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 # what about bpf_jit_enable?
45 # kernel.unprivileged_bpf_disabled=1
46 # net.core.bpf_jit_harden=2
48 # vm.unprivileged_userfaultfd=0
50 # dev.tty.ldisc_autoload=0
51 # fs.protected_symlinks=1
52 # fs.protected_hardlinks=1
53 # fs.protected_fifos=2
54 # fs.protected_regular=2
56 # kernel.modules_disabled=1
59 # pylint: disable=missing-module-docstring,missing-class-docstring,missing-function-docstring
60 # pylint: disable=line-too-long,invalid-name,too-many-branches,too-many-statements
64 from argparse import ArgumentParser
65 from collections import OrderedDict
68 from .__about__ import __version__
72 def __init__(self, reason, decision, name, expected):
74 self.expected = expected
75 self.decision = decision
81 if self.expected == self.state:
83 elif self.state is None:
84 if self.expected == 'is not set':
85 self.result = 'OK: not found'
87 self.result = 'FAIL: not found'
89 self.result = 'FAIL: "' + self.state + '"'
91 if self.result.startswith('OK'):
95 def table_print(self, _mode, with_results):
96 print('CONFIG_{:<38}|{:^13}|{:^10}|{:^20}'.format(self.name, self.expected, self.decision, self.reason), end='')
98 print('| {}'.format(self.result), end='')
102 def __init__(self, ver_expected):
103 self.ver_expected = ver_expected
108 if self.ver[0] > self.ver_expected[0]:
109 self.result = 'OK: version >= ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
111 if self.ver[0] < self.ver_expected[0]:
112 self.result = 'FAIL: version < ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
114 if self.ver[1] >= self.ver_expected[1]:
115 self.result = 'OK: version >= ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
117 self.result = 'FAIL: version < ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
120 def table_print(self, _mode, with_results):
121 ver_req = 'kernel version >= ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
122 print('{:<91}'.format(ver_req), end='')
124 print('| {}'.format(self.result), end='')
128 def __init__(self, name):
134 if self.state is None:
135 self.result = 'FAIL: not present'
137 self.result = 'OK: is present'
140 def table_print(self, _mode, with_results):
141 print('CONFIG_{:<84}'.format(self.name + ' is present'), end='')
143 print('| {}'.format(self.result), end='')
146 class ComplexOptCheck:
147 def __init__(self, *opts):
153 return self.opts[0].name
157 return self.opts[0].expected
161 return self.opts[0].decision
165 return self.opts[0].reason
167 def table_print(self, mode, with_results):
168 if mode == 'verbose':
169 print(' {:87}'.format('<<< ' + self.__class__.__name__ + ' >>>'), end='')
171 print('| {}'.format(self.result), end='')
174 o.table_print(mode, with_results)
177 o.table_print(mode, False)
179 print('| {}'.format(self.result), end='')
182 class OR(ComplexOptCheck):
183 # self.opts[0] is the option that this OR-check is about.
185 # OR(<X_is_hardened>, <X_is_disabled>)
186 # OR(<X_is_hardened>, <old_X_is_hardened>)
190 sys.exit('[!] ERROR: invalid OR check')
192 for i, opt in enumerate(self.opts):
195 if i == 0 or not hasattr(opt, 'expected'):
196 self.result = opt.result
198 self.result = 'OK: CONFIG_{} "{}"'.format(opt.name, opt.expected)
200 self.result = self.opts[0].result
204 class AND(ComplexOptCheck):
205 # self.opts[0] is the option that this AND-check is about.
207 # AND(<suboption>, <main_option>)
208 # Suboption is not checked if checking of the main_option is failed.
209 # AND(<X_is_disabled>, <old_X_is_disabled>)
212 for i, opt in reversed(list(enumerate(self.opts))):
215 self.result = opt.result
218 if hasattr(opt, 'expected'):
219 self.result = 'FAIL: CONFIG_{} not "{}"'.format(opt.name, opt.expected)
221 self.result = opt.result
224 sys.exit('[!] ERROR: invalid AND check')
227 def detect_arch(fname, archs):
228 with open(fname, 'r') as f:
229 arch_pattern = re.compile("CONFIG_[a-zA-Z0-9_]*=y")
231 for line in f.readlines():
232 if arch_pattern.match(line):
233 option, _ = line[7:].split('=', 1)
238 return None, 'more than one supported architecture is detected'
240 return None, 'failed to detect architecture'
244 def detect_version(fname):
245 with open(fname, 'r') as f:
246 ver_pattern = re.compile("# Linux/.* Kernel Configuration")
247 for line in f.readlines():
248 if ver_pattern.match(line):
252 ver_numbers = ver_str.split('.')
253 if len(ver_numbers) < 3 or not ver_numbers[0].isdigit() or not ver_numbers[1].isdigit():
254 msg = 'failed to parse the version "' + ver_str + '"'
256 return (int(ver_numbers[0]), int(ver_numbers[1])), None
257 return None, 'no kernel version detected'
260 def construct_checklist(l, arch):
261 modules_not_set = OptCheck('cut_attack_surface', 'kspp', 'MODULES', 'is not set')
262 devmem_not_set = OptCheck('cut_attack_surface', 'kspp', 'DEVMEM', 'is not set') # refers to LOCKDOWN
264 # 'self_protection', 'defconfig'
265 l += [OptCheck('self_protection', 'defconfig', 'BUG', 'y')]
266 l += [OptCheck('self_protection', 'defconfig', 'SLUB_DEBUG', 'y')]
267 l += [OptCheck('self_protection', 'defconfig', 'GCC_PLUGINS', 'y')]
268 l += [OR(OptCheck('self_protection', 'defconfig', 'STACKPROTECTOR_STRONG', 'y'),
269 OptCheck('self_protection', 'defconfig', 'CC_STACKPROTECTOR_STRONG', 'y'))]
270 l += [OR(OptCheck('self_protection', 'defconfig', 'STRICT_KERNEL_RWX', 'y'),
271 OptCheck('self_protection', 'defconfig', 'DEBUG_RODATA', 'y'))] # before v4.11
272 l += [OR(OptCheck('self_protection', 'defconfig', 'STRICT_MODULE_RWX', 'y'),
273 OptCheck('self_protection', 'defconfig', 'DEBUG_SET_MODULE_RONX', 'y'),
274 modules_not_set)] # DEBUG_SET_MODULE_RONX was before v4.11
275 l += [OR(OptCheck('self_protection', 'defconfig', 'REFCOUNT_FULL', 'y'),
276 VerCheck((5, 5)))] # REFCOUNT_FULL is enabled by default since v5.5
277 iommu_support_is_set = OptCheck('self_protection', 'defconfig', 'IOMMU_SUPPORT', 'y')
278 l += [iommu_support_is_set] # is needed for mitigating DMA attacks
279 if arch in ('X86_64', 'X86_32'):
280 l += [OptCheck('self_protection', 'defconfig', 'MICROCODE', 'y')] # is needed for mitigating CPU bugs
281 l += [OptCheck('self_protection', 'defconfig', 'RETPOLINE', 'y')]
282 l += [OptCheck('self_protection', 'defconfig', 'X86_SMAP', 'y')]
283 l += [OptCheck('self_protection', 'defconfig', 'SYN_COOKIES', 'y')] # another reason?
284 l += [OR(OptCheck('self_protection', 'defconfig', 'X86_UMIP', 'y'),
285 OptCheck('self_protection', 'defconfig', 'X86_INTEL_UMIP', 'y'))]
287 l += [OptCheck('self_protection', 'defconfig', 'PAGE_TABLE_ISOLATION', 'y')]
288 l += [OptCheck('self_protection', 'defconfig', 'RANDOMIZE_MEMORY', 'y')]
289 l += [AND(OptCheck('self_protection', 'defconfig', 'INTEL_IOMMU', 'y'),
290 iommu_support_is_set)]
291 l += [AND(OptCheck('self_protection', 'defconfig', 'AMD_IOMMU', 'y'),
292 iommu_support_is_set)]
294 l += [OptCheck('self_protection', 'defconfig', 'ARM64_PAN', 'y')]
295 l += [OptCheck('self_protection', 'defconfig', 'UNMAP_KERNEL_AT_EL0', 'y')]
296 l += [OptCheck('self_protection', 'defconfig', 'HARDEN_EL2_VECTORS', 'y')]
297 l += [OptCheck('self_protection', 'defconfig', 'RODATA_FULL_DEFAULT_ENABLED', 'y')]
298 l += [OptCheck('self_protection', 'defconfig', 'ARM64_PTR_AUTH', 'y')]
299 if arch in ('X86_64', 'ARM64'):
300 l += [OptCheck('self_protection', 'defconfig', 'VMAP_STACK', 'y')]
301 if arch in ('X86_64', 'ARM64', 'X86_32'):
302 l += [OptCheck('self_protection', 'defconfig', 'RANDOMIZE_BASE', 'y')]
303 l += [OptCheck('self_protection', 'defconfig', 'THREAD_INFO_IN_TASK', 'y')]
305 l += [OptCheck('self_protection', 'defconfig', 'CPU_SW_DOMAIN_PAN', 'y')]
306 l += [OptCheck('self_protection', 'defconfig', 'STACKPROTECTOR_PER_TASK', 'y')]
307 if arch in ('ARM64', 'ARM'):
308 l += [OptCheck('self_protection', 'defconfig', 'HARDEN_BRANCH_PREDICTOR', 'y')]
310 # 'self_protection', 'kspp'
311 l += [OptCheck('self_protection', 'kspp', 'BUG_ON_DATA_CORRUPTION', 'y')]
312 l += [OptCheck('self_protection', 'kspp', 'DEBUG_WX', 'y')]
313 l += [OptCheck('self_protection', 'kspp', 'SCHED_STACK_END_CHECK', 'y')]
314 l += [OptCheck('self_protection', 'kspp', 'SLAB_FREELIST_HARDENED', 'y')]
315 l += [OptCheck('self_protection', 'kspp', 'SLAB_FREELIST_RANDOM', 'y')]
316 l += [OptCheck('self_protection', 'kspp', 'SHUFFLE_PAGE_ALLOCATOR', 'y')]
317 l += [OptCheck('self_protection', 'kspp', 'FORTIFY_SOURCE', 'y')]
318 l += [OptCheck('self_protection', 'kspp', 'DEBUG_LIST', 'y')]
319 l += [OptCheck('self_protection', 'kspp', 'DEBUG_SG', 'y')]
320 l += [OptCheck('self_protection', 'kspp', 'DEBUG_CREDENTIALS', 'y')]
321 l += [OptCheck('self_protection', 'kspp', 'DEBUG_NOTIFIERS', 'y')]
322 l += [OptCheck('self_protection', 'kspp', 'INIT_ON_ALLOC_DEFAULT_ON', 'y')]
323 l += [OptCheck('self_protection', 'kspp', 'GCC_PLUGIN_LATENT_ENTROPY', 'y')]
324 randstruct_is_set = OptCheck('self_protection', 'kspp', 'GCC_PLUGIN_RANDSTRUCT', 'y')
325 l += [randstruct_is_set]
326 hardened_usercopy_is_set = OptCheck('self_protection', 'kspp', 'HARDENED_USERCOPY', 'y')
327 l += [hardened_usercopy_is_set]
328 l += [AND(OptCheck('self_protection', 'kspp', 'HARDENED_USERCOPY_FALLBACK', 'is not set'),
329 hardened_usercopy_is_set)]
330 l += [OR(OptCheck('self_protection', 'kspp', 'MODULE_SIG', 'y'),
332 l += [OR(OptCheck('self_protection', 'kspp', 'MODULE_SIG_ALL', 'y'),
334 l += [OR(OptCheck('self_protection', 'kspp', 'MODULE_SIG_SHA512', 'y'),
336 l += [OR(OptCheck('self_protection', 'kspp', 'MODULE_SIG_FORCE', 'y'),
337 modules_not_set)] # refers to LOCKDOWN
338 l += [OR(OptCheck('self_protection', 'kspp', 'INIT_STACK_ALL', 'y'),
339 OptCheck('self_protection', 'kspp', 'GCC_PLUGIN_STRUCTLEAK_BYREF_ALL', 'y'))]
340 l += [OR(OptCheck('self_protection', 'kspp', 'INIT_ON_FREE_DEFAULT_ON', 'y'),
341 OptCheck('self_protection', 'kspp', 'PAGE_POISONING', 'y'))] # before v5.3
342 if arch in ('X86_64', 'ARM64', 'X86_32'):
343 stackleak_is_set = OptCheck('self_protection', 'kspp', 'GCC_PLUGIN_STACKLEAK', 'y')
344 l += [stackleak_is_set]
345 if arch in ('X86_64', 'X86_32'):
346 l += [OptCheck('self_protection', 'kspp', 'DEFAULT_MMAP_MIN_ADDR', '65536')]
348 l += [OptCheck('self_protection', 'kspp', 'PAGE_TABLE_ISOLATION', 'y')]
349 l += [OptCheck('self_protection', 'kspp', 'HIGHMEM64G', 'y')]
350 l += [OptCheck('self_protection', 'kspp', 'X86_PAE', 'y')]
352 l += [OptCheck('self_protection', 'kspp', 'ARM64_SW_TTBR0_PAN', 'y')]
353 if arch in ('ARM64', 'ARM'):
354 l += [OptCheck('self_protection', 'kspp', 'SYN_COOKIES', 'y')] # another reason?
355 l += [OptCheck('self_protection', 'kspp', 'DEFAULT_MMAP_MIN_ADDR', '32768')]
357 # 'self_protection', 'clipos'
358 l += [OptCheck('self_protection', 'clipos', 'SECURITY_DMESG_RESTRICT', 'y')]
359 l += [OptCheck('self_protection', 'clipos', 'DEBUG_VIRTUAL', 'y')]
360 l += [OptCheck('self_protection', 'clipos', 'STATIC_USERMODEHELPER', 'y')] # needs userspace support
361 l += [OptCheck('self_protection', 'clipos', 'EFI_DISABLE_PCI_DMA', 'y')]
362 l += [OptCheck('self_protection', 'clipos', 'SLAB_MERGE_DEFAULT', 'is not set')] # slab_nomerge
363 l += [OptCheck('self_protection', 'clipos', 'RANDOM_TRUST_BOOTLOADER', 'is not set')]
364 l += [OptCheck('self_protection', 'clipos', 'RANDOM_TRUST_CPU', 'is not set')]
365 l += [AND(OptCheck('self_protection', 'clipos', 'GCC_PLUGIN_RANDSTRUCT_PERFORMANCE', 'is not set'),
367 if arch in ('X86_64', 'ARM64', 'X86_32'):
368 l += [AND(OptCheck('self_protection', 'clipos', 'STACKLEAK_METRICS', 'is not set'),
370 l += [AND(OptCheck('self_protection', 'clipos', 'STACKLEAK_RUNTIME_DISABLE', 'is not set'),
372 if arch in ('X86_64', 'X86_32'):
373 l += [AND(OptCheck('self_protection', 'clipos', 'INTEL_IOMMU_SVM', 'y'),
374 iommu_support_is_set)]
375 l += [AND(OptCheck('self_protection', 'clipos', 'INTEL_IOMMU_DEFAULT_ON', 'y'),
376 iommu_support_is_set)]
378 l += [AND(OptCheck('self_protection', 'clipos', 'INTEL_IOMMU', 'y'),
379 iommu_support_is_set)]
381 # 'self_protection', 'my'
382 l += [OptCheck('self_protection', 'my', 'SLUB_DEBUG_ON', 'y')]
383 l += [OptCheck('self_protection', 'my', 'RESET_ATTACK_MITIGATION', 'y')] # needs userspace support (systemd)
385 l += [AND(OptCheck('self_protection', 'my', 'AMD_IOMMU_V2', 'y'),
386 iommu_support_is_set)]
389 if arch in ('X86_64', 'ARM64', 'X86_32'):
390 l += [OptCheck('security_policy', 'defconfig', 'SECURITY', 'y')] # and choose your favourite LSM
392 l += [OptCheck('security_policy', 'kspp', 'SECURITY', 'y')] # and choose your favourite LSM
393 l += [OptCheck('security_policy', 'kspp', 'SECURITY_YAMA', 'y')]
394 l += [OR(OptCheck('security_policy', 'my', 'SECURITY_WRITABLE_HOOKS', 'is not set'),
395 OptCheck('security_policy', 'kspp', 'SECURITY_SELINUX_DISABLE', 'is not set'))]
396 l += [OptCheck('security_policy', 'clipos', 'SECURITY_LOCKDOWN_LSM', 'y')]
397 l += [OptCheck('security_policy', 'clipos', 'SECURITY_LOCKDOWN_LSM_EARLY', 'y')]
398 l += [OptCheck('security_policy', 'clipos', 'LOCK_DOWN_KERNEL_FORCE_CONFIDENTIALITY', 'y')]
399 l += [OptCheck('security_policy', 'my', 'SECURITY_SAFESETID', 'y')]
400 loadpin_is_set = OptCheck('security_policy', 'my', 'SECURITY_LOADPIN', 'y')
401 l += [loadpin_is_set] # needs userspace support
402 l += [AND(OptCheck('security_policy', 'my', 'SECURITY_LOADPIN_ENFORCE', 'y'),
405 # 'cut_attack_surface', 'defconfig'
406 l += [OptCheck('cut_attack_surface', 'defconfig', 'SECCOMP', 'y')]
407 l += [OptCheck('cut_attack_surface', 'defconfig', 'SECCOMP_FILTER', 'y')]
408 if arch in ('X86_64', 'ARM64', 'X86_32'):
409 l += [OR(OptCheck('cut_attack_surface', 'defconfig', 'STRICT_DEVMEM', 'y'),
410 devmem_not_set)] # refers to LOCKDOWN
412 # 'cut_attack_surface', 'kspp'
413 l += [OptCheck('cut_attack_surface', 'kspp', 'ACPI_CUSTOM_METHOD', 'is not set')] # refers to LOCKDOWN
414 l += [OptCheck('cut_attack_surface', 'kspp', 'COMPAT_BRK', 'is not set')]
415 l += [OptCheck('cut_attack_surface', 'kspp', 'DEVKMEM', 'is not set')] # refers to LOCKDOWN
416 l += [OptCheck('cut_attack_surface', 'kspp', 'COMPAT_VDSO', 'is not set')]
417 l += [OptCheck('cut_attack_surface', 'kspp', 'BINFMT_MISC', 'is not set')]
418 l += [OptCheck('cut_attack_surface', 'kspp', 'INET_DIAG', 'is not set')]
419 l += [OptCheck('cut_attack_surface', 'kspp', 'KEXEC', 'is not set')] # refers to LOCKDOWN
420 l += [OptCheck('cut_attack_surface', 'kspp', 'PROC_KCORE', 'is not set')] # refers to LOCKDOWN
421 l += [OptCheck('cut_attack_surface', 'kspp', 'LEGACY_PTYS', 'is not set')]
422 l += [OptCheck('cut_attack_surface', 'kspp', 'HIBERNATION', 'is not set')] # refers to LOCKDOWN
423 l += [OptCheck('cut_attack_surface', 'kspp', 'IA32_EMULATION', 'is not set')]
424 l += [OptCheck('cut_attack_surface', 'kspp', 'X86_X32', 'is not set')]
425 l += [OptCheck('cut_attack_surface', 'kspp', 'MODIFY_LDT_SYSCALL', 'is not set')]
426 l += [OptCheck('cut_attack_surface', 'kspp', 'OABI_COMPAT', 'is not set')]
427 l += [modules_not_set]
428 l += [devmem_not_set]
429 l += [OR(OptCheck('cut_attack_surface', 'kspp', 'IO_STRICT_DEVMEM', 'y'),
430 devmem_not_set)] # refers to LOCKDOWN
432 l += [OR(OptCheck('cut_attack_surface', 'kspp', 'STRICT_DEVMEM', 'y'),
433 devmem_not_set)] # refers to LOCKDOWN
435 l += [OptCheck('cut_attack_surface', 'kspp', 'LEGACY_VSYSCALL_NONE', 'y')] # 'vsyscall=none'
437 # 'cut_attack_surface', 'grsecurity'
438 l += [OptCheck('cut_attack_surface', 'grsecurity', 'ZSMALLOC_STAT', 'is not set')]
439 l += [OptCheck('cut_attack_surface', 'grsecurity', 'PAGE_OWNER', 'is not set')]
440 l += [OptCheck('cut_attack_surface', 'grsecurity', 'DEBUG_KMEMLEAK', 'is not set')]
441 l += [OptCheck('cut_attack_surface', 'grsecurity', 'BINFMT_AOUT', 'is not set')]
442 l += [OptCheck('cut_attack_surface', 'grsecurity', 'KPROBES', 'is not set')] # refers to LOCKDOWN
443 l += [OptCheck('cut_attack_surface', 'grsecurity', 'UPROBES', 'is not set')]
444 l += [OptCheck('cut_attack_surface', 'grsecurity', 'GENERIC_TRACER', 'is not set')] # refers to LOCKDOWN
445 l += [OptCheck('cut_attack_surface', 'grsecurity', 'PROC_VMCORE', 'is not set')]
446 l += [OptCheck('cut_attack_surface', 'grsecurity', 'PROC_PAGE_MONITOR', 'is not set')]
447 l += [OptCheck('cut_attack_surface', 'grsecurity', 'USELIB', 'is not set')]
448 l += [OptCheck('cut_attack_surface', 'grsecurity', 'CHECKPOINT_RESTORE', 'is not set')]
449 l += [OptCheck('cut_attack_surface', 'grsecurity', 'USERFAULTFD', 'is not set')]
450 l += [OptCheck('cut_attack_surface', 'grsecurity', 'HWPOISON_INJECT', 'is not set')]
451 l += [OptCheck('cut_attack_surface', 'grsecurity', 'MEM_SOFT_DIRTY', 'is not set')]
452 l += [OptCheck('cut_attack_surface', 'grsecurity', 'DEVPORT', 'is not set')] # refers to LOCKDOWN
453 l += [OptCheck('cut_attack_surface', 'grsecurity', 'DEBUG_FS', 'is not set')] # refers to LOCKDOWN
454 l += [OptCheck('cut_attack_surface', 'grsecurity', 'NOTIFIER_ERROR_INJECTION', 'is not set')]
455 l += [AND(OptCheck('cut_attack_surface', 'grsecurity', 'X86_PTDUMP', 'is not set'),
456 OptCheck('cut_attack_surface', 'my', 'PTDUMP_DEBUGFS', 'is not set'))]
458 # 'cut_attack_surface', 'maintainer'
459 l += [OptCheck('cut_attack_surface', 'maintainer', 'DRM_LEGACY', 'is not set')]
460 l += [OptCheck('cut_attack_surface', 'maintainer', 'FB', 'is not set')]
461 l += [OptCheck('cut_attack_surface', 'maintainer', 'VT', 'is not set')]
463 # 'cut_attack_surface', 'grapheneos'
464 l += [OptCheck('cut_attack_surface', 'grapheneos', 'AIO', 'is not set')]
466 # 'cut_attack_surface', 'clipos'
467 l += [OptCheck('cut_attack_surface', 'clipos', 'STAGING', 'is not set')]
468 l += [OptCheck('cut_attack_surface', 'clipos', 'KSM', 'is not set')] # to prevent FLUSH+RELOAD attack
469 # l += [OptCheck('cut_attack_surface', 'clipos', 'IKCONFIG', 'is not set')] # no, IKCONFIG is needed for this check :)
470 l += [OptCheck('cut_attack_surface', 'clipos', 'KALLSYMS', 'is not set')]
471 l += [OptCheck('cut_attack_surface', 'clipos', 'X86_VSYSCALL_EMULATION', 'is not set')]
472 l += [OptCheck('cut_attack_surface', 'clipos', 'MAGIC_SYSRQ', 'is not set')]
473 l += [OptCheck('cut_attack_surface', 'clipos', 'KEXEC_FILE', 'is not set')] # refers to LOCKDOWN (permissive)
474 l += [OptCheck('cut_attack_surface', 'clipos', 'USER_NS', 'is not set')] # user.max_user_namespaces=0
475 l += [OptCheck('cut_attack_surface', 'clipos', 'X86_MSR', 'is not set')] # refers to LOCKDOWN
476 l += [OptCheck('cut_attack_surface', 'clipos', 'X86_CPUID', 'is not set')]
477 l += [OptCheck('cut_attack_surface', 'clipos', 'IO_URING', 'is not set')]
478 l += [OptCheck('cut_attack_surface', 'clipos', 'X86_IOPL_IOPERM', 'is not set')] # refers to LOCKDOWN
479 l += [AND(OptCheck('cut_attack_surface', 'clipos', 'LDISC_AUTOLOAD', 'is not set'),
480 PresenceCheck('LDISC_AUTOLOAD'))]
481 if arch in ('X86_64', 'X86_32'):
482 l += [OptCheck('cut_attack_surface', 'clipos', 'X86_INTEL_TSX_MODE_OFF', 'y')] # tsx=off
484 # 'cut_attack_surface', 'lockdown'
485 l += [OptCheck('cut_attack_surface', 'lockdown', 'ACPI_TABLE_UPGRADE', 'is not set')] # refers to LOCKDOWN
486 l += [OptCheck('cut_attack_surface', 'lockdown', 'EFI_TEST', 'is not set')] # refers to LOCKDOWN
487 l += [OptCheck('cut_attack_surface', 'lockdown', 'BPF_SYSCALL', 'is not set')] # refers to LOCKDOWN
488 l += [OptCheck('cut_attack_surface', 'lockdown', 'MMIOTRACE_TEST', 'is not set')] # refers to LOCKDOWN
490 # 'cut_attack_surface', 'my'
491 l += [OptCheck('cut_attack_surface', 'my', 'MMIOTRACE', 'is not set')] # refers to LOCKDOWN (permissive)
492 l += [OptCheck('cut_attack_surface', 'my', 'LIVEPATCH', 'is not set')]
493 l += [OptCheck('cut_attack_surface', 'my', 'IP_DCCP', 'is not set')]
494 l += [OptCheck('cut_attack_surface', 'my', 'IP_SCTP', 'is not set')]
495 l += [OptCheck('cut_attack_surface', 'my', 'FTRACE', 'is not set')] # refers to LOCKDOWN
496 l += [OptCheck('cut_attack_surface', 'my', 'VIDEO_VIVID', 'is not set')]
497 l += [OptCheck('cut_attack_surface', 'my', 'INPUT_EVBUG', 'is not set')] # Can be used as a keylogger
499 # 'userspace_hardening'
500 if arch in ('X86_64', 'ARM64', 'X86_32'):
501 l += [OptCheck('userspace_hardening', 'defconfig', 'INTEGRITY', 'y')]
503 l += [OptCheck('userspace_hardening', 'my', 'INTEGRITY', 'y')]
504 if arch in ('ARM', 'X86_32'):
505 l += [OptCheck('userspace_hardening', 'defconfig', 'VMSPLIT_3G', 'y')]
506 if arch in ('X86_64', 'ARM64'):
507 l += [OptCheck('userspace_hardening', 'clipos', 'ARCH_MMAP_RND_BITS', '32')]
508 if arch in ('X86_32', 'ARM'):
509 l += [OptCheck('userspace_hardening', 'my', 'ARCH_MMAP_RND_BITS', '16')]
511 # l += [OptCheck('feature_test', 'my', 'LKDTM', 'm')] # only for debugging!
514 def print_unknown_options(checklist, parsed_options):
516 for opt in checklist:
517 if hasattr(opt, 'opts'):
519 if hasattr(o, 'name'):
520 known_options.append(o.name)
522 known_options.append(opt.name)
523 for option, value in parsed_options.items():
524 if option not in known_options:
525 print('[?] No rule for option {} ({})'.format(option, value))
528 def print_checklist(mode, checklist, with_results):
532 opt = ['CONFIG_'+o.name, o.expected, o.decision, o.reason]
536 print(json.dumps(opts))
543 print('=' * sep_line_len)
544 print('{:^45}|{:^13}|{:^10}|{:^20}'.format('option name', 'desired val', 'decision', 'reason'), end='')
546 print('| {}'.format('check result'), end='')
548 print('=' * sep_line_len)
551 for opt in checklist:
553 if mode == 'show_ok':
554 if not opt.result.startswith('OK'):
556 if mode == 'show_fail':
557 if not opt.result.startswith('FAIL'):
559 opt.table_print(mode, with_results)
561 if mode == 'verbose':
562 print('-' * sep_line_len)
567 fail_count = len(list(filter(lambda opt: opt.result.startswith('FAIL'), checklist)))
569 ok_count = len(list(filter(lambda opt: opt.result.startswith('OK'), checklist)))
571 if mode == 'show_ok':
572 fail_suppressed = ' (suppressed in output)'
573 if mode == 'show_fail':
574 ok_suppressed = ' (suppressed in output)'
576 print('[+] Config check is finished: \'OK\' - {}{} / \'FAIL\' - {}{}'.format(ok_count, ok_suppressed, fail_count, fail_suppressed))
579 def perform_checks(checklist, parsed_options, kernel_version):
580 for opt in checklist:
581 if hasattr(opt, 'opts'):
582 # prepare ComplexOptCheck
584 if hasattr(o, 'state'):
585 o.state = parsed_options.get(o.name, None)
586 if hasattr(o, 'ver'):
587 o.ver = kernel_version
589 # prepare simple check
590 if not hasattr(opt, 'state'):
591 sys.exit('[!] ERROR: bad simple check {}'.format(vars(opt)))
592 opt.state = parsed_options.get(opt.name, None)
596 def parse_config_file(parsed_options, fname):
597 with open(fname, 'r') as f:
598 opt_is_on = re.compile("CONFIG_[a-zA-Z0-9_]*=[a-zA-Z0-9_\"]*")
599 opt_is_off = re.compile("# CONFIG_[a-zA-Z0-9_]* is not set")
601 for line in f.readlines():
606 if opt_is_on.match(line):
607 option, value = line[7:].split('=', 1)
608 elif opt_is_off.match(line):
609 option, value = line[9:].split(' ', 1)
610 if value != 'is not set':
611 sys.exit('[!] ERROR: bad disabled config option "{}"'.format(line))
613 if option in parsed_options:
614 sys.exit('[!] ERROR: config option "{}" exists multiple times'.format(line))
617 parsed_options[option] = value
619 return parsed_options
625 # - reporting about unknown kernel options in the config
626 # - verbose printing of ComplexOptCheck items
627 # * json mode for printing the results in JSON format
628 report_modes = ['verbose', 'json', 'show_ok', 'show_fail']
629 supported_archs = ['X86_64', 'X86_32', 'ARM64', 'ARM']
630 parser = ArgumentParser(prog='kconfig-hardened-check',
631 description='Checks the hardening options in the Linux kernel config')
632 parser.add_argument('--version', action='version', version='%(prog)s ' + __version__)
633 parser.add_argument('-p', '--print', choices=supported_archs,
634 help='print hardening preferences for selected architecture')
635 parser.add_argument('-c', '--config',
636 help='check the kernel config file against these preferences')
637 parser.add_argument('-m', '--mode', choices=report_modes,
638 help='choose the report mode')
639 args = parser.parse_args()
645 print("[+] Special report mode: {}".format(mode))
647 config_checklist = []
651 print('[+] Config file to check: {}'.format(args.config))
653 arch, msg = detect_arch(args.config, supported_archs)
655 sys.exit('[!] ERROR: {}'.format(msg))
657 print('[+] Detected architecture: {}'.format(arch))
659 kernel_version, msg = detect_version(args.config)
660 if not kernel_version:
661 sys.exit('[!] ERROR: {}'.format(msg))
663 print('[+] Detected kernel version: {}.{}'.format(kernel_version[0], kernel_version[1]))
665 construct_checklist(config_checklist, arch)
666 parsed_options = OrderedDict()
667 parse_config_file(parsed_options, args.config)
668 perform_checks(config_checklist, parsed_options, kernel_version)
670 if mode == 'verbose':
671 print_unknown_options(config_checklist, parsed_options)
672 print_checklist(mode, config_checklist, True)
677 if mode in ('show_ok', 'show_fail'):
678 sys.exit('[!] ERROR: please use "{}" mode for checking the kernel config'.format(mode))
680 construct_checklist(config_checklist, arch)
682 print('[+] Printing kernel hardening preferences for {}...'.format(arch))
683 print_checklist(mode, config_checklist, False)
689 if __name__ == '__main__':