X-Git-Url: https://jxself.org/git/?a=blobdiff_plain;f=kernel_hardening_checker%2Fchecks.py;h=69a9fd960c90d8eb521cfa759d6d3c85f2173911;hb=303573e55b87ce142a89d48c0a4d2694cf37cae7;hp=a6460d1173141364517b00af302fead9a837e6f6;hpb=f0f405b3d94a905f08778f103e6831f87a349583;p=kconfig-hardened-check.git diff --git a/kernel_hardening_checker/checks.py b/kernel_hardening_checker/checks.py index a6460d1..69a9fd9 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 @@ -58,14 +58,23 @@ def add_kconfig_checks(l, arch): if arch in ('X86_64', 'ARM64', 'ARM'): l += [KconfigCheck('self_protection', 'defconfig', 'VMAP_STACK', 'y')] if arch in ('X86_64', 'X86_32'): + l += [KconfigCheck('self_protection', 'defconfig', 'SPECULATION_MITIGATIONS', 'y')] l += [KconfigCheck('self_protection', 'defconfig', 'DEBUG_WX', 'y')] l += [KconfigCheck('self_protection', 'defconfig', 'WERROR', 'y')] 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', 'CPU_SRSO', '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 +126,12 @@ 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] @@ -217,6 +229,9 @@ def add_kconfig_checks(l, arch): # 'self_protection', 'clipos' l += [KconfigCheck('self_protection', 'clipos', 'SLAB_MERGE_DEFAULT', 'is not set')] + # 'self_protection', 'my' + l += [KconfigCheck('self_protection', 'my', 'LIST_HARDENED', 'y')] + # 'security_policy' if arch in ('X86_64', 'ARM64', 'X86_32'): l += [KconfigCheck('security_policy', 'defconfig', 'SECURITY', 'y')] @@ -231,6 +246,7 @@ def add_kconfig_checks(l, arch): l += [KconfigCheck('security_policy', 'kspp', 'SECURITY_LOCKDOWN_LSM_EARLY', 'y')] l += [KconfigCheck('security_policy', 'kspp', 'LOCK_DOWN_KERNEL_FORCE_CONFIDENTIALITY', 'y')] l += [KconfigCheck('security_policy', 'kspp', 'SECURITY_WRITABLE_HOOKS', 'is not set')] # refers to SECURITY_SELINUX_DISABLE + l += [KconfigCheck('security_policy', 'my', 'SECURITY_SELINUX_DEBUG', 'is not set')] l += [OR(KconfigCheck('security_policy', 'my', 'SECURITY_SELINUX', 'y'), KconfigCheck('security_policy', 'my', 'SECURITY_APPARMOR', 'y'), KconfigCheck('security_policy', 'my', 'SECURITY_SMACK', 'y'), @@ -265,6 +281,7 @@ def add_kconfig_checks(l, arch): l += [KconfigCheck('cut_attack_surface', 'kspp', 'MODIFY_LDT_SYSCALL', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'kspp', 'OABI_COMPAT', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'kspp', 'X86_MSR', 'is not set')] # refers to LOCKDOWN + l += [KconfigCheck('cut_attack_surface', 'kspp', 'LEGACY_TIOCSTI', 'is not set')] l += [modules_not_set] l += [devmem_not_set] l += [OR(KconfigCheck('cut_attack_surface', 'kspp', 'IO_STRICT_DEVMEM', 'y'), @@ -275,6 +292,11 @@ def add_kconfig_checks(l, arch): l += [KconfigCheck('cut_attack_surface', 'kspp', 'COMPAT_VDSO', 'is not set')] # CONFIG_COMPAT_VDSO disabled ASLR of vDSO only on X86_64 and X86_32; # on ARM64 this option has different meaning + if arch == 'X86_64': + l += [OR(KconfigCheck('cut_attack_surface', 'kspp', 'X86_VSYSCALL_EMULATION', 'is not set'), + KconfigCheck('cut_attack_surface', 'kspp', 'LEGACY_VSYSCALL_NONE', 'y'))] + # disabling X86_VSYSCALL_EMULATION turns vsyscall off completely, + # and LEGACY_VSYSCALL_NONE can be changed at boot time via the cmdline parameter if arch == 'ARM': l += [OR(KconfigCheck('cut_attack_surface', 'kspp', 'STRICT_DEVMEM', 'y'), devmem_not_set)] # refers to LOCKDOWN @@ -340,13 +362,7 @@ 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 :) - if arch == 'X86_64': - l += [OR(KconfigCheck('cut_attack_surface', 'clipos', 'X86_VSYSCALL_EMULATION', 'is not set'), - KconfigCheck('cut_attack_surface', 'kspp', 'LEGACY_VSYSCALL_NONE', 'y'))] - # disabling X86_VSYSCALL_EMULATION turns vsyscall off completely, - # and LEGACY_VSYSCALL_NONE can be changed at boot time via the cmdline parameter # 'cut_attack_surface', 'lockdown' l += [KconfigCheck('cut_attack_surface', 'lockdown', 'EFI_TEST', 'is not set')] # refers to LOCKDOWN @@ -355,7 +371,6 @@ def add_kconfig_checks(l, arch): l += [bpf_syscall_not_set] # refers to LOCKDOWN # 'cut_attack_surface', 'my' - l += [KconfigCheck('cut_attack_surface', 'my', 'LEGACY_TIOCSTI', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'my', 'MMIOTRACE', 'is not set')] # refers to LOCKDOWN (permissive) l += [KconfigCheck('cut_attack_surface', 'my', 'LIVEPATCH', 'is not set')] l += [KconfigCheck('cut_attack_surface', 'my', 'IP_DCCP', 'is not set')] @@ -369,6 +384,7 @@ 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 +392,7 @@ 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 +427,7 @@ 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')] @@ -441,6 +459,12 @@ def add_cmdline_checks(l, arch): l += [OR(CmdlineCheck('self_protection', 'defconfig', 'retbleed', 'is not off'), AND(CmdlineCheck('self_protection', 'kspp', 'mitigations', 'auto,nosmt'), CmdlineCheck('self_protection', 'defconfig', 'retbleed', 'is not set')))] + l += [OR(CmdlineCheck('self_protection', 'defconfig', 'spec_rstack_overflow', 'is not off'), + AND(CmdlineCheck('self_protection', 'kspp', 'mitigations', 'auto,nosmt'), + CmdlineCheck('self_protection', 'defconfig', 'spec_rstack_overflow', 'is not set')))] + l += [OR(CmdlineCheck('self_protection', 'defconfig', 'gather_data_sampling', 'is not off'), + AND(CmdlineCheck('self_protection', 'kspp', 'mitigations', 'auto,nosmt'), + CmdlineCheck('self_protection', 'defconfig', 'gather_data_sampling', 'is not set')))] if arch == 'ARM64': l += [OR(CmdlineCheck('self_protection', 'defconfig', 'kpti', 'is not off'), AND(CmdlineCheck('self_protection', 'kspp', 'mitigations', 'auto,nosmt'), @@ -457,10 +481,10 @@ def add_cmdline_checks(l, arch): CmdlineCheck('self_protection', 'defconfig', 'rodata', 'is not set'))] # 'self_protection', 'kspp' - l += [CmdlineCheck('self_protection', 'kspp', 'nosmt', 'is present')] - l += [CmdlineCheck('self_protection', 'kspp', 'mitigations', 'auto,nosmt')] # 'nosmt' by kspp + 'auto' by defconfig + l += [CmdlineCheck('self_protection', 'kspp', 'mitigations', 'auto,nosmt')] 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 +498,13 @@ 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 +520,14 @@ 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'), @@ -508,9 +535,10 @@ 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', 'clipos', 'X86_VSYSCALL_EMULATION', 'is not set'), + KconfigCheck('cut_attack_surface', 'kspp', 'X86_VSYSCALL_EMULATION', 'is not set'), AND(KconfigCheck('cut_attack_surface', 'kspp', 'LEGACY_VSYSCALL_NONE', 'y'), CmdlineCheck('cut_attack_surface', 'kspp', 'vsyscall', 'is not set')))] l += [OR(CmdlineCheck('cut_attack_surface', 'my', 'vdso32', '1'), @@ -553,6 +581,8 @@ no_kstrtobool_options = [ 'retbleed', # See retbleed_parse_cmdline() in arch/x86/kernel/cpu/bugs.c 'rodata', # See set_debug_rodata() in init/main.c 'ssbd', # See parse_spectre_v4_param() in arch/arm64/kernel/proton-pack.c + 'spec_rstack_overflow', # See srso_parse_cmdline() in arch/x86/kernel/cpu/bugs.c + 'gather_data_sampling', # See gds_parse_cmdline() in arch/x86/kernel/cpu/bugs.c 'slub_debug', # See setup_slub_debug() in mm/slub.c 'iommu', # See iommu_setup() in arch/x86/kernel/pci-dma.c 'vsyscall', # See vsyscall_setup() in arch/x86/entry/vsyscall/vsyscall_64.c @@ -579,22 +609,9 @@ 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 +633,18 @@ 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')]