4 # This script 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 # kernel.kptr_restrict=1
17 # lockdown=1 (is it changed?)
18 # page_alloc.shuffle=1
19 # iommu=force (does it help against DMA attacks?)
20 # page_poison=1 (if enabled)
24 # Mitigations of CPU vulnerabilities:
26 # mitigations=auto,nosmt
30 # spec_store_bypass_disable=on
37 # N.B. Hardening sysctls:
38 # net.core.bpf_jit_harden=2
40 # vm.unprivileged_userfaultfd=0
41 # kernel.perf_event_paranoid=3
42 # kernel.yama.ptrace_scope=1 (or even 3?)
43 # kernel.unprivileged_bpf_disabled=1
45 # fs.protected_symlinks = 1
46 # fs.protected_hardlinks = 1
47 # fs.protected_fifos = 2
48 # fs.protected_regular = 2
51 from argparse import ArgumentParser
52 from collections import OrderedDict
57 # - reporting about unknown kernel options in the config,
58 # - showing all checks from all supported platforms,
59 # - verbose printing of ComplexOptChecks (OR, AND).
62 # json_mode is for printing results in JSON format
65 supported_archs = [ 'X86_64', 'X86_32', 'ARM64', 'ARM' ]
71 def __init__(self, name, expected, decision, reason):
73 self.expected = expected
74 self.decision = decision
80 if self.expected == self.state:
82 elif self.state is None:
83 if self.expected == 'is not set':
84 self.result = 'OK: not found'
86 self.result = 'FAIL: not found'
88 self.result = 'FAIL: "' + self.state + '"'
90 if self.result.startswith('OK'):
91 return True, self.result
93 return False, self.result
97 def __init__(self, ver_expected):
98 self.ver_expected = ver_expected
102 if kernel_version[0] > self.ver_expected[0]:
103 self.result = 'OK: version >= ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
104 return True, self.result
105 if kernel_version[0] < self.ver_expected[0]:
106 self.result = 'FAIL: version < ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
107 return False, self.result
108 if kernel_version[1] >= self.ver_expected[1]:
109 self.result = 'OK: version >= ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
110 return True, self.result
112 self.result = 'FAIL: version < ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
113 return False, self.result
116 class ComplexOptCheck:
117 def __init__(self, *opts):
123 return self.opts[0].name
127 return self.opts[0].expected
131 return self.opts[0].state
135 return self.opts[0].decision
139 return self.opts[0].reason
142 class OR(ComplexOptCheck):
143 # self.opts[0] is the option which this OR-check is about.
145 # OR(<X_is_hardened>, <X_is_disabled>)
146 # OR(<X_is_hardened>, <X_is_hardened_old>)
150 sys.exit('[!] ERROR: invalid OR check')
152 for i, opt in enumerate(self.opts):
153 ret, msg = opt.check()
155 if i == 0 or not hasattr(opt, 'name'):
156 self.result = opt.result
158 self.result = 'OK: CONFIG_{} "{}"'.format(opt.name, opt.expected)
159 return True, self.result
160 self.result = self.opts[0].result
161 return False, self.result
164 class AND(ComplexOptCheck):
165 # self.opts[0] is the option which this AND-check is about.
166 # Use case: AND(<suboption>, <main_option>)
167 # Suboption is not checked if checking of the main_option is failed.
170 for i, opt in reversed(list(enumerate(self.opts))):
171 ret, msg = opt.check()
173 self.result = opt.result
174 return ret, self.result
176 if hasattr(opt, 'name'):
177 self.result = 'FAIL: CONFIG_{} is needed'.format(opt.name)
179 self.result = opt.result
180 return False, self.result
182 sys.exit('[!] ERROR: invalid AND check')
185 def detect_arch(fname):
186 with open(fname, 'r') as f:
187 arch_pattern = re.compile("CONFIG_[a-zA-Z0-9_]*=y")
190 print('[+] Trying to detect architecture in "{}"...'.format(fname))
191 for line in f.readlines():
192 if arch_pattern.match(line):
193 option, value = line[7:].split('=', 1)
194 if option in supported_archs:
198 return None, 'more than one supported architecture is detected'
200 return None, 'failed to detect architecture'
205 def detect_version(fname):
206 with open(fname, 'r') as f:
207 ver_pattern = re.compile("# Linux/.* Kernel Configuration")
209 print('[+] Trying to detect kernel version in "{}"...'.format(fname))
210 for line in f.readlines():
211 if ver_pattern.match(line):
214 print('[+] Found version line: "{}"'.format(line))
217 ver_numbers = ver_str.split('.')
218 if len(ver_numbers) < 3 or not ver_numbers[0].isdigit() or not ver_numbers[1].isdigit():
219 msg = 'failed to parse the version "' + ver_str + '"'
222 return (int(ver_numbers[0]), int(ver_numbers[1])), None
223 return None, 'no kernel version detected'
226 def construct_checklist(checklist, arch):
227 modules_not_set = OptCheck('MODULES', 'is not set', 'kspp', 'cut_attack_surface')
228 devmem_not_set = OptCheck('DEVMEM', 'is not set', 'kspp', 'cut_attack_surface') # refers to LOCK_DOWN_KERNEL
230 checklist.append(OptCheck('BUG', 'y', 'defconfig', 'self_protection'))
231 checklist.append(OR(OptCheck('STRICT_KERNEL_RWX', 'y', 'defconfig', 'self_protection'), \
232 OptCheck('DEBUG_RODATA', 'y', 'defconfig', 'self_protection'))) # before v4.11
233 checklist.append(OR(OptCheck('STACKPROTECTOR_STRONG', 'y', 'defconfig', 'self_protection'), \
234 OptCheck('CC_STACKPROTECTOR_STRONG', 'y', 'defconfig', 'self_protection')))
235 checklist.append(OptCheck('SLUB_DEBUG', 'y', 'defconfig', 'self_protection'))
236 checklist.append(OR(OptCheck('STRICT_MODULE_RWX', 'y', 'defconfig', 'self_protection'), \
237 OptCheck('DEBUG_SET_MODULE_RONX', 'y', 'defconfig', 'self_protection'), \
238 modules_not_set)) # DEBUG_SET_MODULE_RONX was before v4.11
239 checklist.append(OptCheck('GCC_PLUGINS', 'y', 'defconfig', 'self_protection'))
240 checklist.append(OR(OptCheck('REFCOUNT_FULL', 'y', 'defconfig', 'self_protection'), \
241 VerCheck((5, 5)))) # REFCOUNT_FULL is enabled by default since v5.5
242 if debug_mode or arch == 'X86_64' or arch == 'X86_32':
243 checklist.append(OptCheck('MICROCODE', 'y', 'defconfig', 'self_protection')) # is needed for mitigating CPU bugs
244 checklist.append(OptCheck('RETPOLINE', 'y', 'defconfig', 'self_protection'))
245 checklist.append(OptCheck('X86_SMAP', 'y', 'defconfig', 'self_protection'))
246 checklist.append(OR(OptCheck('X86_UMIP', 'y', 'defconfig', 'self_protection'), \
247 OptCheck('X86_INTEL_UMIP', 'y', 'defconfig', 'self_protection')))
248 iommu_support_is_set = OptCheck('IOMMU_SUPPORT', 'y', 'defconfig', 'self_protection') # is needed for mitigating DMA attacks
249 checklist.append(iommu_support_is_set)
250 checklist.append(OptCheck('SYN_COOKIES', 'y', 'defconfig', 'self_protection')) # another reason?
251 if debug_mode or arch == 'X86_64':
252 checklist.append(OptCheck('PAGE_TABLE_ISOLATION', 'y', 'defconfig', 'self_protection'))
253 checklist.append(OptCheck('RANDOMIZE_MEMORY', 'y', 'defconfig', 'self_protection'))
254 checklist.append(AND(OptCheck('INTEL_IOMMU', 'y', 'defconfig', 'self_protection'), \
255 iommu_support_is_set))
256 checklist.append(AND(OptCheck('AMD_IOMMU', 'y', 'defconfig', 'self_protection'), \
257 iommu_support_is_set))
258 if debug_mode or arch == 'ARM64':
259 checklist.append(OptCheck('UNMAP_KERNEL_AT_EL0', 'y', 'defconfig', 'self_protection'))
260 checklist.append(OptCheck('HARDEN_EL2_VECTORS', 'y', 'defconfig', 'self_protection'))
261 checklist.append(OptCheck('RODATA_FULL_DEFAULT_ENABLED', 'y', 'defconfig', 'self_protection'))
262 if debug_mode or arch == 'X86_64' or arch == 'ARM64':
263 checklist.append(OptCheck('VMAP_STACK', 'y', 'defconfig', 'self_protection'))
264 if debug_mode or arch == 'X86_64' or arch == 'ARM64' or arch == 'X86_32':
265 checklist.append(OptCheck('RANDOMIZE_BASE', 'y', 'defconfig', 'self_protection'))
266 checklist.append(OptCheck('THREAD_INFO_IN_TASK', 'y', 'defconfig', 'self_protection'))
267 if debug_mode or arch == 'ARM':
268 checklist.append(OptCheck('VMSPLIT_3G', 'y', 'defconfig', 'self_protection'))
269 checklist.append(OptCheck('CPU_SW_DOMAIN_PAN', 'y', 'defconfig', 'self_protection'))
270 checklist.append(OptCheck('STACKPROTECTOR_PER_TASK', 'y', 'defconfig', 'self_protection'))
271 if debug_mode or arch == 'ARM64' or arch == 'ARM':
272 checklist.append(OptCheck('HARDEN_BRANCH_PREDICTOR', 'y', 'defconfig', 'self_protection'))
274 checklist.append(OptCheck('BUG_ON_DATA_CORRUPTION', 'y', 'kspp', 'self_protection'))
275 checklist.append(OptCheck('DEBUG_WX', 'y', 'kspp', 'self_protection'))
276 checklist.append(OptCheck('SCHED_STACK_END_CHECK', 'y', 'kspp', 'self_protection'))
277 checklist.append(OptCheck('SLAB_FREELIST_HARDENED', 'y', 'kspp', 'self_protection'))
278 checklist.append(OptCheck('SLAB_FREELIST_RANDOM', 'y', 'kspp', 'self_protection'))
279 checklist.append(OptCheck('SHUFFLE_PAGE_ALLOCATOR', 'y', 'kspp', 'self_protection'))
280 checklist.append(OptCheck('FORTIFY_SOURCE', 'y', 'kspp', 'self_protection'))
281 randstruct_is_set = OptCheck('GCC_PLUGIN_RANDSTRUCT', 'y', 'kspp', 'self_protection')
282 checklist.append(randstruct_is_set)
283 checklist.append(OptCheck('GCC_PLUGIN_LATENT_ENTROPY', 'y', 'kspp', 'self_protection'))
284 checklist.append(OptCheck('DEBUG_LIST', 'y', 'kspp', 'self_protection'))
285 checklist.append(OptCheck('DEBUG_SG', 'y', 'kspp', 'self_protection'))
286 checklist.append(OptCheck('DEBUG_CREDENTIALS', 'y', 'kspp', 'self_protection'))
287 checklist.append(OptCheck('DEBUG_NOTIFIERS', 'y', 'kspp', 'self_protection'))
288 hardened_usercopy_is_set = OptCheck('HARDENED_USERCOPY', 'y', 'kspp', 'self_protection')
289 checklist.append(hardened_usercopy_is_set)
290 checklist.append(AND(OptCheck('HARDENED_USERCOPY_FALLBACK', 'is not set', 'kspp', 'self_protection'), \
291 hardened_usercopy_is_set))
292 checklist.append(OR(OptCheck('MODULE_SIG', 'y', 'kspp', 'self_protection'), \
294 checklist.append(OR(OptCheck('MODULE_SIG_ALL', 'y', 'kspp', 'self_protection'), \
296 checklist.append(OR(OptCheck('MODULE_SIG_SHA512', 'y', 'kspp', 'self_protection'), \
298 checklist.append(OR(OptCheck('MODULE_SIG_FORCE', 'y', 'kspp', 'self_protection'), \
299 modules_not_set)) # refers to LOCK_DOWN_KERNEL
300 checklist.append(OR(OptCheck('INIT_STACK_ALL', 'y', 'kspp', 'self_protection'), \
301 OptCheck('GCC_PLUGIN_STRUCTLEAK_BYREF_ALL', 'y', 'kspp', 'self_protection')))
302 checklist.append(OptCheck('INIT_ON_ALLOC_DEFAULT_ON', 'y', 'kspp', 'self_protection'))
303 checklist.append(OR(OptCheck('INIT_ON_FREE_DEFAULT_ON', 'y', 'kspp', 'self_protection'), \
304 OptCheck('PAGE_POISONING', 'y', 'kspp', 'self_protection'))) # before v5.3
305 if debug_mode or arch == 'X86_64' or arch == 'ARM64' or arch == 'X86_32':
306 stackleak_is_set = OptCheck('GCC_PLUGIN_STACKLEAK', 'y', 'kspp', 'self_protection')
307 checklist.append(stackleak_is_set)
308 checklist.append(AND(OptCheck('STACKLEAK_METRICS', 'is not set', 'clipos', 'self_protection'), \
310 checklist.append(AND(OptCheck('STACKLEAK_RUNTIME_DISABLE', 'is not set', 'clipos', 'self_protection'), \
312 if debug_mode or arch == 'X86_64' or arch == 'X86_32':
313 checklist.append(OptCheck('DEFAULT_MMAP_MIN_ADDR', '65536', 'kspp', 'self_protection'))
314 if debug_mode or arch == 'X86_32':
315 checklist.append(OptCheck('HIGHMEM64G', 'y', 'kspp', 'self_protection'))
316 checklist.append(OptCheck('X86_PAE', 'y', 'kspp', 'self_protection'))
317 if debug_mode or arch == 'ARM64':
318 checklist.append(OptCheck('ARM64_SW_TTBR0_PAN', 'y', 'kspp', 'self_protection'))
319 if debug_mode or arch == 'ARM64' or arch == 'ARM':
320 checklist.append(OptCheck('SYN_COOKIES', 'y', 'kspp', 'self_protection')) # another reason?
321 checklist.append(OptCheck('DEFAULT_MMAP_MIN_ADDR', '32768', 'kspp', 'self_protection'))
323 checklist.append(OptCheck('SECURITY_DMESG_RESTRICT', 'y', 'clipos', 'self_protection'))
324 checklist.append(OptCheck('DEBUG_VIRTUAL', 'y', 'clipos', 'self_protection'))
325 checklist.append(OptCheck('STATIC_USERMODEHELPER', 'y', 'clipos', 'self_protection')) # needs userspace support (systemd)
326 checklist.append(OptCheck('SLAB_MERGE_DEFAULT', 'is not set', 'clipos', 'self_protection')) # slab_nomerge
327 checklist.append(AND(OptCheck('GCC_PLUGIN_RANDSTRUCT_PERFORMANCE', 'is not set', 'clipos', 'self_protection'), \
329 checklist.append(OptCheck('CONFIG_RANDOM_TRUST_BOOTLOADER', 'is not set', 'clipos', 'self_protection'))
330 if debug_mode or arch == 'X86_64' or arch == 'X86_32':
331 checklist.append(OptCheck('RANDOM_TRUST_CPU', 'is not set', 'clipos', 'self_protection'))
332 checklist.append(AND(OptCheck('INTEL_IOMMU_SVM', 'y', 'clipos', 'self_protection'), \
333 iommu_support_is_set))
334 checklist.append(AND(OptCheck('INTEL_IOMMU_DEFAULT_ON', 'y', 'clipos', 'self_protection'), \
335 iommu_support_is_set))
337 checklist.append(OptCheck('SLUB_DEBUG_ON', 'y', 'my', 'self_protection'))
338 checklist.append(OptCheck('RESET_ATTACK_MITIGATION', 'y', 'my', 'self_protection')) # needs userspace support (systemd)
339 if debug_mode or arch == 'X86_64':
340 checklist.append(AND(OptCheck('AMD_IOMMU_V2', 'y', 'my', 'self_protection'), \
341 iommu_support_is_set))
342 if debug_mode or arch == 'X86_32':
343 checklist.append(OptCheck('PAGE_TABLE_ISOLATION', 'y', 'my', 'self_protection'))
345 if debug_mode or arch == 'X86_64' or arch == 'ARM64' or arch == 'X86_32':
346 checklist.append(OptCheck('SECURITY', 'y', 'defconfig', 'security_policy')) # and choose your favourite LSM
347 if debug_mode or arch == 'ARM':
348 checklist.append(OptCheck('SECURITY', 'y', 'kspp', 'security_policy')) # and choose your favourite LSM
349 checklist.append(OptCheck('SECURITY_YAMA', 'y', 'kspp', 'security_policy'))
350 checklist.append(OptCheck('SECURITY_LOADPIN', 'y', 'my', 'security_policy')) # needs userspace support
351 checklist.append(OptCheck('SECURITY_LOCKDOWN_LSM', 'y', 'my', 'security_policy'))
352 checklist.append(OptCheck('SECURITY_LOCKDOWN_LSM_EARLY', 'y', 'my', 'security_policy'))
353 checklist.append(OptCheck('LOCK_DOWN_KERNEL_FORCE_CONFIDENTIALITY', 'y', 'my', 'security_policy'))
354 checklist.append(OptCheck('SECURITY_SAFESETID', 'y', 'my', 'security_policy'))
355 checklist.append(OptCheck('SECURITY_WRITABLE_HOOKS', 'is not set', 'my', 'security_policy'))
357 checklist.append(OptCheck('SECCOMP', 'y', 'defconfig', 'cut_attack_surface'))
358 checklist.append(OptCheck('SECCOMP_FILTER', 'y', 'defconfig', 'cut_attack_surface'))
359 if debug_mode or arch == 'X86_64' or arch == 'ARM64' or arch == 'X86_32':
360 checklist.append(OR(OptCheck('STRICT_DEVMEM', 'y', 'defconfig', 'cut_attack_surface'), \
361 devmem_not_set)) # refers to LOCK_DOWN_KERNEL
363 checklist.append(modules_not_set)
364 checklist.append(devmem_not_set)
365 checklist.append(OR(OptCheck('IO_STRICT_DEVMEM', 'y', 'kspp', 'cut_attack_surface'), \
366 devmem_not_set)) # refers to LOCK_DOWN_KERNEL
367 if debug_mode or arch == 'ARM':
368 checklist.append(OR(OptCheck('STRICT_DEVMEM', 'y', 'kspp', 'cut_attack_surface'), \
369 devmem_not_set)) # refers to LOCK_DOWN_KERNEL
370 checklist.append(OptCheck('ACPI_CUSTOM_METHOD', 'is not set', 'kspp', 'cut_attack_surface')) # refers to LOCK_DOWN_KERNEL
371 checklist.append(OptCheck('COMPAT_BRK', 'is not set', 'kspp', 'cut_attack_surface'))
372 checklist.append(OptCheck('DEVKMEM', 'is not set', 'kspp', 'cut_attack_surface'))
373 checklist.append(OptCheck('COMPAT_VDSO', 'is not set', 'kspp', 'cut_attack_surface'))
374 checklist.append(OptCheck('BINFMT_MISC', 'is not set', 'kspp', 'cut_attack_surface'))
375 checklist.append(OptCheck('INET_DIAG', 'is not set', 'kspp', 'cut_attack_surface'))
376 checklist.append(OptCheck('KEXEC', 'is not set', 'kspp', 'cut_attack_surface')) # refers to LOCK_DOWN_KERNEL
377 checklist.append(OptCheck('PROC_KCORE', 'is not set', 'kspp', 'cut_attack_surface')) # refers to LOCK_DOWN_KERNEL
378 checklist.append(OptCheck('LEGACY_PTYS', 'is not set', 'kspp', 'cut_attack_surface'))
379 checklist.append(OptCheck('HIBERNATION', 'is not set', 'kspp', 'cut_attack_surface')) # refers to LOCK_DOWN_KERNEL
380 if debug_mode or arch == 'X86_64':
381 checklist.append(OptCheck('LEGACY_VSYSCALL_NONE', 'y', 'kspp', 'cut_attack_surface')) # 'vsyscall=none'
382 checklist.append(OptCheck('IA32_EMULATION', 'is not set', 'kspp', 'cut_attack_surface'))
383 checklist.append(OptCheck('X86_X32', 'is not set', 'kspp', 'cut_attack_surface'))
384 checklist.append(OptCheck('MODIFY_LDT_SYSCALL', 'is not set', 'kspp', 'cut_attack_surface'))
385 if debug_mode or arch == 'ARM':
386 checklist.append(OptCheck('OABI_COMPAT', 'is not set', 'kspp', 'cut_attack_surface'))
388 checklist.append(OptCheck('X86_PTDUMP', 'is not set', 'grsecurity', 'cut_attack_surface'))
389 checklist.append(OptCheck('ZSMALLOC_STAT', 'is not set', 'grsecurity', 'cut_attack_surface'))
390 checklist.append(OptCheck('PAGE_OWNER', 'is not set', 'grsecurity', 'cut_attack_surface'))
391 checklist.append(OptCheck('DEBUG_KMEMLEAK', 'is not set', 'grsecurity', 'cut_attack_surface'))
392 checklist.append(OptCheck('BINFMT_AOUT', 'is not set', 'grsecurity', 'cut_attack_surface'))
393 checklist.append(OptCheck('KPROBES', 'is not set', 'grsecurity', 'cut_attack_surface')) # refers to LOCK_DOWN_KERNEL
394 checklist.append(OptCheck('UPROBES', 'is not set', 'grsecurity', 'cut_attack_surface'))
395 checklist.append(OptCheck('GENERIC_TRACER', 'is not set', 'grsecurity', 'cut_attack_surface'))
396 checklist.append(OptCheck('PROC_VMCORE', 'is not set', 'grsecurity', 'cut_attack_surface'))
397 checklist.append(OptCheck('PROC_PAGE_MONITOR', 'is not set', 'grsecurity', 'cut_attack_surface'))
398 checklist.append(OptCheck('USELIB', 'is not set', 'grsecurity', 'cut_attack_surface'))
399 checklist.append(OptCheck('CHECKPOINT_RESTORE', 'is not set', 'grsecurity', 'cut_attack_surface'))
400 checklist.append(OptCheck('USERFAULTFD', 'is not set', 'grsecurity', 'cut_attack_surface'))
401 checklist.append(OptCheck('HWPOISON_INJECT', 'is not set', 'grsecurity', 'cut_attack_surface'))
402 checklist.append(OptCheck('MEM_SOFT_DIRTY', 'is not set', 'grsecurity', 'cut_attack_surface'))
403 checklist.append(OptCheck('DEVPORT', 'is not set', 'grsecurity', 'cut_attack_surface')) # refers to LOCK_DOWN_KERNEL
404 checklist.append(OptCheck('DEBUG_FS', 'is not set', 'grsecurity', 'cut_attack_surface')) # refers to LOCK_DOWN_KERNEL
405 checklist.append(OptCheck('NOTIFIER_ERROR_INJECTION','is not set', 'grsecurity', 'cut_attack_surface'))
407 checklist.append(OptCheck('ACPI_TABLE_UPGRADE', 'is not set', 'lockdown', 'cut_attack_surface')) # refers to LOCK_DOWN_KERNEL
408 checklist.append(OptCheck('ACPI_APEI_EINJ', 'is not set', 'lockdown', 'cut_attack_surface')) # refers to LOCK_DOWN_KERNEL
409 checklist.append(OptCheck('PROFILING', 'is not set', 'lockdown', 'cut_attack_surface')) # refers to LOCK_DOWN_KERNEL
410 checklist.append(OptCheck('BPF_SYSCALL', 'is not set', 'lockdown', 'cut_attack_surface')) # refers to LOCK_DOWN_KERNEL
411 checklist.append(OptCheck('MMIOTRACE_TEST', 'is not set', 'lockdown', 'cut_attack_surface')) # refers to LOCK_DOWN_KERNEL
413 checklist.append(OptCheck('KSM', 'is not set', 'clipos', 'cut_attack_surface')) # to prevent FLUSH+RELOAD attack
414 # checklist.append(OptCheck('IKCONFIG', 'is not set', 'clipos', 'cut_attack_surface')) # no, this info is needed for this check :)
415 checklist.append(OptCheck('KALLSYMS', 'is not set', 'clipos', 'cut_attack_surface'))
416 checklist.append(OptCheck('X86_VSYSCALL_EMULATION', 'is not set', 'clipos', 'cut_attack_surface'))
417 checklist.append(OptCheck('MAGIC_SYSRQ', 'is not set', 'clipos', 'cut_attack_surface'))
418 checklist.append(OptCheck('KEXEC_FILE', 'is not set', 'clipos', 'cut_attack_surface')) # refers to LOCK_DOWN_KERNEL (permissive)
419 checklist.append(OptCheck('USER_NS', 'is not set', 'clipos', 'cut_attack_surface')) # user.max_user_namespaces=0
420 checklist.append(AND(OptCheck('LDISC_AUTOLOAD', 'is not set', 'clipos', 'cut_attack_surface'), \
421 VerCheck((5, 1)))) # LDISC_AUTOLOAD can be disabled since v5.1
423 checklist.append(OptCheck('MMIOTRACE', 'is not set', 'my', 'cut_attack_surface')) # refers to LOCK_DOWN_KERNEL (permissive)
424 checklist.append(OptCheck('LIVEPATCH', 'is not set', 'my', 'cut_attack_surface'))
425 checklist.append(OptCheck('IP_DCCP', 'is not set', 'my', 'cut_attack_surface'))
426 checklist.append(OptCheck('IP_SCTP', 'is not set', 'my', 'cut_attack_surface'))
427 checklist.append(OptCheck('FTRACE', 'is not set', 'my', 'cut_attack_surface'))
428 checklist.append(OptCheck('BPF_JIT', 'is not set', 'my', 'cut_attack_surface'))
429 checklist.append(OptCheck('VIDEO_VIVID', 'is not set', 'my', 'cut_attack_surface'))
430 if debug_mode or arch == 'X86_32':
431 checklist.append(OptCheck('MODIFY_LDT_SYSCALL', 'is not set', 'my', 'cut_attack_surface'))
433 if debug_mode or arch == 'ARM64':
434 checklist.append(OptCheck('ARM64_PTR_AUTH', 'y', 'defconfig', 'userspace_hardening'))
435 if debug_mode or arch == 'X86_64' or arch == 'ARM64':
436 checklist.append(OptCheck('ARCH_MMAP_RND_BITS', '32', 'clipos', 'userspace_hardening'))
437 if debug_mode or arch == 'X86_32' or arch == 'ARM':
438 checklist.append(OptCheck('ARCH_MMAP_RND_BITS', '16', 'my', 'userspace_hardening'))
440 # checklist.append(OptCheck('LKDTM', 'm', 'my', 'feature_test'))
443 def print_opt(opt, with_results):
444 print('CONFIG_{:<38}|{:^13}|{:^10}|{:^20}'.format(opt.name, opt.expected, opt.decision, opt.reason), end='')
446 print('| {}'.format(opt.result), end='')
450 def print_checklist(checklist, with_results):
454 opt = ['CONFIG_'+o.name, o.expected, o.decision, o.reason]
458 print(json.dumps(opts))
465 print('=' * sep_line_len)
466 print('{:^45}|{:^13}|{:^10}|{:^20}'.format('option name', 'desired val', 'decision', 'reason'), end='')
468 print('| {}'.format('check result'), end='')
470 print('=' * sep_line_len)
473 for opt in checklist:
474 if debug_mode and hasattr(opt, 'opts'):
475 print(' {:87}'.format('<<< ' + opt.__class__.__name__ + ' >>>'), end='')
477 print('| {}'.format(opt.result), end='')
480 if hasattr(o, 'ver_expected'):
481 ver_req = 'kernel version >= ' + str(o.ver_expected[0]) + '.' + str(o.ver_expected[1])
482 print('{:<91}'.format(ver_req), end='')
484 print('| {}'.format(o.result), end='')
487 print_opt(o, with_results)
489 print_opt(opt, with_results)
491 print('-' * sep_line_len)
495 def perform_checks(checklist, parsed_options):
496 for opt in checklist:
497 if hasattr(opt, 'opts'):
498 # prepare ComplexOptCheck
500 if hasattr(o, 'name'):
501 o.state = parsed_options.get(o.name, None)
503 # prepare simple OptCheck
504 if not hasattr(opt, 'name'):
505 sys.exit('[!] ERROR: bad OptCheck {}'.format(vars(opt)))
506 opt.state = parsed_options.get(opt.name, None)
510 def check_config_file(checklist, fname):
511 with open(fname, 'r') as f:
512 parsed_options = OrderedDict()
513 opt_is_on = re.compile("CONFIG_[a-zA-Z0-9_]*=[a-zA-Z0-9_\"]*")
514 opt_is_off = re.compile("# CONFIG_[a-zA-Z0-9_]* is not set")
520 which = 'ALL (debug)'
521 print('[+] Checking "{}" against {} hardening preferences...'.format(fname, which))
522 for line in f.readlines():
527 if opt_is_on.match(line):
528 option, value = line[7:].split('=', 1)
529 elif opt_is_off.match(line):
530 option, value = line[9:].split(' ', 1)
531 if value != 'is not set':
532 sys.exit('[!] ERROR: bad disabled config option "{}"'.format(line))
534 if option in parsed_options:
535 sys.exit('[!] ERROR: config option "{}" exists multiple times'.format(line))
537 if option is not None:
538 parsed_options[option] = value
540 perform_checks(checklist, parsed_options)
543 known_options = [opt.name for opt in checklist]
544 for option, value in parsed_options.items():
545 if option not in known_options:
546 print('DEBUG: dunno about option {} ({})'.format(option, value))
548 print_checklist(checklist, True)
551 if __name__ == '__main__':
552 parser = ArgumentParser(description='Checks the hardening options in the Linux kernel config')
553 parser.add_argument('-p', '--print', choices=supported_archs,
554 help='print hardening preferences for selected architecture')
555 parser.add_argument('-c', '--config',
556 help='check the config_file against these preferences')
557 parser.add_argument('--debug', action='store_true',
558 help='enable internal debug mode (not for production use)')
559 parser.add_argument('--json', action='store_true',
560 help='print results in JSON format')
561 args = parser.parse_args()
565 print('[!] WARNING: debug mode is enabled')
568 if debug_mode and json_mode:
569 sys.exit('[!] ERROR: options --debug and --json cannot be used simultaneously')
572 arch, msg = detect_arch(args.config)
574 sys.exit('[!] ERROR: {}'.format(msg))
576 print('[+] Detected architecture: {}'.format(arch))
578 kernel_version, msg = detect_version(args.config)
579 if not kernel_version:
580 sys.exit('[!] ERROR: {}'.format(msg))
582 print('[+] Detected kernel version: {}.{}'.format(kernel_version[0], kernel_version[1]))
584 construct_checklist(config_checklist, arch)
585 check_config_file(config_checklist, args.config)
586 error_count = len(list(filter(lambda opt: opt.result.startswith('FAIL'), config_checklist)))
587 ok_count = len(list(filter(lambda opt: opt.result.startswith('OK'), config_checklist)))
591 print('[+] config check is finished: \'OK\' - {} / \'FAIL\' - {}'.format(ok_count, error_count))
596 construct_checklist(config_checklist, arch)
601 which = 'ALL architectures (debug)'
602 print('[+] Printing kernel hardening preferences for {}...'.format(which))
603 print_checklist(config_checklist, False)