But nobody likes checking configs manually. So let the computers do their job!
-__kconfig-hardened-check__ is a tool for checking the security hardening options of the Linux kernel.
-The recommendations are based on
+__kconfig-hardened-check__ is a tool for checking the security hardening options of the Linux kernel. It supports checking:
+
+ - Kconfig options (compile-time)
+ - Kernel cmdline arguments (boot-time)
+ - Sysctl parameters (runtime)
+
+The security hardening recommendations are based on:
- [KSPP recommended settings][1]
- [CLIP OS kernel configuration][2]
- [SECURITY_LOCKDOWN_LSM][5] patchset
- [Direct feedback from the Linux kernel maintainers][23]
-This tool supports checking __Kconfig__ options and __kernel cmdline__ parameters.
-
I also created the [__Linux Kernel Defence Map__][4], which is a graphical representation of the
relationships between security hardening features and the corresponding vulnerability classes
or exploitation techniques.
__Attention!__ Changing Linux kernel security parameters may also affect system performance
-and functionality of userspace software. So for choosing these parameters consider
+and functionality of userspace software. So for choosing these parameters, consider
the threat model of your Linux-based information system and perform thorough testing
of its typical workload.
## Usage
```
usage: kconfig-hardened-check [-h] [--version] [-m {verbose,json,show_ok,show_fail}]
- [-c CONFIG] [-l CMDLINE] [-p {X86_64,X86_32,ARM64,ARM}]
+ [-c CONFIG] [-l CMDLINE] [-s SYSCTL]
+ [-p {X86_64,X86_32,ARM64,ARM}]
[-g {X86_64,X86_32,ARM64,ARM}]
A tool for checking the security hardening options of the Linux kernel
-l CMDLINE, --cmdline CMDLINE
check the security hardening options in the kernel cmdline file
(contents of /proc/cmdline)
+ -s SYSCTL, --sysctl SYSCTL
+ check the security hardening options in the sysctl output file
+ (`sudo sysctl -a > file`)
-p {X86_64,X86_32,ARM64,ARM}, --print {X86_64,X86_32,ARM64,ARM}
print the security hardening recommendations for the selected
microarchitecture
```
-------------------------------------------------------------------------------------------
<<< OR >>>
-CONFIG_STRICT_DEVMEM | y |defconfig | cut_attack_surface
-CONFIG_DEVMEM | is not set | kspp | cut_attack_surface
+CONFIG_STRICT_DEVMEM |kconfig| y |defconfig |cut_attack_surface
+CONFIG_DEVMEM |kconfig| is not set | kspp |cut_attack_surface
-------------------------------------------------------------------------------------------
```
- `-m show_fail` for showing only the failed checks
- `-m show_ok` for showing only the successful checks
- `-m json` for printing the results in JSON format (for combining `kconfig-hardened-check` with other tools)
-## Example output for `Fedora 36` kernel configuration
+## Example output for `Fedora 38` kernel configuration
```
-$ ./bin/kconfig-hardened-check -c /boot/config-6.0.18-200.fc36.x86_64 -l /proc/cmdline
-[+] Kconfig file to check: /boot/config-6.0.18-200.fc36.x86_64
+$ ./bin/kconfig-hardened-check -c kconfig_hardened_check/config_files/distros/fedora_38.config -l /proc/cmdline -s kconfig_hardened_check/config_files/distros/example_sysctls.txt
+[+] Kconfig file to check: kconfig_hardened_check/config_files/distros/fedora_38.config
[+] Kernel cmdline file to check: /proc/cmdline
-[+] Detected architecture: X86_64
-[+] Detected kernel version: 6.0
-[+] Detected compiler: GCC 120201
+[+] Sysctl output file to check: kconfig_hardened_check/config_files/distros/example_sysctls.txt
+[+] Detected microarchitecture: X86_64
+[+] Detected kernel version: 6.3
+[+] Detected compiler: GCC 130101
=========================================================================================================================
option name | type |desired val | decision | reason | check result
=========================================================================================================================
CONFIG_BUG |kconfig| y |defconfig | self_protection | OK
CONFIG_SLUB_DEBUG |kconfig| y |defconfig | self_protection | OK
CONFIG_THREAD_INFO_IN_TASK |kconfig| y |defconfig | self_protection | OK
-CONFIG_GCC_PLUGINS |kconfig| y |defconfig | self_protection | OK
+CONFIG_GCC_PLUGINS |kconfig| y |defconfig | self_protection | FAIL: "is not set"
CONFIG_IOMMU_SUPPORT |kconfig| y |defconfig | self_protection | OK
CONFIG_STACKPROTECTOR |kconfig| y |defconfig | self_protection | OK
-CONFIG_STACKPROTECTOR_STRONG |kconfig| y |defconfig | self_protection | FAIL: "is not set"
+CONFIG_STACKPROTECTOR_STRONG |kconfig| y |defconfig | self_protection | OK
CONFIG_STRICT_KERNEL_RWX |kconfig| y |defconfig | self_protection | OK
CONFIG_STRICT_MODULE_RWX |kconfig| y |defconfig | self_protection | OK
CONFIG_REFCOUNT_FULL |kconfig| y |defconfig | self_protection | OK: version >= 5.5
CONFIG_X86_UMIP |kconfig| y |defconfig | self_protection | OK
CONFIG_PAGE_TABLE_ISOLATION |kconfig| y |defconfig | self_protection | OK
CONFIG_RANDOMIZE_MEMORY |kconfig| y |defconfig | self_protection | OK
+CONFIG_X86_KERNEL_IBT |kconfig| y |defconfig | self_protection | OK
CONFIG_INTEL_IOMMU |kconfig| y |defconfig | self_protection | OK
CONFIG_AMD_IOMMU |kconfig| y |defconfig | self_protection | OK
CONFIG_BUG_ON_DATA_CORRUPTION |kconfig| y | kspp | self_protection | OK
CONFIG_ZERO_CALL_USED_REGS |kconfig| y | kspp | self_protection | FAIL: "is not set"
CONFIG_HW_RANDOM_TPM |kconfig| y | kspp | self_protection | OK
CONFIG_STATIC_USERMODEHELPER |kconfig| y | kspp | self_protection | FAIL: "is not set"
-CONFIG_RANDSTRUCT_FULL |kconfig| y | kspp | self_protection | FAIL: "is not set"
+CONFIG_RANDSTRUCT_FULL |kconfig| y | kspp | self_protection | FAIL: is not found
CONFIG_RANDSTRUCT_PERFORMANCE |kconfig| is not set | kspp | self_protection | FAIL: CONFIG_RANDSTRUCT_FULL is not "y"
CONFIG_HARDENED_USERCOPY |kconfig| y | kspp | self_protection | OK
CONFIG_HARDENED_USERCOPY_FALLBACK |kconfig| is not set | kspp | self_protection | OK: is not found
CONFIG_HARDENED_USERCOPY_PAGESPAN |kconfig| is not set | kspp | self_protection | OK: is not found
-CONFIG_GCC_PLUGIN_LATENT_ENTROPY |kconfig| y | kspp | self_protection | FAIL: "is not set"
+CONFIG_GCC_PLUGIN_LATENT_ENTROPY |kconfig| y | kspp | self_protection | FAIL: CONFIG_GCC_PLUGINS is not "y"
CONFIG_MODULE_SIG |kconfig| y | kspp | self_protection | OK
CONFIG_MODULE_SIG_ALL |kconfig| y | kspp | self_protection | OK
CONFIG_MODULE_SIG_SHA512 |kconfig| y | kspp | self_protection | OK
CONFIG_UBSAN_LOCAL_BOUNDS |kconfig| y | kspp | self_protection | FAIL: is not found
CONFIG_UBSAN_TRAP |kconfig| y | kspp | self_protection | FAIL: CONFIG_UBSAN_BOUNDS is not "y"
CONFIG_UBSAN_SANITIZE_ALL |kconfig| y | kspp | self_protection | FAIL: CONFIG_UBSAN_BOUNDS is not "y"
-CONFIG_GCC_PLUGIN_STACKLEAK |kconfig| y | kspp | self_protection | FAIL: "is not set"
-CONFIG_STACKLEAK_METRICS |kconfig| is not set | kspp | self_protection | FAIL: CONFIG_GCC_PLUGIN_STACKLEAK is not "y"
-CONFIG_STACKLEAK_RUNTIME_DISABLE |kconfig| is not set | kspp | self_protection | FAIL: CONFIG_GCC_PLUGIN_STACKLEAK is not "y"
+CONFIG_GCC_PLUGIN_STACKLEAK |kconfig| y | kspp | self_protection | FAIL: CONFIG_GCC_PLUGINS is not "y"
+CONFIG_STACKLEAK_METRICS |kconfig| is not set | kspp | self_protection | FAIL: CONFIG_GCC_PLUGINS is not "y"
+CONFIG_STACKLEAK_RUNTIME_DISABLE |kconfig| is not set | kspp | self_protection | FAIL: CONFIG_GCC_PLUGINS is not "y"
CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT |kconfig| y | kspp | self_protection | OK
CONFIG_CFI_CLANG |kconfig| y | kspp | self_protection | FAIL: is not found
CONFIG_CFI_PERMISSIVE |kconfig| is not set | kspp | self_protection | FAIL: CONFIG_CFI_CLANG is not "y"
CONFIG_SECURITY_LOCKDOWN_LSM_EARLY |kconfig| y | kspp | security_policy | OK
CONFIG_LOCK_DOWN_KERNEL_FORCE_CONFIDENTIALITY|kconfig| y | kspp | security_policy | FAIL: "is not set"
CONFIG_SECURITY_WRITABLE_HOOKS |kconfig| is not set | kspp | security_policy | OK: is not found
+CONFIG_SECURITY_SELINUX |kconfig| y | my | security_policy | OK
CONFIG_SECCOMP |kconfig| y |defconfig |cut_attack_surface| OK
CONFIG_SECCOMP_FILTER |kconfig| y |defconfig |cut_attack_surface| OK
CONFIG_BPF_UNPRIV_DEFAULT_OFF |kconfig| y |defconfig |cut_attack_surface| OK
CONFIG_ACPI_CUSTOM_METHOD |kconfig| is not set | kspp |cut_attack_surface| OK
CONFIG_COMPAT_BRK |kconfig| is not set | kspp |cut_attack_surface| OK
CONFIG_DEVKMEM |kconfig| is not set | kspp |cut_attack_surface| OK: is not found
-CONFIG_COMPAT_VDSO |kconfig| is not set | kspp |cut_attack_surface| OK
CONFIG_BINFMT_MISC |kconfig| is not set | kspp |cut_attack_surface| FAIL: "m"
CONFIG_INET_DIAG |kconfig| is not set | kspp |cut_attack_surface| FAIL: "y"
CONFIG_KEXEC |kconfig| is not set | kspp |cut_attack_surface| FAIL: "y"
CONFIG_DEVMEM |kconfig| is not set | kspp |cut_attack_surface| FAIL: "y"
CONFIG_IO_STRICT_DEVMEM |kconfig| y | kspp |cut_attack_surface| OK
CONFIG_LDISC_AUTOLOAD |kconfig| is not set | kspp |cut_attack_surface| FAIL: "y"
-CONFIG_LEGACY_VSYSCALL_NONE |kconfig| y | kspp |cut_attack_surface| FAIL: "is not set"
+CONFIG_COMPAT_VDSO |kconfig| is not set | kspp |cut_attack_surface| OK
CONFIG_ZSMALLOC_STAT |kconfig| is not set | grsec |cut_attack_surface| OK
CONFIG_PAGE_OWNER |kconfig| is not set | grsec |cut_attack_surface| FAIL: "y"
CONFIG_DEBUG_KMEMLEAK |kconfig| is not set | grsec |cut_attack_surface| OK
CONFIG_VT |kconfig| is not set |maintainer|cut_attack_surface| FAIL: "y"
CONFIG_BLK_DEV_FD |kconfig| is not set |maintainer|cut_attack_surface| FAIL: "m"
CONFIG_BLK_DEV_FD_RAWCMD |kconfig| is not set |maintainer|cut_attack_surface| OK
+CONFIG_NOUVEAU_LEGACY_CTX_SUPPORT |kconfig| is not set |maintainer|cut_attack_surface| OK: is not found
CONFIG_STAGING |kconfig| is not set | clipos |cut_attack_surface| FAIL: "y"
CONFIG_KSM |kconfig| is not set | clipos |cut_attack_surface| FAIL: "y"
CONFIG_KALLSYMS |kconfig| is not set | clipos |cut_attack_surface| FAIL: "y"
-CONFIG_X86_VSYSCALL_EMULATION |kconfig| is not set | clipos |cut_attack_surface| FAIL: "y"
CONFIG_MAGIC_SYSRQ |kconfig| is not set | clipos |cut_attack_surface| FAIL: "y"
CONFIG_KEXEC_FILE |kconfig| is not set | clipos |cut_attack_surface| FAIL: "y"
CONFIG_USER_NS |kconfig| is not set | clipos |cut_attack_surface| FAIL: "y"
CONFIG_ACPI_TABLE_UPGRADE |kconfig| is not set | clipos |cut_attack_surface| FAIL: "y"
CONFIG_EFI_CUSTOM_SSDT_OVERLAYS |kconfig| is not set | clipos |cut_attack_surface| FAIL: "y"
CONFIG_COREDUMP |kconfig| is not set | clipos |cut_attack_surface| FAIL: "y"
+CONFIG_X86_VSYSCALL_EMULATION |kconfig| is not set | clipos |cut_attack_surface| FAIL: "y"
CONFIG_EFI_TEST |kconfig| is not set | lockdown |cut_attack_surface| FAIL: "m"
CONFIG_MMIOTRACE_TEST |kconfig| is not set | lockdown |cut_attack_surface| OK
CONFIG_KPROBES |kconfig| is not set | lockdown |cut_attack_surface| FAIL: "y"
CONFIG_BPF_SYSCALL |kconfig| is not set | lockdown |cut_attack_surface| FAIL: "y"
+CONFIG_LEGACY_TIOCSTI |kconfig| is not set | my |cut_attack_surface| OK
CONFIG_MMIOTRACE |kconfig| is not set | my |cut_attack_surface| FAIL: "y"
CONFIG_LIVEPATCH |kconfig| is not set | my |cut_attack_surface| FAIL: "y"
CONFIG_IP_DCCP |kconfig| is not set | my |cut_attack_surface| OK
CONFIG_IP_SCTP |kconfig| is not set | my |cut_attack_surface| FAIL: "m"
CONFIG_FTRACE |kconfig| is not set | my |cut_attack_surface| FAIL: "y"
-CONFIG_VIDEO_VIVID |kconfig| is not set | my |cut_attack_surface| OK: is not found
+CONFIG_VIDEO_VIVID |kconfig| is not set | my |cut_attack_surface| FAIL: "m"
CONFIG_INPUT_EVBUG |kconfig| is not set | my |cut_attack_surface| OK
CONFIG_KGDB |kconfig| is not set | my |cut_attack_surface| FAIL: "y"
+CONFIG_AIO |kconfig| is not set | my |cut_attack_surface| FAIL: "y"
+CONFIG_CORESIGHT |kconfig| is not set | my |cut_attack_surface| OK: is not found
+CONFIG_XFS_SUPPORT_V4 |kconfig| is not set | my |cut_attack_surface| FAIL: "y"
CONFIG_TRIM_UNUSED_KSYMS |kconfig| y | my |cut_attack_surface| FAIL: is not found
-CONFIG_INTEGRITY |kconfig| y |defconfig | harden_userspace | OK
-CONFIG_ARCH_MMAP_RND_BITS |kconfig| 32 | clipos | harden_userspace | FAIL: "28"
+CONFIG_ARCH_MMAP_RND_BITS |kconfig| 32 | my | harden_userspace | FAIL: "28"
nosmep |cmdline| is not set |defconfig | self_protection | OK: is not found
nosmap |cmdline| is not set |defconfig | self_protection | OK: is not found
nokaslr |cmdline| is not set |defconfig | self_protection | OK: is not found
arm64.nobti |cmdline| is not set |defconfig | self_protection | OK: is not found
arm64.nopauth |cmdline| is not set |defconfig | self_protection | OK: is not found
arm64.nomte |cmdline| is not set |defconfig | self_protection | OK: is not found
-mitigations |cmdline| is not off |defconfig | self_protection | OK: mitigations is not found
-spectre_v2 |cmdline| is not off |defconfig | self_protection | OK: spectre_v2 is not found
-spectre_v2_user |cmdline| is not off |defconfig | self_protection | OK: spectre_v2_user is not found
-spec_store_bypass_disable |cmdline| is not off |defconfig | self_protection | OK: spec_store_bypass_disable is not found
-l1tf |cmdline| is not off |defconfig | self_protection | OK: l1tf is not found
-mds |cmdline| is not off |defconfig | self_protection | OK: mds is not found
-tsx_async_abort |cmdline| is not off |defconfig | self_protection | OK: tsx_async_abort is not found
-srbds |cmdline| is not off |defconfig | self_protection | OK: srbds is not found
-mmio_stale_data |cmdline| is not off |defconfig | self_protection | OK: mmio_stale_data is not found
-retbleed |cmdline| is not off |defconfig | self_protection | OK: retbleed is not found
-kpti |cmdline| is not off |defconfig | self_protection | OK: kpti is not found
-kvm.nx_huge_pages |cmdline| is not off |defconfig | self_protection | OK: kvm.nx_huge_pages is not found
-rodata |cmdline| 1 |defconfig | self_protection | OK: rodata is not found
+spectre_v2 |cmdline| is not off |defconfig | self_protection | FAIL: is off, not found
+spectre_v2_user |cmdline| is not off |defconfig | self_protection | FAIL: is off, not found
+spec_store_bypass_disable |cmdline| is not off |defconfig | self_protection | FAIL: is off, not found
+l1tf |cmdline| is not off |defconfig | self_protection | FAIL: is off, not found
+mds |cmdline| is not off |defconfig | self_protection | FAIL: is off, not found
+tsx_async_abort |cmdline| is not off |defconfig | self_protection | FAIL: is off, not found
+srbds |cmdline| is not off |defconfig | self_protection | FAIL: is off, not found
+mmio_stale_data |cmdline| is not off |defconfig | self_protection | FAIL: is off, not found
+retbleed |cmdline| is not off |defconfig | self_protection | FAIL: is off, not found
+kpti |cmdline| is not off |defconfig | self_protection | FAIL: is off, not found
+rodata |cmdline| on |defconfig | self_protection | OK: rodata is not found
nosmt |cmdline| is present | kspp | self_protection | FAIL: is not present
+mitigations |cmdline| auto,nosmt | kspp | self_protection | FAIL: is not found
+slab_merge |cmdline| is not set | kspp | self_protection | OK: is not found
+slub_merge |cmdline| is not set | kspp | self_protection | OK: is not found
+slab_nomerge |cmdline| is present | kspp | self_protection | OK: CONFIG_SLAB_MERGE_DEFAULT is "is not set"
init_on_alloc |cmdline| 1 | kspp | self_protection | FAIL: is not found
init_on_free |cmdline| 1 | kspp | self_protection | FAIL: is not found
-slab_nomerge |cmdline| is present | kspp | self_protection | OK: CONFIG_SLAB_MERGE_DEFAULT is "is not set"
iommu.strict |cmdline| 1 | kspp | self_protection | FAIL: is not found
iommu.passthrough |cmdline| 0 | kspp | self_protection | OK: CONFIG_IOMMU_DEFAULT_PASSTHROUGH is "is not set"
hardened_usercopy |cmdline| 1 | kspp | self_protection | OK: CONFIG_HARDENED_USERCOPY is "y"
iommu |cmdline| force | clipos | self_protection | FAIL: is not found
tsx |cmdline| off |defconfig |cut_attack_surface| OK: CONFIG_X86_INTEL_TSX_MODE_OFF is "y"
vsyscall |cmdline| none | kspp |cut_attack_surface| FAIL: is not found
+vdso32 |cmdline| 1 | my |cut_attack_surface| OK: CONFIG_COMPAT_VDSO is "is not set"
debugfs |cmdline| off | grsec |cut_attack_surface| FAIL: is not found
sysrq_always_enabled |cmdline| is not set | my |cut_attack_surface| OK: is not found
-
-[+] Config check is finished: 'OK' - 122 / 'FAIL' - 101
+norandmaps |cmdline| is not set |defconfig | harden_userspace | OK: is not found
+net.core.bpf_jit_harden |sysctl | 2 | kspp | self_protection | FAIL: "0"
+kernel.dmesg_restrict |sysctl | 1 | kspp |cut_attack_surface| FAIL: "0"
+kernel.perf_event_paranoid |sysctl | 3 | kspp |cut_attack_surface| FAIL: "2"
+kernel.kexec_load_disabled |sysctl | 1 | kspp |cut_attack_surface| FAIL: "0"
+user.max_user_namespaces |sysctl | 0 | kspp |cut_attack_surface| FAIL: "31021"
+dev.tty.ldisc_autoload |sysctl | 0 | kspp |cut_attack_surface| FAIL: "1"
+kernel.unprivileged_bpf_disabled |sysctl | 1 | kspp |cut_attack_surface| OK
+kernel.kptr_restrict |sysctl | 1 | kspp |cut_attack_surface| FAIL: "0"
+kernel.yama.ptrace_scope |sysctl | 1 | kspp |cut_attack_surface| FAIL: "0"
+
+[+] Config check is finished: 'OK' - 118 / 'FAIL' - 122
```
## Generating a Kconfig fragment with the security hardening options
projects / kconfig-hardened-check.git / commitdiff