X-Git-Url: https://jxself.org/git/?a=blobdiff_plain;f=kernel_hardening_checker%2Fchecks.py;h=9dacb51be97c614a8ecec22128b59033702043d8;hb=e5f804ede6ea7f66f674c2825396c15c216c718d;hp=f1530f58af99a6bf403ad96bd4dbffdb657be578;hpb=83ae91cf9781cdc69fe272444af177f1ae4bc1b5;p=kconfig-hardened-check.git diff --git a/kernel_hardening_checker/checks.py b/kernel_hardening_checker/checks.py index f1530f5..9dacb51 100644 --- a/kernel_hardening_checker/checks.py +++ b/kernel_hardening_checker/checks.py @@ -27,7 +27,7 @@ def add_kconfig_checks(l, arch): cc_is_gcc = KconfigCheck('-', '-', 'CC_IS_GCC', 'y') # exists since v4.18 cc_is_clang = KconfigCheck('-', '-', 'CC_IS_CLANG', 'y') # exists since v4.18 - modules_not_set = KconfigCheck('cut_attack_surface', 'kspp', 'MODULES', 'is not set') + modules_not_set = KconfigCheck('cut_attack_surface', 'kspp', 'MODULES', 'is not set') # radical, but may be useful in some cases devmem_not_set = KconfigCheck('cut_attack_surface', 'kspp', 'DEVMEM', 'is not set') # refers to LOCKDOWN bpf_syscall_not_set = KconfigCheck('cut_attack_surface', 'lockdown', 'BPF_SYSCALL', 'is not set') # refers to LOCKDOWN @@ -63,9 +63,16 @@ def add_kconfig_checks(l, arch): l += [KconfigCheck('self_protection', 'defconfig', 'X86_MCE', 'y')] l += [KconfigCheck('self_protection', 'defconfig', 'X86_MCE_INTEL', 'y')] l += [KconfigCheck('self_protection', 'defconfig', 'X86_MCE_AMD', 'y')] - l += [KconfigCheck('self_protection', 'defconfig', 'MICROCODE', 'y')] # is needed for mitigating CPU bugs l += [KconfigCheck('self_protection', 'defconfig', 'RETPOLINE', 'y')] l += [KconfigCheck('self_protection', 'defconfig', 'SYN_COOKIES', 'y')] # another reason? + microcode_is_set = KconfigCheck('self_protection', 'defconfig', 'MICROCODE', 'y') + l += [microcode_is_set] # is needed for mitigating CPU bugs + l += [OR(KconfigCheck('self_protection', 'defconfig', 'MICROCODE_INTEL', 'y'), + AND(microcode_is_set, + VersionCheck((6, 6))))] # MICROCODE_INTEL was included in MICROCODE since v6.6 + l += [OR(KconfigCheck('self_protection', 'defconfig', 'MICROCODE_AMD', 'y'), + AND(microcode_is_set, + VersionCheck((6, 6))))] # MICROCODE_AMD was included in MICROCODE since v6.6 l += [OR(KconfigCheck('self_protection', 'defconfig', 'X86_SMAP', 'y'), VersionCheck((5, 19)))] # X86_SMAP is enabled by default since v5.19 l += [OR(KconfigCheck('self_protection', 'defconfig', 'X86_UMIP', 'y'), @@ -117,9 +124,12 @@ def add_kconfig_checks(l, arch): l += [KconfigCheck('self_protection', 'kspp', 'DEBUG_CREDENTIALS', 'y')] l += [KconfigCheck('self_protection', 'kspp', 'DEBUG_NOTIFIERS', 'y')] l += [KconfigCheck('self_protection', 'kspp', 'INIT_ON_ALLOC_DEFAULT_ON', 'y')] - l += [KconfigCheck('self_protection', 'kspp', 'KFENCE', 'y')] l += [KconfigCheck('self_protection', 'kspp', 'HW_RANDOM_TPM', 'y')] l += [KconfigCheck('self_protection', 'kspp', 'STATIC_USERMODEHELPER', 'y')] # needs userspace support + kfence_is_set = KconfigCheck('self_protection', 'kspp', 'KFENCE', 'y') + l += [kfence_is_set] + l += [AND(KconfigCheck('self_protection', 'my', 'KFENCE_SAMPLE_INTERVAL', 'is not off'), + kfence_is_set)] randstruct_is_set = OR(KconfigCheck('self_protection', 'kspp', 'RANDSTRUCT_FULL', 'y'), KconfigCheck('self_protection', 'kspp', 'GCC_PLUGIN_RANDSTRUCT', 'y')) l += [randstruct_is_set] @@ -345,7 +355,6 @@ def add_kconfig_checks(l, arch): l += [KconfigCheck('cut_attack_surface', 'clipos', 'X86_IOPL_IOPERM', 'is not set')] # refers to LOCKDOWN l += [KconfigCheck('cut_attack_surface', 'clipos', 'ACPI_TABLE_UPGRADE', 'is not set')] # refers to LOCKDOWN l += [KconfigCheck('cut_attack_surface', 'clipos', 'EFI_CUSTOM_SSDT_OVERLAYS', 'is not set')] - l += [KconfigCheck('cut_attack_surface', 'clipos', 'COREDUMP', 'is not set')] # cut userspace attack surface # l += [KconfigCheck('cut_attack_surface', 'clipos', 'IKCONFIG', 'is not set')] # no, IKCONFIG is needed for this check :) # 'cut_attack_surface', 'lockdown' @@ -369,6 +378,7 @@ def add_kconfig_checks(l, arch): l += [KconfigCheck('cut_attack_surface', 'my', 'XFS_SUPPORT_V4', 'is not set')] l += [OR(KconfigCheck('cut_attack_surface', 'my', 'TRIM_UNUSED_KSYMS', 'y'), modules_not_set)] + l += [KconfigCheck('cut_attack_surface', 'my', 'MODULE_FORCE_LOAD', 'is not set')] # 'harden_userspace' if arch == 'ARM64': @@ -376,6 +386,7 @@ def add_kconfig_checks(l, arch): l += [KconfigCheck('harden_userspace', 'defconfig', 'ARM64_BTI', 'y')] if arch in ('ARM', 'X86_32'): l += [KconfigCheck('harden_userspace', 'defconfig', 'VMSPLIT_3G', 'y')] + l += [KconfigCheck('harden_userspace', 'clipos', 'COREDUMP', 'is not set')] l += [KconfigCheck('harden_userspace', 'my', 'ARCH_MMAP_RND_BITS', 'MAX')] # 'MAX' value is refined using ARCH_MMAP_RND_BITS_MAX @@ -410,6 +421,7 @@ def add_cmdline_checks(l, arch): l += [CmdlineCheck('self_protection', 'defconfig', 'nospectre_v2', 'is not set')] l += [CmdlineCheck('self_protection', 'defconfig', 'nospectre_bhb', 'is not set')] l += [CmdlineCheck('self_protection', 'defconfig', 'nospec_store_bypass_disable', 'is not set')] + l += [CmdlineCheck('self_protection', 'defconfig', 'dis_ucode_ldr', 'is not set')] l += [CmdlineCheck('self_protection', 'defconfig', 'arm64.nobti', 'is not set')] l += [CmdlineCheck('self_protection', 'defconfig', 'arm64.nopauth', 'is not set')] l += [CmdlineCheck('self_protection', 'defconfig', 'arm64.nomte', 'is not set')] @@ -458,9 +470,9 @@ def add_cmdline_checks(l, arch): # 'self_protection', 'kspp' l += [CmdlineCheck('self_protection', 'kspp', 'mitigations', 'auto,nosmt')] - l += [CmdlineCheck('self_protection', 'kspp', 'nosmt', 'is present')] # slow (high performance penalty) l += [CmdlineCheck('self_protection', 'kspp', 'slab_merge', 'is not set')] # consequence of 'slab_nomerge' by kspp l += [CmdlineCheck('self_protection', 'kspp', 'slub_merge', 'is not set')] # consequence of 'slab_nomerge' by kspp + l += [CmdlineCheck('self_protection', 'kspp', 'page_alloc.shuffle', '1')] l += [OR(CmdlineCheck('self_protection', 'kspp', 'slab_nomerge', 'is present'), AND(KconfigCheck('self_protection', 'clipos', 'SLAB_MERGE_DEFAULT', 'is not set'), CmdlineCheck('self_protection', 'kspp', 'slab_merge', 'is not set'), @@ -474,14 +486,13 @@ def add_cmdline_checks(l, arch): AND(CmdlineCheck('self_protection', 'kspp', 'page_poison', '1'), KconfigCheck('self_protection', 'kspp', 'PAGE_POISONING_ZERO', 'y'), CmdlineCheck('self_protection', 'kspp', 'slub_debug', 'P')))] - # The cmdline checks compatible with the kconfig recommendations of the KSPP project... l += [OR(CmdlineCheck('self_protection', 'kspp', 'hardened_usercopy', '1'), AND(KconfigCheck('self_protection', 'kspp', 'HARDENED_USERCOPY', 'y'), CmdlineCheck('self_protection', 'kspp', 'hardened_usercopy', 'is not set')))] - l += [OR(CmdlineCheck('self_protection', 'kspp', 'slab_common.usercopy_fallback', '0'), - AND(KconfigCheck('self_protection', 'kspp', 'HARDENED_USERCOPY_FALLBACK', 'is not set'), - CmdlineCheck('self_protection', 'kspp', 'slab_common.usercopy_fallback', 'is not set')))] - # ... the end + l += [AND(CmdlineCheck('self_protection', 'kspp', 'slab_common.usercopy_fallback', 'is not set'), + KconfigCheck('self_protection', 'kspp', 'HARDENED_USERCOPY_FALLBACK', 'is not set'))] + # don't require slab_common.usercopy_fallback=0, + # since HARDENED_USERCOPY_FALLBACK was removed in Linux v5.16 if arch in ('X86_64', 'ARM64', 'X86_32'): l += [OR(CmdlineCheck('self_protection', 'kspp', 'iommu.strict', '1'), AND(KconfigCheck('self_protection', 'kspp', 'IOMMU_DEFAULT_DMA_STRICT', 'y'), @@ -497,10 +508,14 @@ def add_cmdline_checks(l, arch): CmdlineCheck('self_protection', 'defconfig', 'nopti', 'is not set'))] # 'self_protection', 'clipos' - l += [CmdlineCheck('self_protection', 'clipos', 'page_alloc.shuffle', '1')] if arch in ('X86_64', 'X86_32'): l += [CmdlineCheck('self_protection', 'clipos', 'iommu', 'force')] + # 'self_protection', 'my' + l += [OR(CmdlineCheck('self_protection', 'my', 'kfence.sample_interval', 'is not off'), + AND(KconfigCheck('self_protection', 'my', 'KFENCE_SAMPLE_INTERVAL', 'is not off'), + CmdlineCheck('self_protection', 'my', 'kfence.sample_interval', 'is not set')))] + # 'cut_attack_surface', 'defconfig' if arch in ('X86_64', 'X86_32'): l += [OR(CmdlineCheck('cut_attack_surface', 'defconfig', 'tsx', 'off'), @@ -508,6 +523,7 @@ def add_cmdline_checks(l, arch): CmdlineCheck('cut_attack_surface', 'defconfig', 'tsx', 'is not set')))] # 'cut_attack_surface', 'kspp' + l += [CmdlineCheck('cut_attack_surface', 'kspp', 'nosmt', 'is present')] # slow (high performance penalty) if arch == 'X86_64': l += [OR(CmdlineCheck('cut_attack_surface', 'kspp', 'vsyscall', 'none'), KconfigCheck('cut_attack_surface', 'kspp', 'X86_VSYSCALL_EMULATION', 'is not set'), @@ -579,22 +595,9 @@ def normalize_cmdline_options(option, value): # TODO: draft of security hardening sysctls: -# kernel.kptr_restrict=2 (or 1?) -# kernel.yama.ptrace_scope=3 # what about bpf_jit_enable? -# vm.unprivileged_userfaultfd=0 -# (at first, it disabled unprivileged userfaultfd, -# and since v5.11 it enables unprivileged userfaultfd for user-mode only) # vm.mmap_min_addr has a good value -# fs.protected_symlinks=1 -# fs.protected_hardlinks=1 -# fs.protected_fifos=2 -# fs.protected_regular=2 -# fs.suid_dumpable=0 -# kernel.modules_disabled=1 -# kernel.randomize_va_space=2 # nosmt sysfs control file -# dev.tty.legacy_tiocsti=0 # vm.mmap_rnd_bits=max (?) # kernel.sysrq=0 # abi.vsyscall32 (any value except 2) @@ -616,3 +619,18 @@ def add_sysctl_checks(l, arch): l += [SysctlCheck('cut_attack_surface', 'kspp', 'user.max_user_namespaces', '0')] l += [SysctlCheck('cut_attack_surface', 'kspp', 'dev.tty.ldisc_autoload', '0')] l += [SysctlCheck('cut_attack_surface', 'kspp', 'kernel.unprivileged_bpf_disabled', '1')] + l += [SysctlCheck('cut_attack_surface', 'kspp', 'kernel.kptr_restrict', '2')] + l += [SysctlCheck('cut_attack_surface', 'kspp', 'dev.tty.legacy_tiocsti', '0')] + l += [SysctlCheck('cut_attack_surface', 'kspp', 'vm.unprivileged_userfaultfd', '0')] + # At first, it disabled unprivileged userfaultfd, + # and since v5.11 it enables unprivileged userfaultfd for user-mode only. + + l += [SysctlCheck('cut_attack_surface', 'clipos', 'kernel.modules_disabled', '1')] # radical, but may be useful in some cases + + l += [SysctlCheck('harden_userspace', 'kspp', 'fs.protected_symlinks', '1')] + l += [SysctlCheck('harden_userspace', 'kspp', 'fs.protected_hardlinks', '1')] + l += [SysctlCheck('harden_userspace', 'kspp', 'fs.protected_fifos', '2')] + l += [SysctlCheck('harden_userspace', 'kspp', 'fs.protected_regular', '2')] + l += [SysctlCheck('harden_userspace', 'kspp', 'fs.suid_dumpable', '0')] + l += [SysctlCheck('harden_userspace', 'kspp', 'kernel.randomize_va_space', '2')] + l += [SysctlCheck('harden_userspace', 'kspp', 'kernel.yama.ptrace_scope', '3')]