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)
25 # Mitigations of CPU vulnerabilities:
27 # mitigations=auto,nosmt
31 # spec_store_bypass_disable=on
38 # N.B. Hardening sysctls:
39 # net.core.bpf_jit_harden=2
41 # vm.unprivileged_userfaultfd=0
42 # kernel.perf_event_paranoid=3
43 # kernel.yama.ptrace_scope=1 (or even 3?)
44 # kernel.unprivileged_bpf_disabled=1
46 # fs.protected_symlinks = 1
47 # fs.protected_hardlinks = 1
48 # fs.protected_fifos = 2
49 # fs.protected_regular = 2
52 from argparse import ArgumentParser
53 from collections import OrderedDict
58 # - reporting about unknown kernel options in the config,
59 # - showing all checks from all supported platforms,
60 # - verbose printing of ComplexOptChecks (OR, AND).
63 # json_mode is for printing results in JSON format
66 supported_archs = [ 'X86_64', 'X86_32', 'ARM64', 'ARM' ]
72 def __init__(self, name, expected, decision, reason):
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'):
92 return True, self.result
94 return False, self.result
98 def __init__(self, ver_expected):
99 self.ver_expected = ver_expected
103 if kernel_version[0] > self.ver_expected[0]:
104 self.result = 'OK: version >= ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
105 return True, self.result
106 if kernel_version[0] < self.ver_expected[0]:
107 self.result = 'FAIL: version < ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
108 return False, self.result
109 if kernel_version[1] >= self.ver_expected[1]:
110 self.result = 'OK: version >= ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
111 return True, self.result
113 self.result = 'FAIL: version < ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
114 return False, self.result
117 class ComplexOptCheck:
118 def __init__(self, *opts):
124 return self.opts[0].name
128 return self.opts[0].expected
132 return self.opts[0].state
136 return self.opts[0].decision
140 return self.opts[0].reason
143 class OR(ComplexOptCheck):
144 # self.opts[0] is the option which this OR-check is about.
146 # OR(<X_is_hardened>, <X_is_disabled>)
147 # OR(<X_is_hardened>, <X_is_hardened_old>)
151 sys.exit('[!] ERROR: invalid OR check')
153 for i, opt in enumerate(self.opts):
154 ret, msg = opt.check()
156 if i == 0 or not hasattr(opt, 'name'):
157 self.result = opt.result
159 self.result = 'OK: CONFIG_{} "{}"'.format(opt.name, opt.expected)
160 return True, self.result
161 self.result = self.opts[0].result
162 return False, self.result
165 class AND(ComplexOptCheck):
166 # self.opts[0] is the option which this AND-check is about.
167 # Use case: AND(<suboption>, <main_option>)
168 # Suboption is not checked if checking of the main_option is failed.
171 for i, opt in reversed(list(enumerate(self.opts))):
172 ret, msg = opt.check()
174 self.result = opt.result
175 return ret, self.result
177 if hasattr(opt, 'name'):
178 self.result = 'FAIL: CONFIG_{} is needed'.format(opt.name)
180 self.result = opt.result
181 return False, self.result
183 sys.exit('[!] ERROR: invalid AND check')
186 def detect_arch(fname):
187 with open(fname, 'r') as f:
188 arch_pattern = re.compile("CONFIG_[a-zA-Z0-9_]*=y")
191 print('[+] Trying to detect architecture in "{}"...'.format(fname))
192 for line in f.readlines():
193 if arch_pattern.match(line):
194 option, value = line[7:].split('=', 1)
195 if option in supported_archs:
199 return None, 'more than one supported architecture is detected'
201 return None, 'failed to detect architecture'
206 def detect_version(fname):
207 with open(fname, 'r') as f:
208 ver_pattern = re.compile("# Linux/.* Kernel Configuration")
210 print('[+] Trying to detect kernel version in "{}"...'.format(fname))
211 for line in f.readlines():
212 if ver_pattern.match(line):
215 print('[+] Found version line: "{}"'.format(line))
218 ver_numbers = ver_str.split('.')
219 if len(ver_numbers) < 3 or not ver_numbers[0].isdigit() or not ver_numbers[1].isdigit():
220 msg = 'failed to parse the version "' + ver_str + '"'
223 return (int(ver_numbers[0]), int(ver_numbers[1])), None
224 return None, 'no kernel version detected'
227 def construct_checklist(checklist, arch):
228 modules_not_set = OptCheck('MODULES', 'is not set', 'kspp', 'cut_attack_surface')
229 devmem_not_set = OptCheck('DEVMEM', 'is not set', 'kspp', 'cut_attack_surface') # refers to LOCK_DOWN_KERNEL
231 checklist.append(OptCheck('BUG', 'y', 'defconfig', 'self_protection'))
232 checklist.append(OR(OptCheck('STRICT_KERNEL_RWX', 'y', 'defconfig', 'self_protection'), \
233 OptCheck('DEBUG_RODATA', 'y', 'defconfig', 'self_protection'))) # before v4.11
234 checklist.append(OR(OptCheck('STACKPROTECTOR_STRONG', 'y', 'defconfig', 'self_protection'), \
235 OptCheck('CC_STACKPROTECTOR_STRONG', 'y', 'defconfig', 'self_protection')))
236 checklist.append(OptCheck('SLUB_DEBUG', 'y', 'defconfig', 'self_protection'))
237 checklist.append(OR(OptCheck('STRICT_MODULE_RWX', 'y', 'defconfig', 'self_protection'), \
238 OptCheck('DEBUG_SET_MODULE_RONX', 'y', 'defconfig', 'self_protection'), \
239 modules_not_set)) # DEBUG_SET_MODULE_RONX was before v4.11
240 checklist.append(OptCheck('GCC_PLUGINS', 'y', 'defconfig', 'self_protection'))
241 checklist.append(OR(OptCheck('REFCOUNT_FULL', 'y', 'defconfig', 'self_protection'), \
242 VerCheck((5, 5)))) # REFCOUNT_FULL is enabled by default since v5.5
243 if debug_mode or arch == 'X86_64' or arch == 'X86_32':
244 checklist.append(OptCheck('MICROCODE', 'y', 'defconfig', 'self_protection')) # is needed for mitigating CPU bugs
245 checklist.append(OptCheck('RETPOLINE', 'y', 'defconfig', 'self_protection'))
246 checklist.append(OptCheck('X86_SMAP', 'y', 'defconfig', 'self_protection'))
247 checklist.append(OR(OptCheck('X86_UMIP', 'y', 'defconfig', 'self_protection'), \
248 OptCheck('X86_INTEL_UMIP', 'y', 'defconfig', 'self_protection')))
249 iommu_support_is_set = OptCheck('IOMMU_SUPPORT', 'y', 'defconfig', 'self_protection') # is needed for mitigating DMA attacks
250 checklist.append(iommu_support_is_set)
251 checklist.append(OptCheck('SYN_COOKIES', 'y', 'defconfig', 'self_protection')) # another reason?
252 if debug_mode or arch == 'X86_64':
253 checklist.append(OptCheck('PAGE_TABLE_ISOLATION', 'y', 'defconfig', 'self_protection'))
254 checklist.append(OptCheck('RANDOMIZE_MEMORY', 'y', 'defconfig', 'self_protection'))
255 checklist.append(AND(OptCheck('INTEL_IOMMU', 'y', 'defconfig', 'self_protection'), \
256 iommu_support_is_set))
257 checklist.append(AND(OptCheck('AMD_IOMMU', 'y', 'defconfig', 'self_protection'), \
258 iommu_support_is_set))
259 if debug_mode or arch == 'ARM64':
260 checklist.append(OptCheck('UNMAP_KERNEL_AT_EL0', 'y', 'defconfig', 'self_protection'))
261 checklist.append(OptCheck('HARDEN_EL2_VECTORS', 'y', 'defconfig', 'self_protection'))
262 checklist.append(OptCheck('RODATA_FULL_DEFAULT_ENABLED', 'y', 'defconfig', 'self_protection'))
263 if debug_mode or arch == 'X86_64' or arch == 'ARM64':
264 checklist.append(OptCheck('VMAP_STACK', 'y', 'defconfig', 'self_protection'))
265 if debug_mode or arch == 'X86_64' or arch == 'ARM64' or arch == 'X86_32':
266 checklist.append(OptCheck('RANDOMIZE_BASE', 'y', 'defconfig', 'self_protection'))
267 checklist.append(OptCheck('THREAD_INFO_IN_TASK', 'y', 'defconfig', 'self_protection'))
268 if debug_mode or arch == 'ARM':
269 checklist.append(OptCheck('VMSPLIT_3G', 'y', 'defconfig', 'self_protection'))
270 checklist.append(OptCheck('CPU_SW_DOMAIN_PAN', 'y', 'defconfig', 'self_protection'))
271 checklist.append(OptCheck('STACKPROTECTOR_PER_TASK', 'y', 'defconfig', 'self_protection'))
272 if debug_mode or arch == 'ARM64' or arch == 'ARM':
273 checklist.append(OptCheck('HARDEN_BRANCH_PREDICTOR', 'y', 'defconfig', 'self_protection'))
275 checklist.append(OptCheck('BUG_ON_DATA_CORRUPTION', 'y', 'kspp', 'self_protection'))
276 checklist.append(OptCheck('DEBUG_WX', 'y', 'kspp', 'self_protection'))
277 checklist.append(OptCheck('SCHED_STACK_END_CHECK', 'y', 'kspp', 'self_protection'))
278 checklist.append(OptCheck('SLAB_FREELIST_HARDENED', 'y', 'kspp', 'self_protection'))
279 checklist.append(OptCheck('SLAB_FREELIST_RANDOM', 'y', 'kspp', 'self_protection'))
280 checklist.append(OptCheck('SHUFFLE_PAGE_ALLOCATOR', 'y', 'kspp', 'self_protection'))
281 checklist.append(OptCheck('FORTIFY_SOURCE', 'y', 'kspp', 'self_protection'))
282 randstruct_is_set = OptCheck('GCC_PLUGIN_RANDSTRUCT', 'y', 'kspp', 'self_protection')
283 checklist.append(randstruct_is_set)
284 checklist.append(OptCheck('GCC_PLUGIN_LATENT_ENTROPY', 'y', 'kspp', 'self_protection'))
285 checklist.append(OptCheck('DEBUG_LIST', 'y', 'kspp', 'self_protection'))
286 checklist.append(OptCheck('DEBUG_SG', 'y', 'kspp', 'self_protection'))
287 checklist.append(OptCheck('DEBUG_CREDENTIALS', 'y', 'kspp', 'self_protection'))
288 checklist.append(OptCheck('DEBUG_NOTIFIERS', 'y', 'kspp', 'self_protection'))
289 hardened_usercopy_is_set = OptCheck('HARDENED_USERCOPY', 'y', 'kspp', 'self_protection')
290 checklist.append(hardened_usercopy_is_set)
291 checklist.append(AND(OptCheck('HARDENED_USERCOPY_FALLBACK', 'is not set', 'kspp', 'self_protection'), \
292 hardened_usercopy_is_set))
293 checklist.append(OR(OptCheck('MODULE_SIG', 'y', 'kspp', 'self_protection'), \
295 checklist.append(OR(OptCheck('MODULE_SIG_ALL', 'y', 'kspp', 'self_protection'), \
297 checklist.append(OR(OptCheck('MODULE_SIG_SHA512', 'y', 'kspp', 'self_protection'), \
299 checklist.append(OR(OptCheck('MODULE_SIG_FORCE', 'y', 'kspp', 'self_protection'), \
300 modules_not_set)) # refers to LOCK_DOWN_KERNEL
301 checklist.append(OR(OptCheck('INIT_STACK_ALL', 'y', 'kspp', 'self_protection'), \
302 OptCheck('GCC_PLUGIN_STRUCTLEAK_BYREF_ALL', 'y', 'kspp', 'self_protection')))
303 checklist.append(OptCheck('INIT_ON_ALLOC_DEFAULT_ON', 'y', 'kspp', 'self_protection'))
304 checklist.append(OR(OptCheck('INIT_ON_FREE_DEFAULT_ON', 'y', 'kspp', 'self_protection'), \
305 OptCheck('PAGE_POISONING', 'y', 'kspp', 'self_protection'))) # before v5.3
306 if debug_mode or arch == 'X86_64' or arch == 'ARM64' or arch == 'X86_32':
307 stackleak_is_set = OptCheck('GCC_PLUGIN_STACKLEAK', 'y', 'kspp', 'self_protection')
308 checklist.append(stackleak_is_set)
309 checklist.append(AND(OptCheck('STACKLEAK_METRICS', 'is not set', 'clipos', 'self_protection'), \
311 checklist.append(AND(OptCheck('STACKLEAK_RUNTIME_DISABLE', 'is not set', 'clipos', 'self_protection'), \
313 if debug_mode or arch == 'X86_64' or arch == 'X86_32':
314 checklist.append(OptCheck('DEFAULT_MMAP_MIN_ADDR', '65536', 'kspp', 'self_protection'))
315 if debug_mode or arch == 'X86_32':
316 checklist.append(OptCheck('HIGHMEM64G', 'y', 'kspp', 'self_protection'))
317 checklist.append(OptCheck('X86_PAE', 'y', 'kspp', 'self_protection'))
318 if debug_mode or arch == 'ARM64':
319 checklist.append(OptCheck('ARM64_SW_TTBR0_PAN', 'y', 'kspp', 'self_protection'))
320 if debug_mode or arch == 'ARM64' or arch == 'ARM':
321 checklist.append(OptCheck('SYN_COOKIES', 'y', 'kspp', 'self_protection')) # another reason?
322 checklist.append(OptCheck('DEFAULT_MMAP_MIN_ADDR', '32768', 'kspp', 'self_protection'))
324 checklist.append(OptCheck('SECURITY_DMESG_RESTRICT', 'y', 'clipos', 'self_protection'))
325 checklist.append(OptCheck('DEBUG_VIRTUAL', 'y', 'clipos', 'self_protection'))
326 checklist.append(OptCheck('STATIC_USERMODEHELPER', 'y', 'clipos', 'self_protection')) # needs userspace support (systemd)
327 checklist.append(OptCheck('SLAB_MERGE_DEFAULT', 'is not set', 'clipos', 'self_protection')) # slab_nomerge
328 checklist.append(AND(OptCheck('GCC_PLUGIN_RANDSTRUCT_PERFORMANCE', 'is not set', 'clipos', 'self_protection'), \
330 checklist.append(OptCheck('CONFIG_RANDOM_TRUST_BOOTLOADER', 'is not set', 'clipos', 'self_protection'))
331 if debug_mode or arch == 'X86_64' or arch == 'X86_32':
332 checklist.append(OptCheck('RANDOM_TRUST_CPU', 'is not set', 'clipos', 'self_protection'))
333 checklist.append(AND(OptCheck('INTEL_IOMMU_SVM', 'y', 'clipos', 'self_protection'), \
334 iommu_support_is_set))
335 checklist.append(AND(OptCheck('INTEL_IOMMU_DEFAULT_ON', 'y', 'clipos', 'self_protection'), \
336 iommu_support_is_set))
338 checklist.append(OptCheck('SLUB_DEBUG_ON', 'y', 'my', 'self_protection'))
339 checklist.append(OptCheck('RESET_ATTACK_MITIGATION', 'y', 'my', 'self_protection')) # needs userspace support (systemd)
340 if debug_mode or arch == 'X86_64':
341 checklist.append(AND(OptCheck('AMD_IOMMU_V2', 'y', 'my', 'self_protection'), \
342 iommu_support_is_set))
343 if debug_mode or arch == 'X86_32':
344 checklist.append(OptCheck('PAGE_TABLE_ISOLATION', 'y', 'my', 'self_protection'))
346 if debug_mode or arch == 'X86_64' or arch == 'ARM64' or arch == 'X86_32':
347 checklist.append(OptCheck('SECURITY', 'y', 'defconfig', 'security_policy')) # and choose your favourite LSM
348 if debug_mode or arch == 'ARM':
349 checklist.append(OptCheck('SECURITY', 'y', 'kspp', 'security_policy')) # and choose your favourite LSM
350 checklist.append(OptCheck('SECURITY_YAMA', 'y', 'kspp', 'security_policy'))
351 loadpin_is_set = OptCheck('SECURITY_LOADPIN', 'y', 'my', 'security_policy') # needs userspace support
352 checklist.append(loadpin_is_set)
353 checklist.append(AND(OptCheck('SECURITY_LOADPIN_ENFORCE', 'y', 'my', 'security_policy'), \
355 checklist.append(OptCheck('SECURITY_LOCKDOWN_LSM', 'y', 'my', 'security_policy'))
356 checklist.append(OptCheck('SECURITY_LOCKDOWN_LSM_EARLY', 'y', 'my', 'security_policy'))
357 checklist.append(OptCheck('LOCK_DOWN_KERNEL_FORCE_CONFIDENTIALITY', 'y', 'my', 'security_policy'))
358 checklist.append(OptCheck('SECURITY_SAFESETID', 'y', 'my', 'security_policy'))
359 checklist.append(OptCheck('SECURITY_WRITABLE_HOOKS', 'is not set', 'my', 'security_policy'))
361 checklist.append(OptCheck('SECCOMP', 'y', 'defconfig', 'cut_attack_surface'))
362 checklist.append(OptCheck('SECCOMP_FILTER', 'y', 'defconfig', 'cut_attack_surface'))
363 if debug_mode or arch == 'X86_64' or arch == 'ARM64' or arch == 'X86_32':
364 checklist.append(OR(OptCheck('STRICT_DEVMEM', 'y', 'defconfig', 'cut_attack_surface'), \
365 devmem_not_set)) # refers to LOCK_DOWN_KERNEL
367 checklist.append(modules_not_set)
368 checklist.append(devmem_not_set)
369 checklist.append(OR(OptCheck('IO_STRICT_DEVMEM', 'y', 'kspp', 'cut_attack_surface'), \
370 devmem_not_set)) # refers to LOCK_DOWN_KERNEL
371 if debug_mode or arch == 'ARM':
372 checklist.append(OR(OptCheck('STRICT_DEVMEM', 'y', 'kspp', 'cut_attack_surface'), \
373 devmem_not_set)) # refers to LOCK_DOWN_KERNEL
374 checklist.append(OptCheck('ACPI_CUSTOM_METHOD', 'is not set', 'kspp', 'cut_attack_surface')) # refers to LOCK_DOWN_KERNEL
375 checklist.append(OptCheck('COMPAT_BRK', 'is not set', 'kspp', 'cut_attack_surface'))
376 checklist.append(OptCheck('DEVKMEM', 'is not set', 'kspp', 'cut_attack_surface'))
377 checklist.append(OptCheck('COMPAT_VDSO', 'is not set', 'kspp', 'cut_attack_surface'))
378 checklist.append(OptCheck('BINFMT_MISC', 'is not set', 'kspp', 'cut_attack_surface'))
379 checklist.append(OptCheck('INET_DIAG', 'is not set', 'kspp', 'cut_attack_surface'))
380 checklist.append(OptCheck('KEXEC', 'is not set', 'kspp', 'cut_attack_surface')) # refers to LOCK_DOWN_KERNEL
381 checklist.append(OptCheck('PROC_KCORE', 'is not set', 'kspp', 'cut_attack_surface')) # refers to LOCK_DOWN_KERNEL
382 checklist.append(OptCheck('LEGACY_PTYS', 'is not set', 'kspp', 'cut_attack_surface'))
383 checklist.append(OptCheck('HIBERNATION', 'is not set', 'kspp', 'cut_attack_surface')) # refers to LOCK_DOWN_KERNEL
384 if debug_mode or arch == 'X86_64':
385 checklist.append(OptCheck('LEGACY_VSYSCALL_NONE', 'y', 'kspp', 'cut_attack_surface')) # 'vsyscall=none'
386 checklist.append(OptCheck('IA32_EMULATION', 'is not set', 'kspp', 'cut_attack_surface'))
387 checklist.append(OptCheck('X86_X32', 'is not set', 'kspp', 'cut_attack_surface'))
388 checklist.append(OptCheck('MODIFY_LDT_SYSCALL', 'is not set', 'kspp', 'cut_attack_surface'))
389 if debug_mode or arch == 'ARM':
390 checklist.append(OptCheck('OABI_COMPAT', 'is not set', 'kspp', 'cut_attack_surface'))
392 checklist.append(OptCheck('X86_PTDUMP', 'is not set', 'grsecurity', 'cut_attack_surface'))
393 checklist.append(OptCheck('ZSMALLOC_STAT', 'is not set', 'grsecurity', 'cut_attack_surface'))
394 checklist.append(OptCheck('PAGE_OWNER', 'is not set', 'grsecurity', 'cut_attack_surface'))
395 checklist.append(OptCheck('DEBUG_KMEMLEAK', 'is not set', 'grsecurity', 'cut_attack_surface'))
396 checklist.append(OptCheck('BINFMT_AOUT', 'is not set', 'grsecurity', 'cut_attack_surface'))
397 checklist.append(OptCheck('KPROBES', 'is not set', 'grsecurity', 'cut_attack_surface')) # refers to LOCK_DOWN_KERNEL
398 checklist.append(OptCheck('UPROBES', 'is not set', 'grsecurity', 'cut_attack_surface'))
399 checklist.append(OptCheck('GENERIC_TRACER', 'is not set', 'grsecurity', 'cut_attack_surface'))
400 checklist.append(OptCheck('PROC_VMCORE', 'is not set', 'grsecurity', 'cut_attack_surface'))
401 checklist.append(OptCheck('PROC_PAGE_MONITOR', 'is not set', 'grsecurity', 'cut_attack_surface'))
402 checklist.append(OptCheck('USELIB', 'is not set', 'grsecurity', 'cut_attack_surface'))
403 checklist.append(OptCheck('CHECKPOINT_RESTORE', 'is not set', 'grsecurity', 'cut_attack_surface'))
404 checklist.append(OptCheck('USERFAULTFD', 'is not set', 'grsecurity', 'cut_attack_surface'))
405 checklist.append(OptCheck('HWPOISON_INJECT', 'is not set', 'grsecurity', 'cut_attack_surface'))
406 checklist.append(OptCheck('MEM_SOFT_DIRTY', 'is not set', 'grsecurity', 'cut_attack_surface'))
407 checklist.append(OptCheck('DEVPORT', 'is not set', 'grsecurity', 'cut_attack_surface')) # refers to LOCK_DOWN_KERNEL
408 checklist.append(OptCheck('DEBUG_FS', 'is not set', 'grsecurity', 'cut_attack_surface')) # refers to LOCK_DOWN_KERNEL
409 checklist.append(OptCheck('NOTIFIER_ERROR_INJECTION','is not set', 'grsecurity', 'cut_attack_surface'))
411 checklist.append(OptCheck('ACPI_TABLE_UPGRADE', 'is not set', 'lockdown', 'cut_attack_surface')) # refers to LOCK_DOWN_KERNEL
412 checklist.append(OptCheck('ACPI_APEI_EINJ', 'is not set', 'lockdown', 'cut_attack_surface')) # refers to LOCK_DOWN_KERNEL
413 checklist.append(OptCheck('PROFILING', 'is not set', 'lockdown', 'cut_attack_surface')) # refers to LOCK_DOWN_KERNEL
414 checklist.append(OptCheck('BPF_SYSCALL', 'is not set', 'lockdown', 'cut_attack_surface')) # refers to LOCK_DOWN_KERNEL
415 checklist.append(OptCheck('MMIOTRACE_TEST', 'is not set', 'lockdown', 'cut_attack_surface')) # refers to LOCK_DOWN_KERNEL
417 checklist.append(OptCheck('STAGING', 'is not set', 'clipos', 'cut_attack_surface'))
418 checklist.append(OptCheck('KSM', 'is not set', 'clipos', 'cut_attack_surface')) # to prevent FLUSH+RELOAD attack
419 # checklist.append(OptCheck('IKCONFIG', 'is not set', 'clipos', 'cut_attack_surface')) # no, this info is needed for this check :)
420 checklist.append(OptCheck('KALLSYMS', 'is not set', 'clipos', 'cut_attack_surface'))
421 checklist.append(OptCheck('X86_VSYSCALL_EMULATION', 'is not set', 'clipos', 'cut_attack_surface'))
422 checklist.append(OptCheck('MAGIC_SYSRQ', 'is not set', 'clipos', 'cut_attack_surface'))
423 checklist.append(OptCheck('KEXEC_FILE', 'is not set', 'clipos', 'cut_attack_surface')) # refers to LOCK_DOWN_KERNEL (permissive)
424 checklist.append(OptCheck('USER_NS', 'is not set', 'clipos', 'cut_attack_surface')) # user.max_user_namespaces=0
425 checklist.append(AND(OptCheck('LDISC_AUTOLOAD', 'is not set', 'clipos', 'cut_attack_surface'), \
426 VerCheck((5, 1)))) # LDISC_AUTOLOAD can be disabled since v5.1
428 checklist.append(OptCheck('MMIOTRACE', 'is not set', 'my', 'cut_attack_surface')) # refers to LOCK_DOWN_KERNEL (permissive)
429 checklist.append(OptCheck('LIVEPATCH', 'is not set', 'my', 'cut_attack_surface'))
430 checklist.append(OptCheck('IP_DCCP', 'is not set', 'my', 'cut_attack_surface'))
431 checklist.append(OptCheck('IP_SCTP', 'is not set', 'my', 'cut_attack_surface'))
432 checklist.append(OptCheck('FTRACE', 'is not set', 'my', 'cut_attack_surface'))
433 checklist.append(OptCheck('BPF_JIT', 'is not set', 'my', 'cut_attack_surface'))
434 checklist.append(OptCheck('VIDEO_VIVID', 'is not set', 'my', 'cut_attack_surface'))
435 if debug_mode or arch == 'X86_32':
436 checklist.append(OptCheck('MODIFY_LDT_SYSCALL', 'is not set', 'my', 'cut_attack_surface'))
438 if debug_mode or arch == 'ARM64':
439 checklist.append(OptCheck('ARM64_PTR_AUTH', 'y', 'defconfig', 'userspace_hardening'))
440 if debug_mode or arch == 'X86_64' or arch == 'ARM64':
441 checklist.append(OptCheck('ARCH_MMAP_RND_BITS', '32', 'clipos', 'userspace_hardening'))
442 if debug_mode or arch == 'X86_32' or arch == 'ARM':
443 checklist.append(OptCheck('ARCH_MMAP_RND_BITS', '16', 'my', 'userspace_hardening'))
445 # checklist.append(OptCheck('LKDTM', 'm', 'my', 'feature_test'))
448 def print_opt(opt, with_results):
449 print('CONFIG_{:<38}|{:^13}|{:^10}|{:^20}'.format(opt.name, opt.expected, opt.decision, opt.reason), end='')
451 print('| {}'.format(opt.result), end='')
455 def print_checklist(checklist, with_results):
459 opt = ['CONFIG_'+o.name, o.expected, o.decision, o.reason]
463 print(json.dumps(opts))
470 print('=' * sep_line_len)
471 print('{:^45}|{:^13}|{:^10}|{:^20}'.format('option name', 'desired val', 'decision', 'reason'), end='')
473 print('| {}'.format('check result'), end='')
475 print('=' * sep_line_len)
478 for opt in checklist:
479 if debug_mode and hasattr(opt, 'opts'):
480 print(' {:87}'.format('<<< ' + opt.__class__.__name__ + ' >>>'), end='')
482 print('| {}'.format(opt.result), end='')
485 if hasattr(o, 'ver_expected'):
486 ver_req = 'kernel version >= ' + str(o.ver_expected[0]) + '.' + str(o.ver_expected[1])
487 print('{:<91}'.format(ver_req), end='')
489 print('| {}'.format(o.result), end='')
492 print_opt(o, with_results)
494 print_opt(opt, with_results)
496 print('-' * sep_line_len)
500 def perform_checks(checklist, parsed_options):
501 for opt in checklist:
502 if hasattr(opt, 'opts'):
503 # prepare ComplexOptCheck
505 if hasattr(o, 'name'):
506 o.state = parsed_options.get(o.name, None)
508 # prepare simple OptCheck
509 if not hasattr(opt, 'name'):
510 sys.exit('[!] ERROR: bad OptCheck {}'.format(vars(opt)))
511 opt.state = parsed_options.get(opt.name, None)
515 def check_config_file(checklist, fname):
516 with open(fname, 'r') as f:
517 parsed_options = OrderedDict()
518 opt_is_on = re.compile("CONFIG_[a-zA-Z0-9_]*=[a-zA-Z0-9_\"]*")
519 opt_is_off = re.compile("# CONFIG_[a-zA-Z0-9_]* is not set")
525 which = 'ALL (debug)'
526 print('[+] Checking "{}" against {} hardening preferences...'.format(fname, which))
527 for line in f.readlines():
532 if opt_is_on.match(line):
533 option, value = line[7:].split('=', 1)
534 elif opt_is_off.match(line):
535 option, value = line[9:].split(' ', 1)
536 if value != 'is not set':
537 sys.exit('[!] ERROR: bad disabled config option "{}"'.format(line))
539 if option in parsed_options:
540 sys.exit('[!] ERROR: config option "{}" exists multiple times'.format(line))
542 if option is not None:
543 parsed_options[option] = value
545 perform_checks(checklist, parsed_options)
548 known_options = [opt.name for opt in checklist]
549 for option, value in parsed_options.items():
550 if option not in known_options:
551 print('DEBUG: dunno about option {} ({})'.format(option, value))
553 print_checklist(checklist, True)
556 if __name__ == '__main__':
557 parser = ArgumentParser(description='Checks the hardening options in the Linux kernel config')
558 parser.add_argument('-p', '--print', choices=supported_archs,
559 help='print hardening preferences for selected architecture')
560 parser.add_argument('-c', '--config',
561 help='check the config_file against these preferences')
562 parser.add_argument('--debug', action='store_true',
563 help='enable internal debug mode (not for production use)')
564 parser.add_argument('--json', action='store_true',
565 help='print results in JSON format')
566 args = parser.parse_args()
570 print('[!] WARNING: debug mode is enabled')
573 if debug_mode and json_mode:
574 sys.exit('[!] ERROR: options --debug and --json cannot be used simultaneously')
577 arch, msg = detect_arch(args.config)
579 sys.exit('[!] ERROR: {}'.format(msg))
581 print('[+] Detected architecture: {}'.format(arch))
583 kernel_version, msg = detect_version(args.config)
584 if not kernel_version:
585 sys.exit('[!] ERROR: {}'.format(msg))
587 print('[+] Detected kernel version: {}.{}'.format(kernel_version[0], kernel_version[1]))
589 construct_checklist(config_checklist, arch)
590 check_config_file(config_checklist, args.config)
591 error_count = len(list(filter(lambda opt: opt.result.startswith('FAIL'), config_checklist)))
592 ok_count = len(list(filter(lambda opt: opt.result.startswith('OK'), config_checklist)))
596 print('[+] config check is finished: \'OK\' - {} / \'FAIL\' - {}'.format(ok_count, error_count))
601 construct_checklist(config_checklist, arch)
606 which = 'ALL architectures (debug)'
607 print('[+] Printing kernel hardening preferences for {}...'.format(which))
608 print_checklist(config_checklist, False)