X-Git-Url: https://jxself.org/git/?a=blobdiff_plain;f=README.md;h=1cb7075fa9c5d84ea2d78c1d7b9ab10b079305a8;hb=HEAD;hp=03b8bcfbc7d6ee781e0f3700eb04b8e0d687e693;hpb=fb49a54262d88811268cea84e0b3b2f8f246fc44;p=kconfig-hardened-check.git diff --git a/README.md b/README.md index 03b8bcf..1cb7075 100644 --- a/README.md +++ b/README.md @@ -1,8 +1,11 @@ -# kconfig-hardened-check +# kernel-hardening-checker -![GitHub tag (latest by date)](https://img.shields.io/github/v/tag/a13xp0p0v/kconfig-hardened-check?label=release) -![functional test](https://github.com/a13xp0p0v/kconfig-hardened-check/workflows/functional%20test/badge.svg) -[![Coverage Status](https://codecov.io/gh/a13xp0p0v/kconfig-hardened-check/graph/badge.svg)](https://codecov.io/gh/a13xp0p0v/kconfig-hardened-check) +__(formerly kconfig-hardened-check)__

+[![functional test](https://github.com/a13xp0p0v/kernel-hardening-checker/workflows/functional%20test/badge.svg)](https://github.com/a13xp0p0v/kernel-hardening-checker/actions/workflows/functional_test.yml) +[![functional test coverage](https://codecov.io/gh/a13xp0p0v/kernel-hardening-checker/graph/badge.svg?flag=functional_test)](https://app.codecov.io/gh/a13xp0p0v/kernel-hardening-checker?flags%5B0%5D=functional_test)
+[![engine unit-test](https://github.com/a13xp0p0v/kernel-hardening-checker/workflows/engine%20unit-test/badge.svg)](https://github.com/a13xp0p0v/kernel-hardening-checker/actions/workflows/engine_unit-test.yml) +[![unit-test coverage](https://codecov.io/gh/a13xp0p0v/kernel-hardening-checker/graph/badge.svg?flag=engine_unit-test)](https://app.codecov.io/gh/a13xp0p0v/kernel-hardening-checker?flags%5B0%5D=engine_unit-test)
+[![GitHub tag (latest by date)](https://img.shields.io/github/v/tag/a13xp0p0v/kernel-hardening-checker?label=release)](https://github.com/a13xp0p0v/kernel-hardening-checker/tags) ## Motivation @@ -12,8 +15,13 @@ make our systems more secure. But nobody likes checking configs manually. So let the computers do their job! -__kconfig-hardened-check__ helps me to check the Linux kernel options -against my security hardening preferences, which are based on the +__kernel-hardening-checker__ (formerly __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] @@ -21,12 +29,21 @@ against my security hardening preferences, which are based on the - [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 +the threat model of your Linux-based information system and perform thorough testing +of its typical workload. + +## Repositories + + - Main at GitHub + - Mirror at Codeberg: + - Mirror at GitFlic: + ## Supported microarchitectures - X86_64 @@ -41,33 +58,45 @@ TODO: RISC-V (issue [#56][22]) You can install the package: ``` -pip install git+https://github.com/a13xp0p0v/kconfig-hardened-check +pip install git+https://github.com/a13xp0p0v/kernel-hardening-checker ``` -or simply run `./bin/kconfig-hardened-check` from the cloned repository. +or simply run `./bin/kernel-hardening-checker` from the cloned repository. -Some Linux distributions also provide `kconfig-hardened-check` as a package. +Some Linux distributions also provide `kernel-hardening-checker` as a package. ## Usage ``` -usage: kconfig-hardened-check [-h] [--version] [-p {X86_64,X86_32,ARM64,ARM}] - [-c CONFIG] - [-l CMDLINE] - [-m {verbose,json,show_ok,show_fail}] +usage: kernel-hardening-checker [-h] [--version] [-m {verbose,json,show_ok,show_fail}] + [-c CONFIG] [-l CMDLINE] [-s SYSCTL] [-v KERNEL_VERSION] + [-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 -optional arguments: +options: -h, --help show this help message and exit --version show program's version number and exit - -p {X86_64,X86_32,ARM64,ARM}, --print {X86_64,X86_32,ARM64,ARM} - print security hardening preferences for the selected architecture - -c CONFIG, --config CONFIG - check the kernel kconfig file against these preferences - -l CMDLINE, --cmdline CMDLINE - check the kernel cmdline file against these preferences -m {verbose,json,show_ok,show_fail}, --mode {verbose,json,show_ok,show_fail} choose the report mode + -c CONFIG, --config CONFIG + check the security hardening options in the kernel Kconfig file + (also supports *.gz files) + -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`) + -v KERNEL_VERSION, --kernel-version KERNEL_VERSION + extract the version from the kernel version file (contents of + /proc/version) + -p {X86_64,X86_32,ARM64,ARM}, --print {X86_64,X86_32,ARM64,ARM} + print the security hardening recommendations for the selected + microarchitecture + -g {X86_64,X86_32,ARM64,ARM}, --generate {X86_64,X86_32,ARM64,ARM} + generate a Kconfig fragment with the security hardening options + for the selected microarchitecture ``` ## Output modes @@ -79,135 +108,152 @@ optional arguments: ``` ------------------------------------------------------------------------------------------- <<< 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) + - `-m json` for printing the results in JSON format (for combining `kernel-hardening-checker` with other tools) -## Example output for `Fedora 34` kernel configuration +## Example output for `Ubuntu 22.04` kernel configuration ``` -$ ./bin/kconfig-hardened-check -c /boot/config-5.19.4-200.fc36.x86_64 -l /proc/cmdline -[+] Kconfig file to check: /boot/config-5.19.4-200.fc36.x86_64 +$ ./bin/kernel-hardening-checker -c kernel_hardening_checker/config_files/distros/ubuntu-22.04.config -l /proc/cmdline -s kernel_hardening_checker/config_files/distros/example_sysctls.txt +[+] Kconfig file to check: kernel_hardening_checker/config_files/distros/ubuntu-22.04.config [+] Kernel cmdline file to check: /proc/cmdline -[+] Detected architecture: X86_64 -[+] Detected kernel version: 5.19 -[+] Detected compiler: GCC 120201 +[+] Sysctl output file to check: kernel_hardening_checker/config_files/distros/example_sysctls.txt +[+] Detected microarchitecture: X86_64 +[+] Detected kernel version: (5, 15, 0) +[+] Detected compiler: GCC 110200 ========================================================================================================================= - option name | type |desired val | decision | reason | check result + 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_GCC_PLUGINS |kconfig| y |defconfig | self_protection | OK +CONFIG_THREAD_INFO_IN_TASK |kconfig| y |defconfig | self_protection | OK +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_THREAD_INFO_IN_TASK |kconfig| y |defconfig | self_protection | OK -CONFIG_IOMMU_SUPPORT |kconfig| y |defconfig | self_protection | OK +CONFIG_REFCOUNT_FULL |kconfig| y |defconfig | self_protection | OK: version >= (5, 4, 208) +CONFIG_INIT_STACK_ALL_ZERO |kconfig| y |defconfig | self_protection | FAIL: is not found CONFIG_RANDOMIZE_BASE |kconfig| y |defconfig | self_protection | OK CONFIG_VMAP_STACK |kconfig| y |defconfig | self_protection | OK -CONFIG_MICROCODE |kconfig| y |defconfig | self_protection | OK +CONFIG_SPECULATION_MITIGATIONS |kconfig| y |defconfig | self_protection | FAIL: is not found +CONFIG_DEBUG_WX |kconfig| y |defconfig | self_protection | OK +CONFIG_WERROR |kconfig| y |defconfig | self_protection | FAIL: "is not set" +CONFIG_X86_MCE |kconfig| y |defconfig | self_protection | OK +CONFIG_X86_MCE_INTEL |kconfig| y |defconfig | self_protection | OK +CONFIG_X86_MCE_AMD |kconfig| y |defconfig | self_protection | OK CONFIG_RETPOLINE |kconfig| y |defconfig | self_protection | OK -CONFIG_X86_SMAP |kconfig| y |defconfig | self_protection | OK: version >= 5.19 CONFIG_SYN_COOKIES |kconfig| y |defconfig | self_protection | OK +CONFIG_MICROCODE |kconfig| y |defconfig | self_protection | OK +CONFIG_MICROCODE_INTEL |kconfig| y |defconfig | self_protection | OK +CONFIG_MICROCODE_AMD |kconfig| y |defconfig | self_protection | OK +CONFIG_X86_SMAP |kconfig| y |defconfig | self_protection | OK 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 | FAIL: is not found +CONFIG_CPU_SRSO |kconfig| y |defconfig | self_protection | FAIL: is not found 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_DEBUG_WX |kconfig| y | kspp | self_protection | OK -CONFIG_SCHED_STACK_END_CHECK |kconfig| y | kspp | self_protection | OK +CONFIG_BUG_ON_DATA_CORRUPTION |kconfig| y | kspp | self_protection | FAIL: "is not set" CONFIG_SLAB_FREELIST_HARDENED |kconfig| y | kspp | self_protection | OK CONFIG_SLAB_FREELIST_RANDOM |kconfig| y | kspp | self_protection | OK CONFIG_SHUFFLE_PAGE_ALLOCATOR |kconfig| y | kspp | self_protection | OK CONFIG_FORTIFY_SOURCE |kconfig| y | kspp | self_protection | OK -CONFIG_DEBUG_LIST |kconfig| y | kspp | self_protection | OK +CONFIG_DEBUG_LIST |kconfig| y | kspp | self_protection | FAIL: "is not set" +CONFIG_DEBUG_VIRTUAL |kconfig| y | kspp | self_protection | FAIL: "is not set" CONFIG_DEBUG_SG |kconfig| y | kspp | self_protection | FAIL: "is not set" +CONFIG_INIT_ON_ALLOC_DEFAULT_ON |kconfig| y | kspp | self_protection | OK +CONFIG_STATIC_USERMODEHELPER |kconfig| y | kspp | self_protection | FAIL: "is not set" +CONFIG_SCHED_CORE |kconfig| y | kspp | self_protection | OK +CONFIG_SECURITY_LOCKDOWN_LSM |kconfig| y | kspp | self_protection | OK +CONFIG_SECURITY_LOCKDOWN_LSM_EARLY |kconfig| y | kspp | self_protection | OK +CONFIG_LOCK_DOWN_KERNEL_FORCE_CONFIDENTIALITY|kconfig| y | kspp | self_protection | FAIL: "is not set" CONFIG_DEBUG_CREDENTIALS |kconfig| y | kspp | self_protection | FAIL: "is not set" CONFIG_DEBUG_NOTIFIERS |kconfig| y | kspp | self_protection | FAIL: "is not set" -CONFIG_INIT_ON_ALLOC_DEFAULT_ON |kconfig| y | kspp | self_protection | FAIL: "is not set" -CONFIG_GCC_PLUGIN_LATENT_ENTROPY |kconfig| y | kspp | self_protection | FAIL: "is not set" +CONFIG_SCHED_STACK_END_CHECK |kconfig| y | kspp | self_protection | OK CONFIG_KFENCE |kconfig| y | kspp | self_protection | OK -CONFIG_WERROR |kconfig| y | kspp | self_protection | FAIL: "is not set" -CONFIG_IOMMU_DEFAULT_DMA_STRICT |kconfig| y | kspp | self_protection | FAIL: "is not set" -CONFIG_IOMMU_DEFAULT_PASSTHROUGH |kconfig| is not set | kspp | self_protection | OK -CONFIG_ZERO_CALL_USED_REGS |kconfig| y | kspp | self_protection | FAIL: "is not set" -CONFIG_RANDSTRUCT_FULL |kconfig| y | kspp | self_protection | FAIL: "is not set" +CONFIG_KFENCE_SAMPLE_INTERVAL |kconfig| is not off |a13xp0p0v | self_protection | FAIL: is off, "0" +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: not found -CONFIG_HARDENED_USERCOPY_PAGESPAN |kconfig| is not set | kspp | self_protection | OK: not found +CONFIG_HARDENED_USERCOPY_FALLBACK |kconfig| is not set | kspp | self_protection | OK +CONFIG_HARDENED_USERCOPY_PAGESPAN |kconfig| is not set | kspp | self_protection | OK +CONFIG_GCC_PLUGIN_LATENT_ENTROPY |kconfig| y | kspp | self_protection | FAIL: is not found 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_MODULE_SIG_FORCE |kconfig| y | kspp | self_protection | FAIL: "is not set" -CONFIG_INIT_STACK_ALL_ZERO |kconfig| y | kspp | self_protection | FAIL: "is not set" CONFIG_INIT_ON_FREE_DEFAULT_ON |kconfig| y | kspp | self_protection | FAIL: "is not set" -CONFIG_GCC_PLUGIN_STACKLEAK |kconfig| y | kspp | self_protection | FAIL: "is not set" +CONFIG_EFI_DISABLE_PCI_DMA |kconfig| y | kspp | self_protection | FAIL: "is not set" +CONFIG_RESET_ATTACK_MITIGATION |kconfig| y | kspp | self_protection | OK +CONFIG_UBSAN_BOUNDS |kconfig| y | kspp | self_protection | OK +CONFIG_UBSAN_LOCAL_BOUNDS |kconfig| y | kspp | self_protection | OK: CONFIG_UBSAN_BOUNDS is "y" +CONFIG_UBSAN_TRAP |kconfig| y | kspp | self_protection | FAIL: CONFIG_UBSAN_ENUM is not "is not set" +CONFIG_UBSAN_SANITIZE_ALL |kconfig| y | kspp | self_protection | OK +CONFIG_GCC_PLUGIN_STACKLEAK |kconfig| y | kspp | self_protection | FAIL: is not found +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_RANDOMIZE_KSTACK_OFFSET_DEFAULT |kconfig| y | kspp | self_protection | OK -CONFIG_SCHED_CORE |kconfig| y | kspp | self_protection | OK +CONFIG_CFI_CLANG |kconfig| y | kspp | self_protection | FAIL: CONFIG_CC_IS_CLANG is not "y" +CONFIG_CFI_PERMISSIVE |kconfig| is not set | kspp | self_protection | FAIL: CONFIG_CC_IS_CLANG is not "y" +CONFIG_HW_RANDOM_TPM |kconfig| y | kspp | self_protection | OK CONFIG_DEFAULT_MMAP_MIN_ADDR |kconfig| 65536 | kspp | self_protection | OK -CONFIG_UBSAN_BOUNDS |kconfig| y |maintainer| self_protection | FAIL: not found -CONFIG_UBSAN_SANITIZE_ALL |kconfig| y |maintainer| self_protection | FAIL: CONFIG_UBSAN_BOUNDS not "y" -CONFIG_UBSAN_TRAP |kconfig| y |maintainer| self_protection | FAIL: CONFIG_UBSAN_BOUNDS not "y" -CONFIG_DEBUG_VIRTUAL |kconfig| y | clipos | self_protection | FAIL: "is not set" -CONFIG_STATIC_USERMODEHELPER |kconfig| y | clipos | self_protection | FAIL: "is not set" -CONFIG_EFI_DISABLE_PCI_DMA |kconfig| y | clipos | self_protection | FAIL: "is not set" -CONFIG_SLAB_MERGE_DEFAULT |kconfig| is not set | clipos | self_protection | OK -CONFIG_RANDOM_TRUST_BOOTLOADER |kconfig| is not set | clipos | self_protection | FAIL: "y" -CONFIG_RANDOM_TRUST_CPU |kconfig| is not set | clipos | self_protection | FAIL: "y" -CONFIG_RANDSTRUCT_PERFORMANCE |kconfig| is not set | clipos | self_protection | FAIL: CONFIG_RANDSTRUCT_FULL not "y" -CONFIG_STACKLEAK_METRICS |kconfig| is not set | clipos | self_protection | FAIL: CONFIG_GCC_PLUGIN_STACKLEAK not "y" -CONFIG_STACKLEAK_RUNTIME_DISABLE |kconfig| is not set | clipos | self_protection | FAIL: CONFIG_GCC_PLUGIN_STACKLEAK not "y" -CONFIG_INTEL_IOMMU_DEFAULT_ON |kconfig| y | clipos | self_protection | FAIL: "is not set" -CONFIG_INTEL_IOMMU_SVM |kconfig| y | clipos | self_protection | OK -CONFIG_RESET_ATTACK_MITIGATION |kconfig| y | my | self_protection | FAIL: "is not set" -CONFIG_UBSAN_LOCAL_BOUNDS |kconfig| y | my | self_protection | FAIL: not found -CONFIG_SLS |kconfig| y | my | self_protection | OK -CONFIG_AMD_IOMMU_V2 |kconfig| y | my | self_protection | FAIL: "m" +CONFIG_IOMMU_DEFAULT_DMA_STRICT |kconfig| y | kspp | self_protection | FAIL: "is not set" +CONFIG_IOMMU_DEFAULT_PASSTHROUGH |kconfig| is not set | kspp | self_protection | OK +CONFIG_INTEL_IOMMU_DEFAULT_ON |kconfig| y | kspp | self_protection | OK +CONFIG_SLS |kconfig| y | kspp | self_protection | FAIL: is not found +CONFIG_INTEL_IOMMU_SVM |kconfig| y | kspp | self_protection | OK +CONFIG_AMD_IOMMU_V2 |kconfig| y | kspp | self_protection | FAIL: "m" +CONFIG_SLAB_MERGE_DEFAULT |kconfig| is not set | clipos | self_protection | FAIL: "y" +CONFIG_LIST_HARDENED |kconfig| y |a13xp0p0v | self_protection | FAIL: is not found +CONFIG_RANDOM_KMALLOC_CACHES |kconfig| y |a13xp0p0v | self_protection | FAIL: is not found CONFIG_SECURITY |kconfig| y |defconfig | security_policy | OK CONFIG_SECURITY_YAMA |kconfig| y | kspp | security_policy | OK CONFIG_SECURITY_LANDLOCK |kconfig| y | kspp | security_policy | OK CONFIG_SECURITY_SELINUX_DISABLE |kconfig| is not set | kspp | security_policy | OK -CONFIG_SECURITY_LOCKDOWN_LSM |kconfig| y | clipos | security_policy | OK -CONFIG_SECURITY_LOCKDOWN_LSM_EARLY |kconfig| y | clipos | security_policy | OK -CONFIG_LOCK_DOWN_KERNEL_FORCE_CONFIDENTIALITY|kconfig| y | clipos | security_policy | FAIL: "is not set" -CONFIG_SECURITY_WRITABLE_HOOKS |kconfig| is not set | my | security_policy | OK: not found -CONFIG_SECURITY_SAFESETID |kconfig| y | my | security_policy | FAIL: "is not set" -CONFIG_SECURITY_LOADPIN |kconfig| y | my | security_policy | FAIL: "is not set" -CONFIG_SECURITY_LOADPIN_ENFORCE |kconfig| y | my | security_policy | FAIL: CONFIG_SECURITY_LOADPIN not "y" -CONFIG_BPF_UNPRIV_DEFAULT_OFF |kconfig| y |defconfig |cut_attack_surface| OK +CONFIG_SECURITY_SELINUX_BOOTPARAM |kconfig| is not set | kspp | security_policy | FAIL: "y" +CONFIG_SECURITY_SELINUX_DEVELOP |kconfig| is not set | kspp | security_policy | FAIL: "y" +CONFIG_SECURITY_WRITABLE_HOOKS |kconfig| is not set | kspp | security_policy | OK: is not found +CONFIG_SECURITY_SELINUX_DEBUG |kconfig| is not set |a13xp0p0v | security_policy | OK: is not found +CONFIG_SECURITY_SELINUX |kconfig| y |a13xp0p0v | 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_STRICT_DEVMEM |kconfig| y |defconfig |cut_attack_surface| OK -CONFIG_SECURITY_DMESG_RESTRICT |kconfig| y | kspp |cut_attack_surface| FAIL: "is not set" +CONFIG_X86_INTEL_TSX_MODE_OFF |kconfig| y |defconfig |cut_attack_surface| OK +CONFIG_SECURITY_DMESG_RESTRICT |kconfig| y | kspp |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: not found -CONFIG_COMPAT_VDSO |kconfig| is not set | kspp |cut_attack_surface| OK +CONFIG_DEVKMEM |kconfig| is not set | kspp |cut_attack_surface| OK: is not found 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_INET_DIAG |kconfig| is not set | kspp |cut_attack_surface| FAIL: "m" CONFIG_KEXEC |kconfig| is not set | kspp |cut_attack_surface| FAIL: "y" CONFIG_PROC_KCORE |kconfig| is not set | kspp |cut_attack_surface| FAIL: "y" -CONFIG_LEGACY_PTYS |kconfig| is not set | kspp |cut_attack_surface| OK +CONFIG_LEGACY_PTYS |kconfig| is not set | kspp |cut_attack_surface| FAIL: "y" CONFIG_HIBERNATION |kconfig| is not set | kspp |cut_attack_surface| FAIL: "y" +CONFIG_COMPAT |kconfig| is not set | kspp |cut_attack_surface| FAIL: "y" CONFIG_IA32_EMULATION |kconfig| is not set | kspp |cut_attack_surface| FAIL: "y" -CONFIG_X86_X32 |kconfig| is not set | kspp |cut_attack_surface| OK: not found +CONFIG_X86_X32 |kconfig| is not set | kspp |cut_attack_surface| FAIL: "y" +CONFIG_X86_X32_ABI |kconfig| is not set | kspp |cut_attack_surface| OK: is not found CONFIG_MODIFY_LDT_SYSCALL |kconfig| is not set | kspp |cut_attack_surface| FAIL: "y" -CONFIG_OABI_COMPAT |kconfig| is not set | kspp |cut_attack_surface| OK: not found -CONFIG_X86_MSR |kconfig| is not set | kspp |cut_attack_surface| FAIL: "y" +CONFIG_OABI_COMPAT |kconfig| is not set | kspp |cut_attack_surface| OK: is not found +CONFIG_X86_MSR |kconfig| is not set | kspp |cut_attack_surface| FAIL: "m" +CONFIG_LEGACY_TIOCSTI |kconfig| is not set | kspp |cut_attack_surface| OK: is not found CONFIG_MODULES |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_LEGACY_VSYSCALL_NONE |kconfig| y | kspp |cut_attack_surface| FAIL: "is not set" +CONFIG_IO_STRICT_DEVMEM |kconfig| y | kspp |cut_attack_surface| FAIL: "is not set" +CONFIG_LDISC_AUTOLOAD |kconfig| is not set | kspp |cut_attack_surface| FAIL: "y" +CONFIG_COMPAT_VDSO |kconfig| is not set | kspp |cut_attack_surface| OK +CONFIG_X86_VSYSCALL_EMULATION |kconfig| is not set | kspp |cut_attack_surface| FAIL: "y" 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_PAGE_OWNER |kconfig| is not set | grsec |cut_attack_surface| OK CONFIG_DEBUG_KMEMLEAK |kconfig| is not set | grsec |cut_attack_surface| OK -CONFIG_BINFMT_AOUT |kconfig| is not set | grsec |cut_attack_surface| OK: not found +CONFIG_BINFMT_AOUT |kconfig| is not set | grsec |cut_attack_surface| OK: is not found CONFIG_KPROBE_EVENTS |kconfig| is not set | grsec |cut_attack_surface| FAIL: "y" CONFIG_UPROBE_EVENTS |kconfig| is not set | grsec |cut_attack_surface| FAIL: "y" CONFIG_GENERIC_TRACER |kconfig| is not set | grsec |cut_attack_surface| FAIL: "y" @@ -217,99 +263,160 @@ CONFIG_HIST_TRIGGERS |kconfig| is not set | grsec |cut_att CONFIG_BLK_DEV_IO_TRACE |kconfig| is not set | grsec |cut_attack_surface| FAIL: "y" CONFIG_PROC_VMCORE |kconfig| is not set | grsec |cut_attack_surface| FAIL: "y" CONFIG_PROC_PAGE_MONITOR |kconfig| is not set | grsec |cut_attack_surface| FAIL: "y" -CONFIG_USELIB |kconfig| is not set | grsec |cut_attack_surface| OK +CONFIG_USELIB |kconfig| is not set | grsec |cut_attack_surface| FAIL: "y" CONFIG_CHECKPOINT_RESTORE |kconfig| is not set | grsec |cut_attack_surface| FAIL: "y" CONFIG_USERFAULTFD |kconfig| is not set | grsec |cut_attack_surface| FAIL: "y" CONFIG_HWPOISON_INJECT |kconfig| is not set | grsec |cut_attack_surface| FAIL: "m" CONFIG_MEM_SOFT_DIRTY |kconfig| is not set | grsec |cut_attack_surface| FAIL: "y" CONFIG_DEVPORT |kconfig| is not set | grsec |cut_attack_surface| FAIL: "y" CONFIG_DEBUG_FS |kconfig| is not set | grsec |cut_attack_surface| FAIL: "y" -CONFIG_NOTIFIER_ERROR_INJECTION |kconfig| is not set | grsec |cut_attack_surface| OK -CONFIG_FAIL_FUTEX |kconfig| is not set | grsec |cut_attack_surface| OK: not found -CONFIG_PUNIT_ATOM_DEBUG |kconfig| is not set | grsec |cut_attack_surface| OK -CONFIG_ACPI_CONFIGFS |kconfig| is not set | grsec |cut_attack_surface| OK +CONFIG_NOTIFIER_ERROR_INJECTION |kconfig| is not set | grsec |cut_attack_surface| FAIL: "m" +CONFIG_FAIL_FUTEX |kconfig| is not set | grsec |cut_attack_surface| OK: is not found +CONFIG_PUNIT_ATOM_DEBUG |kconfig| is not set | grsec |cut_attack_surface| FAIL: "m" +CONFIG_ACPI_CONFIGFS |kconfig| is not set | grsec |cut_attack_surface| FAIL: "m" CONFIG_EDAC_DEBUG |kconfig| is not set | grsec |cut_attack_surface| OK -CONFIG_DRM_I915_DEBUG |kconfig| is not set | grsec |cut_attack_surface| OK: not found +CONFIG_DRM_I915_DEBUG |kconfig| is not set | grsec |cut_attack_surface| OK CONFIG_BCACHE_CLOSURES_DEBUG |kconfig| is not set | grsec |cut_attack_surface| OK -CONFIG_DVB_C8SECTPFE |kconfig| is not set | grsec |cut_attack_surface| OK: not found -CONFIG_MTD_SLRAM |kconfig| is not set | grsec |cut_attack_surface| OK -CONFIG_MTD_PHRAM |kconfig| is not set | grsec |cut_attack_surface| OK +CONFIG_DVB_C8SECTPFE |kconfig| is not set | grsec |cut_attack_surface| OK: is not found +CONFIG_MTD_SLRAM |kconfig| is not set | grsec |cut_attack_surface| FAIL: "m" +CONFIG_MTD_PHRAM |kconfig| is not set | grsec |cut_attack_surface| FAIL: "m" CONFIG_IO_URING |kconfig| is not set | grsec |cut_attack_surface| FAIL: "y" CONFIG_KCMP |kconfig| is not set | grsec |cut_attack_surface| FAIL: "y" CONFIG_RSEQ |kconfig| is not set | grsec |cut_attack_surface| FAIL: "y" -CONFIG_LATENCYTOP |kconfig| is not set | grsec |cut_attack_surface| FAIL: "y" +CONFIG_LATENCYTOP |kconfig| is not set | grsec |cut_attack_surface| OK CONFIG_KCOV |kconfig| is not set | grsec |cut_attack_surface| OK -CONFIG_PROVIDE_OHCI1394_DMA_INIT |kconfig| is not set | grsec |cut_attack_surface| FAIL: "y" +CONFIG_PROVIDE_OHCI1394_DMA_INIT |kconfig| is not set | grsec |cut_attack_surface| OK CONFIG_SUNRPC_DEBUG |kconfig| is not set | grsec |cut_attack_surface| FAIL: "y" CONFIG_PTDUMP_DEBUGFS |kconfig| is not set | grsec |cut_attack_surface| OK CONFIG_DRM_LEGACY |kconfig| is not set |maintainer|cut_attack_surface| OK CONFIG_FB |kconfig| is not set |maintainer|cut_attack_surface| FAIL: "y" 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_AIO |kconfig| is not set |grapheneos|cut_attack_surface| FAIL: "y" +CONFIG_BLK_DEV_FD_RAWCMD |kconfig| is not set |maintainer|cut_attack_surface| OK: is not found +CONFIG_NOUVEAU_LEGACY_CTX_SUPPORT |kconfig| is not set |maintainer|cut_attack_surface| OK 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_X86_CPUID |kconfig| is not set | clipos |cut_attack_surface| FAIL: "y" +CONFIG_X86_CPUID |kconfig| is not set | clipos |cut_attack_surface| FAIL: "m" CONFIG_X86_IOPL_IOPERM |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_LDISC_AUTOLOAD |kconfig| is not set | clipos |cut_attack_surface| FAIL: "y" -CONFIG_X86_INTEL_TSX_MODE_OFF |kconfig| y | clipos |cut_attack_surface| OK -CONFIG_BPF_SYSCALL |kconfig| is not set | lockdown |cut_attack_surface| FAIL: "y" +CONFIG_AIO |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_TRIM_UNUSED_KSYMS |kconfig| y | my |cut_attack_surface| FAIL: not found -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: not found -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_INTEGRITY |kconfig| y |defconfig | harden_userspace | OK -CONFIG_ARCH_MMAP_RND_BITS |kconfig| 32 | clipos | harden_userspace | FAIL: "28" -nosmep |cmdline| is not set |defconfig | self_protection | OK: not found -nosmap |cmdline| is not set |defconfig | self_protection | OK: not found -nokaslr |cmdline| is not set |defconfig | self_protection | OK: not found -nopti |cmdline| is not set |defconfig | self_protection | OK: not found -nospectre_v1 |cmdline| is not set |defconfig | self_protection | OK: not found -nospectre_v2 |cmdline| is not set |defconfig | self_protection | OK: not found -rodata |cmdline| 1 |defconfig | self_protection | OK: rodata not found -init_on_alloc |cmdline| 1 | kspp | self_protection | FAIL: not found -init_on_free |cmdline| 1 | kspp | self_protection | FAIL: not found -slab_nomerge |cmdline| | kspp | self_protection | OK: CONFIG_SLAB_MERGE_DEFAULT "is not set" -iommu.strict |cmdline| 1 | kspp | self_protection | FAIL: not found -iommu.passthrough |cmdline| 0 | kspp | self_protection | OK: CONFIG_IOMMU_DEFAULT_PASSTHROUGH "is not set" -hardened_usercopy |cmdline| 1 | kspp | self_protection | OK: CONFIG_HARDENED_USERCOPY "y" -slab_common.usercopy_fallback |cmdline| 0 | kspp | self_protection | OK: CONFIG_HARDENED_USERCOPY_FALLBACK not found -randomize_kstack_offset |cmdline| 1 | kspp | self_protection | OK: CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT "y" -pti |cmdline| on | kspp | self_protection | FAIL: not found -page_alloc.shuffle |cmdline| 1 | clipos | self_protection | FAIL: not found -spectre_v2 |cmdline| on | clipos | self_protection | FAIL: not found -vsyscall |cmdline| none | kspp |cut_attack_surface| FAIL: not found -debugfs |cmdline| off | grsec |cut_attack_surface| FAIL: not found - -[+] Config check is finished: 'OK' - 97 / 'FAIL' - 101 +CONFIG_BPF_SYSCALL |kconfig| is not set | lockdown |cut_attack_surface| FAIL: "y" +CONFIG_MMIOTRACE |kconfig| is not set |a13xp0p0v |cut_attack_surface| FAIL: "y" +CONFIG_LIVEPATCH |kconfig| is not set |a13xp0p0v |cut_attack_surface| FAIL: "y" +CONFIG_IP_DCCP |kconfig| is not set |a13xp0p0v |cut_attack_surface| FAIL: "m" +CONFIG_IP_SCTP |kconfig| is not set |a13xp0p0v |cut_attack_surface| FAIL: "m" +CONFIG_FTRACE |kconfig| is not set |a13xp0p0v |cut_attack_surface| FAIL: "y" +CONFIG_VIDEO_VIVID |kconfig| is not set |a13xp0p0v |cut_attack_surface| FAIL: "m" +CONFIG_INPUT_EVBUG |kconfig| is not set |a13xp0p0v |cut_attack_surface| FAIL: "m" +CONFIG_KGDB |kconfig| is not set |a13xp0p0v |cut_attack_surface| FAIL: "y" +CONFIG_CORESIGHT |kconfig| is not set |a13xp0p0v |cut_attack_surface| OK: is not found +CONFIG_XFS_SUPPORT_V4 |kconfig| is not set |a13xp0p0v |cut_attack_surface| FAIL: "y" +CONFIG_TRIM_UNUSED_KSYMS |kconfig| y |a13xp0p0v |cut_attack_surface| FAIL: "is not set" +CONFIG_MODULE_FORCE_LOAD |kconfig| is not set |a13xp0p0v |cut_attack_surface| OK +CONFIG_COREDUMP |kconfig| is not set | clipos | harden_userspace | FAIL: "y" +CONFIG_ARCH_MMAP_RND_BITS |kconfig| 32 |a13xp0p0v | 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 +nopti |cmdline| is not set |defconfig | self_protection | OK: is not found +nospectre_v1 |cmdline| is not set |defconfig | self_protection | OK: is not found +nospectre_v2 |cmdline| is not set |defconfig | self_protection | OK: is not found +nospectre_bhb |cmdline| is not set |defconfig | self_protection | OK: is not found +nospec_store_bypass_disable |cmdline| is not set |defconfig | self_protection | OK: is not found +dis_ucode_ldr |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 +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 +spec_rstack_overflow |cmdline| is not off |defconfig | self_protection | FAIL: is off, not found +gather_data_sampling |cmdline| is not off |defconfig | self_protection | FAIL: is off, not found +rodata |cmdline| on |defconfig | self_protection | OK: rodata is not found +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 +page_alloc.shuffle |cmdline| 1 | kspp | self_protection | FAIL: is not found +slab_nomerge |cmdline| is present | kspp | self_protection | FAIL: is not present +init_on_alloc |cmdline| 1 | kspp | self_protection | OK: CONFIG_INIT_ON_ALLOC_DEFAULT_ON is "y" +init_on_free |cmdline| 1 | kspp | self_protection | FAIL: is not found +hardened_usercopy |cmdline| 1 | kspp | self_protection | OK: CONFIG_HARDENED_USERCOPY is "y" +slab_common.usercopy_fallback |cmdline| is not set | kspp | self_protection | OK: is not found +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" +randomize_kstack_offset |cmdline| 1 | kspp | self_protection | OK: CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT is "y" +pti |cmdline| on | kspp | self_protection | FAIL: is not found +iommu |cmdline| force | clipos | self_protection | FAIL: is not found +kfence.sample_interval |cmdline| is not off |a13xp0p0v | self_protection | FAIL: is off, not found +tsx |cmdline| off |defconfig |cut_attack_surface| OK: CONFIG_X86_INTEL_TSX_MODE_OFF is "y" +nosmt |cmdline| is present | kspp |cut_attack_surface| FAIL: is not present +vsyscall |cmdline| none | kspp |cut_attack_surface| FAIL: is not found +vdso32 |cmdline| 0 | kspp |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 |a13xp0p0v |cut_attack_surface| OK: is not found +ia32_emulation |cmdline| 0 |a13xp0p0v |cut_attack_surface| FAIL: is not found +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| OK +kernel.perf_event_paranoid |sysctl | 3 | kspp |cut_attack_surface| FAIL: "4" +kernel.kexec_load_disabled |sysctl | 1 | kspp |cut_attack_surface| FAIL: "0" +user.max_user_namespaces |sysctl | 0 | kspp |cut_attack_surface| FAIL: "31231" +dev.tty.ldisc_autoload |sysctl | 0 | kspp |cut_attack_surface| FAIL: "1" +kernel.unprivileged_bpf_disabled |sysctl | 1 | kspp |cut_attack_surface| FAIL: "2" +kernel.kptr_restrict |sysctl | 2 | kspp |cut_attack_surface| FAIL: "1" +dev.tty.legacy_tiocsti |sysctl | 0 | kspp |cut_attack_surface| FAIL: is not found +vm.unprivileged_userfaultfd |sysctl | 0 | kspp |cut_attack_surface| OK +kernel.modules_disabled |sysctl | 1 | clipos |cut_attack_surface| FAIL: "0" +fs.protected_symlinks |sysctl | 1 | kspp | harden_userspace | OK +fs.protected_hardlinks |sysctl | 1 | kspp | harden_userspace | OK +fs.protected_fifos |sysctl | 2 | kspp | harden_userspace | FAIL: "1" +fs.protected_regular |sysctl | 2 | kspp | harden_userspace | OK +fs.suid_dumpable |sysctl | 0 | kspp | harden_userspace | FAIL: "2" +kernel.randomize_va_space |sysctl | 2 | kspp | harden_userspace | OK +kernel.yama.ptrace_scope |sysctl | 3 | kspp | harden_userspace | FAIL: "1" + +[+] Config check is finished: 'OK' - 121 / 'FAIL' - 139 ``` -## kconfig-hardened-check versioning +## Generating a Kconfig fragment with the security hardening options -I usually update the kernel security hardening recommendations every few kernel releases. +With the `-g` argument, the tool generates a Kconfig fragment with the security hardening options for the selected microarchitecture. + +This Kconfig fragment can be merged with the existing Linux kernel config: +``` +$ ./bin/kernel-hardening-checker -g X86_64 > /tmp/fragment +$ cd ~/linux-src/ +$ ./scripts/kconfig/merge_config.sh .config /tmp/fragment +Using .config as base +Merging /tmp/fragment +Value of CONFIG_BUG_ON_DATA_CORRUPTION is redefined by fragment /tmp/fragment: +Previous value: # CONFIG_BUG_ON_DATA_CORRUPTION is not set +New value: CONFIG_BUG_ON_DATA_CORRUPTION=y + ... +``` -So the version of `kconfig-hardened-check` is associated with the corresponding version of the kernel. +## Questions and answers -The version format is: __[major_number].[kernel_version].[kernel_patchlevel]__ +__Q:__ How all these kernel parameters influence the Linux kernel security? +__A:__ To answer this question, you can use the `kernel-hardening-checker` [sources of recommendations][24] +and the [Linux Kernel Defence Map][4] with its references. -## Questions and answers +
__Q:__ How disabling `CONFIG_USER_NS` cuts the attack surface? It's needed for containers! @@ -326,13 +433,6 @@ The rationale:
-__Q:__ Why `CONFIG_GCC_PLUGINS` is automatically disabled during the kernel compilation? - -__A:__ It means that your gcc doesn't support plugins. For example, if you have `gcc-7` on Ubuntu, -try to install `gcc-7-plugin-dev` package, it should help. - -
- __Q:__ KSPP and CLIP OS recommend `CONFIG_PANIC_ON_OOPS=y`. Why doesn't this tool do the same? __A:__ I personally don't support this recommendation because: @@ -345,6 +445,16 @@ In other cases, the kernel panics, which is similar to `CONFIG_PANIC_ON_OOPS=y`.
+__Q:__ Why enabling `CONFIG_STATIC_USERMODEHELPER` breaks various things in my GNU/Linux system? +Do I really need that feature? + +__A:__ Linux kernel usermode helpers can be used for privilege escalation in kernel exploits +([example 1][9], [example 2][10]). `CONFIG_STATIC_USERMODEHELPER` prevents that method. But it +requires the corresponding support in the userspace: see the [example implementation][11] by +Tycho Andersen [@tych0][12]. + +
+ __Q:__ What about performance impact of these security hardening options? __A:__ Ike Devolder [@BlackIkeEagle][7] made some performance tests and described the results in [this article][8]. @@ -359,20 +469,17 @@ You can use it for the `mainline` or `stable` tree from [kernel.org][20] or for
-__Q:__ Why enabling `CONFIG_STATIC_USERMODEHELPER` breaks various things in my GNU/Linux system? -Do I really need that feature? +__Q:__ Does my kernel have all those mitigations of Transient Execution Vulnerabilities in my hardware? -__A:__ Linux kernel usermode helpers can be used for privilege escalation in kernel exploits -([example 1][9], [example 2][10]). `CONFIG_STATIC_USERMODEHELPER` prevents that method. But it -requires the corresponding support in the userspace: see the [example implementation][11] by -Tycho Andersen [@tych0][12]. +__A:__ Checking the kernel config is not enough to answer this question. +I highly recommend using [spectre-meltdown-checker][13] tool maintained by Stéphane Lesimple [@speed47][14].
-__Q:__ Does my kernel have all those mitigations of Transient Execution Vulnerabilities in my hardware? +__Q:__ Why the `CONFIG_GCC_PLUGINS` option is automatically disabled during the kernel compilation? -__A:__ Checking the kernel config is not enough to answer this question. -I highly recommend using [spectre-meltdown-checker][13] tool maintained by Stéphane Lesimple [@speed47][14]. +__A:__ It means that your gcc doesn't support plugins. For example, if you have `gcc-7` on Ubuntu, +try to install `gcc-7-plugin-dev` package, it should help. [1]: http://kernsec.org/wiki/index.php/Kernel_Self_Protection_Project/Recommended_Settings @@ -380,7 +487,7 @@ I highly recommend using [spectre-meltdown-checker][13] tool maintained by Stép [3]: https://grsecurity.net/ [4]: https://github.com/a13xp0p0v/linux-kernel-defence-map [5]: https://lwn.net/Articles/791863/ -[6]: https://github.com/a13xp0p0v/kconfig-hardened-check/issues/38 +[6]: https://github.com/a13xp0p0v/kernel-hardening-checker/issues/38 [7]: https://github.com/BlackIkeEagle [8]: https://blog.herecura.eu/blog/2020-05-30-kconfig-hardening-tests/ [9]: https://googleprojectzero.blogspot.com/2018/09/a-cache-invalidation-bug-in-linux.html @@ -389,12 +496,13 @@ I highly recommend using [spectre-meltdown-checker][13] tool maintained by Stép [12]: https://github.com/tych0 [13]: https://github.com/speed47/spectre-meltdown-checker [14]: https://github.com/speed47 -[15]: https://github.com/a13xp0p0v/kconfig-hardened-check/issues/53 -[16]: https://github.com/a13xp0p0v/kconfig-hardened-check/pull/54 -[17]: https://github.com/a13xp0p0v/kconfig-hardened-check/pull/62 +[15]: https://github.com/a13xp0p0v/kernel-hardening-checker/issues/53 +[16]: https://github.com/a13xp0p0v/kernel-hardening-checker/pull/54 +[17]: https://github.com/a13xp0p0v/kernel-hardening-checker/pull/62 [18]: https://cateee.net/lkddb/web-lkddb/ [19]: https://github.com/cateee/lkddb [20]: https://kernel.org/ -[21]: https://github.com/a13xp0p0v/kconfig-hardened-check/issues/66 -[22]: https://github.com/a13xp0p0v/kconfig-hardened-check/issues/56 -[23]: https://github.com/a13xp0p0v/kconfig-hardened-check/issues?q=label%3Akernel_maintainer_feedback +[21]: https://github.com/a13xp0p0v/kernel-hardening-checker/issues/66 +[22]: https://github.com/a13xp0p0v/kernel-hardening-checker/issues/56 +[23]: https://github.com/a13xp0p0v/kernel-hardening-checker/issues?q=label%3Akernel_maintainer_feedback +[24]: https://github.com/a13xp0p0v/kernel-hardening-checker#motivation