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, name, expected, decision, reason):
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].state
173 return self.opts[0].decision
177 return self.opts[0].reason
179 def table_print(self, with_results):
181 print(' {:87}'.format('<<< ' + self.__class__.__name__ + ' >>>'), end='')
183 print('| {}'.format(self.result), end='')
186 o.table_print(with_results)
191 print('| {}'.format(self.result), end='')
194 class OR(ComplexOptCheck):
195 # self.opts[0] is the option that this OR-check is about.
197 # OR(<X_is_hardened>, <X_is_disabled>)
198 # OR(<X_is_hardened>, <X_is_hardened_old>)
202 sys.exit('[!] ERROR: invalid OR check')
204 for i, opt in enumerate(self.opts):
207 if i == 0 or not hasattr(opt, 'expected'):
208 self.result = opt.result
210 self.result = 'OK: CONFIG_{} "{}"'.format(opt.name, opt.expected)
212 self.result = self.opts[0].result
216 class AND(ComplexOptCheck):
217 # self.opts[0] is the option that this AND-check is about.
218 # Use case: AND(<suboption>, <main_option>)
219 # Suboption is not checked if checking of the main_option is failed.
222 for i, opt in reversed(list(enumerate(self.opts))):
225 self.result = opt.result
228 if hasattr(opt, 'expected'):
229 self.result = 'FAIL: CONFIG_{} is needed'.format(opt.name)
231 self.result = opt.result
234 sys.exit('[!] ERROR: invalid AND check')
237 def detect_arch(fname):
238 with open(fname, 'r') as f:
239 arch_pattern = re.compile("CONFIG_[a-zA-Z0-9_]*=y")
242 print('[+] Trying to detect architecture in "{}"...'.format(fname))
243 for line in f.readlines():
244 if arch_pattern.match(line):
245 option, _ = line[7:].split('=', 1)
246 if option in supported_archs:
250 return None, 'more than one supported architecture is detected'
252 return None, 'failed to detect architecture'
256 def detect_version(fname):
257 with open(fname, 'r') as f:
258 ver_pattern = re.compile("# Linux/.* Kernel Configuration")
260 print('[+] Trying to detect kernel version in "{}"...'.format(fname))
261 for line in f.readlines():
262 if ver_pattern.match(line):
265 print('[+] Found version line: "{}"'.format(line))
268 ver_numbers = ver_str.split('.')
269 if len(ver_numbers) < 3 or not ver_numbers[0].isdigit() or not ver_numbers[1].isdigit():
270 msg = 'failed to parse the version "' + ver_str + '"'
272 return (int(ver_numbers[0]), int(ver_numbers[1])), None
273 return None, 'no kernel version detected'
276 def construct_checklist(checklist, arch):
277 modules_not_set = OptCheck('MODULES', 'is not set', 'kspp', 'cut_attack_surface')
278 devmem_not_set = OptCheck('DEVMEM', 'is not set', 'kspp', 'cut_attack_surface') # refers to LOCKDOWN
280 checklist.append(OptCheck('BUG', 'y', 'defconfig', 'self_protection'))
281 checklist.append(OR(OptCheck('STRICT_KERNEL_RWX', 'y', 'defconfig', 'self_protection'), \
282 OptCheck('DEBUG_RODATA', 'y', 'defconfig', 'self_protection'))) # before v4.11
283 checklist.append(OR(OptCheck('STACKPROTECTOR_STRONG', 'y', 'defconfig', 'self_protection'), \
284 OptCheck('CC_STACKPROTECTOR_STRONG', 'y', 'defconfig', 'self_protection')))
285 checklist.append(OptCheck('SLUB_DEBUG', 'y', 'defconfig', 'self_protection'))
286 checklist.append(OR(OptCheck('STRICT_MODULE_RWX', 'y', 'defconfig', 'self_protection'), \
287 OptCheck('DEBUG_SET_MODULE_RONX', 'y', 'defconfig', 'self_protection'), \
288 modules_not_set)) # DEBUG_SET_MODULE_RONX was before v4.11
289 checklist.append(OptCheck('GCC_PLUGINS', 'y', 'defconfig', 'self_protection'))
290 checklist.append(OR(OptCheck('REFCOUNT_FULL', 'y', 'defconfig', 'self_protection'), \
291 VerCheck((5, 5)))) # REFCOUNT_FULL is enabled by default since v5.5
292 iommu_support_is_set = OptCheck('IOMMU_SUPPORT', 'y', 'defconfig', 'self_protection') # is needed for mitigating DMA attacks
293 checklist.append(iommu_support_is_set)
294 if arch in ('X86_64', 'X86_32'):
295 checklist.append(OptCheck('MICROCODE', 'y', 'defconfig', 'self_protection')) # is needed for mitigating CPU bugs
296 checklist.append(OptCheck('RETPOLINE', 'y', 'defconfig', 'self_protection'))
297 checklist.append(OptCheck('X86_SMAP', 'y', 'defconfig', 'self_protection'))
298 checklist.append(OR(OptCheck('X86_UMIP', 'y', 'defconfig', 'self_protection'), \
299 OptCheck('X86_INTEL_UMIP', 'y', 'defconfig', 'self_protection')))
300 checklist.append(OptCheck('SYN_COOKIES', 'y', 'defconfig', 'self_protection')) # another reason?
302 checklist.append(OptCheck('PAGE_TABLE_ISOLATION', 'y', 'defconfig', 'self_protection'))
303 checklist.append(OptCheck('RANDOMIZE_MEMORY', 'y', 'defconfig', 'self_protection'))
304 checklist.append(AND(OptCheck('INTEL_IOMMU', 'y', 'defconfig', 'self_protection'), \
305 iommu_support_is_set))
306 checklist.append(AND(OptCheck('AMD_IOMMU', 'y', 'defconfig', 'self_protection'), \
307 iommu_support_is_set))
309 checklist.append(OptCheck('UNMAP_KERNEL_AT_EL0', 'y', 'defconfig', 'self_protection'))
310 checklist.append(OptCheck('HARDEN_EL2_VECTORS', 'y', 'defconfig', 'self_protection'))
311 checklist.append(OptCheck('RODATA_FULL_DEFAULT_ENABLED', 'y', 'defconfig', 'self_protection'))
312 checklist.append(OptCheck('ARM64_PTR_AUTH', 'y', 'defconfig', 'self_protection'))
313 if arch in ('X86_64', 'ARM64'):
314 checklist.append(OptCheck('VMAP_STACK', 'y', 'defconfig', 'self_protection'))
315 if arch in ('X86_64', 'ARM64', 'X86_32'):
316 checklist.append(OptCheck('RANDOMIZE_BASE', 'y', 'defconfig', 'self_protection'))
317 checklist.append(OptCheck('THREAD_INFO_IN_TASK', 'y', 'defconfig', 'self_protection'))
319 checklist.append(OptCheck('CPU_SW_DOMAIN_PAN', 'y', 'defconfig', 'self_protection'))
320 checklist.append(OptCheck('STACKPROTECTOR_PER_TASK', 'y', 'defconfig', 'self_protection'))
321 if arch in ('ARM64', 'ARM'):
322 checklist.append(OptCheck('HARDEN_BRANCH_PREDICTOR', 'y', 'defconfig', 'self_protection'))
324 checklist.append(OptCheck('BUG_ON_DATA_CORRUPTION', 'y', 'kspp', 'self_protection'))
325 checklist.append(OptCheck('DEBUG_WX', 'y', 'kspp', 'self_protection'))
326 checklist.append(OptCheck('SCHED_STACK_END_CHECK', 'y', 'kspp', 'self_protection'))
327 checklist.append(OptCheck('SLAB_FREELIST_HARDENED', 'y', 'kspp', 'self_protection'))
328 checklist.append(OptCheck('SLAB_FREELIST_RANDOM', 'y', 'kspp', 'self_protection'))
329 checklist.append(OptCheck('SHUFFLE_PAGE_ALLOCATOR', 'y', 'kspp', 'self_protection'))
330 checklist.append(OptCheck('FORTIFY_SOURCE', 'y', 'kspp', 'self_protection'))
331 randstruct_is_set = OptCheck('GCC_PLUGIN_RANDSTRUCT', 'y', 'kspp', 'self_protection')
332 checklist.append(randstruct_is_set)
333 checklist.append(OptCheck('GCC_PLUGIN_LATENT_ENTROPY', 'y', 'kspp', 'self_protection'))
334 checklist.append(OptCheck('DEBUG_LIST', 'y', 'kspp', 'self_protection'))
335 checklist.append(OptCheck('DEBUG_SG', 'y', 'kspp', 'self_protection'))
336 checklist.append(OptCheck('DEBUG_CREDENTIALS', 'y', 'kspp', 'self_protection'))
337 checklist.append(OptCheck('DEBUG_NOTIFIERS', 'y', 'kspp', 'self_protection'))
338 hardened_usercopy_is_set = OptCheck('HARDENED_USERCOPY', 'y', 'kspp', 'self_protection')
339 checklist.append(hardened_usercopy_is_set)
340 checklist.append(AND(OptCheck('HARDENED_USERCOPY_FALLBACK', 'is not set', 'kspp', 'self_protection'), \
341 hardened_usercopy_is_set))
342 checklist.append(OR(OptCheck('MODULE_SIG', 'y', 'kspp', 'self_protection'), \
344 checklist.append(OR(OptCheck('MODULE_SIG_ALL', 'y', 'kspp', 'self_protection'), \
346 checklist.append(OR(OptCheck('MODULE_SIG_SHA512', 'y', 'kspp', 'self_protection'), \
348 checklist.append(OR(OptCheck('MODULE_SIG_FORCE', 'y', 'kspp', 'self_protection'), \
349 modules_not_set)) # refers to LOCKDOWN
350 checklist.append(OR(OptCheck('INIT_STACK_ALL', 'y', 'kspp', 'self_protection'), \
351 OptCheck('GCC_PLUGIN_STRUCTLEAK_BYREF_ALL', 'y', 'kspp', 'self_protection')))
352 checklist.append(OptCheck('INIT_ON_ALLOC_DEFAULT_ON', 'y', 'kspp', 'self_protection'))
353 checklist.append(OR(OptCheck('INIT_ON_FREE_DEFAULT_ON', 'y', 'kspp', 'self_protection'), \
354 OptCheck('PAGE_POISONING', 'y', 'kspp', 'self_protection'))) # before v5.3
355 if arch in ('X86_64', 'ARM64', 'X86_32'):
356 stackleak_is_set = OptCheck('GCC_PLUGIN_STACKLEAK', 'y', 'kspp', 'self_protection')
357 checklist.append(stackleak_is_set)
358 checklist.append(AND(OptCheck('STACKLEAK_METRICS', 'is not set', 'clipos', 'self_protection'), \
360 checklist.append(AND(OptCheck('STACKLEAK_RUNTIME_DISABLE', 'is not set', 'clipos', 'self_protection'), \
362 if arch in ('X86_64', 'X86_32'):
363 checklist.append(OptCheck('DEFAULT_MMAP_MIN_ADDR', '65536', 'kspp', 'self_protection'))
365 checklist.append(OptCheck('PAGE_TABLE_ISOLATION', 'y', 'kspp', 'self_protection'))
366 checklist.append(OptCheck('HIGHMEM64G', 'y', 'kspp', 'self_protection'))
367 checklist.append(OptCheck('X86_PAE', 'y', 'kspp', 'self_protection'))
369 checklist.append(OptCheck('ARM64_SW_TTBR0_PAN', 'y', 'kspp', 'self_protection'))
370 if arch in ('ARM64', 'ARM'):
371 checklist.append(OptCheck('SYN_COOKIES', 'y', 'kspp', 'self_protection')) # another reason?
372 checklist.append(OptCheck('DEFAULT_MMAP_MIN_ADDR', '32768', 'kspp', 'self_protection'))
374 checklist.append(OptCheck('SECURITY_DMESG_RESTRICT', 'y', 'clipos', 'self_protection'))
375 checklist.append(OptCheck('DEBUG_VIRTUAL', 'y', 'clipos', 'self_protection'))
376 checklist.append(OptCheck('STATIC_USERMODEHELPER', 'y', 'clipos', 'self_protection')) # needs userspace support (systemd)
377 checklist.append(OptCheck('SLAB_MERGE_DEFAULT', 'is not set', 'clipos', 'self_protection')) # slab_nomerge
378 checklist.append(AND(OptCheck('GCC_PLUGIN_RANDSTRUCT_PERFORMANCE', 'is not set', 'clipos', 'self_protection'), \
380 checklist.append(OptCheck('RANDOM_TRUST_BOOTLOADER', 'is not set', 'clipos', 'self_protection'))
381 checklist.append(OptCheck('RANDOM_TRUST_CPU', 'is not set', 'clipos', 'self_protection'))
382 if arch in ('X86_64', 'X86_32'):
383 checklist.append(AND(OptCheck('INTEL_IOMMU_SVM', 'y', 'clipos', 'self_protection'), \
384 iommu_support_is_set))
385 checklist.append(AND(OptCheck('INTEL_IOMMU_DEFAULT_ON', 'y', 'clipos', 'self_protection'), \
386 iommu_support_is_set))
388 checklist.append(AND(OptCheck('INTEL_IOMMU', 'y', 'clipos', 'self_protection'), \
389 iommu_support_is_set))
391 checklist.append(OptCheck('SLUB_DEBUG_ON', 'y', 'my', 'self_protection'))
392 checklist.append(OptCheck('RESET_ATTACK_MITIGATION', 'y', 'my', 'self_protection')) # needs userspace support (systemd)
394 checklist.append(AND(OptCheck('AMD_IOMMU_V2', 'y', 'my', 'self_protection'), \
395 iommu_support_is_set))
397 if arch in ('X86_64', 'ARM64', 'X86_32'):
398 checklist.append(OptCheck('SECURITY', 'y', 'defconfig', 'security_policy')) # and choose your favourite LSM
400 checklist.append(OptCheck('SECURITY', 'y', 'kspp', 'security_policy')) # and choose your favourite LSM
401 checklist.append(OptCheck('SECURITY_YAMA', 'y', 'kspp', 'security_policy'))
402 checklist.append(OR(OptCheck('SECURITY_WRITABLE_HOOKS', 'is not set', 'my', 'security_policy'), \
403 OptCheck('SECURITY_SELINUX_DISABLE', 'is not set', 'kspp', 'security_policy')))
404 checklist.append(OptCheck('SECURITY_LOCKDOWN_LSM', 'y', 'clipos', 'security_policy'))
405 checklist.append(OptCheck('SECURITY_LOCKDOWN_LSM_EARLY', 'y', 'clipos', 'security_policy'))
406 checklist.append(OptCheck('LOCK_DOWN_KERNEL_FORCE_CONFIDENTIALITY', 'y', 'clipos', 'security_policy'))
407 loadpin_is_set = OptCheck('SECURITY_LOADPIN', 'y', 'my', 'security_policy') # needs userspace support
408 checklist.append(loadpin_is_set)
409 checklist.append(AND(OptCheck('SECURITY_LOADPIN_ENFORCE', 'y', 'my', 'security_policy'), \
411 checklist.append(OptCheck('SECURITY_SAFESETID', 'y', 'my', 'security_policy'))
413 checklist.append(OptCheck('SECCOMP', 'y', 'defconfig', 'cut_attack_surface'))
414 checklist.append(OptCheck('SECCOMP_FILTER', 'y', 'defconfig', 'cut_attack_surface'))
415 if arch in ('X86_64', 'ARM64', 'X86_32'):
416 checklist.append(OR(OptCheck('STRICT_DEVMEM', 'y', 'defconfig', 'cut_attack_surface'), \
417 devmem_not_set)) # refers to LOCKDOWN
419 checklist.append(modules_not_set)
420 checklist.append(devmem_not_set)
421 checklist.append(OR(OptCheck('IO_STRICT_DEVMEM', 'y', 'kspp', 'cut_attack_surface'), \
422 devmem_not_set)) # refers to LOCKDOWN
424 checklist.append(OR(OptCheck('STRICT_DEVMEM', 'y', 'kspp', 'cut_attack_surface'), \
425 devmem_not_set)) # refers to LOCKDOWN
427 checklist.append(OptCheck('LEGACY_VSYSCALL_NONE', 'y', 'kspp', 'cut_attack_surface')) # 'vsyscall=none'
428 checklist.append(OptCheck('ACPI_CUSTOM_METHOD', 'is not set', 'kspp', 'cut_attack_surface')) # refers to LOCKDOWN
429 checklist.append(OptCheck('COMPAT_BRK', 'is not set', 'kspp', 'cut_attack_surface'))
430 checklist.append(OptCheck('DEVKMEM', 'is not set', 'kspp', 'cut_attack_surface')) # refers to LOCKDOWN
431 checklist.append(OptCheck('COMPAT_VDSO', 'is not set', 'kspp', 'cut_attack_surface'))
432 checklist.append(OptCheck('BINFMT_MISC', 'is not set', 'kspp', 'cut_attack_surface'))
433 checklist.append(OptCheck('INET_DIAG', 'is not set', 'kspp', 'cut_attack_surface'))
434 checklist.append(OptCheck('KEXEC', 'is not set', 'kspp', 'cut_attack_surface')) # refers to LOCKDOWN
435 checklist.append(OptCheck('PROC_KCORE', 'is not set', 'kspp', 'cut_attack_surface')) # refers to LOCKDOWN
436 checklist.append(OptCheck('LEGACY_PTYS', 'is not set', 'kspp', 'cut_attack_surface'))
437 checklist.append(OptCheck('HIBERNATION', 'is not set', 'kspp', 'cut_attack_surface')) # refers to LOCKDOWN
438 checklist.append(OptCheck('IA32_EMULATION', 'is not set', 'kspp', 'cut_attack_surface'))
439 checklist.append(OptCheck('X86_X32', 'is not set', 'kspp', 'cut_attack_surface'))
440 checklist.append(OptCheck('MODIFY_LDT_SYSCALL', 'is not set', 'kspp', 'cut_attack_surface'))
441 checklist.append(OptCheck('OABI_COMPAT', 'is not set', 'kspp', 'cut_attack_surface'))
443 checklist.append(OptCheck('X86_PTDUMP', 'is not set', 'grsecurity', 'cut_attack_surface'))
444 checklist.append(OptCheck('ZSMALLOC_STAT', 'is not set', 'grsecurity', 'cut_attack_surface'))
445 checklist.append(OptCheck('PAGE_OWNER', 'is not set', 'grsecurity', 'cut_attack_surface'))
446 checklist.append(OptCheck('DEBUG_KMEMLEAK', 'is not set', 'grsecurity', 'cut_attack_surface'))
447 checklist.append(OptCheck('BINFMT_AOUT', 'is not set', 'grsecurity', 'cut_attack_surface'))
448 checklist.append(OptCheck('KPROBES', 'is not set', 'grsecurity', 'cut_attack_surface')) # refers to LOCKDOWN
449 checklist.append(OptCheck('UPROBES', 'is not set', 'grsecurity', 'cut_attack_surface'))
450 checklist.append(OptCheck('GENERIC_TRACER', 'is not set', 'grsecurity', 'cut_attack_surface')) # refers to LOCKDOWN
451 checklist.append(OptCheck('PROC_VMCORE', 'is not set', 'grsecurity', 'cut_attack_surface'))
452 checklist.append(OptCheck('PROC_PAGE_MONITOR', 'is not set', 'grsecurity', 'cut_attack_surface'))
453 checklist.append(OptCheck('USELIB', 'is not set', 'grsecurity', 'cut_attack_surface'))
454 checklist.append(OptCheck('CHECKPOINT_RESTORE', 'is not set', 'grsecurity', 'cut_attack_surface'))
455 checklist.append(OptCheck('USERFAULTFD', 'is not set', 'grsecurity', 'cut_attack_surface'))
456 checklist.append(OptCheck('HWPOISON_INJECT', 'is not set', 'grsecurity', 'cut_attack_surface'))
457 checklist.append(OptCheck('MEM_SOFT_DIRTY', 'is not set', 'grsecurity', 'cut_attack_surface'))
458 checklist.append(OptCheck('DEVPORT', 'is not set', 'grsecurity', 'cut_attack_surface')) # refers to LOCKDOWN
459 checklist.append(OptCheck('DEBUG_FS', 'is not set', 'grsecurity', 'cut_attack_surface')) # refers to LOCKDOWN
460 checklist.append(OptCheck('NOTIFIER_ERROR_INJECTION','is not set', 'grsecurity', 'cut_attack_surface'))
462 checklist.append(OptCheck('DRM_LEGACY', 'is not set', 'maintainer', 'cut_attack_surface'))
463 checklist.append(OptCheck('FB', 'is not set', 'maintainer', 'cut_attack_surface'))
464 checklist.append(OptCheck('VT', 'is not set', 'maintainer', 'cut_attack_surface'))
466 checklist.append(OptCheck('ACPI_TABLE_UPGRADE', 'is not set', 'lockdown', 'cut_attack_surface')) # refers to LOCKDOWN
467 checklist.append(OptCheck('X86_IOPL_IOPERM', 'is not set', 'lockdown', 'cut_attack_surface')) # refers to LOCKDOWN
468 checklist.append(OptCheck('EFI_TEST', 'is not set', 'lockdown', 'cut_attack_surface')) # refers to LOCKDOWN
469 checklist.append(OptCheck('BPF_SYSCALL', 'is not set', 'lockdown', 'cut_attack_surface')) # refers to LOCKDOWN
470 checklist.append(OptCheck('MMIOTRACE_TEST', 'is not set', 'lockdown', 'cut_attack_surface')) # refers to LOCKDOWN
472 if arch in ('X86_64', 'X86_32'):
473 checklist.append(OptCheck('X86_INTEL_TSX_MODE_OFF', 'y', 'clipos', 'cut_attack_surface')) # tsx=off
474 checklist.append(OptCheck('STAGING', 'is not set', 'clipos', 'cut_attack_surface'))
475 checklist.append(OptCheck('KSM', 'is not set', 'clipos', 'cut_attack_surface')) # to prevent FLUSH+RELOAD attack
476 # checklist.append(OptCheck('IKCONFIG', 'is not set', 'clipos', 'cut_attack_surface')) # no, this info is needed for this check :)
477 checklist.append(OptCheck('KALLSYMS', 'is not set', 'clipos', 'cut_attack_surface'))
478 checklist.append(OptCheck('X86_VSYSCALL_EMULATION', 'is not set', 'clipos', 'cut_attack_surface'))
479 checklist.append(OptCheck('MAGIC_SYSRQ', 'is not set', 'clipos', 'cut_attack_surface'))
480 checklist.append(OptCheck('KEXEC_FILE', 'is not set', 'clipos', 'cut_attack_surface')) # refers to LOCKDOWN (permissive)
481 checklist.append(OptCheck('USER_NS', 'is not set', 'clipos', 'cut_attack_surface')) # user.max_user_namespaces=0
482 checklist.append(OptCheck('X86_MSR', 'is not set', 'clipos', 'cut_attack_surface')) # refers to LOCKDOWN
483 checklist.append(OptCheck('X86_CPUID', 'is not set', 'clipos', 'cut_attack_surface'))
484 checklist.append(AND(OptCheck('LDISC_AUTOLOAD', 'is not set', 'clipos', 'cut_attack_surface'), \
485 PresenceCheck('LDISC_AUTOLOAD')))
487 checklist.append(OptCheck('AIO', 'is not set', 'grapheneos', 'cut_attack_surface'))
489 checklist.append(OptCheck('MMIOTRACE', 'is not set', 'my', 'cut_attack_surface')) # refers to LOCKDOWN (permissive)
490 checklist.append(OptCheck('LIVEPATCH', 'is not set', 'my', 'cut_attack_surface'))
491 checklist.append(OptCheck('IP_DCCP', 'is not set', 'my', 'cut_attack_surface'))
492 checklist.append(OptCheck('IP_SCTP', 'is not set', 'my', 'cut_attack_surface'))
493 checklist.append(OptCheck('FTRACE', 'is not set', 'my', 'cut_attack_surface')) # refers to LOCKDOWN
494 checklist.append(OptCheck('BPF_JIT', 'is not set', 'my', 'cut_attack_surface'))
495 checklist.append(OptCheck('VIDEO_VIVID', 'is not set', 'my', 'cut_attack_surface'))
496 checklist.append(OptCheck('INPUT_EVBUG', 'is not set', 'my', 'cut_attack_surface')) # Can be used as a keylogger
498 checklist.append(OptCheck('INTEGRITY', 'y', 'defconfig', 'userspace_hardening'))
499 if arch in ('ARM', 'X86_32'):
500 checklist.append(OptCheck('VMSPLIT_3G', 'y', 'defconfig', 'userspace_hardening'))
501 if arch in ('X86_64', 'ARM64'):
502 checklist.append(OptCheck('ARCH_MMAP_RND_BITS', '32', 'clipos', 'userspace_hardening'))
503 if arch in ('X86_32', 'ARM'):
504 checklist.append(OptCheck('ARCH_MMAP_RND_BITS', '16', 'my', 'userspace_hardening'))
506 # checklist.append(OptCheck('LKDTM', 'm', 'my', 'feature_test'))
509 def print_checklist(checklist, with_results):
513 opt = ['CONFIG_'+o.name, o.expected, o.decision, o.reason]
517 print(json.dumps(opts))
524 print('=' * sep_line_len)
525 print('{:^45}|{:^13}|{:^10}|{:^20}'.format('option name', 'desired val', 'decision', 'reason'), end='')
527 print('| {}'.format('check result'), end='')
529 print('=' * sep_line_len)
532 for opt in checklist:
533 opt.table_print(with_results)
536 print('-' * sep_line_len)
540 def perform_checks(checklist, parsed_options):
541 for opt in checklist:
542 if hasattr(opt, 'opts'):
543 # prepare ComplexOptCheck
545 if hasattr(o, 'state'):
546 o.state = parsed_options.get(o.name, None)
548 # prepare simple check
549 if not hasattr(opt, 'state'):
550 sys.exit('[!] ERROR: bad simple check {}'.format(vars(opt)))
551 opt.state = parsed_options.get(opt.name, None)
555 def check_config_file(checklist, fname, arch):
556 with open(fname, 'r') as f:
557 parsed_options = OrderedDict()
558 opt_is_on = re.compile("CONFIG_[a-zA-Z0-9_]*=[a-zA-Z0-9_\"]*")
559 opt_is_off = re.compile("# CONFIG_[a-zA-Z0-9_]* is not set")
562 print('[+] Checking "{}" against {} hardening preferences...'.format(fname, arch))
563 for line in f.readlines():
568 if opt_is_on.match(line):
569 option, value = line[7:].split('=', 1)
570 elif opt_is_off.match(line):
571 option, value = line[9:].split(' ', 1)
572 if value != 'is not set':
573 sys.exit('[!] ERROR: bad disabled config option "{}"'.format(line))
575 if option in parsed_options:
576 sys.exit('[!] ERROR: config option "{}" exists multiple times'.format(line))
578 if option is not None:
579 parsed_options[option] = value
581 perform_checks(checklist, parsed_options)
585 for opt in checklist:
586 if hasattr(opt, 'opts'):
588 if hasattr(o, 'name'):
589 known_options.append(o.name)
591 known_options.append(opt.name)
592 for option, value in parsed_options.items():
593 if option not in known_options:
594 print('DEBUG: dunno about option {} ({})'.format(option, value))
596 print_checklist(checklist, True)
601 global kernel_version
603 config_checklist = []
605 parser = ArgumentParser(prog='kconfig-hardened-check',
606 description='Checks the hardening options in the Linux kernel config')
607 parser.add_argument('-p', '--print', choices=supported_archs,
608 help='print hardening preferences for selected architecture')
609 parser.add_argument('-c', '--config',
610 help='check the config_file against these preferences')
611 parser.add_argument('--debug', action='store_true',
612 help='enable verbose debug mode')
613 parser.add_argument('--json', action='store_true',
614 help='print results in JSON format')
615 parser.add_argument('--version', action='version', version='%(prog)s ' + __version__)
616 args = parser.parse_args()
620 print('[!] WARNING: debug mode is enabled')
623 if debug_mode and json_mode:
624 sys.exit('[!] ERROR: options --debug and --json cannot be used simultaneously')
627 arch, msg = detect_arch(args.config)
629 sys.exit('[!] ERROR: {}'.format(msg))
631 print('[+] Detected architecture: {}'.format(arch))
633 kernel_version, msg = detect_version(args.config)
634 if not kernel_version:
635 sys.exit('[!] ERROR: {}'.format(msg))
637 print('[+] Detected kernel version: {}.{}'.format(kernel_version[0], kernel_version[1]))
639 construct_checklist(config_checklist, arch)
640 check_config_file(config_checklist, args.config, arch)
641 error_count = len(list(filter(lambda opt: opt.result.startswith('FAIL'), config_checklist)))
642 ok_count = len(list(filter(lambda opt: opt.result.startswith('OK'), config_checklist)))
643 if not debug_mode and not json_mode:
644 print('[+] config check is finished: \'OK\' - {} / \'FAIL\' - {}'.format(ok_count, error_count))
649 construct_checklist(config_checklist, arch)
651 print('[+] Printing kernel hardening preferences for {}...'.format(arch))
652 print_checklist(config_checklist, False)
658 if __name__ == '__main__':