Add the CPU_SRSO check

[kconfig-hardened-check.git] / kernel_hardening_checker / checks.py

diff --git a/kernel_hardening_checker/checks.py b/kernel_hardening_checker/checks.py
index 0a10ae770ff446568e775a4710cefaab4d4212d7..ff42ca735d684fd7e6598371ac4b19eb6beec526 100644 (file)
--- 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]
@@ -368,6 +380,7 @@ 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':
@@ -410,6 +423,7 @@ 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 +455,9 @@ 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')))]
     if arch == 'ARM64':
         l += [OR(CmdlineCheck('self_protection', 'defconfig', 'kpti', 'is not off'),
                  AND(CmdlineCheck('self_protection', 'kspp', 'mitigations', 'auto,nosmt'),
@@ -458,7 +475,6 @@ 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')]
@@ -500,6 +516,11 @@ def add_cmdline_checks(l, arch):
     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'),
@@ -507,6 +528,7 @@ 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'),
@@ -552,6 +574,7 @@ 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
     '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
@@ -580,7 +603,6 @@ def normalize_cmdline_options(option, value):
 # TODO: draft of security hardening sysctls:
 #    what about bpf_jit_enable?
 #    vm.mmap_min_addr has a good value
-#    kernel.modules_disabled=1
 #    nosmt sysfs control file
 #    vm.mmap_rnd_bits=max (?)
 #    kernel.sysrq=0
@@ -604,15 +626,17 @@ def add_sysctl_checks(l, arch):
     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')]