4 # This script helps me to check the Linux kernel Kconfig option list
5 # against my hardening preferences for x86_64. Let the computers do their job!
7 # Author: Alexander Popov <alex.popov@linux.com>
9 # Please don't cry if my Python code looks like C.
12 # N.B Hardening command line parameters:
17 # kernel.kptr_restrict=1
20 from argparse import ArgumentParser
21 from collections import OrderedDict
24 debug_mode = False # set it to True to print the unknown options from the config
30 def __init__(self, name, expected, decision, reason):
32 self.expected = expected
33 self.decision = decision
40 if self.expected == self.state:
43 if self.state is None:
44 if self.expected == 'is not set':
45 return True, 'OK: not found'
48 return False, 'FAIL: not found'
51 return False, 'FAIL: "' + self.state + '"'
54 return '{} = {}'.format(self.name, self.state)
57 def construct_opt_checks():
58 opt_list.append([Opt('BUG', 'y', 'ubuntu18', 'self_protection'), ''])
59 opt_list.append([Opt('PAGE_TABLE_ISOLATION', 'y', 'ubuntu18', 'self_protection'), ''])
60 opt_list.append([Opt('RETPOLINE', 'y', 'ubuntu18', 'self_protection'), ''])
61 opt_list.append([Opt('X86_64', 'y', 'ubuntu18', 'self_protection'), ''])
62 opt_list.append([Opt('STRICT_KERNEL_RWX', 'y', 'ubuntu18', 'self_protection'), ''])
63 opt_list.append([Opt('STRICT_MODULE_RWX', 'y', 'ubuntu18', 'self_protection'), ''])
64 opt_list.append([Opt('DEBUG_WX', 'y', 'ubuntu18', 'self_protection'), ''])
65 opt_list.append([Opt('RANDOMIZE_BASE', 'y', 'ubuntu18', 'self_protection'), ''])
66 opt_list.append([Opt('RANDOMIZE_MEMORY', 'y', 'ubuntu18', 'self_protection'), ''])
67 opt_list.append([Opt('CC_STACKPROTECTOR', 'y', 'ubuntu18', 'self_protection'), ''])
68 opt_list.append([Opt('CC_STACKPROTECTOR_STRONG','y', 'ubuntu18', 'self_protection'), ''])
69 opt_list.append([Opt('VMAP_STACK', 'y', 'ubuntu18', 'self_protection'), ''])
70 opt_list.append([Opt('THREAD_INFO_IN_TASK', 'y', 'ubuntu18', 'self_protection'), ''])
71 opt_list.append([Opt('SCHED_STACK_END_CHECK', 'y', 'ubuntu18', 'self_protection'), ''])
72 opt_list.append([Opt('SLUB_DEBUG', 'y', 'ubuntu18', 'self_protection'), ''])
73 opt_list.append([Opt('SLAB_FREELIST_HARDENED', 'y', 'ubuntu18', 'self_protection'), ''])
74 opt_list.append([Opt('SLAB_FREELIST_RANDOM', 'y', 'ubuntu18', 'self_protection'), ''])
75 opt_list.append([Opt('HARDENED_USERCOPY', 'y', 'ubuntu18', 'self_protection'), ''])
76 opt_list.append([Opt('FORTIFY_SOURCE', 'y', 'ubuntu18', 'self_protection'), ''])
77 opt_list.append([Opt('MODULE_SIG', 'y', 'ubuntu18', 'self_protection'), ''])
78 opt_list.append([Opt('MODULE_SIG_ALL', 'y', 'ubuntu18', 'self_protection'), ''])
79 opt_list.append([Opt('MODULE_SIG_SHA512', 'y', 'ubuntu18', 'self_protection'), ''])
80 opt_list.append([Opt('SYN_COOKIES', 'y', 'ubuntu18', 'self_protection'), '']) # another reason?
81 opt_list.append([Opt('DEFAULT_MMAP_MIN_ADDR', '65536', 'ubuntu18', 'self_protection'), ''])
83 opt_list.append([Opt('BUG_ON_DATA_CORRUPTION', 'y', 'kspp', 'self_protection'), ''])
84 opt_list.append([Opt('PAGE_POISONING', 'y', 'kspp', 'self_protection'), ''])
85 opt_list.append([Opt('GCC_PLUGINS', 'y', 'kspp', 'self_protection'), ''])
86 opt_list.append([Opt('GCC_PLUGIN_RANDSTRUCT', 'y', 'kspp', 'self_protection'), ''])
87 opt_list.append([Opt('GCC_PLUGIN_STRUCTLEAK', 'y', 'kspp', 'self_protection'), ''])
88 opt_list.append([Opt('GCC_PLUGIN_STRUCTLEAK_BYREF_ALL', 'y', 'kspp', 'self_protection'), ''])
89 opt_list.append([Opt('GCC_PLUGIN_LATENT_ENTROPY', 'y', 'kspp', 'self_protection'), ''])
90 opt_list.append([Opt('REFCOUNT_FULL', 'y', 'kspp', 'self_protection'), ''])
91 opt_list.append([Opt('DEBUG_LIST', 'y', 'kspp', 'self_protection'), ''])
92 opt_list.append([Opt('DEBUG_SG', 'y', 'kspp', 'self_protection'), ''])
93 opt_list.append([Opt('DEBUG_CREDENTIALS', 'y', 'kspp', 'self_protection'), ''])
94 opt_list.append([Opt('DEBUG_NOTIFIERS', 'y', 'kspp', 'self_protection'), ''])
95 opt_list.append([Opt('MODULE_SIG_FORCE', 'y', 'kspp', 'self_protection'), ''])
96 opt_list.append([Opt('HARDENED_USERCOPY_FALLBACK', 'is not set', 'kspp', 'self_protection'), ''])
98 opt_list.append([Opt('GCC_PLUGIN_STACKLEAK', 'y', 'my', 'self_protection'), ''])
99 opt_list.append([Opt('SLUB_DEBUG_ON', 'y', 'my', 'self_protection'), ''])
100 opt_list.append([Opt('SECURITY_DMESG_RESTRICT', 'y', 'my', 'self_protection'), ''])
101 opt_list.append([Opt('STATIC_USERMODEHELPER', 'y', 'my', 'self_protection'), '']) # breaks systemd?
102 opt_list.append([Opt('PAGE_POISONING_NO_SANITY', 'is not set', 'my', 'self_protection'), ''])
103 opt_list.append([Opt('PAGE_POISONING_ZERO', 'is not set', 'my', 'self_protection'), ''])
105 opt_list.append([Opt('SECURITY', 'y', 'ubuntu18', 'security_policy'), ''])
106 opt_list.append([Opt('SECURITY_YAMA', 'y', 'ubuntu18', 'security_policy'), ''])
107 opt_list.append([Opt('SECURITY_SELINUX_DISABLE', 'is not set', 'ubuntu18', 'security_policy'), ''])
109 opt_list.append([Opt('SECCOMP', 'y', 'ubuntu18', 'cut_attack_surface'), ''])
110 opt_list.append([Opt('SECCOMP_FILTER', 'y', 'ubuntu18', 'cut_attack_surface'), ''])
111 opt_list.append([Opt('STRICT_DEVMEM', 'y', 'ubuntu18', 'cut_attack_surface'), ''])
112 opt_list.append([Opt('ACPI_CUSTOM_METHOD', 'is not set', 'ubuntu18', 'cut_attack_surface'), ''])
113 opt_list.append([Opt('COMPAT_BRK', 'is not set', 'ubuntu18', 'cut_attack_surface'), ''])
114 opt_list.append([Opt('DEVKMEM', 'is not set', 'ubuntu18', 'cut_attack_surface'), ''])
115 opt_list.append([Opt('COMPAT_VDSO', 'is not set', 'ubuntu18', 'cut_attack_surface'), ''])
116 opt_list.append([Opt('X86_PTDUMP', 'is not set', 'ubuntu18', 'cut_attack_surface'), ''])
117 opt_list.append([Opt('ZSMALLOC_STAT', 'is not set', 'ubuntu18', 'cut_attack_surface'), ''])
118 opt_list.append([Opt('PAGE_OWNER', 'is not set', 'ubuntu18', 'cut_attack_surface'), ''])
119 opt_list.append([Opt('DEBUG_KMEMLEAK', 'is not set', 'ubuntu18', 'cut_attack_surface'), ''])
121 opt_list.append([Opt('IO_STRICT_DEVMEM', 'y', 'kspp', 'cut_attack_surface'), ''])
122 opt_list.append([Opt('LEGACY_VSYSCALL_NONE', 'y', 'kspp', 'cut_attack_surface'), '']) # 'vsyscall=none'
123 opt_list.append([Opt('BINFMT_MISC', 'is not set', 'kspp', 'cut_attack_surface'), ''])
124 opt_list.append([Opt('INET_DIAG', 'is not set', 'kspp', 'cut_attack_surface'), ''])
125 opt_list.append([Opt('KEXEC', 'is not set', 'kspp', 'cut_attack_surface'), ''])
126 opt_list.append([Opt('PROC_KCORE', 'is not set', 'kspp', 'cut_attack_surface'), ''])
127 opt_list.append([Opt('LEGACY_PTYS', 'is not set', 'kspp', 'cut_attack_surface'), ''])
128 opt_list.append([Opt('IA32_EMULATION', 'is not set', 'kspp', 'cut_attack_surface'), ''])
129 opt_list.append([Opt('X86_X32', 'is not set', 'kspp', 'cut_attack_surface'), ''])
130 opt_list.append([Opt('MODIFY_LDT_SYSCALL', 'is not set', 'kspp', 'cut_attack_surface'), ''])
131 opt_list.append([Opt('HIBERNATION', 'is not set', 'kspp', 'cut_attack_surface'), ''])
133 opt_list.append([Opt('KPROBES', 'is not set', 'grsecurity', 'cut_attack_surface'), ''])
134 opt_list.append([Opt('UPROBES', 'is not set', 'grsecurity', 'cut_attack_surface'), ''])
135 opt_list.append([Opt('GENERIC_TRACER', 'is not set', 'grsecurity', 'cut_attack_surface'), ''])
136 opt_list.append([Opt('PROC_VMCORE', 'is not set', 'grsecurity', 'cut_attack_surface'), ''])
137 opt_list.append([Opt('PROC_PAGE_MONITOR', 'is not set', 'grsecurity', 'cut_attack_surface'), ''])
138 opt_list.append([Opt('USELIB', 'is not set', 'grsecurity', 'cut_attack_surface'), ''])
139 opt_list.append([Opt('CHECKPOINT_RESTORE', 'is not set', 'grsecurity', 'cut_attack_surface'), ''])
140 opt_list.append([Opt('USERFAULTFD', 'is not set', 'grsecurity', 'cut_attack_surface'), ''])
141 opt_list.append([Opt('HWPOISON_INJECT', 'is not set', 'grsecurity', 'cut_attack_surface'), ''])
142 opt_list.append([Opt('MEM_SOFT_DIRTY', 'is not set', 'grsecurity', 'cut_attack_surface'), ''])
143 opt_list.append([Opt('DEVPORT', 'is not set', 'grsecurity', 'cut_attack_surface'), ''])
144 opt_list.append([Opt('DEBUG_FS', 'is not set', 'grsecurity', 'cut_attack_surface'), ''])
145 opt_list.append([Opt('NOTIFIER_ERROR_INJECTION','is not set', 'grsecurity', 'cut_attack_surface'), ''])
147 opt_list.append([Opt('KEXEC_FILE', 'is not set', 'my', 'cut_attack_surface'), ''])
148 opt_list.append([Opt('LIVEPATCH', 'is not set', 'my', 'cut_attack_surface'), ''])
149 opt_list.append([Opt('USER_NS', 'is not set', 'my', 'cut_attack_surface'), '']) # user.max_user_namespaces=0
150 opt_list.append([Opt('IP_DCCP', 'is not set', 'my', 'cut_attack_surface'), ''])
151 opt_list.append([Opt('IP_SCTP', 'is not set', 'my', 'cut_attack_surface'), ''])
152 opt_list.append([Opt('FTRACE', 'is not set', 'my', 'cut_attack_surface'), ''])
153 opt_list.append([Opt('PROFILING', 'is not set', 'my', 'cut_attack_surface'), ''])
154 opt_list.append([Opt('BPF_JIT', 'is not set', 'my', 'cut_attack_surface'), ''])
155 opt_list.append([Opt('BPF_SYSCALL', 'is not set', 'my', 'cut_attack_surface'), ''])
157 opt_list.append([Opt('ARCH_MMAP_RND_BITS', '32', 'my', 'userspace_protection'), ''])
159 opt_list.append([Opt('LKDTM', 'm', 'my', 'feature_test'), ''])
162 def print_opt_checks():
163 print('[+] Printing kernel hardening preferences...')
164 print(' {:<39}|{:^13}|{:^10}|{:^20}'.format('option name', 'desired val', 'decision', 'reason'))
165 print(' ======================================================================================')
167 print(' CONFIG_{:<32}|{:^13}|{:^10}|{:^20}'.format(o[0].name, o[0].expected, o[0].decision, o[0].reason))
171 def print_check_results():
174 print(' {:<39}|{:^13}|{:^10}|{:^20}||{:^20}'.format('option name', 'desired val', 'decision', 'reason', 'check result'))
175 print(' ===========================================================================================================')
177 print(' CONFIG_{:<32}|{:^13}|{:^10}|{:^20}||{:^20}'.format(o[0].name, o[0].expected, o[0].decision, o[0].reason, o[1]))
181 def get_option_state(options, name):
182 return options[name] if name in options else None
185 def perform_checks(parsed_options):
188 opt.state = get_option_state(parsed_options, opt.name)
189 _, o[1] = opt.check()
192 def check_config_file(fname):
193 with open(fname, 'r') as f:
194 parsed_options = OrderedDict()
195 opt_is_on = re.compile("CONFIG_[a-zA-Z0-9_]*=[a-zA-Z0-9_\"]*")
196 opt_is_off = re.compile("# CONFIG_[a-zA-Z0-9_]* is not set")
198 print('[+] Checking "{}" against hardening preferences...'.format(fname))
199 for line in f.readlines():
204 if opt_is_on.match(line):
205 option, value = line[7:].split('=', 1)
206 elif opt_is_off.match(line):
207 option, value = line[9:].split(' ', 1)
208 if value != 'is not set':
209 sys.exit('[!] BUG: bad disabled config option "{}"'.format(line))
211 if option in parsed_options:
212 sys.exit('[!] ERROR: config option "{}" exists multiple times'.format(line))
214 if option is not None:
215 parsed_options[option] = value
217 perform_checks(parsed_options)
218 print_check_results()
221 opt_list_names = [opt[0].name for opt in opt_list]
222 for option in filter(lambda option: option not in opt_list_names, parsed_options.keys()):
223 print("DEBUG: dunno about option {} ".format(option))
226 if __name__ == '__main__':
227 parser = ArgumentParser(description='Checks the hardening options in the Linux kernel config')
228 parser.add_argument('-p', '--print', action='store_true', help='print hardening preferences')
229 parser.add_argument('-c', '--config', help='check the config_file against these preferences')
230 parser.add_argument('--debug', action='store_true', help='enable internal debug mode')
231 args = parser.parse_args()
233 construct_opt_checks()
243 check_config_file(args.config)
245 print('[+] config check is PASSED')
248 sys.exit('[-] config check is NOT PASSED: {} errors'.format(error_count))