# slab_nomerge
# page_alloc.shuffle=1
# iommu=force (does it help against DMA attacks?)
+# iommu.passthrough=0
+# iommu.strict=1
# slub_debug=FZ (slow)
# init_on_alloc=1 (since v5.3)
# init_on_free=1 (since v5.3, otherwise slub_debug=P and page_poison=1)
# pti=on
# spec_store_bypass_disable=on
# l1tf=full,force
+# l1d_flush=on (a part of the l1tf option)
# mds=full,nosmt
# tsx=off
-# l1d_flush=on
# ARM64:
# kpti=on
# ssbd=force-on
TYPES_OF_CHECKS = ('kconfig', 'version')
class OptCheck:
- def __init__(self, reason, decision, name, expected):
+ # Constructor without the 'expected' parameter is for option presence checks (any value is OK)
+ def __init__(self, reason, decision, name, expected=None):
+ if not reason or not decision or not name:
+ sys.exit('[!] ERROR: invalid {} check for "{}"'.format(self.__class__.__name__, name))
self.name = name
self.expected = expected
self.decision = decision
self.result = None
def check(self):
+ # handle the option presence check
+ if self.expected is None:
+ if self.state is None:
+ self.result = 'FAIL: not present'
+ else:
+ self.result = 'OK: is present'
+ return
+
+ # handle the option value check
if self.expected == self.state:
self.result = 'OK'
elif self.state is None:
else:
self.result = 'FAIL: "' + self.state + '"'
- if self.result.startswith('OK'):
- return True
- return False
-
def table_print(self, _mode, with_results):
- print('{:<40}|{:^7}|{:^12}|{:^10}|{:^18}'.format(self.name, self.type, self.expected, self.decision, self.reason), end='')
+ if self.expected is None:
+ expected = ''
+ else:
+ expected = self.expected
+ print('{:<40}|{:^7}|{:^12}|{:^10}|{:^18}'.format(self.name, self.type, expected, self.decision, self.reason), end='')
if with_results:
print('| {}'.format(self.result), end='')
def check(self):
if self.ver[0] > self.ver_expected[0]:
self.result = 'OK: version >= ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
- return True
+ return
if self.ver[0] < self.ver_expected[0]:
self.result = 'FAIL: version < ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
- return False
+ return
if self.ver[1] >= self.ver_expected[1]:
self.result = 'OK: version >= ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
- return True
+ return
self.result = 'FAIL: version < ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
- return False
def table_print(self, _mode, with_results):
ver_req = 'kernel version >= ' + str(self.ver_expected[0]) + '.' + str(self.ver_expected[1])
print('| {}'.format(self.result), end='')
-class PresenceCheck:
- def __init__(self, name, type):
- self.type = type
- if self.type == 'kconfig':
- self.name = 'CONFIG_' + name
- else:
- sys.exit('[!] ERROR: unsupported type "{}" for {}'.format(type, self.__class__.__name__))
- self.state = None
- self.result = None
-
- def check(self):
- if self.state is None:
- self.result = 'FAIL: not present'
- return False
- self.result = 'OK: is present'
- return True
-
- def table_print(self, _mode, with_results):
- print('{:<91}'.format(self.name + ' is present'), end='')
- if with_results:
- print('| {}'.format(self.result), end='')
-
-
class ComplexOptCheck:
def __init__(self, *opts):
self.opts = opts
# Use cases:
# OR(<X_is_hardened>, <X_is_disabled>)
# OR(<X_is_hardened>, <old_X_is_hardened>)
-
def check(self):
if not self.opts:
sys.exit('[!] ERROR: invalid OR check')
-
for i, opt in enumerate(self.opts):
- ret = opt.check()
- if ret:
- if opt.result == 'OK' and i != 0:
- # Simple OK is not enough for additional checks, add more info:
- self.result = 'OK: {} "{}"'.format(opt.name, opt.expected)
- else:
- self.result = opt.result
- return True
+ opt.check()
+ if opt.result.startswith('OK'):
+ self.result = opt.result
+ # Add more info for additional checks:
+ if i != 0:
+ if opt.result == 'OK':
+ self.result = 'OK: {} "{}"'.format(opt.name, opt.expected)
+ elif opt.result == 'OK: not found':
+ self.result = 'OK: {} not found'.format(opt.name)
+ elif opt.result == 'OK: is present':
+ self.result = 'OK: {} is present'.format(opt.name)
+ # VersionCheck provides enough info
+ elif not opt.result.startswith('OK: version'):
+ sys.exit('[!] ERROR: unexpected OK description "{}"'.format(opt.result))
+ return
self.result = self.opts[0].result
- return False
class AND(ComplexOptCheck):
# AND(<suboption>, <main_option>)
# Suboption is not checked if checking of the main_option is failed.
# AND(<X_is_disabled>, <old_X_is_disabled>)
-
def check(self):
for i, opt in reversed(list(enumerate(self.opts))):
- ret = opt.check()
+ opt.check()
if i == 0:
self.result = opt.result
- return ret
- if not ret:
+ return
+ if not opt.result.startswith('OK'):
# This FAIL is caused by additional checks,
# and not by the main option that this AND-check is about.
# Describe the reason of the FAIL.
elif opt.result == 'FAIL: not present':
self.result = 'FAIL: {} not present'.format(opt.name)
else:
- # This FAIL message is self-explaining.
+ # VersionCheck provides enough info
self.result = opt.result
- return False
-
+ if not opt.result.startswith('FAIL: version'):
+ sys.exit('[!] ERROR: unexpected FAIL description "{}"'.format(opt.result))
+ return
sys.exit('[!] ERROR: invalid AND check')
modules_not_set = KconfigCheck('cut_attack_surface', 'kspp', 'MODULES', 'is not set')
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
+ efi_not_set = KconfigCheck('cut_attack_surface', 'my', 'EFI', 'is not set')
# 'self_protection', 'defconfig'
l += [KconfigCheck('self_protection', 'defconfig', 'BUG', 'y')]
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 += [KconfigCheck('self_protection', 'defconfig', 'THREAD_INFO_IN_TASK', 'y')]
iommu_support_is_set = KconfigCheck('self_protection', 'defconfig', 'IOMMU_SUPPORT', 'y')
l += [iommu_support_is_set] # is needed for mitigating DMA attacks
if arch in ('X86_64', 'ARM64', 'X86_32'):
l += [KconfigCheck('self_protection', 'defconfig', 'RANDOMIZE_BASE', 'y')]
- l += [KconfigCheck('self_protection', 'defconfig', 'THREAD_INFO_IN_TASK', 'y')]
if arch in ('X86_64', 'ARM64'):
l += [KconfigCheck('self_protection', 'defconfig', 'VMAP_STACK', 'y')]
if arch in ('X86_64', 'X86_32'):
l += [KconfigCheck('self_protection', 'defconfig', 'ARM64_BTI_KERNEL', 'y')]
l += [OR(KconfigCheck('self_protection', 'defconfig', 'HARDEN_BRANCH_PREDICTOR', 'y'),
VersionCheck((5, 10)))] # HARDEN_BRANCH_PREDICTOR is enabled by default since v5.10
+ l += [KconfigCheck('self_protection', 'defconfig', 'MITIGATE_SPECTRE_BRANCH_HISTORY', 'y')]
l += [KconfigCheck('self_protection', 'defconfig', 'ARM64_MTE', 'y')]
if arch == 'ARM':
l += [KconfigCheck('self_protection', 'defconfig', 'CPU_SW_DOMAIN_PAN', 'y')]
l += [KconfigCheck('self_protection', 'defconfig', 'HARDEN_BRANCH_PREDICTOR', 'y')]
+ l += [KconfigCheck('self_protection', 'defconfig', 'HARDEN_BRANCH_HISTORY', 'y')]
# 'self_protection', 'kspp'
l += [KconfigCheck('self_protection', 'kspp', 'SECURITY_DMESG_RESTRICT', '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', 'GCC_PLUGIN_LATENT_ENTROPY', 'y')]
+ l += [KconfigCheck('self_protection', 'kspp', 'KFENCE', 'y')]
+ l += [KconfigCheck('self_protection', 'kspp', 'WERROR', 'y')]
+ l += [KconfigCheck('self_protection', 'kspp', 'IOMMU_DEFAULT_DMA_STRICT', 'y')]
randstruct_is_set = KconfigCheck('self_protection', 'kspp', 'GCC_PLUGIN_RANDSTRUCT', 'y')
l += [randstruct_is_set]
hardened_usercopy_is_set = KconfigCheck('self_protection', 'kspp', 'HARDENED_USERCOPY', 'y')
stackleak_is_set = KconfigCheck('self_protection', 'kspp', 'GCC_PLUGIN_STACKLEAK', 'y')
l += [stackleak_is_set]
l += [KconfigCheck('self_protection', 'kspp', 'RANDOMIZE_KSTACK_OFFSET_DEFAULT', 'y')]
+ l += [KconfigCheck('self_protection', 'kspp', 'SCHED_CORE', 'y')]
if arch in ('X86_64', 'X86_32'):
l += [KconfigCheck('self_protection', 'kspp', 'DEFAULT_MMAP_MIN_ADDR', '65536')]
if arch in ('ARM64', 'ARM'):
# 'self_protection', 'maintainer'
ubsan_bounds_is_set = KconfigCheck('self_protection', 'maintainer', 'UBSAN_BOUNDS', 'y') # only array index bounds checking
l += [ubsan_bounds_is_set] # recommended by Kees Cook in /issues/53
- l += [AND(KconfigCheck('self_protection', 'maintainer', 'UBSAN_SANITIZE_ALL', 'y'),
- ubsan_bounds_is_set)] # recommended by Kees Cook in /issues/53
+ if arch in ('X86_64', 'ARM64', 'X86_32'): # ARCH_HAS_UBSAN_SANITIZE_ALL is not enabled for ARM
+ l += [AND(KconfigCheck('self_protection', 'maintainer', 'UBSAN_SANITIZE_ALL', 'y'),
+ ubsan_bounds_is_set)] # recommended by Kees Cook in /issues/53
l += [AND(KconfigCheck('self_protection', 'maintainer', 'UBSAN_TRAP', 'y'),
ubsan_bounds_is_set)] # recommended by Kees Cook in /issues/53
# 'self_protection', 'clipos'
l += [KconfigCheck('self_protection', 'clipos', 'DEBUG_VIRTUAL', 'y')]
l += [KconfigCheck('self_protection', 'clipos', 'STATIC_USERMODEHELPER', 'y')] # needs userspace support
- l += [KconfigCheck('self_protection', 'clipos', 'EFI_DISABLE_PCI_DMA', 'y')]
+ l += [OR(KconfigCheck('self_protection', 'clipos', 'EFI_DISABLE_PCI_DMA', 'y'),
+ efi_not_set)]
l += [KconfigCheck('self_protection', 'clipos', 'SLAB_MERGE_DEFAULT', 'is not set')] # slab_nomerge
l += [KconfigCheck('self_protection', 'clipos', 'RANDOM_TRUST_BOOTLOADER', 'is not set')]
l += [KconfigCheck('self_protection', 'clipos', 'RANDOM_TRUST_CPU', 'is not set')]
iommu_support_is_set)]
# 'self_protection', 'my'
- l += [KconfigCheck('self_protection', 'my', 'RESET_ATTACK_MITIGATION', 'y')] # needs userspace support (systemd)
+ l += [OR(KconfigCheck('self_protection', 'my', 'RESET_ATTACK_MITIGATION', 'y'),
+ efi_not_set)] # needs userspace support (systemd)
if arch == 'X86_64':
+ l += [KconfigCheck('self_protection', 'my', 'SLS', 'y')] # vs CVE-2021-26341 in Straight-Line-Speculation
l += [AND(KconfigCheck('self_protection', 'my', 'AMD_IOMMU_V2', 'y'),
iommu_support_is_set)]
if arch == 'ARM64':
loadpin_is_set)]
# 'cut_attack_surface', 'defconfig'
+ l += [OR(KconfigCheck('cut_attack_surface', 'defconfig', 'BPF_UNPRIV_DEFAULT_OFF', 'y'),
+ bpf_syscall_not_set)] # see unprivileged_bpf_disabled
l += [KconfigCheck('cut_attack_surface', 'defconfig', 'SECCOMP', 'y')]
l += [KconfigCheck('cut_attack_surface', 'defconfig', 'SECCOMP_FILTER', 'y')]
if arch in ('X86_64', 'ARM64', 'X86_32'):
l += [KconfigCheck('cut_attack_surface', 'kspp', 'X86_X32', 'is not set')]
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 += [modules_not_set]
l += [devmem_not_set]
l += [OR(KconfigCheck('cut_attack_surface', 'kspp', 'IO_STRICT_DEVMEM', 'y'),
l += [KconfigCheck('cut_attack_surface', 'clipos', 'MAGIC_SYSRQ', 'is not set')]
l += [KconfigCheck('cut_attack_surface', 'clipos', 'KEXEC_FILE', 'is not set')] # refers to LOCKDOWN (permissive)
l += [KconfigCheck('cut_attack_surface', 'clipos', 'USER_NS', 'is not set')] # user.max_user_namespaces=0
- l += [KconfigCheck('cut_attack_surface', 'clipos', 'X86_MSR', 'is not set')] # refers to LOCKDOWN
l += [KconfigCheck('cut_attack_surface', 'clipos', 'X86_CPUID', 'is not set')]
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 += [AND(KconfigCheck('cut_attack_surface', 'clipos', 'LDISC_AUTOLOAD', 'is not set'),
- PresenceCheck('LDISC_AUTOLOAD', 'kconfig'))]
+ KconfigCheck('cut_attack_surface', 'clipos', 'LDISC_AUTOLOAD'))] # option presence check
if arch in ('X86_64', 'X86_32'):
l += [KconfigCheck('cut_attack_surface', 'clipos', 'X86_INTEL_TSX_MODE_OFF', 'y')] # tsx=off
# 'cut_attack_surface', 'lockdown'
+ l += [bpf_syscall_not_set] # refers to LOCKDOWN
l += [KconfigCheck('cut_attack_surface', 'lockdown', 'EFI_TEST', 'is not set')] # refers to LOCKDOWN
- l += [KconfigCheck('cut_attack_surface', 'lockdown', 'BPF_SYSCALL', 'is not set')] # refers to LOCKDOWN
l += [KconfigCheck('cut_attack_surface', 'lockdown', 'MMIOTRACE_TEST', 'is not set')] # refers to LOCKDOWN
l += [KconfigCheck('cut_attack_surface', 'lockdown', 'KPROBES', 'is not set')] # refers to LOCKDOWN
# 'cut_attack_surface', 'my'
l += [OR(KconfigCheck('cut_attack_surface', 'my', 'TRIM_UNUSED_KSYMS', 'y'),
modules_not_set)]
- l += [KconfigCheck('cut_attack_surface', 'my', 'BPF_UNPRIV_DEFAULT_OFF', 'y')] # see kernel.unprivileged_bpf_disabled
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')]
opt.state = data.get(opt.name, None)
elif data_type == 'version':
opt.ver = data
+ else:
+ sys.exit('[!] ERROR: unexpected data type "{}"'.format(data_type))
def populate_opt_with_data(opt, data, data_type):
if option:
parsed_options[option] = value
- return parsed_options
-
def main():
# Report modes:
projects / kconfig-hardened-check.git / blobdiff