspp', 'init_on_free', 'is not set')),
760 AND(CmdlineCheck('self_protection', 'kspp', 'page_poison', '1'),
761 KconfigCheck('self_protection', 'kspp', 'PAGE_POISONING_ZERO', 'y'),
762 CmdlineCheck('self_protection', 'kspp', 'slub_debug', 'P')))]
763 l += [OR(CmdlineCheck('self_protection', 'kspp', 'slab_nomerge', 'is present'),
764 AND(KconfigCheck('self_protection', 'clipos', 'SLAB_MERGE_DEFAULT', 'is not set'),
765 CmdlineCheck('self_protection', 'kspp', 'slab_merge', 'is not set')))]
766 l += [OR(CmdlineCheck('self_protection', 'kspp', 'iommu.strict', '1'),
767 AND(KconfigCheck('self_protection', 'kspp', 'IOMMU_DEFAULT_DMA_STRICT', 'y'),
768 CmdlineCheck('self_protection', 'kspp', 'iommu.strict', 'is not set')))]
769 l += [OR(CmdlineCheck('self_protection', 'kspp', 'iommu.passthrough', '0'),
770 AND(KconfigCheck('self_protection', 'kspp', 'IOMMU_DEFAULT_PASSTHROUGH', 'is not set'),
771 CmdlineCheck('self_protection', 'kspp', 'iommu.passthrough', 'is not set')))]
772 # The cmdline checks compatible with the kconfig recommendations of the KSPP project...
773 l += [OR(CmdlineCheck('self_protection', 'kspp', 'hardened_usercopy', '1'),
774 AND(KconfigCheck('self_protection', 'kspp', 'HARDENED_USERCOPY', 'y'),
775 CmdlineCheck('self_protection', 'kspp', 'hardened_usercopy', 'is not set')))]
776 l += [OR(CmdlineCheck('self_protection', 'kspp', 'slab_common.usercopy_fallback', '0'),
777 AND(KconfigCheck('self_protection', 'kspp', 'HARDENED_USERCOPY_FALLBACK', 'is not set'),
778 CmdlineCheck('self_protection', 'kspp', 'slab_common.usercopy_fallback', 'is not set')))]
780 if arch in ('X86_64', 'ARM64', 'X86_32'):
781 l += [OR(CmdlineCheck('self_protection', 'kspp', 'randomize_kstack_offset', '1'),
782 AND(KconfigCheck('self_protection', 'kspp', 'RANDOMIZE_KSTACK_OFFSET_DEFAULT', 'y'),
783 CmdlineCheck('self_protection', 'kspp', 'randomize_kstack_offset', 'is not set')))]
784 if arch in ('X86_64', 'X86_32'):
785 l += [AND(CmdlineCheck('self_protection', 'kspp', 'pti', 'on'),
786 CmdlineCheck('self_protection', 'defconfig', 'nopti', 'is not set'))]
788 # 'self_protection', 'clipos'
789 l += [CmdlineCheck('self_protection', 'clipos', 'page_alloc.shuffle', '1')]
791 # 'cut_attack_surface', 'kspp'
793 l += [OR(CmdlineCheck('cut_attack_surface', 'kspp', 'vsyscall', 'none'),
794 AND(KconfigCheck('cut_attack_surface', 'kspp', 'LEGACY_VSYSCALL_NONE', 'y'),
795 CmdlineCheck('cut_attack_surface', 'kspp', 'vsyscall', 'is not set')))]
797 # 'cut_attack_surface', 'grsec'
798 # The cmdline checks compatible with the kconfig options disabled by grsecurity...
799 l += [OR(CmdlineCheck('cut_attack_surface', 'grsec', 'debugfs', 'off'),
800 KconfigCheck('cut_attack_surface', 'grsec', 'DEBUG_FS', 'is not set'))] # ... the end
803 def print_unknown_options(checklist, parsed_options):
807 if o1.type != 'complex':
808 known_options.append(o1.name)
811 if o2.type != 'complex':
812 if hasattr(o2, 'name'):
813 known_options.append(o2.name)
816 assert(o3.type != 'complex'), \
817 'unexpected ComplexOptCheck inside {}'.format(o2.name)
818 if hasattr(o3, 'name'):
819 known_options.append(o3.name)
821 for option, value in parsed_options.items():
822 if option not in known_options:
823 print('[?] No check for option {} ({})'.format(option, value))
826 def print_checklist(mode, checklist, with_results):
830 output.append(o.json_dump(with_results))
831 print(json.dumps(output))
838 print('=' * sep_line_len)
839 print('{:^40}|{:^7}|{:^12}|{:^10}|{:^18}'.format('option name', 'type', 'desired val', 'decision', 'reason'), end='')
841 print('| {}'.format('check result'), end='')
843 print('=' * sep_line_len)
846 for opt in checklist:
848 if mode == 'show_ok':
849 if not opt.result.startswith('OK'):
851 if mode == 'show_fail':
852 if not opt.result.startswith('FAIL'):
854 opt.table_print(mode, with_results)
856 if mode == 'verbose':
857 print('-' * sep_line_len)
862 fail_count = len(list(filter(lambda opt: opt.result.startswith('FAIL'), checklist)))
864 ok_count = len(list(filter(lambda opt: opt.result.startswith('OK'), checklist)))
866 if mode == 'show_ok':
867 fail_suppressed = ' (suppressed in output)'
868 if mode == 'show_fail':
869 ok_suppressed = ' (suppressed in output)'
871 print('[+] Config check is finished: \'OK\' - {}{} / \'FAIL\' - {}{}'.format(ok_count, ok_suppressed, fail_count, fail_suppressed))
874 def populate_simple_opt_with_data(opt, data, data_type):
875 assert(opt.type != 'complex'), \
876 'unexpected ComplexOptCheck "{}"'.format(opt.name)
877 assert(opt.type in SIMPLE_OPTION_TYPES), \
878 'invalid opt type "{}"'.format(opt.type)
879 assert(data_type in SIMPLE_OPTION_TYPES), \
880 'invalid data type "{}"'.format(data_type)
882 if data_type != opt.type:
885 if data_type in ('kconfig', 'cmdline'):
886 opt.state = data.get(opt.name, None)
888 assert(data_type == 'version'), \
889 'unexpected data type "{}"'.format(data_type)
893 def populate_opt_with_data(opt, data, data_type):
894 if opt.type == 'complex':
896 if o.type == 'complex':
897 # Recursion for nested ComplexOptCheck objects
898 populate_opt_with_data(o, data, data_type)
900 populate_simple_opt_with_data(o, data, data_type)
902 assert(opt.type in ('kconfig', 'cmdline')), \
903 'bad type "{}" for a simple check'.format(opt.type)
904 populate_simple_opt_with_data(opt, data, data_type)
907 def populate_with_data(checklist, data, data_type):
908 for opt in checklist:
909 populate_opt_with_data(opt, data, data_type)
912 def perform_checks(checklist):
913 for opt in checklist:
917 def parse_kconfig_file(parsed_options, fname):
918 with open(fname, 'r') as f:
919 opt_is_on = re.compile("CONFIG_[a-zA-Z0-9_]*=[a-zA-Z0-9_\"]*")
920 opt_is_off = re.compile("# CONFIG_[a-zA-Z0-9_]* is not set")
922 for line in f.readlines():
927 if opt_is_on.match(line):
928 option, value = line.split('=', 1)
929 if value == 'is not set':
930 sys.exit('[!] ERROR: bad enabled kconfig option "{}"'.format(line))
931 elif opt_is_off.match(line):
932 option, value = line[2:].split(' ', 1)
933 if value != 'is not set':
934 sys.exit('[!] ERROR: bad disabled kconfig option "{}"'.format(line))
936 if option in parsed_options:
937 sys.exit('[!] ERROR: kconfig option "{}" exists multiple times'.format(line))
940 parsed_options[option] = value
943 def normalize_cmdline_options(option, value):
944 # Don't normalize the cmdline option values if
945 # the Linux kernel doesn't use kstrtobool() for them
946 if option == 'debugfs':
947 # See debugfs_kernel() in fs/debugfs/inode.c
949 if option == 'mitigations':
950 # See mitigations_parse_cmdline() in kernel/cpu.c
953 # See pti_check_boottime_disable() in arch/x86/mm/pti.c
955 if option == 'spectre_v2':
956 # See spectre_v2_parse_cmdline() in arch/x86/kernel/cpu/bugs.c
958 if option == 'spectre_v2_user':
959 # See spectre_v2_parse_user_cmdline() in arch/x86/kernel/cpu/bugs.c
961 if option == 'spec_store_bypass_disable':
962 # See ssb_parse_cmdline() in arch/x86/kernel/cpu/bugs.c
965 # See l1tf_cmdline() in arch/x86/kernel/cpu/bugs.c
968 # Implement a limited part of the kstrtobool() logic
969 if value in ('1', 'on', 'On', 'ON', 'y', 'Y', 'yes', 'Yes', 'YES'):
971 if value in ('0', 'off', 'Off', 'OFF', 'n', 'N', 'no', 'No', 'NO'):
974 # Preserve unique values
978 def parse_cmdline_file(parsed_options, fname):
979 with open(fname, 'r') as f:
985 sys.exit('[!] ERROR: more than one line in "{}"'.format(fname))
989 name, value = opt.split('=', 1)
992 value = '' # '' is not None
993 value = normalize_cmdline_options(name, value)
994 parsed_options[name] = value
1000 # - reporting about unknown kernel options in the kconfig
1001 # - verbose printing of ComplexOptCheck items
1002 # * json mode for printing the results in JSON format
1003 report_modes = ['verbose', 'json', 'show_ok', 'show_fail']
1004 supported_archs = ['X86_64', 'X86_32', 'ARM64', 'ARM']
1005 parser = ArgumentParser(prog='kconfig-hardened-check',
1006 description='A tool for checking the security hardening options of the Linux kernel')
1007 parser.add_argument('--version', action='version', version='%(prog)s ' + __version__)
1008 parser.add_argument('-p', '--print', choices=supported_archs,
1009 help='print security hardening preferences for the selected architecture')
1010 parser.add_argument('-c', '--config',
1011 help='check the kernel kconfig file against these preferences')
1012 parser.add_argument('-l', '--cmdline',
1013 help='check the kernel cmdline file against these preferences')
1014 parser.add_argument('-m', '--mode', choices=report_modes,
1015 help='choose the report mode')
1016 args = parser.parse_args()
1022 print('[+] Special report mode: {}'.format(mode))
1024 config_checklist = []
1028 sys.exit('[!] ERROR: --config and --print can\'t be used together')
1031 print('[+] Kconfig file to check: {}'.format(args.config))
1033 print('[+] Kernel cmdline file to check: {}'.format(args.cmdline))
1035 arch, msg = detect_arch(args.config, supported_archs)
1037 sys.exit('[!] ERROR: {}'.format(msg))
1039 print('[+] Detected architecture: {}'.format(arch))
1041 kernel_version, msg = detect_kernel_version(args.config)
1042 if not kernel_version:
1043 sys.exit('[!] ERROR: {}'.format(msg))
1045 print('[+] Detected kernel version: {}.{}'.format(kernel_version[0], kernel_version[1]))
1047 compiler, msg = detect_compiler(args.config)
1050 print('[+] Detected compiler: {}'.format(compiler))
1052 print('[-] Can\'t detect the compiler: {}'.format(msg))
1054 # add relevant kconfig checks to the checklist
1055 add_kconfig_checks(config_checklist, arch)
1058 # add relevant cmdline checks to the checklist
1059 add_cmdline_checks(config_checklist, arch)
1061 # populate the checklist with the parsed kconfig data
1062 parsed_kconfig_options = OrderedDict()
1063 parse_kconfig_file(parsed_kconfig_options, args.config)
1064 populate_with_data(config_checklist, parsed_kconfig_options, 'kconfig')
1065 populate_with_data(config_checklist, kernel_version, 'version')
1068 # populate the checklist with the parsed kconfig data
1069 parsed_cmdline_options = OrderedDict()
1070 parse_cmdline_file(parsed_cmdline_options, args.cmdline)
1071 populate_with_data(config_checklist, parsed_cmdline_options, 'cmdline')
1073 # now everything is ready for performing the checks
1074 perform_checks(config_checklist)
1076 # finally print the results
1077 if mode == 'verbose':
1078 print_unknown_options(config_checklist, parsed_kconfig_options)
1079 print_checklist(mode, config_checklist, True)
1083 sys.exit('[!] ERROR: checking cmdline doesn\'t work without checking kconfig')
1086 if mode in ('show_ok', 'show_fail'):
1087 sys.exit('[!] ERROR: wrong mode "{}" for --print'.format(mode))
1089 add_kconfig_checks(config_checklist, arch)
1090 add_cmdline_checks(config_checklist, arch)
1092 print('[+] Printing kernel security hardening preferences for {}...'.format(arch))
1093 print_checklist(mode, config_checklist, False)