4 This tool is for checking the security hardening options of the Linux kernel.
6 Author: Alexander Popov <alex.popov@linux.com>
8 This module contains knowledge for checks.
11 # pylint: disable=missing-function-docstring,line-too-long,invalid-name
12 # pylint: disable=too-many-branches,too-many-statements,too-many-locals
14 from .engine import KconfigCheck, CmdlineCheck, SysctlCheck, VersionCheck, OR, AND
17 def add_kconfig_checks(l, arch: str):
18 assert(arch), 'empty arch'
20 # Calling the KconfigCheck class constructor:
21 # KconfigCheck(reason, decision, name, expected)
23 # [!] Don't add CmdlineChecks in add_kconfig_checks() to avoid wrong results
24 # when the tool doesn't check the cmdline.
26 efi_not_set = KconfigCheck('-', '-', 'EFI', 'is not set')
27 cc_is_gcc = KconfigCheck('-', '-', 'CC_IS_GCC', 'y') # exists since v4.18
28 cc_is_clang = KconfigCheck('-', '-', 'CC_IS_CLANG', 'y') # exists since v4.18
29 if arch in ('X86_64', 'X86_32'):
30 cpu_sup_amd_not_set = KconfigCheck('-', '-', 'CPU_SUP_AMD', 'is not set')
31 cpu_sup_intel_not_set = KconfigCheck('-', '-', 'CPU_SUP_INTEL', 'is not set')
33 modules_not_set = KconfigCheck('cut_attack_surface', 'kspp', 'MODULES', 'is not set') # radical, but may be useful in some cases
34 devmem_not_set = KconfigCheck('cut_attack_surface', 'kspp', 'DEVMEM', 'is not set') # refers to LOCKDOWN
35 bpf_syscall_not_set = KconfigCheck('cut_attack_surface', 'lockdown', 'BPF_SYSCALL', 'is not set') # refers to LOCKDOWN
37 # 'self_protection', 'defconfig'
38 l += [KconfigCheck('self_protection', 'defconfig', 'BUG', 'y')]
39 l += [KconfigCheck('self_protection', 'defconfig', 'SLUB_DEBUG', 'y')]
40 l += [KconfigCheck('self_protection', 'defconfig', 'THREAD_INFO_IN_TASK', 'y')]
41 iommu_support_is_set = KconfigCheck('self_protection', 'defconfig', 'IOMMU_SUPPORT', 'y')
42 l += [iommu_support_is_set] # is needed for mitigating DMA attacks
43 l += [OR(KconfigCheck('self_protection', 'defconfig', 'STACKPROTECTOR', 'y'),
44 KconfigCheck('self_protection', 'defconfig', 'CC_STACKPROTECTOR', 'y'),
45 KconfigCheck('self_protection', 'defconfig', 'CC_STACKPROTECTOR_REGULAR', 'y'),
46 KconfigCheck('self_protection', 'defconfig', 'CC_STACKPROTECTOR_AUTO', 'y'),
47 KconfigCheck('self_protection', 'defconfig', 'CC_STACKPROTECTOR_STRONG', 'y'))]
48 l += [OR(KconfigCheck('self_protection', 'defconfig', 'STACKPROTECTOR_STRONG', 'y'),
49 KconfigCheck('self_protection', 'defconfig', 'CC_STACKPROTECTOR_STRONG', 'y'))]
50 l += [OR(KconfigCheck('self_protection', 'defconfig', 'STRICT_KERNEL_RWX', 'y'),
51 KconfigCheck('self_protection', 'defconfig', 'DEBUG_RODATA', 'y'))] # before v4.11
52 l += [OR(KconfigCheck('self_protection', 'defconfig', 'STRICT_MODULE_RWX', 'y'),
53 KconfigCheck('self_protection', 'defconfig', 'DEBUG_SET_MODULE_RONX', 'y'),
54 modules_not_set)] # DEBUG_SET_MODULE_RONX was before v4.11
55 l += [OR(KconfigCheck('self_protection', 'defconfig', 'REFCOUNT_FULL', 'y'),
56 VersionCheck((5, 4, 208)))]
57 # REFCOUNT_FULL is enabled by default since v5.5,
58 # and this is backported to v5.4.208
59 l += [OR(KconfigCheck('self_protection', 'defconfig', 'INIT_STACK_ALL_ZERO', 'y'),
60 KconfigCheck('self_protection', 'kspp', 'GCC_PLUGIN_STRUCTLEAK_BYREF_ALL', 'y'))]
61 if arch in ('X86_64', 'ARM64', 'X86_32'):
62 l += [KconfigCheck('self_protection', 'defconfig', 'RANDOMIZE_BASE', 'y')]
63 vmap_stack_is_set = KconfigCheck('self_protection', 'defconfig', 'VMAP_STACK', 'y')
64 if arch in ('X86_64', 'ARM64', 'ARM'):
65 l += [vmap_stack_is_set]
66 if arch in ('X86_64', 'X86_32'):
67 l += [KconfigCheck('self_protection', 'defconfig', 'SPECULATION_MITIGATIONS', 'y')]
68 l += [KconfigCheck('self_protection', 'defconfig', 'DEBUG_WX', 'y')]
69 l += [KconfigCheck('self_protection', 'defconfig', 'WERROR', 'y')]
70 l += [KconfigCheck('self_protection', 'defconfig', 'X86_MCE', 'y')]
71 l += [KconfigCheck('self_protection', 'defconfig', 'RETPOLINE', 'y')]
72 l += [KconfigCheck('self_protection', 'defconfig', 'SYN_COOKIES', 'y')] # another reason?
73 microcode_is_set = KconfigCheck('self_protection', 'defconfig', 'MICROCODE', 'y')
74 l += [microcode_is_set] # is needed for mitigating CPU bugs
75 l += [OR(KconfigCheck('self_protection', 'defconfig', 'MICROCODE_INTEL', 'y'),
76 cpu_sup_intel_not_set,
78 VersionCheck((6, 6, 0))))] # MICROCODE_INTEL was included in MICROCODE since v6.6
79 l += [OR(KconfigCheck('self_protection', 'defconfig', 'MICROCODE_AMD', 'y'),
82 VersionCheck((6, 6, 0))))] # MICROCODE_AMD was included in MICROCODE since v6.6
83 l += [OR(KconfigCheck('self_protection', 'defconfig', 'X86_SMAP', 'y'),
84 VersionCheck((5, 19, 0)))] # X86_SMAP is enabled by default since v5.19
85 l += [OR(KconfigCheck('self_protection', 'defconfig', 'X86_UMIP', 'y'),
86 KconfigCheck('self_protection', 'defconfig', 'X86_INTEL_UMIP', 'y'))]
87 l += [OR(KconfigCheck('self_protection', 'defconfig', 'X86_MCE_INTEL', 'y'),
88 cpu_sup_intel_not_set)]
89 l += [OR(KconfigCheck('self_protection', 'defconfig', 'X86_MCE_AMD', 'y'),
91 if arch in ('ARM64', 'ARM'):
92 l += [KconfigCheck('self_protection', 'defconfig', 'HW_RANDOM_TPM', 'y')]
93 l += [KconfigCheck('self_protection', 'defconfig', 'IOMMU_DEFAULT_DMA_STRICT', 'y')]
94 l += [KconfigCheck('self_protection', 'defconfig', 'IOMMU_DEFAULT_PASSTHROUGH', 'is not set')] # true if IOMMU_DEFAULT_DMA_STRICT is set
95 l += [KconfigCheck('self_protection', 'defconfig', 'STACKPROTECTOR_PER_TASK', 'y')]
97 l += [KconfigCheck('self_protection', 'defconfig', 'PAGE_TABLE_ISOLATION', 'y')]
98 l += [KconfigCheck('self_protection', 'defconfig', 'RANDOMIZE_MEMORY', 'y')]
99 l += [KconfigCheck('self_protection', 'defconfig', 'X86_KERNEL_IBT', 'y')]
100 l += [OR(KconfigCheck('self_protection', 'defconfig', 'CPU_SRSO', 'y'),
101 cpu_sup_amd_not_set)]
102 l += [AND(KconfigCheck('self_protection', 'defconfig', 'INTEL_IOMMU', 'y'),
103 iommu_support_is_set)]
104 l += [AND(KconfigCheck('self_protection', 'defconfig', 'AMD_IOMMU', 'y'),
105 iommu_support_is_set)]
107 l += [KconfigCheck('self_protection', 'defconfig', 'ARM64_PAN', 'y')]
108 l += [KconfigCheck('self_protection', 'defconfig', 'ARM64_EPAN', 'y')]
109 l += [KconfigCheck('self_protection', 'defconfig', 'UNMAP_KERNEL_AT_EL0', 'y')]
110 l += [KconfigCheck('self_protection', 'defconfig', 'ARM64_E0PD', 'y')]
111 l += [KconfigCheck('self_protection', 'defconfig', 'RODATA_FULL_DEFAULT_ENABLED', 'y')]
112 l += [KconfigCheck('self_protection', 'defconfig', 'ARM64_PTR_AUTH_KERNEL', 'y')]
113 l += [KconfigCheck('self_protection', 'defconfig', 'ARM64_BTI_KERNEL', 'y')]
114 l += [KconfigCheck('self_protection', 'defconfig', 'MITIGATE_SPECTRE_BRANCH_HISTORY', 'y')]
115 l += [KconfigCheck('self_protection', 'defconfig', 'ARM64_MTE', 'y')]
116 l += [KconfigCheck('self_protection', 'defconfig', 'RANDOMIZE_MODULE_REGION_FULL', 'y')]
117 l += [OR(KconfigCheck('self_protection', 'defconfig', 'HARDEN_EL2_VECTORS', 'y'),
118 AND(KconfigCheck('self_protection', 'defconfig', 'RANDOMIZE_BASE', 'y'),
119 VersionCheck((5, 9, 0))))] # HARDEN_EL2_VECTORS was included in RANDOMIZE_BASE in v5.9
120 l += [OR(KconfigCheck('self_protection', 'defconfig', 'HARDEN_BRANCH_PREDICTOR', 'y'),
121 VersionCheck((5, 10, 0)))] # HARDEN_BRANCH_PREDICTOR is enabled by default since v5.10
123 l += [KconfigCheck('self_protection', 'defconfig', 'CPU_SW_DOMAIN_PAN', 'y')]
124 l += [KconfigCheck('self_protection', 'defconfig', 'HARDEN_BRANCH_PREDICTOR', 'y')]
125 l += [KconfigCheck('self_protection', 'defconfig', 'HARDEN_BRANCH_HISTORY', 'y')]
126 l += [KconfigCheck('self_protection', 'defconfig', 'DEBUG_ALIGN_RODATA', 'y')]
128 # 'self_protection', 'kspp'
129 l += [KconfigCheck('self_protection', 'kspp', 'BUG_ON_DATA_CORRUPTION', 'y')]
130 l += [KconfigCheck('self_protection', 'kspp', 'SLAB_FREELIST_HARDENED', 'y')]
131 l += [KconfigCheck('self_protection', 'kspp', 'SLAB_FREELIST_RANDOM', 'y')]
132 l += [KconfigCheck('self_protection', 'kspp', 'SHUFFLE_PAGE_ALLOCATOR', 'y')]
133 l += [KconfigCheck('self_protection', 'kspp', 'FORTIFY_SOURCE', 'y')]
134 l += [KconfigCheck('self_protection', 'kspp', 'DEBUG_LIST', 'y')]
135 l += [KconfigCheck('self_protection', 'kspp', 'DEBUG_VIRTUAL', 'y')]
136 l += [KconfigCheck('self_protection', 'kspp', 'DEBUG_SG', 'y')]
137 l += [KconfigCheck('self_protection', 'kspp', 'INIT_ON_ALLOC_DEFAULT_ON', 'y')]
138 l += [KconfigCheck('self_protection', 'kspp', 'STATIC_USERMODEHELPER', 'y')] # needs userspace support
139 l += [KconfigCheck('self_protection', 'kspp', 'SCHED_CORE', 'y')]
140 l += [KconfigCheck('self_protection', 'kspp', 'SECURITY_LOCKDOWN_LSM', 'y')]
141 l += [KconfigCheck('self_protection', 'kspp', 'SECURITY_LOCKDOWN_LSM_EARLY', 'y')]
142 l += [KconfigCheck('self_protection', 'kspp', 'LOCK_DOWN_KERNEL_FORCE_CONFIDENTIALITY', 'y')]
143 cfi_clang_is_set = KconfigCheck('self_protection', 'kspp', 'CFI_CLANG', 'y')
144 cfi_clang_permissive_not_set = KconfigCheck('self_protection', 'kspp', 'CFI_PERMISSIVE', 'is not set')
145 l += [OR(KconfigCheck('self_protection', 'kspp', 'DEBUG_CREDENTIALS', 'y'),
146 VersionCheck((6, 6, 8)))] # DEBUG_CREDENTIALS was dropped in v6.6.8
147 l += [OR(KconfigCheck('self_protection', 'kspp', 'DEBUG_NOTIFIERS', 'y'),
148 AND(cfi_clang_is_set,
149 cfi_clang_permissive_not_set,
151 l += [OR(KconfigCheck('self_protection', 'kspp', 'SCHED_STACK_END_CHECK', 'y'),
153 kfence_is_set = KconfigCheck('self_protection', 'kspp', 'KFENCE', 'y')
155 l += [AND(KconfigCheck('self_protection', 'a13xp0p0v', 'KFENCE_SAMPLE_INTERVAL', 'is not off'),
157 randstruct_is_set = OR(KconfigCheck('self_protection', 'kspp', 'RANDSTRUCT_FULL', 'y'),
158 KconfigCheck('self_protection', 'kspp', 'GCC_PLUGIN_RANDSTRUCT', 'y'))
159 l += [randstruct_is_set]
160 l += [AND(KconfigCheck('self_protection', 'kspp', 'RANDSTRUCT_PERFORMANCE', 'is not set'),
161 KconfigCheck('self_protection', 'kspp', 'GCC_PLUGIN_RANDSTRUCT_PERFORMANCE', 'is not set'),
163 hardened_usercopy_is_set = KconfigCheck('self_protection', 'kspp', 'HARDENED_USERCOPY', 'y')
164 l += [hardened_usercopy_is_set]
165 l += [AND(KconfigCheck('self_protection', 'kspp', 'HARDENED_USERCOPY_FALLBACK', 'is not set'),
166 hardened_usercopy_is_set)] # usercopy whitelist violations should be prohibited
167 l += [AND(KconfigCheck('self_protection', 'kspp', 'HARDENED_USERCOPY_PAGESPAN', 'is not set'),
168 hardened_usercopy_is_set)] # this debugging for HARDENED_USERCOPY is not needed for security
169 l += [AND(KconfigCheck('self_protection', 'kspp', 'GCC_PLUGIN_LATENT_ENTROPY', 'y'),
171 l += [OR(KconfigCheck('self_protection', 'kspp', 'MODULE_SIG', 'y'),
173 l += [OR(KconfigCheck('self_protection', 'kspp', 'MODULE_SIG_ALL', 'y'),
175 l += [OR(KconfigCheck('self_protection', 'kspp', 'MODULE_SIG_SHA512', 'y'),
176 KconfigCheck('self_protection', 'a13xp0p0v', 'MODULE_SIG_SHA3_512', 'y'),
178 l += [OR(KconfigCheck('self_protection', 'kspp', 'MODULE_SIG_FORCE', 'y'),
179 modules_not_set)] # refers to LOCKDOWN
180 l += [OR(KconfigCheck('self_protection', 'kspp', 'INIT_ON_FREE_DEFAULT_ON', 'y'),
181 KconfigCheck('self_protection', 'kspp', 'PAGE_POISONING_ZERO', 'y'))]
182 # CONFIG_INIT_ON_FREE_DEFAULT_ON was added in v5.3.
183 # CONFIG_PAGE_POISONING_ZERO was removed in v5.11.
184 # Starting from v5.11 CONFIG_PAGE_POISONING unconditionally checks
185 # the 0xAA poison pattern on allocation.
186 # That brings higher performance penalty.
187 l += [OR(KconfigCheck('self_protection', 'kspp', 'EFI_DISABLE_PCI_DMA', 'y'),
189 l += [OR(KconfigCheck('self_protection', 'kspp', 'RESET_ATTACK_MITIGATION', 'y'),
190 efi_not_set)] # needs userspace support (systemd)
191 ubsan_bounds_is_set = KconfigCheck('self_protection', 'kspp', 'UBSAN_BOUNDS', 'y')
192 l += [ubsan_bounds_is_set]
193 l += [OR(KconfigCheck('self_protection', 'kspp', 'UBSAN_LOCAL_BOUNDS', 'y'),
194 AND(ubsan_bounds_is_set,
196 l += [AND(KconfigCheck('self_protection', 'kspp', 'UBSAN_TRAP', 'y'),
198 KconfigCheck('self_protection', 'kspp', 'UBSAN_SHIFT', 'is not set'),
199 KconfigCheck('self_protection', 'kspp', 'UBSAN_DIV_ZERO', 'is not set'),
200 KconfigCheck('self_protection', 'kspp', 'UBSAN_UNREACHABLE', 'is not set'),
201 KconfigCheck('self_protection', 'kspp', 'UBSAN_BOOL', 'is not set'),
202 KconfigCheck('self_protection', 'kspp', 'UBSAN_ENUM', 'is not set'),
203 KconfigCheck('self_protection', 'kspp', 'UBSAN_ALIGNMENT', 'is not set'))] # only array index bounds checking with traps
204 l += [AND(KconfigCheck('self_protection', 'kspp', 'UBSAN_SANITIZE_ALL', 'y'),
205 ubsan_bounds_is_set)]
206 if arch in ('X86_64', 'ARM64', 'X86_32'):
207 stackleak_is_set = KconfigCheck('self_protection', 'kspp', 'GCC_PLUGIN_STACKLEAK', 'y')
208 l += [AND(stackleak_is_set,
210 l += [AND(KconfigCheck('self_protection', 'kspp', 'STACKLEAK_METRICS', 'is not set'),
213 l += [AND(KconfigCheck('self_protection', 'kspp', 'STACKLEAK_RUNTIME_DISABLE', 'is not set'),
216 l += [KconfigCheck('self_protection', 'kspp', 'RANDOMIZE_KSTACK_OFFSET_DEFAULT', 'y')]
217 if arch in ('X86_64', 'ARM64'):
218 l += [AND(cfi_clang_is_set,
220 l += [AND(cfi_clang_permissive_not_set,
223 if arch in ('X86_64', 'X86_32'):
224 l += [KconfigCheck('self_protection', 'kspp', 'HW_RANDOM_TPM', 'y')]
225 l += [KconfigCheck('self_protection', 'kspp', 'DEFAULT_MMAP_MIN_ADDR', '65536')]
226 l += [KconfigCheck('self_protection', 'kspp', 'IOMMU_DEFAULT_DMA_STRICT', 'y')]
227 l += [KconfigCheck('self_protection', 'kspp', 'IOMMU_DEFAULT_PASSTHROUGH', 'is not set')] # true if IOMMU_DEFAULT_DMA_STRICT is set
228 l += [AND(KconfigCheck('self_protection', 'kspp', 'INTEL_IOMMU_DEFAULT_ON', 'y'),
229 iommu_support_is_set)]
230 if arch in ('ARM64', 'ARM'):
231 l += [KconfigCheck('self_protection', 'kspp', 'DEBUG_WX', 'y')]
232 l += [KconfigCheck('self_protection', 'kspp', 'WERROR', 'y')]
233 l += [KconfigCheck('self_protection', 'kspp', 'DEFAULT_MMAP_MIN_ADDR', '32768')]
234 l += [KconfigCheck('self_protection', 'kspp', 'SYN_COOKIES', 'y')] # another reason?
236 l += [KconfigCheck('self_protection', 'kspp', 'SLS', 'y')] # vs CVE-2021-26341 in Straight-Line-Speculation
237 l += [AND(KconfigCheck('self_protection', 'kspp', 'INTEL_IOMMU_SVM', 'y'),
238 iommu_support_is_set)]
239 l += [AND(KconfigCheck('self_protection', 'kspp', 'AMD_IOMMU_V2', 'y'),
240 iommu_support_is_set)]
242 l += [KconfigCheck('self_protection', 'kspp', 'ARM64_SW_TTBR0_PAN', 'y')]
243 l += [KconfigCheck('self_protection', 'kspp', 'SHADOW_CALL_STACK', 'y')]
244 l += [KconfigCheck('self_protection', 'kspp', 'KASAN_HW_TAGS', 'y')] # see also: kasan=on, kasan.stacktrace=off, kasan.fault=panic
246 l += [KconfigCheck('self_protection', 'kspp', 'PAGE_TABLE_ISOLATION', 'y')]
247 l += [KconfigCheck('self_protection', 'kspp', 'HIGHMEM64G', 'y')]
248 l += [KconfigCheck('self_protection', 'kspp', 'X86_PAE', 'y')]
249 l += [AND(KconfigCheck('self_protection', 'kspp', 'INTEL_IOMMU', 'y'),
250 iommu_support_is_set)]
252 # 'self_protection', 'clipos'
253 l += [KconfigCheck('self_protection', 'clipos', 'SLAB_MERGE_DEFAULT', 'is not set')]
255 # 'self_protection', 'a13xp0p0v'
256 l += [KconfigCheck('self_protection', 'a13xp0p0v', 'LIST_HARDENED', 'y')]
257 l += [KconfigCheck('self_protection', 'a13xp0p0v', 'RANDOM_KMALLOC_CACHES', 'y')]
260 if arch in ('X86_64', 'ARM64', 'X86_32'):
261 l += [KconfigCheck('security_policy', 'defconfig', 'SECURITY', 'y')]
263 l += [KconfigCheck('security_policy', 'kspp', 'SECURITY', 'y')]
264 l += [KconfigCheck('security_policy', 'kspp', 'SECURITY_YAMA', 'y')]
265 l += [KconfigCheck('security_policy', 'kspp', 'SECURITY_LANDLOCK', 'y')]
266 l += [KconfigCheck('security_policy', 'kspp', 'SECURITY_SELINUX_DISABLE', 'is not set')]
267 l += [KconfigCheck('security_policy', 'kspp', 'SECURITY_SELINUX_BOOTPARAM', 'is not set')]
268 l += [KconfigCheck('security_policy', 'kspp', 'SECURITY_SELINUX_DEVELOP', 'is not set')]
269 l += [KconfigCheck('security_policy', 'kspp', 'SECURITY_WRITABLE_HOOKS', 'is not set')] # refers to SECURITY_SELINUX_DISABLE
270 l += [KconfigCheck('security_policy', 'a13xp0p0v', 'SECURITY_SELINUX_DEBUG', 'is not set')]
271 l += [OR(KconfigCheck('security_policy', 'a13xp0p0v', 'SECURITY_SELINUX', 'y'),
272 KconfigCheck('security_policy', 'a13xp0p0v', 'SECURITY_APPARMOR', 'y'),
273 KconfigCheck('security_policy', 'a13xp0p0v', 'SECURITY_SMACK', 'y'),
274 KconfigCheck('security_policy', 'a13xp0p0v', 'SECURITY_TOMOYO', 'y'))] # one of major LSMs implementing MAC
276 # 'cut_attack_surface', 'defconfig'
277 l += [KconfigCheck('cut_attack_surface', 'defconfig', 'SECCOMP', 'y')]
278 l += [KconfigCheck('cut_attack_surface', 'defconfig', 'SECCOMP_FILTER', 'y')]
279 l += [OR(KconfigCheck('cut_attack_surface', 'defconfig', 'BPF_UNPRIV_DEFAULT_OFF', 'y'),
280 bpf_syscall_not_set)] # see unprivileged_bpf_disabled
281 if arch in ('X86_64', 'ARM64', 'X86_32'):
282 l += [OR(KconfigCheck('cut_attack_surface', 'defconfig', 'STRICT_DEVMEM', 'y'),
283 devmem_not_set)] # refers to LOCKDOWN
284 if arch in ('X86_64', 'X86_32'):
285 l += [OR(KconfigCheck('cut_attack_surface', 'defconfig', 'X86_INTEL_TSX_MODE_OFF', 'y'),
286 cpu_sup_intel_not_set)] # tsx=off
288 # 'cut_attack_surface', 'kspp'
289 l += [KconfigCheck('cut_attack_surface', 'kspp', 'SECURITY_DMESG_RESTRICT', 'y')]
290 l += [KconfigCheck('cut_attack_surface', 'kspp', 'ACPI_CUSTOM_METHOD', 'is not set')] # refers to LOCKDOWN
291 l += [KconfigCheck('cut_attack_surface', 'kspp', 'COMPAT_BRK', 'is not set')]
292 l += [KconfigCheck('cut_attack_surface', 'kspp', 'DEVKMEM', 'is not set')] # refers to LOCKDOWN
293 l += [KconfigCheck('cut_attack_surface', 'kspp', 'BINFMT_MISC', 'is not set')]
294 l += [KconfigCheck('cut_attack_surface', 'kspp', 'INET_DIAG', 'is not set')]
295 l += [KconfigCheck('cut_attack_surface', 'kspp', 'KEXEC', 'is not set')] # refers to LOCKDOWN
296 l += [KconfigCheck('cut_attack_surface', 'kspp', 'PROC_KCORE', 'is not set')] # refers to LOCKDOWN
297 l += [KconfigCheck('cut_attack_surface', 'kspp', 'LEGACY_PTYS', 'is not set')]
298 l += [KconfigCheck('cut_attack_surface', 'kspp', 'HIBERNATION', 'is not set')] # refers to LOCKDOWN
299 l += [KconfigCheck('cut_attack_surface', 'kspp', 'COMPAT', 'is not set')]
300 l += [KconfigCheck('cut_attack_surface', 'kspp', 'IA32_EMULATION', 'is not set')]
301 l += [KconfigCheck('cut_attack_surface', 'kspp', 'X86_X32', 'is not set')]
302 l += [KconfigCheck('cut_attack_surface', 'kspp', 'X86_X32_ABI', 'is not set')]
303 l += [KconfigCheck('cut_attack_surface', 'kspp', 'MODIFY_LDT_SYSCALL', 'is not set')]
304 l += [KconfigCheck('cut_attack_surface', 'kspp', 'OABI_COMPAT', 'is not set')]
305 l += [KconfigCheck('cut_attack_surface', 'kspp', 'X86_MSR', 'is not set')] # refers to LOCKDOWN
306 l += [KconfigCheck('cut_attack_surface', 'kspp', 'LEGACY_TIOCSTI', 'is not set')]
307 l += [modules_not_set]
308 l += [devmem_not_set]
309 l += [OR(KconfigCheck('cut_attack_surface', 'kspp', 'IO_STRICT_DEVMEM', 'y'),
310 devmem_not_set)] # refers to LOCKDOWN
311 l += [AND(KconfigCheck('cut_attack_surface', 'kspp', 'LDISC_AUTOLOAD', 'is not set'),
312 KconfigCheck('cut_attack_surface', 'kspp', 'LDISC_AUTOLOAD', 'is present'))]
313 if arch in ('X86_64', 'X86_32'):
314 l += [KconfigCheck('cut_attack_surface', 'kspp', 'COMPAT_VDSO', 'is not set')]
315 # CONFIG_COMPAT_VDSO disabled ASLR of vDSO only on X86_64 and X86_32;
316 # on ARM64 this option has different meaning
318 l += [OR(KconfigCheck('cut_attack_surface', 'kspp', 'X86_VSYSCALL_EMULATION', 'is not set'),
319 KconfigCheck('cut_attack_surface', 'kspp', 'LEGACY_VSYSCALL_NONE', 'y'))]
320 # disabling X86_VSYSCALL_EMULATION turns vsyscall off completely,
321 # and LEGACY_VSYSCALL_NONE can be changed at boot time via the cmdline parameter
323 l += [OR(KconfigCheck('cut_attack_surface', 'kspp', 'STRICT_DEVMEM', 'y'),
324 devmem_not_set)] # refers to LOCKDOWN
326 # 'cut_attack_surface', 'grsec'
327 l += [KconfigCheck('cut_attack_surface', 'grsec', 'ZSMALLOC_STAT', 'is not set')]
328 l += [KconfigCheck('cut_attack_surface', 'grsec', 'PAGE_OWNER', 'is not set')]
329 l += [KconfigCheck('cut_attack_surface', 'grsec', 'DEBUG_KMEMLEAK', 'is not set')]
330 l += [KconfigCheck('cut_attack_surface', 'grsec', 'BINFMT_AOUT', 'is not set')]
331 l += [KconfigCheck('cut_attack_surface', 'grsec', 'KPROBE_EVENTS', 'is not set')]
332 l += [KconfigCheck('cut_attack_surface', 'grsec', 'UPROBE_EVENTS', 'is not set')]
333 l += [KconfigCheck('cut_attack_surface', 'grsec', 'GENERIC_TRACER', 'is not set')] # refers to LOCKDOWN
334 l += [KconfigCheck('cut_attack_surface', 'grsec', 'FUNCTION_TRACER', 'is not set')]
335 l += [KconfigCheck('cut_attack_surface', 'grsec', 'STACK_TRACER', 'is not set')]
336 l += [KconfigCheck('cut_attack_surface', 'grsec', 'HIST_TRIGGERS', 'is not set')]
337 l += [KconfigCheck('cut_attack_surface', 'grsec', 'BLK_DEV_IO_TRACE', 'is not set')]
338 l += [KconfigCheck('cut_attack_surface', 'grsec', 'PROC_VMCORE', 'is not set')]
339 l += [KconfigCheck('cut_attack_surface', 'grsec', 'PROC_PAGE_MONITOR', 'is not set')]
340 l += [KconfigCheck('cut_attack_surface', 'grsec', 'USELIB', 'is not set')]
341 l += [KconfigCheck('cut_attack_surface', 'grsec', 'CHECKPOINT_RESTORE', 'is not set')]
342 l += [KconfigCheck('cut_attack_surface', 'grsec', 'USERFAULTFD', 'is not set')]
343 l += [KconfigCheck('cut_attack_surface', 'grsec', 'HWPOISON_INJECT', 'is not set')]
344 l += [KconfigCheck('cut_attack_surface', 'grsec', 'MEM_SOFT_DIRTY', 'is not set')]
345 l += [KconfigCheck('cut_attack_surface', 'grsec', 'DEVPORT', 'is not set')] # refers to LOCKDOWN
346 l += [KconfigCheck('cut_attack_surface', 'grsec', 'DEBUG_FS', 'is not set')] # refers to LOCKDOWN
347 l += [KconfigCheck('cut_attack_surface', 'grsec', 'NOTIFIER_ERROR_INJECTION', 'is not set')]
348 l += [KconfigCheck('cut_attack_surface', 'grsec', 'FAIL_FUTEX', 'is not set')]
349 l += [KconfigCheck('cut_attack_surface', 'grsec', 'PUNIT_ATOM_DEBUG', 'is not set')]
350 l += [KconfigCheck('cut_attack_surface', 'grsec', 'ACPI_CONFIGFS', 'is not set')]
351 l += [KconfigCheck('cut_attack_surface', 'grsec', 'EDAC_DEBUG', 'is not set')]
352 l += [KconfigCheck('cut_attack_surface', 'grsec', 'DRM_I915_DEBUG', 'is not set')]
353 l += [KconfigCheck('cut_attack_surface', 'grsec', 'BCACHE_CLOSURES_DEBUG', 'is not set')]
354 l += [KconfigCheck('cut_attack_surface', 'grsec', 'DVB_C8SECTPFE', 'is not set')]
355 l += [KconfigCheck('cut_attack_surface', 'grsec', 'MTD_SLRAM', 'is not set')]
356 l += [KconfigCheck('cut_attack_surface', 'grsec', 'MTD_PHRAM', 'is not set')]
357 l += [KconfigCheck('cut_attack_surface', 'grsec', 'IO_URING', 'is not set')]
358 l += [KconfigCheck('cut_attack_surface', 'grsec', 'KCMP', 'is not set')]
359 l += [KconfigCheck('cut_attack_surface', 'grsec', 'RSEQ', 'is not set')]
360 l += [KconfigCheck('cut_attack_surface', 'grsec', 'LATENCYTOP', 'is not set')]
361 l += [KconfigCheck('cut_attack_surface', 'grsec', 'KCOV', 'is not set')]
362 l += [KconfigCheck('cut_attack_surface', 'grsec', 'PROVIDE_OHCI1394_DMA_INIT', 'is not set')]
363 l += [KconfigCheck('cut_attack_surface', 'grsec', 'SUNRPC_DEBUG', 'is not set')]
364 l += [AND(KconfigCheck('cut_attack_surface', 'grsec', 'PTDUMP_DEBUGFS', 'is not set'),
365 KconfigCheck('cut_attack_surface', 'grsec', 'X86_PTDUMP', 'is not set'))]
367 # 'cut_attack_surface', 'maintainer'
368 l += [KconfigCheck('cut_attack_surface', 'maintainer', 'DRM_LEGACY', 'is not set')] # recommended by Daniel Vetter in /issues/38
369 l += [KconfigCheck('cut_attack_surface', 'maintainer', 'FB', 'is not set')] # recommended by Daniel Vetter in /issues/38
370 l += [KconfigCheck('cut_attack_surface', 'maintainer', 'VT', 'is not set')] # recommended by Daniel Vetter in /issues/38
371 l += [KconfigCheck('cut_attack_surface', 'maintainer', 'BLK_DEV_FD', 'is not set')] # recommended by Denis Efremov in /pull/54
372 l += [KconfigCheck('cut_attack_surface', 'maintainer', 'BLK_DEV_FD_RAWCMD', 'is not set')] # recommended by Denis Efremov in /pull/62
373 l += [KconfigCheck('cut_attack_surface', 'maintainer', 'NOUVEAU_LEGACY_CTX_SUPPORT', 'is not set')]
374 # recommended by Dave Airlie in kernel commit b30a43ac7132cdda
376 # 'cut_attack_surface', 'clipos'
377 l += [KconfigCheck('cut_attack_surface', 'clipos', 'STAGING', 'is not set')]
378 l += [KconfigCheck('cut_attack_surface', 'clipos', 'KSM', 'is not set')] # to prevent FLUSH+RELOAD attack
379 l += [KconfigCheck('cut_attack_surface', 'clipos', 'KALLSYMS', 'is not set')]
380 l += [KconfigCheck('cut_attack_surface', 'clipos', 'MAGIC_SYSRQ', 'is not set')]
381 l += [KconfigCheck('cut_attack_surface', 'clipos', 'KEXEC_FILE', 'is not set')] # refers to LOCKDOWN (permissive)
382 l += [KconfigCheck('cut_attack_surface', 'clipos', 'USER_NS', 'is not set')] # user.max_user_namespaces=0
383 l += [KconfigCheck('cut_attack_surface', 'clipos', 'X86_CPUID', 'is not set')]
384 l += [KconfigCheck('cut_attack_surface', 'clipos', 'X86_IOPL_IOPERM', 'is not set')] # refers to LOCKDOWN
385 l += [KconfigCheck('cut_attack_surface', 'clipos', 'ACPI_TABLE_UPGRADE', 'is not set')] # refers to LOCKDOWN
386 l += [KconfigCheck('cut_attack_surface', 'clipos', 'EFI_CUSTOM_SSDT_OVERLAYS', 'is not set')]
387 l += [KconfigCheck('cut_attack_surface', 'clipos', 'AIO', 'is not set')]
388 # l += [KconfigCheck('cut_attack_surface', 'clipos', 'IKCONFIG', 'is not set')] # no, IKCONFIG is needed for this check :)
390 # 'cut_attack_surface', 'lockdown'
391 l += [KconfigCheck('cut_attack_surface', 'lockdown', 'EFI_TEST', 'is not set')] # refers to LOCKDOWN
392 l += [KconfigCheck('cut_attack_surface', 'lockdown', 'MMIOTRACE_TEST', 'is not set')] # refers to LOCKDOWN
393 l += [KconfigCheck('cut_attack_surface', 'lockdown', 'KPROBES', 'is not set')] # refers to LOCKDOWN
394 l += [bpf_syscall_not_set] # refers to LOCKDOWN
396 # 'cut_attack_surface', 'a13xp0p0v'
397 l += [KconfigCheck('cut_attack_surface', 'a13xp0p0v', 'MMIOTRACE', 'is not set')] # refers to LOCKDOWN (permissive)
398 l += [KconfigCheck('cut_attack_surface', 'a13xp0p0v', 'LIVEPATCH', 'is not set')]
399 l += [KconfigCheck('cut_attack_surface', 'a13xp0p0v', 'IP_DCCP', 'is not set')]
400 l += [KconfigCheck('cut_attack_surface', 'a13xp0p0v', 'IP_SCTP', 'is not set')]
401 l += [KconfigCheck('cut_attack_surface', 'a13xp0p0v', 'FTRACE', 'is not set')] # refers to LOCKDOWN
402 l += [KconfigCheck('cut_attack_surface', 'a13xp0p0v', 'VIDEO_VIVID', 'is not set')]
403 l += [KconfigCheck('cut_attack_surface', 'a13xp0p0v', 'INPUT_EVBUG', 'is not set')] # Can be used as a keylogger
404 l += [KconfigCheck('cut_attack_surface', 'a13xp0p0v', 'KGDB', 'is not set')]
405 l += [KconfigCheck('cut_attack_surface', 'a13xp0p0v', 'CORESIGHT', 'is not set')]
406 l += [KconfigCheck('cut_attack_surface', 'a13xp0p0v', 'XFS_SUPPORT_V4', 'is not set')]
407 l += [KconfigCheck('cut_attack_surface', 'a13xp0p0v', 'MODULE_FORCE_LOAD', 'is not set')]
408 l += [KconfigCheck('cut_attack_surface', 'a13xp0p0v', 'BLK_DEV_WRITE_MOUNTED', 'is not set')]
409 l += [OR(KconfigCheck('cut_attack_surface', 'a13xp0p0v', 'TRIM_UNUSED_KSYMS', 'y'),
415 l += [KconfigCheck('harden_userspace', 'defconfig', 'ARM64_PTR_AUTH', 'y')]
416 l += [KconfigCheck('harden_userspace', 'defconfig', 'ARM64_BTI', 'y')]
417 if arch in ('ARM', 'X86_32'):
418 l += [KconfigCheck('harden_userspace', 'defconfig', 'VMSPLIT_3G', 'y')]
419 l += [KconfigCheck('harden_userspace', 'clipos', 'COREDUMP', 'is not set')]
420 l += [KconfigCheck('harden_userspace', 'a13xp0p0v', 'ARCH_MMAP_RND_BITS', 'MAX')] # 'MAX' value is refined using ARCH_MMAP_RND_BITS_MAX
422 l += [KconfigCheck('harden_userspace', 'a13xp0p0v', 'X86_USER_SHADOW_STACK', 'y')]
425 def add_cmdline_checks(l, arch: str):
426 assert(arch), 'empty arch'
428 # Calling the CmdlineCheck class constructor:
429 # CmdlineCheck(reason, decision, name, expected)
431 # [!] Don't add CmdlineChecks in add_kconfig_checks() to avoid wrong results
432 # when the tool doesn't check the cmdline.
434 # [!] Make sure that values of the options in CmdlineChecks need normalization.
435 # For more info see normalize_cmdline_options().
437 # A common pattern for checking the 'param_x' cmdline parameter
438 # that __overrides__ the 'PARAM_X_DEFAULT' kconfig option:
439 # l += [OR(CmdlineCheck(reason, decision, 'param_x', '1'),
440 # AND(KconfigCheck(reason, decision, 'PARAM_X_DEFAULT_ON', 'y'),
441 # CmdlineCheck(reason, decision, 'param_x, 'is not set')))]
443 # Here we don't check the kconfig options or minimal kernel version
444 # required for the cmdline parameters. That would make the checks
445 # very complex and not give a 100% guarantee anyway.
447 # 'self_protection', 'defconfig'
448 l += [CmdlineCheck('self_protection', 'defconfig', 'nosmep', 'is not set')]
449 l += [CmdlineCheck('self_protection', 'defconfig', 'nosmap', 'is not set')]
450 l += [CmdlineCheck('self_protection', 'defconfig', 'nokaslr', 'is not set')]
451 l += [CmdlineCheck('self_protection', 'defconfig', 'nopti', 'is not set')]
452 l += [CmdlineCheck('self_protection', 'defconfig', 'nospectre_v1', 'is not set')]
453 l += [CmdlineCheck('self_protection', 'defconfig', 'nospectre_v2', 'is not set')]
454 l += [CmdlineCheck('self_protection', 'defconfig', 'nospectre_bhb', 'is not set')]
455 l += [CmdlineCheck('self_protection', 'defconfig', 'nospec_store_bypass_disable', 'is not set')]
456 l += [CmdlineCheck('self_protection', 'defconfig', 'dis_ucode_ldr', 'is not set')]
457 l += [CmdlineCheck('self_protection', 'defconfig', 'arm64.nobti', 'is not set')]
458 l += [CmdlineCheck('self_protection', 'defconfig', 'arm64.nopauth', 'is not set')]
459 l += [CmdlineCheck('self_protection', 'defconfig', 'arm64.nomte', 'is not set')]
460 if arch in ('X86_64', 'X86_32'):
461 l += [OR(CmdlineCheck('self_protection', 'defconfig', 'spectre_v2', 'is not off'),
462 AND(CmdlineCheck('self_protection', 'kspp', 'mitigations', 'auto,nosmt'),
463 CmdlineCheck('self_protection', 'defconfig', 'spectre_v2', 'is not set')))]
464 l += [OR(CmdlineCheck('self_protection', 'defconfig', 'spectre_v2_user', 'is not off'),
465 AND(CmdlineCheck('self_protection', 'kspp', 'mitigations', 'auto,nosmt'),
466 CmdlineCheck('self_protection', 'defconfig', 'spectre_v2_user', 'is not set')))]
467 l += [OR(CmdlineCheck('self_protection', 'defconfig', 'spec_store_bypass_disable', 'is not off'),
468 AND(CmdlineCheck('self_protection', 'kspp', 'mitigations', 'auto,nosmt'),
469 CmdlineCheck('self_protection', 'defconfig', 'spec_store_bypass_disable', 'is not set')))]
470 l += [OR(CmdlineCheck('self_protection', 'defconfig', 'l1tf', 'is not off'),
471 AND(CmdlineCheck('self_protection', 'kspp', 'mitigations', 'auto,nosmt'),
472 CmdlineCheck('self_protection', 'defconfig', 'l1tf', 'is not set')))]
473 l += [OR(CmdlineCheck('self_protection', 'defconfig', 'mds', 'is not off'),
474 AND(CmdlineCheck('self_protection', 'kspp', 'mitigations', 'auto,nosmt'),
475 CmdlineCheck('self_protection', 'defconfig', 'mds', 'is not set')))]
476 l += [OR(CmdlineCheck('self_protection', 'defconfig', 'tsx_async_abort', 'is not off'),
477 AND(CmdlineCheck('self_protection', 'kspp', 'mitigations', 'auto,nosmt'),
478 CmdlineCheck('self_protection', 'defconfig', 'tsx_async_abort', 'is not set')))]
479 l += [OR(CmdlineCheck('self_protection', 'defconfig', 'srbds', 'is not off'),
480 AND(CmdlineCheck('self_protection', 'kspp', 'mitigations', 'auto,nosmt'),
481 CmdlineCheck('self_protection', 'defconfig', 'srbds', 'is not set')))]
482 l += [OR(CmdlineCheck('self_protection', 'defconfig', 'mmio_stale_data', 'is not off'),
483 AND(CmdlineCheck('self_protection', 'kspp', 'mitigations', 'auto,nosmt'),
484 CmdlineCheck('self_protection', 'defconfig', 'mmio_stale_data', 'is not set')))]
485 l += [OR(CmdlineCheck('self_protection', 'defconfig', 'retbleed', 'is not off'),
486 AND(CmdlineCheck('self_protection', 'kspp', 'mitigations', 'auto,nosmt'),
487 CmdlineCheck('self_protection', 'defconfig', 'retbleed', 'is not set')))]
488 l += [OR(CmdlineCheck('self_protection', 'defconfig', 'spec_rstack_overflow', 'is not off'),
489 AND(CmdlineCheck('self_protection', 'kspp', 'mitigations', 'auto,nosmt'),
490 CmdlineCheck('self_protection', 'defconfig', 'spec_rstack_overflow', 'is not set')))]
491 l += [OR(CmdlineCheck('self_protection', 'defconfig', 'gather_data_sampling', 'is not off'),
492 AND(CmdlineCheck('self_protection', 'kspp', 'mitigations', 'auto,nosmt'),
493 CmdlineCheck('self_protection', 'defconfig', 'gather_data_sampling', 'is not set')))]
495 l += [OR(CmdlineCheck('self_protection', 'defconfig', 'kpti', 'is not off'),
496 AND(CmdlineCheck('self_protection', 'kspp', 'mitigations', 'auto,nosmt'),
497 CmdlineCheck('self_protection', 'defconfig', 'kpti', 'is not set')))]
498 l += [OR(CmdlineCheck('self_protection', 'defconfig', 'ssbd', 'kernel'),
499 CmdlineCheck('self_protection', 'a13xp0p0v', 'ssbd', 'force-on'),
500 AND(CmdlineCheck('self_protection', 'kspp', 'mitigations', 'auto,nosmt'),
501 CmdlineCheck('self_protection', 'defconfig', 'ssbd', 'is not set')))]
502 l += [OR(CmdlineCheck('self_protection', 'defconfig', 'rodata', 'full'),
503 AND(KconfigCheck('self_protection', 'defconfig', 'RODATA_FULL_DEFAULT_ENABLED', 'y'),
504 CmdlineCheck('self_protection', 'defconfig', 'rodata', 'is not set')))]
506 l += [OR(CmdlineCheck('self_protection', 'defconfig', 'rodata', 'on'),
507 CmdlineCheck('self_protection', 'defconfig', 'rodata', 'is not set'))]
509 # 'self_protection', 'kspp'
510 l += [CmdlineCheck('self_protection', 'kspp', 'mitigations', 'auto,nosmt')]
511 l += [CmdlineCheck('self_protection', 'kspp', 'slab_merge', 'is not set')] # consequence of 'slab_nomerge' by kspp
512 l += [CmdlineCheck('self_protection', 'kspp', 'slub_merge', 'is not set')] # consequence of 'slab_nomerge' by kspp
513 l += [CmdlineCheck('self_protection', 'kspp', 'page_alloc.shuffle', '1')]
514 l += [OR(CmdlineCheck('self_protection', 'kspp', 'slab_nomerge', 'is present'),
515 AND(KconfigCheck('self_protection', 'clipos', 'SLAB_MERGE_DEFAULT', 'is not set'),
516 CmdlineCheck('self_protection', 'kspp', 'slab_merge', 'is not set'),
517 CmdlineCheck('self_protection', 'kspp', 'slub_merge', 'is not set')))]
518 l += [OR(CmdlineCheck('self_protection', 'kspp', 'init_on_alloc', '1'),
519 AND(KconfigCheck('self_protection', 'kspp', 'INIT_ON_ALLOC_DEFAULT_ON', 'y'),
520 CmdlineCheck('self_protection', 'kspp', 'init_on_alloc', 'is not set')))]
521 l += [OR(CmdlineCheck('self_protection', 'kspp', 'init_on_free', '1'),
522 AND(KconfigCheck('self_protection', 'kspp', 'INIT_ON_FREE_DEFAULT_ON', 'y'),
523 CmdlineCheck('self_protection', 'kspp', 'init_on_free', 'is not set')),
524 AND(CmdlineCheck('self_protection', 'kspp', 'page_poison', '1'),
525 KconfigCheck('self_protection', 'kspp', 'PAGE_POISONING_ZERO', 'y'),
526 CmdlineCheck('self_protection', 'kspp', 'slub_debug', 'P')))]
527 l += [OR(CmdlineCheck('self_protection', 'kspp', 'hardened_usercopy', '1'),
528 AND(KconfigCheck('self_protection', 'kspp', 'HARDENED_USERCOPY', 'y'),
529 CmdlineCheck('self_protection', 'kspp', 'hardened_usercopy', 'is not set')))]
530 l += [AND(CmdlineCheck('self_protection', 'kspp', 'slab_common.usercopy_fallback', 'is not set'),
531 KconfigCheck('self_protection', 'kspp', 'HARDENED_USERCOPY_FALLBACK', 'is not set'))]
532 # Consequence of the HARDENED_USERCOPY_FALLBACK check by kspp.
533 # Don't require slab_common.usercopy_fallback=0,
534 # since HARDENED_USERCOPY_FALLBACK was removed in Linux v5.16.
535 if arch in ('X86_64', 'ARM64', 'X86_32'):
536 l += [OR(CmdlineCheck('self_protection', 'kspp', 'iommu.strict', '1'),
537 AND(KconfigCheck('self_protection', 'kspp', 'IOMMU_DEFAULT_DMA_STRICT', 'y'),
538 CmdlineCheck('self_protection', 'kspp', 'iommu.strict', 'is not set')))]
539 l += [OR(CmdlineCheck('self_protection', 'kspp', 'iommu.passthrough', '0'),
540 AND(KconfigCheck('self_protection', 'kspp', 'IOMMU_DEFAULT_PASSTHROUGH', 'is not set'),
541 CmdlineCheck('self_protection', 'kspp', 'iommu.passthrough', 'is not set')))]
542 l += [OR(CmdlineCheck('self_protection', 'kspp', 'randomize_kstack_offset', '1'),
543 AND(KconfigCheck('self_protection', 'kspp', 'RANDOMIZE_KSTACK_OFFSET_DEFAULT', 'y'),
544 CmdlineCheck('self_protection', 'kspp', 'randomize_kstack_offset', 'is not set')))]
545 if arch in ('X86_64', 'X86_32'):
546 l += [AND(CmdlineCheck('self_protection', 'kspp', 'pti', 'on'),
547 CmdlineCheck('self_protection', 'defconfig', 'nopti', 'is not set'))]
549 # 'self_protection', 'clipos'
550 if arch in ('X86_64', 'X86_32'):
551 l += [CmdlineCheck('self_protection', 'clipos', 'iommu', 'force')]
553 # 'self_protection', 'a13xp0p0v'
554 l += [OR(CmdlineCheck('self_protection', 'a13xp0p0v', 'kfence.sample_interval', 'is not off'),
555 AND(KconfigCheck('self_protection', 'a13xp0p0v', 'KFENCE_SAMPLE_INTERVAL', 'is not off'),
556 CmdlineCheck('self_protection', 'a13xp0p0v', 'kfence.sample_interval', 'is not set')))]
558 # 'cut_attack_surface', 'defconfig'
559 if arch in ('X86_64', 'X86_32'):
560 tsx_not_set = CmdlineCheck('cut_attack_surface', 'defconfig', 'tsx', 'is not set')
561 l += [OR(CmdlineCheck('cut_attack_surface', 'defconfig', 'tsx', 'off'),
562 AND(KconfigCheck('cut_attack_surface', 'defconfig', 'X86_INTEL_TSX_MODE_OFF', 'y'),
564 AND(KconfigCheck('-', '-', 'CPU_SUP_INTEL', 'is not set'),
567 # 'cut_attack_surface', 'kspp'
568 l += [CmdlineCheck('cut_attack_surface', 'kspp', 'nosmt', 'is present')] # slow (high performance penalty)
570 l += [OR(CmdlineCheck('cut_attack_surface', 'kspp', 'vsyscall', 'none'),
571 KconfigCheck('cut_attack_surface', 'kspp', 'X86_VSYSCALL_EMULATION', 'is not set'),
572 AND(KconfigCheck('cut_attack_surface', 'kspp', 'LEGACY_VSYSCALL_NONE', 'y'),
573 CmdlineCheck('cut_attack_surface', 'kspp', 'vsyscall', 'is not set')))]
574 l += [OR(CmdlineCheck('cut_attack_surface', 'kspp', 'vdso32', '0'),
575 CmdlineCheck('cut_attack_surface', 'a13xp0p0v', 'vdso32', '1'),
576 AND(KconfigCheck('cut_attack_surface', 'kspp', 'COMPAT_VDSO', 'is not set'),
577 CmdlineCheck('cut_attack_surface', 'a13xp0p0v', 'vdso32', 'is not set')))] # the vdso32 parameter must not be 2
579 l += [OR(CmdlineCheck('cut_attack_surface', 'kspp', 'vdso32', '0'),
580 CmdlineCheck('cut_attack_surface', 'a13xp0p0v', 'vdso', '0'),
581 CmdlineCheck('cut_attack_surface', 'a13xp0p0v', 'vdso32', '1'),
582 CmdlineCheck('cut_attack_surface', 'a13xp0p0v', 'vdso', '1'),
583 AND(KconfigCheck('cut_attack_surface', 'kspp', 'COMPAT_VDSO', 'is not set'),
584 CmdlineCheck('cut_attack_surface', 'a13xp0p0v', 'vdso32', 'is not set'),
585 CmdlineCheck('cut_attack_surface', 'a13xp0p0v', 'vdso', 'is not set')))] # the vdso and vdso32 parameters must not be 2
587 # 'cut_attack_surface', 'grsec'
588 # The cmdline checks compatible with the kconfig options disabled by grsecurity...
589 l += [OR(CmdlineCheck('cut_attack_surface', 'grsec', 'debugfs', 'off'),
590 KconfigCheck('cut_attack_surface', 'grsec', 'DEBUG_FS', 'is not set'))] # ... the end
592 # 'cut_attack_surface', 'a13xp0p0v'
593 l += [CmdlineCheck('cut_attack_surface', 'a13xp0p0v', 'sysrq_always_enabled', 'is not set')]
594 l += [OR(CmdlineCheck('cut_attack_surface', 'a13xp0p0v', 'bdev_allow_write_mounted', '0'),
595 AND(KconfigCheck('cut_attack_surface', 'a13xp0p0v', 'BLK_DEV_WRITE_MOUNTED', 'is not set'),
596 CmdlineCheck('cut_attack_surface', 'a13xp0p0v', 'bdev_allow_write_mounted', 'is not set')))]
598 l += [OR(CmdlineCheck('cut_attack_surface', 'a13xp0p0v', 'ia32_emulation', '0'),
599 KconfigCheck('cut_attack_surface', 'kspp', 'IA32_EMULATION', 'is not set'),
600 AND(KconfigCheck('cut_attack_surface', 'a13xp0p0v', 'IA32_EMULATION_DEFAULT_DISABLED', 'y'),
601 CmdlineCheck('cut_attack_surface', 'a13xp0p0v', 'ia32_emulation', 'is not set')))]
604 l += [CmdlineCheck('harden_userspace', 'defconfig', 'norandmaps', 'is not set')]
607 no_kstrtobool_options = [
608 'debugfs', # See debugfs_kernel() in fs/debugfs/inode.c
609 'mitigations', # See mitigations_parse_cmdline() in kernel/cpu.c
610 'pti', # See pti_check_boottime_disable() in arch/x86/mm/pti.c
611 'spectre_v2', # See spectre_v2_parse_cmdline() in arch/x86/kernel/cpu/bugs.c
612 'spectre_v2_user', # See spectre_v2_parse_user_cmdline() in arch/x86/kernel/cpu/bugs.c
613 'spec_store_bypass_disable', # See ssb_parse_cmdline() in arch/x86/kernel/cpu/bugs.c
614 'l1tf', # See l1tf_cmdline() in arch/x86/kernel/cpu/bugs.c
615 'mds', # See mds_cmdline() in arch/x86/kernel/cpu/bugs.c
616 'tsx_async_abort', # See tsx_async_abort_parse_cmdline() in arch/x86/kernel/cpu/bugs.c
617 'srbds', # See srbds_parse_cmdline() in arch/x86/kernel/cpu/bugs.c
618 'mmio_stale_data', # See mmio_stale_data_parse_cmdline() in arch/x86/kernel/cpu/bugs.c
619 'retbleed', # See retbleed_parse_cmdline() in arch/x86/kernel/cpu/bugs.c
620 'rodata', # See set_debug_rodata() in init/main.c
621 'ssbd', # See parse_spectre_v4_param() in arch/arm64/kernel/proton-pack.c
622 'spec_rstack_overflow', # See srso_parse_cmdline() in arch/x86/kernel/cpu/bugs.c
623 'gather_data_sampling', # See gds_parse_cmdline() in arch/x86/kernel/cpu/bugs.c
624 'slub_debug', # See setup_slub_debug() in mm/slub.c
625 'iommu', # See iommu_setup() in arch/x86/kernel/pci-dma.c
626 'vsyscall', # See vsyscall_setup() in arch/x86/entry/vsyscall/vsyscall_64.c
627 'vdso32', # See vdso32_setup() in arch/x86/entry/vdso/vdso32-setup.c
628 'vdso', # See vdso32_setup() in arch/x86/entry/vdso/vdso32-setup.c
629 'tsx' # See tsx_init() in arch/x86/kernel/cpu/tsx.c
633 def normalize_cmdline_options(option: str, value: str) -> str:
634 # Don't normalize the cmdline option values if
635 # the Linux kernel doesn't use kstrtobool() for them
636 if option in no_kstrtobool_options:
639 # Implement a limited part of the kstrtobool() logic
640 if value.lower() in ('1', 'on', 'y', 'yes', 't', 'true'):
642 if value.lower() in ('0', 'off', 'n', 'no', 'f', 'false'):
645 # Preserve unique values
649 # TODO: draft of security hardening sysctls:
650 # what about bpf_jit_enable?
651 # vm.mmap_min_addr has a good value
652 # nosmt sysfs control file
653 # vm.mmap_rnd_bits=max (?)
655 # abi.vsyscall32 (any value except 2)
656 # kernel.oops_limit (think about a proper value)
657 # kernel.warn_limit (think about a proper value)
658 # net.ipv4.tcp_syncookies=1 (?)
660 def add_sysctl_checks(l, _arch: str):
661 # This function may be called with arch=None
663 # Calling the SysctlCheck class constructor:
664 # SysctlCheck(reason, decision, name, expected)
666 # Use an omnipresent kconfig symbol to see if we have a kconfig file for checking
667 have_kconfig = KconfigCheck('-', '-', 'LOCALVERSION', 'is present')
669 l += [OR(SysctlCheck('self_protection', 'kspp', 'net.core.bpf_jit_harden', '2'),
670 AND(KconfigCheck('-', '-', 'BPF_JIT', 'is not set'),
673 l += [SysctlCheck('cut_attack_surface', 'kspp', 'kernel.dmesg_restrict', '1')]
674 l += [SysctlCheck('cut_attack_surface', 'kspp', 'kernel.perf_event_paranoid', '3')] # with a custom patch, see https://lwn.net/Articles/696216/
675 l += [SysctlCheck('cut_attack_surface', 'kspp', 'user.max_user_namespaces', '0')] # may break the upower daemon in Ubuntu
676 l += [SysctlCheck('cut_attack_surface', 'kspp', 'dev.tty.ldisc_autoload', '0')]
677 l += [SysctlCheck('cut_attack_surface', 'kspp', 'kernel.kptr_restrict', '2')]
678 l += [SysctlCheck('cut_attack_surface', 'kspp', 'dev.tty.legacy_tiocsti', '0')]
679 l += [OR(SysctlCheck('cut_attack_surface', 'kspp', 'kernel.kexec_load_disabled', '1'),
680 AND(KconfigCheck('-', '-', 'KEXEC_CORE', 'is not set'),
682 l += [OR(SysctlCheck('cut_attack_surface', 'kspp', 'kernel.unprivileged_bpf_disabled', '1'),
683 AND(KconfigCheck('cut_attack_surface', 'lockdown', 'BPF_SYSCALL', 'is not set'),
685 l += [OR(SysctlCheck('cut_attack_surface', 'kspp', 'vm.unprivileged_userfaultfd', '0'),
686 AND(KconfigCheck('cut_attack_surface', 'grsec', 'USERFAULTFD', 'is not set'),
688 # At first, it disabled unprivileged userfaultfd,
689 # and since v5.11 it enables unprivileged userfaultfd for user-mode only.
691 l += [OR(SysctlCheck('cut_attack_surface', 'clipos', 'kernel.modules_disabled', '1'),
692 AND(KconfigCheck('cut_attack_surface', 'kspp', 'MODULES', 'is not set'),
693 have_kconfig))] # radical, but may be useful in some cases
695 l += [SysctlCheck('harden_userspace', 'kspp', 'fs.protected_symlinks', '1')]
696 l += [SysctlCheck('harden_userspace', 'kspp', 'fs.protected_hardlinks', '1')]
697 l += [SysctlCheck('harden_userspace', 'kspp', 'fs.protected_fifos', '2')]
698 l += [SysctlCheck('harden_userspace', 'kspp', 'fs.protected_regular', '2')]
699 l += [SysctlCheck('harden_userspace', 'kspp', 'fs.suid_dumpable', '0')]
700 l += [SysctlCheck('harden_userspace', 'kspp', 'kernel.randomize_va_space', '2')]
701 l += [SysctlCheck('harden_userspace', 'kspp', 'kernel.yama.ptrace_scope', '3')]