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
modules_not_set)] # DEBUG_SET_MODULE_RONX was before v4.11
l += [OR(KconfigCheck('self_protection', 'defconfig', 'REFCOUNT_FULL', 'y'),
VersionCheck((5, 5)))] # REFCOUNT_FULL is enabled by default since v5.5
+ l += [OR(KconfigCheck('self_protection', 'defconfig', 'INIT_STACK_ALL_ZERO', 'y'),
+ KconfigCheck('self_protection', 'kspp', 'GCC_PLUGIN_STRUCTLEAK_BYREF_ALL', 'y'))]
if arch in ('X86_64', 'ARM64', 'X86_32'):
l += [KconfigCheck('self_protection', 'defconfig', 'RANDOMIZE_BASE', 'y')]
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', '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'),
KconfigCheck('self_protection', 'defconfig', 'X86_INTEL_UMIP', 'y'))]
if arch in ('ARM64', 'ARM'):
+ l += [KconfigCheck('self_protection', 'defconfig', 'HW_RANDOM_TPM', 'y')]
l += [KconfigCheck('self_protection', 'defconfig', 'IOMMU_DEFAULT_DMA_STRICT', 'y')]
l += [KconfigCheck('self_protection', 'defconfig', 'IOMMU_DEFAULT_PASSTHROUGH', 'is not set')] # true if IOMMU_DEFAULT_DMA_STRICT is set
l += [KconfigCheck('self_protection', 'defconfig', 'STACKPROTECTOR_PER_TASK', 'y')]
l += [KconfigCheck('self_protection', 'defconfig', 'PAGE_TABLE_ISOLATION', 'y')]
l += [KconfigCheck('self_protection', 'defconfig', 'RANDOMIZE_MEMORY', 'y')]
l += [KconfigCheck('self_protection', 'defconfig', 'X86_KERNEL_IBT', 'y')]
+ l += [KconfigCheck('self_protection', 'defconfig', 'CPU_SRSO', 'y')]
l += [AND(KconfigCheck('self_protection', 'defconfig', 'INTEL_IOMMU', 'y'),
iommu_support_is_set)]
l += [AND(KconfigCheck('self_protection', 'defconfig', 'AMD_IOMMU', 'y'),
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
+ l += [KconfigCheck('self_protection', 'kspp', 'SCHED_CORE', 'y')]
+ 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]
modules_not_set)]
l += [OR(KconfigCheck('self_protection', 'kspp', 'MODULE_SIG_FORCE', 'y'),
modules_not_set)] # refers to LOCKDOWN
- l += [OR(KconfigCheck('self_protection', 'kspp', 'INIT_STACK_ALL_ZERO', 'y'),
- KconfigCheck('self_protection', 'kspp', 'GCC_PLUGIN_STRUCTLEAK_BYREF_ALL', 'y'))]
l += [OR(KconfigCheck('self_protection', 'kspp', 'INIT_ON_FREE_DEFAULT_ON', 'y'),
KconfigCheck('self_protection', 'kspp', 'PAGE_POISONING_ZERO', 'y'))]
# CONFIG_INIT_ON_FREE_DEFAULT_ON was added in v5.3.
KconfigCheck('self_protection', 'kspp', 'UBSAN_BOOL', 'is not set'),
KconfigCheck('self_protection', 'kspp', 'UBSAN_ENUM', 'is not set'),
KconfigCheck('self_protection', 'kspp', 'UBSAN_ALIGNMENT', 'is not set'))] # only array index bounds checking with traps
+ l += [AND(KconfigCheck('self_protection', 'kspp', 'UBSAN_SANITIZE_ALL', 'y'),
+ ubsan_bounds_is_set)]
if arch in ('X86_64', 'ARM64', 'X86_32'):
- l += [AND(KconfigCheck('self_protection', 'kspp', 'UBSAN_SANITIZE_ALL', 'y'),
- ubsan_bounds_is_set)] # ARCH_HAS_UBSAN_SANITIZE_ALL is not enabled for ARM
stackleak_is_set = KconfigCheck('self_protection', 'kspp', 'GCC_PLUGIN_STACKLEAK', 'y')
l += [AND(stackleak_is_set, gcc_plugins_support_is_set)]
l += [AND(KconfigCheck('self_protection', 'kspp', 'STACKLEAK_METRICS', 'is not set'),
l += [AND(KconfigCheck('self_protection', 'kspp', 'CFI_PERMISSIVE', 'is not set'),
cfi_clang_is_set)]
if arch in ('X86_64', 'X86_32'):
- l += [KconfigCheck('self_protection', 'kspp', 'SCHED_CORE', 'y')]
+ l += [KconfigCheck('self_protection', 'kspp', 'HW_RANDOM_TPM', 'y')]
l += [KconfigCheck('self_protection', 'kspp', 'DEFAULT_MMAP_MIN_ADDR', '65536')]
l += [KconfigCheck('self_protection', 'kspp', 'IOMMU_DEFAULT_DMA_STRICT', 'y')]
l += [KconfigCheck('self_protection', 'kspp', 'IOMMU_DEFAULT_PASSTHROUGH', 'is not set')] # true if IOMMU_DEFAULT_DMA_STRICT is set
# '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')]
+ l += [KconfigCheck('self_protection', 'my', 'RANDOM_KMALLOC_CACHES', 'y')]
+
# 'security_policy'
if arch in ('X86_64', 'ARM64', 'X86_32'):
l += [KconfigCheck('security_policy', 'defconfig', 'SECURITY', 'y')]
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'),
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'),
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', 'AIO', 'is not set')]
# l += [KconfigCheck('cut_attack_surface', 'clipos', 'IKCONFIG', 'is not set')] # no, IKCONFIG is needed for this check :)
# 'cut_attack_surface', 'lockdown'
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')]
l += [KconfigCheck('cut_attack_surface', 'my', 'VIDEO_VIVID', 'is not set')]
l += [KconfigCheck('cut_attack_surface', 'my', 'INPUT_EVBUG', 'is not set')] # Can be used as a keylogger
l += [KconfigCheck('cut_attack_surface', 'my', 'KGDB', 'is not set')]
- l += [KconfigCheck('cut_attack_surface', 'my', 'AIO', 'is not set')]
l += [KconfigCheck('cut_attack_surface', 'my', 'CORESIGHT', 'is not set')]
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':
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
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')]
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'),
# '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')]
CmdlineCheck('self_protection', 'kspp', 'hardened_usercopy', 'is not set')))]
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
+ # Consequence of the HARDENED_USERCOPY_FALLBACK check by kspp.
+ # 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'),
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'),
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'),
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'),
- CmdlineCheck('cut_attack_surface', 'my', 'vdso32', '0'),
+ l += [OR(CmdlineCheck('cut_attack_surface', 'kspp', 'vdso32', '0'),
+ CmdlineCheck('cut_attack_surface', 'my', 'vdso32', '1'),
AND(KconfigCheck('cut_attack_surface', 'kspp', 'COMPAT_VDSO', 'is not set'),
CmdlineCheck('cut_attack_surface', 'my', 'vdso32', 'is not set')))] # the vdso32 parameter must not be 2
if arch == 'X86_32':
- l += [OR(CmdlineCheck('cut_attack_surface', 'my', 'vdso32', '1'),
- CmdlineCheck('cut_attack_surface', 'my', 'vdso', '1'),
- CmdlineCheck('cut_attack_surface', 'my', 'vdso32', '0'),
+ l += [OR(CmdlineCheck('cut_attack_surface', 'kspp', 'vdso32', '0'),
CmdlineCheck('cut_attack_surface', 'my', 'vdso', '0'),
+ CmdlineCheck('cut_attack_surface', 'my', 'vdso32', '1'),
+ CmdlineCheck('cut_attack_surface', 'my', 'vdso', '1'),
AND(KconfigCheck('cut_attack_surface', 'kspp', 'COMPAT_VDSO', 'is not set'),
CmdlineCheck('cut_attack_surface', 'my', 'vdso32', 'is not set'),
CmdlineCheck('cut_attack_surface', 'my', 'vdso', 'is not set')))] # the vdso and vdso32 parameters must not be 2
'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
# TODO: draft of security hardening sysctls:
# 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)
# kernel.warn_limit (think about a proper value)
# net.ipv4.tcp_syncookies=1 (?)
-def add_sysctl_checks(l, arch):
+def add_sysctl_checks(l, _arch):
# This function may be called with arch=None
# Calling the SysctlCheck class constructor:
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', 'kernel.yama.ptrace_scope', '3')]
+ 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')]
projects / kconfig-hardened-check.git / blobdiff