4 # This tool helps me to check the Linux kernel Kconfig option list
5 # against my 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:
16 # page_alloc.shuffle=1
17 # iommu=force (does it help against DMA attacks?)
18 # page_poison=1 (if enabled)
23 # Mitigations of CPU vulnerabilities:
25 # mitigations=auto,nosmt
29 # spec_store_bypass_disable=on
37 # N.B. Hardening sysctls:
38 # kernel.kptr_restrict=2
39 # kernel.dmesg_restrict=1
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 # kernel.unprivileged_bpf_disabled=1
45 # net.core.bpf_jit_harden=2
47 # vm.unprivileged_userfaultfd=0
49 # dev.tty.ldisc_autoload=0
50 # fs.protected_symlinks=1
51 # fs.protected_hardlinks=1
52 # fs.protected_fifos=2
53 # fs.protected_regular=2
55 # kernel.modules_disabled=1
58 from argparse import ArgumentParser
59 from collections import OrderedDict
62 from .__about__ import __version__
64 # pylint: disable=line-too-long,bad-whitespace,too-many-branches
65 # pylint: disable=too-many-statements,global-statement
68 # - reporting about unknown kernel options in the config,
69 # - verbose printing of ComplexOptChecks (OR, AND).
72 # json_mode is for printing results in JSON format
75 supported_archs = ['X86_64', 'X86_32', 'ARM64', 'ARM']
81 def __init__(self, reason, decision, name, expected):
83 self.expected = expected
84 self.decision = decision
90 if self.expected == self.state:
92 elif self.state is None:
93 if self.expected == 'is not set':
94 self.result = 'OK: not found'
96 self.result = 'FAIL: not found'
98 self.result = 'FAIL: "' + self.state + '"'
100 if self.result.startswith('OK'):
104 def table_print(self, with_results):
105 print('CONFIG_{:<38}|{:^13}|{:^10}|{:^20}'.format(self.name, self.expected, self.decision, self.reason), end='')
107 print('| {}'.format(self.result), end='')
111 def __init__(self, ver_expected):
112 self.ver_expected = ver_expected
116 if kernel_version[0] > self.ver_expected[0]:
117 self.result = 'OK: version >= ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
119 if kernel_version[0] < self.ver_expected[0]:
120 self.result = 'FAIL: version < ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
122 if kernel_version[1] >= self.ver_expected[1]:
123 self.result = 'OK: version >= ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
125 self.result = 'FAIL: version < ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
128 def table_print(self, with_results):
129 ver_req = 'kernel version >= ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
130 print('{:<91}'.format(ver_req), end='')
132 print('| {}'.format(self.result), end='')
136 def __init__(self, name):
142 if self.state is None:
143 self.result = 'FAIL: not present'
145 self.result = 'OK: is present'
148 def table_print(self, with_results):
149 print('CONFIG_{:<84}'.format(self.name + ' is present'), end='')
151 print('| {}'.format(self.result), end='')
154 class ComplexOptCheck:
155 def __init__(self, *opts):
161 return self.opts[0].name
165 return self.opts[0].expected
169 return self.opts[0].decision
173 return self.opts[0].reason
175 def table_print(self, with_results):
177 print(' {:87}'.format('<<< ' + self.__class__.__name__ + ' >>>'), end='')
179 print('| {}'.format(self.result), end='')
182 o.table_print(with_results)
187 print('| {}'.format(self.result), end='')
190 class OR(ComplexOptCheck):
191 # self.opts[0] is the option that this OR-check is about.
193 # OR(<X_is_hardened>, <X_is_disabled>)
194 # OR(<X_is_hardened>, <X_is_hardened_old>)
198 sys.exit('[!] ERROR: invalid OR check')
200 for i, opt in enumerate(self.opts):
203 if i == 0 or not hasattr(opt, 'expected'):
204 self.result = opt.result
206 self.result = 'OK: CONFIG_{} "{}"'.format(opt.name, opt.expected)
208 self.result = self.opts[0].result
212 class AND(ComplexOptCheck):
213 # self.opts[0] is the option that this AND-check is about.
214 # Use case: AND(<suboption>, <main_option>)
215 # Suboption is not checked if checking of the main_option is failed.
218 for i, opt in reversed(list(enumerate(self.opts))):
221 self.result = opt.result
224 if hasattr(opt, 'expected'):
225 self.result = 'FAIL: CONFIG_{} is needed'.format(opt.name)
227 self.result = opt.result
230 sys.exit('[!] ERROR: invalid AND check')
233 def detect_arch(fname):
234 with open(fname, 'r') as f:
235 arch_pattern = re.compile("CONFIG_[a-zA-Z0-9_]*=y")
238 print('[+] Trying to detect architecture in "{}"...'.format(fname))
239 for line in f.readlines():
240 if arch_pattern.match(line):
241 option, _ = line[7:].split('=', 1)
242 if option in supported_archs:
246 return None, 'more than one supported architecture is detected'
248 return None, 'failed to detect architecture'
252 def detect_version(fname):
253 with open(fname, 'r') as f:
254 ver_pattern = re.compile("# Linux/.* Kernel Configuration")
256 print('[+] Trying to detect kernel version in "{}"...'.format(fname))
257 for line in f.readlines():
258 if ver_pattern.match(line):
261 print('[+] Found version line: "{}"'.format(line))
264 ver_numbers = ver_str.split('.')
265 if len(ver_numbers) < 3 or not ver_numbers[0].isdigit() or not ver_numbers[1].isdigit():
266 msg = 'failed to parse the version "' + ver_str + '"'
268 return (int(ver_numbers[0]), int(ver_numbers[1])), None
269 return None, 'no kernel version detected'
272 def construct_checklist(checklist, arch):
273 modules_not_set = OptCheck('cut_attack_surface', 'kspp', 'MODULES', 'is not set')
274 devmem_not_set = OptCheck('cut_attack_surface', 'kspp', 'DEVMEM', 'is not set') # refers to LOCKDOWN
276 # 'self_protection', 'defconfig'
277 checklist.append(OptCheck('self_protection', 'defconfig', 'BUG', 'y'))
278 checklist.append(OR(OptCheck('self_protection', 'defconfig', 'STRICT_KERNEL_RWX', 'y'), \
279 OptCheck('self_protection', 'defconfig', 'DEBUG_RODATA', 'y'))) # before v4.11
280 checklist.append(OR(OptCheck('self_protection', 'defconfig', 'STACKPROTECTOR_STRONG', 'y'), \
281 OptCheck('self_protection', 'defconfig', 'CC_STACKPROTECTOR_STRONG', 'y')))
282 checklist.append(OptCheck('self_protection', 'defconfig', 'SLUB_DEBUG', 'y'))
283 checklist.append(OR(OptCheck('self_protection', 'defconfig', 'STRICT_MODULE_RWX', 'y'), \
284 OptCheck('self_protection', 'defconfig', 'DEBUG_SET_MODULE_RONX', 'y'), \
285 modules_not_set)) # DEBUG_SET_MODULE_RONX was before v4.11
286 checklist.append(OptCheck('self_protection', 'defconfig', 'GCC_PLUGINS', 'y'))
287 checklist.append(OR(OptCheck('self_protection', 'defconfig', 'REFCOUNT_FULL', 'y'), \
288 VerCheck((5, 5)))) # REFCOUNT_FULL is enabled by default since v5.5
289 iommu_support_is_set = OptCheck('self_protection', 'defconfig', 'IOMMU_SUPPORT', 'y') # is needed for mitigating DMA attacks
290 checklist.append(iommu_support_is_set)
291 if arch in ('X86_64', 'X86_32'):
292 checklist.append(OptCheck('self_protection', 'defconfig', 'MICROCODE', 'y')) # is needed for mitigating CPU bugs
293 checklist.append(OptCheck('self_protection', 'defconfig', 'RETPOLINE', 'y'))
294 checklist.append(OptCheck('self_protection', 'defconfig', 'X86_SMAP', 'y'))
295 checklist.append(OR(OptCheck('self_protection', 'defconfig', 'X86_UMIP', 'y'), \
296 OptCheck('self_protection', 'defconfig', 'X86_INTEL_UMIP', 'y')))
297 checklist.append(OptCheck('self_protection', 'defconfig', 'SYN_COOKIES', 'y')) # another reason?
299 checklist.append(OptCheck('self_protection', 'defconfig', 'PAGE_TABLE_ISOLATION', 'y'))
300 checklist.append(OptCheck('self_protection', 'defconfig', 'RANDOMIZE_MEMORY', 'y'))
301 checklist.append(AND(OptCheck('self_protection', 'defconfig', 'INTEL_IOMMU', 'y'), \
302 iommu_support_is_set))
303 checklist.append(AND(OptCheck('self_protection', 'defconfig', 'AMD_IOMMU', 'y'), \
304 iommu_support_is_set))
306 checklist.append(OptCheck('self_protection', 'defconfig', 'UNMAP_KERNEL_AT_EL0', 'y'))
307 checklist.append(OptCheck('self_protection', 'defconfig', 'HARDEN_EL2_VECTORS', 'y'))
308 checklist.append(OptCheck('self_protection', 'defconfig', 'RODATA_FULL_DEFAULT_ENABLED', 'y'))
309 checklist.append(OptCheck('self_protection', 'defconfig', 'ARM64_PTR_AUTH', 'y'))
310 if arch in ('X86_64', 'ARM64'):
311 checklist.append(OptCheck('self_protection', 'defconfig', 'VMAP_STACK', 'y'))
312 if arch in ('X86_64', 'ARM64', 'X86_32'):
313 checklist.append(OptCheck('self_protection', 'defconfig', 'RANDOMIZE_BASE', 'y'))
314 checklist.append(OptCheck('self_protection', 'defconfig', 'THREAD_INFO_IN_TASK', 'y'))
316 checklist.append(OptCheck('self_protection', 'defconfig', 'CPU_SW_DOMAIN_PAN', 'y'))
317 checklist.append(OptCheck('self_protection', 'defconfig', 'STACKPROTECTOR_PER_TASK', 'y'))
318 if arch in ('ARM64', 'ARM'):
319 checklist.append(OptCheck('self_protection', 'defconfig', 'HARDEN_BRANCH_PREDICTOR', 'y'))
321 # 'self_protection', 'kspp'
322 checklist.append(OptCheck('self_protection', 'kspp', 'BUG_ON_DATA_CORRUPTION', 'y'))
323 checklist.append(OptCheck('self_protection', 'kspp', 'DEBUG_WX', 'y'))
324 checklist.append(OptCheck('self_protection', 'kspp', 'SCHED_STACK_END_CHECK', 'y'))
325 checklist.append(OptCheck('self_protection', 'kspp', 'SLAB_FREELIST_HARDENED', 'y'))
326 checklist.append(OptCheck('self_protection', 'kspp', 'SLAB_FREELIST_RANDOM', 'y'))
327 checklist.append(OptCheck('self_protection', 'kspp', 'SHUFFLE_PAGE_ALLOCATOR', 'y'))
328 checklist.append(OptCheck('self_protection', 'kspp', 'FORTIFY_SOURCE', 'y'))
329 randstruct_is_set = OptCheck('self_protection', 'kspp', 'GCC_PLUGIN_RANDSTRUCT', 'y')
330 checklist.append(randstruct_is_set)
331 checklist.append(OptCheck('self_protection', 'kspp', 'GCC_PLUGIN_LATENT_ENTROPY', 'y'))
332 checklist.append(OptCheck('self_protection', 'kspp', 'DEBUG_LIST', 'y'))
333 checklist.append(OptCheck('self_protection', 'kspp', 'DEBUG_SG', 'y'))
334 checklist.append(OptCheck('self_protection', 'kspp', 'DEBUG_CREDENTIALS', 'y'))
335 checklist.append(OptCheck('self_protection', 'kspp', 'DEBUG_NOTIFIERS', 'y'))
336 hardened_usercopy_is_set = OptCheck('self_protection', 'kspp', 'HARDENED_USERCOPY', 'y')
337 checklist.append(hardened_usercopy_is_set)
338 checklist.append(AND(OptCheck('self_protection', 'kspp', 'HARDENED_USERCOPY_FALLBACK', 'is not set'), \
339 hardened_usercopy_is_set))
340 checklist.append(OR(OptCheck('self_protection', 'kspp', 'MODULE_SIG', 'y'), \
342 checklist.append(OR(OptCheck('self_protection', 'kspp', 'MODULE_SIG_ALL', 'y'), \
344 checklist.append(OR(OptCheck('self_protection', 'kspp', 'MODULE_SIG_SHA512', 'y'), \
346 checklist.append(OR(OptCheck('self_protection', 'kspp', 'MODULE_SIG_FORCE', 'y'), \
347 modules_not_set)) # refers to LOCKDOWN
348 checklist.append(OR(OptCheck('self_protection', 'kspp', 'INIT_STACK_ALL', 'y'), \
349 OptCheck('self_protection', 'kspp', 'GCC_PLUGIN_STRUCTLEAK_BYREF_ALL', 'y')))
350 checklist.append(OptCheck('self_protection', 'kspp', 'INIT_ON_ALLOC_DEFAULT_ON', 'y'))
351 checklist.append(OR(OptCheck('self_protection', 'kspp', 'INIT_ON_FREE_DEFAULT_ON', 'y'), \
352 OptCheck('self_protection', 'kspp', 'PAGE_POISONING', 'y'))) # before v5.3
353 if arch in ('X86_64', 'ARM64', 'X86_32'):
354 stackleak_is_set = OptCheck('self_protection', 'kspp', 'GCC_PLUGIN_STACKLEAK', 'y')
355 checklist.append(stackleak_is_set)
356 checklist.append(AND(OptCheck('self_protection', 'clipos', 'STACKLEAK_METRICS', 'is not set'), \
358 checklist.append(AND(OptCheck('self_protection', 'clipos', 'STACKLEAK_RUNTIME_DISABLE', 'is not set'), \
360 if arch in ('X86_64', 'X86_32'):
361 checklist.append(OptCheck('self_protection', 'kspp', 'DEFAULT_MMAP_MIN_ADDR', '65536'))
363 checklist.append(OptCheck('self_protection', 'kspp', 'PAGE_TABLE_ISOLATION', 'y'))
364 checklist.append(OptCheck('self_protection', 'kspp', 'HIGHMEM64G', 'y'))
365 checklist.append(OptCheck('self_protection', 'kspp', 'X86_PAE', 'y'))
367 checklist.append(OptCheck('self_protection', 'kspp', 'ARM64_SW_TTBR0_PAN', 'y'))
368 if arch in ('ARM64', 'ARM'):
369 checklist.append(OptCheck('self_protection', 'kspp', 'SYN_COOKIES', 'y')) # another reason?
370 checklist.append(OptCheck('self_protection', 'kspp', 'DEFAULT_MMAP_MIN_ADDR', '32768'))
372 # 'self_protection', 'clipos'
373 checklist.append(OptCheck('self_protection', 'clipos', 'SECURITY_DMESG_RESTRICT', 'y'))
374 checklist.append(OptCheck('self_protection', 'clipos', 'DEBUG_VIRTUAL', 'y'))
375 checklist.append(OptCheck('self_protection', 'clipos', 'STATIC_USERMODEHELPER', 'y')) # needs userspace support
376 checklist.append(OptCheck('self_protection', 'clipos', 'SLAB_MERGE_DEFAULT', 'is not set')) # slab_nomerge
377 checklist.append(AND(OptCheck('self_protection', 'clipos', 'GCC_PLUGIN_RANDSTRUCT_PERFORMANCE', 'is not set'), \
379 checklist.append(OptCheck('self_protection', 'clipos', 'RANDOM_TRUST_BOOTLOADER', 'is not set'))
380 checklist.append(OptCheck('self_protection', 'clipos', 'RANDOM_TRUST_CPU', 'is not set'))
381 if arch in ('X86_64', 'X86_32'):
382 checklist.append(AND(OptCheck('self_protection', 'clipos', 'INTEL_IOMMU_SVM', 'y'), \
383 iommu_support_is_set))
384 checklist.append(AND(OptCheck('self_protection', 'clipos', 'INTEL_IOMMU_DEFAULT_ON', 'y'), \
385 iommu_support_is_set))
387 checklist.append(AND(OptCheck('self_protection', 'clipos', 'INTEL_IOMMU', 'y'), \
388 iommu_support_is_set))
390 # 'self_protection', 'my'
391 checklist.append(OptCheck('self_protection', 'my', 'SLUB_DEBUG_ON', 'y'))
392 checklist.append(OptCheck('self_protection', 'my', 'RESET_ATTACK_MITIGATION', 'y')) # needs userspace support (systemd)
394 checklist.append(AND(OptCheck('self_protection', 'my', 'AMD_IOMMU_V2', 'y'), \
395 iommu_support_is_set))
398 if arch in ('X86_64', 'ARM64', 'X86_32'):
399 checklist.append(OptCheck('security_policy', 'defconfig', 'SECURITY', 'y')) # and choose your favourite LSM
401 checklist.append(OptCheck('security_policy', 'kspp', 'SECURITY', 'y')) # and choose your favourite LSM
402 checklist.append(OptCheck('security_policy', 'kspp', 'SECURITY_YAMA', 'y'))
403 checklist.append(OR(OptCheck('security_policy', 'my', 'SECURITY_WRITABLE_HOOKS', 'is not set'), \
404 OptCheck('security_policy', 'kspp', 'SECURITY_SELINUX_DISABLE', 'is not set')))
405 checklist.append(OptCheck('security_policy', 'clipos', 'SECURITY_LOCKDOWN_LSM', 'y'))
406 checklist.append(OptCheck('security_policy', 'clipos', 'SECURITY_LOCKDOWN_LSM_EARLY', 'y'))
407 checklist.append(OptCheck('security_policy', 'clipos', 'LOCK_DOWN_KERNEL_FORCE_CONFIDENTIALITY', 'y'))
408 loadpin_is_set = OptCheck('security_policy', 'my', 'SECURITY_LOADPIN', 'y') # needs userspace support
409 checklist.append(loadpin_is_set)
410 checklist.append(AND(OptCheck('security_policy', 'my', 'SECURITY_LOADPIN_ENFORCE', 'y'), \
412 checklist.append(OptCheck('security_policy', 'my', 'SECURITY_SAFESETID', 'y'))
414 # 'cut_attack_surface', 'defconfig'
415 checklist.append(OptCheck('cut_attack_surface', 'defconfig', 'SECCOMP', 'y'))
416 checklist.append(OptCheck('cut_attack_surface', 'defconfig', 'SECCOMP_FILTER', 'y'))
417 if arch in ('X86_64', 'ARM64', 'X86_32'):
418 checklist.append(OR(OptCheck('cut_attack_surface', 'defconfig', 'STRICT_DEVMEM', 'y'), \
419 devmem_not_set)) # refers to LOCKDOWN
421 # 'cut_attack_surface', 'kspp'
422 checklist.append(modules_not_set)
423 checklist.append(devmem_not_set)
424 checklist.append(OR(OptCheck('cut_attack_surface', 'kspp', 'IO_STRICT_DEVMEM', 'y'), \
425 devmem_not_set)) # refers to LOCKDOWN
427 checklist.append(OR(OptCheck('cut_attack_surface', 'kspp', 'STRICT_DEVMEM', 'y'), \
428 devmem_not_set)) # refers to LOCKDOWN
430 checklist.append(OptCheck('cut_attack_surface', 'kspp', 'LEGACY_VSYSCALL_NONE', 'y')) # 'vsyscall=none'
431 checklist.append(OptCheck('cut_attack_surface', 'kspp', 'ACPI_CUSTOM_METHOD', 'is not set')) # refers to LOCKDOWN
432 checklist.append(OptCheck('cut_attack_surface', 'kspp', 'COMPAT_BRK', 'is not set'))
433 checklist.append(OptCheck('cut_attack_surface', 'kspp', 'DEVKMEM', 'is not set')) # refers to LOCKDOWN
434 checklist.append(OptCheck('cut_attack_surface', 'kspp', 'COMPAT_VDSO', 'is not set'))
435 checklist.append(OptCheck('cut_attack_surface', 'kspp', 'BINFMT_MISC', 'is not set'))
436 checklist.append(OptCheck('cut_attack_surface', 'kspp', 'INET_DIAG', 'is not set'))
437 checklist.append(OptCheck('cut_attack_surface', 'kspp', 'KEXEC', 'is not set')) # refers to LOCKDOWN
438 checklist.append(OptCheck('cut_attack_surface', 'kspp', 'PROC_KCORE', 'is not set')) # refers to LOCKDOWN
439 checklist.append(OptCheck('cut_attack_surface', 'kspp', 'LEGACY_PTYS', 'is not set'))
440 checklist.append(OptCheck('cut_attack_surface', 'kspp', 'HIBERNATION', 'is not set')) # refers to LOCKDOWN
441 checklist.append(OptCheck('cut_attack_surface', 'kspp', 'IA32_EMULATION', 'is not set'))
442 checklist.append(OptCheck('cut_attack_surface', 'kspp', 'X86_X32', 'is not set'))
443 checklist.append(OptCheck('cut_attack_surface', 'kspp', 'MODIFY_LDT_SYSCALL', 'is not set'))
444 checklist.append(OptCheck('cut_attack_surface', 'kspp', 'OABI_COMPAT', 'is not set'))
446 # 'cut_attack_surface', 'grsecurity'
447 checklist.append(OptCheck('cut_attack_surface', 'grsecurity', 'X86_PTDUMP', 'is not set'))
448 checklist.append(OptCheck('cut_attack_surface', 'grsecurity', 'ZSMALLOC_STAT', 'is not set'))
449 checklist.append(OptCheck('cut_attack_surface', 'grsecurity', 'PAGE_OWNER', 'is not set'))
450 checklist.append(OptCheck('cut_attack_surface', 'grsecurity', 'DEBUG_KMEMLEAK', 'is not set'))
451 checklist.append(OptCheck('cut_attack_surface', 'grsecurity', 'BINFMT_AOUT', 'is not set'))
452 checklist.append(OptCheck('cut_attack_surface', 'grsecurity', 'KPROBES', 'is not set')) # refers to LOCKDOWN
453 checklist.append(OptCheck('cut_attack_surface', 'grsecurity', 'UPROBES', 'is not set'))
454 checklist.append(OptCheck('cut_attack_surface', 'grsecurity', 'GENERIC_TRACER', 'is not set')) # refers to LOCKDOWN
455 checklist.append(OptCheck('cut_attack_surface', 'grsecurity', 'PROC_VMCORE', 'is not set'))
456 checklist.append(OptCheck('cut_attack_surface', 'grsecurity', 'PROC_PAGE_MONITOR', 'is not set'))
457 checklist.append(OptCheck('cut_attack_surface', 'grsecurity', 'USELIB', 'is not set'))
458 checklist.append(OptCheck('cut_attack_surface', 'grsecurity', 'CHECKPOINT_RESTORE', 'is not set'))
459 checklist.append(OptCheck('cut_attack_surface', 'grsecurity', 'USERFAULTFD', 'is not set'))
460 checklist.append(OptCheck('cut_attack_surface', 'grsecurity', 'HWPOISON_INJECT', 'is not set'))
461 checklist.append(OptCheck('cut_attack_surface', 'grsecurity', 'MEM_SOFT_DIRTY', 'is not set'))
462 checklist.append(OptCheck('cut_attack_surface', 'grsecurity', 'DEVPORT', 'is not set')) # refers to LOCKDOWN
463 checklist.append(OptCheck('cut_attack_surface', 'grsecurity', 'DEBUG_FS', 'is not set')) # refers to LOCKDOWN
464 checklist.append(OptCheck('cut_attack_surface', 'grsecurity', 'NOTIFIER_ERROR_INJECTION','is not set'))
466 # 'cut_attack_surface', 'maintainer'
467 checklist.append(OptCheck('cut_attack_surface', 'maintainer', 'DRM_LEGACY', 'is not set'))
468 checklist.append(OptCheck('cut_attack_surface', 'maintainer', 'FB', 'is not set'))
469 checklist.append(OptCheck('cut_attack_surface', 'maintainer', 'VT', 'is not set'))
471 # 'cut_attack_surface', 'lockdown'
472 checklist.append(OptCheck('cut_attack_surface', 'lockdown', 'ACPI_TABLE_UPGRADE', 'is not set')) # refers to LOCKDOWN
473 checklist.append(OptCheck('cut_attack_surface', 'lockdown', 'X86_IOPL_IOPERM', 'is not set')) # refers to LOCKDOWN
474 checklist.append(OptCheck('cut_attack_surface', 'lockdown', 'EFI_TEST', 'is not set')) # refers to LOCKDOWN
475 checklist.append(OptCheck('cut_attack_surface', 'lockdown', 'BPF_SYSCALL', 'is not set')) # refers to LOCKDOWN
476 checklist.append(OptCheck('cut_attack_surface', 'lockdown', 'MMIOTRACE_TEST', 'is not set')) # refers to LOCKDOWN
478 # 'cut_attack_surface', 'clipos'
479 if arch in ('X86_64', 'X86_32'):
480 checklist.append(OptCheck('cut_attack_surface', 'clipos', 'X86_INTEL_TSX_MODE_OFF', 'y')) # tsx=off
481 checklist.append(OptCheck('cut_attack_surface', 'clipos', 'STAGING', 'is not set'))
482 checklist.append(OptCheck('cut_attack_surface', 'clipos', 'KSM', 'is not set')) # to prevent FLUSH+RELOAD attack
483 # checklist.append(OptCheck('cut_attack_surface', 'clipos', 'IKCONFIG', 'is not set')) # no, this info is needed for this check :)
484 checklist.append(OptCheck('cut_attack_surface', 'clipos', 'KALLSYMS', 'is not set'))
485 checklist.append(OptCheck('cut_attack_surface', 'clipos', 'X86_VSYSCALL_EMULATION', 'is not set'))
486 checklist.append(OptCheck('cut_attack_surface', 'clipos', 'MAGIC_SYSRQ', 'is not set'))
487 checklist.append(OptCheck('cut_attack_surface', 'clipos', 'KEXEC_FILE', 'is not set')) # refers to LOCKDOWN (permissive)
488 checklist.append(OptCheck('cut_attack_surface', 'clipos', 'USER_NS', 'is not set')) # user.max_user_namespaces=0
489 checklist.append(OptCheck('cut_attack_surface', 'clipos', 'X86_MSR', 'is not set')) # refers to LOCKDOWN
490 checklist.append(OptCheck('cut_attack_surface', 'clipos', 'X86_CPUID', 'is not set'))
491 checklist.append(AND(OptCheck('cut_attack_surface', 'clipos', 'LDISC_AUTOLOAD', 'is not set'), \
492 PresenceCheck('LDISC_AUTOLOAD')))
494 # 'cut_attack_surface', 'grapheneos'
495 checklist.append(OptCheck('cut_attack_surface', 'grapheneos', 'AIO', 'is not set'))
497 # 'cut_attack_surface', 'my'
498 checklist.append(OptCheck('cut_attack_surface', 'my', 'MMIOTRACE', 'is not set')) # refers to LOCKDOWN (permissive)
499 checklist.append(OptCheck('cut_attack_surface', 'my', 'LIVEPATCH', 'is not set'))
500 checklist.append(OptCheck('cut_attack_surface', 'my', 'IP_DCCP', 'is not set'))
501 checklist.append(OptCheck('cut_attack_surface', 'my', 'IP_SCTP', 'is not set'))
502 checklist.append(OptCheck('cut_attack_surface', 'my', 'FTRACE', 'is not set')) # refers to LOCKDOWN
503 checklist.append(OptCheck('cut_attack_surface', 'my', 'BPF_JIT', 'is not set'))
504 checklist.append(OptCheck('cut_attack_surface', 'my', 'VIDEO_VIVID', 'is not set'))
505 checklist.append(OptCheck('cut_attack_surface', 'my', 'INPUT_EVBUG', 'is not set')) # Can be used as a keylogger
507 # 'userspace_hardening'
508 checklist.append(OptCheck('userspace_hardening', 'defconfig', 'INTEGRITY', 'y'))
509 if arch in ('ARM', 'X86_32'):
510 checklist.append(OptCheck('userspace_hardening', 'defconfig', 'VMSPLIT_3G', 'y'))
511 if arch in ('X86_64', 'ARM64'):
512 checklist.append(OptCheck('userspace_hardening', 'clipos', 'ARCH_MMAP_RND_BITS', '32'))
513 if arch in ('X86_32', 'ARM'):
514 checklist.append(OptCheck('userspace_hardening', 'my', 'ARCH_MMAP_RND_BITS', '16'))
516 # checklist.append(OptCheck('feature_test', 'my', 'LKDTM', 'm')) # only for debugging!
519 def print_checklist(checklist, with_results):
523 opt = ['CONFIG_'+o.name, o.expected, o.decision, o.reason]
527 print(json.dumps(opts))
534 print('=' * sep_line_len)
535 print('{:^45}|{:^13}|{:^10}|{:^20}'.format('option name', 'desired val', 'decision', 'reason'), end='')
537 print('| {}'.format('check result'), end='')
539 print('=' * sep_line_len)
542 for opt in checklist:
543 opt.table_print(with_results)
546 print('-' * sep_line_len)
550 def perform_checks(checklist, parsed_options):
551 for opt in checklist:
552 if hasattr(opt, 'opts'):
553 # prepare ComplexOptCheck
555 if hasattr(o, 'state'):
556 o.state = parsed_options.get(o.name, None)
558 # prepare simple check
559 if not hasattr(opt, 'state'):
560 sys.exit('[!] ERROR: bad simple check {}'.format(vars(opt)))
561 opt.state = parsed_options.get(opt.name, None)
565 def check_config_file(checklist, fname, arch):
566 with open(fname, 'r') as f:
567 parsed_options = OrderedDict()
568 opt_is_on = re.compile("CONFIG_[a-zA-Z0-9_]*=[a-zA-Z0-9_\"]*")
569 opt_is_off = re.compile("# CONFIG_[a-zA-Z0-9_]* is not set")
572 print('[+] Checking "{}" against {} hardening preferences...'.format(fname, arch))
573 for line in f.readlines():
578 if opt_is_on.match(line):
579 option, value = line[7:].split('=', 1)
580 elif opt_is_off.match(line):
581 option, value = line[9:].split(' ', 1)
582 if value != 'is not set':
583 sys.exit('[!] ERROR: bad disabled config option "{}"'.format(line))
585 if option in parsed_options:
586 sys.exit('[!] ERROR: config option "{}" exists multiple times'.format(line))
588 if option is not None:
589 parsed_options[option] = value
591 perform_checks(checklist, parsed_options)
595 for opt in checklist:
596 if hasattr(opt, 'opts'):
598 if hasattr(o, 'name'):
599 known_options.append(o.name)
601 known_options.append(opt.name)
602 for option, value in parsed_options.items():
603 if option not in known_options:
604 print('DEBUG: dunno about option {} ({})'.format(option, value))
606 print_checklist(checklist, True)
611 global kernel_version
613 config_checklist = []
615 parser = ArgumentParser(prog='kconfig-hardened-check',
616 description='Checks the hardening options in the Linux kernel config')
617 parser.add_argument('-p', '--print', choices=supported_archs,
618 help='print hardening preferences for selected architecture')
619 parser.add_argument('-c', '--config',
620 help='check the config_file against these preferences')
621 parser.add_argument('--debug', action='store_true',
622 help='enable verbose debug mode')
623 parser.add_argument('--json', action='store_true',
624 help='print results in JSON format')
625 parser.add_argument('--version', action='version', version='%(prog)s ' + __version__)
626 args = parser.parse_args()
630 print('[!] WARNING: debug mode is enabled')
633 if debug_mode and json_mode:
634 sys.exit('[!] ERROR: options --debug and --json cannot be used simultaneously')
637 arch, msg = detect_arch(args.config)
639 sys.exit('[!] ERROR: {}'.format(msg))
641 print('[+] Detected architecture: {}'.format(arch))
643 kernel_version, msg = detect_version(args.config)
644 if not kernel_version:
645 sys.exit('[!] ERROR: {}'.format(msg))
647 print('[+] Detected kernel version: {}.{}'.format(kernel_version[0], kernel_version[1]))
649 construct_checklist(config_checklist, arch)
650 check_config_file(config_checklist, args.config, arch)
651 error_count = len(list(filter(lambda opt: opt.result.startswith('FAIL'), config_checklist)))
652 ok_count = len(list(filter(lambda opt: opt.result.startswith('OK'), config_checklist)))
653 if not debug_mode and not json_mode:
654 print('[+] config check is finished: \'OK\' - {} / \'FAIL\' - {}'.format(ok_count, error_count))
659 construct_checklist(config_checklist, arch)
661 print('[+] Printing kernel hardening preferences for {}...'.format(arch))
662 print_checklist(config_checklist, False)
668 if __name__ == '__main__':