1 # Kconfig hardened check
5 There are plenty of Linux kernel hardening config options. A lot of them are
6 not enabled by the major distros. We have to enable these options ourselves to
7 make our systems more secure.
9 But nobody likes checking configs manually. So let the computers do their job!
11 __kconfig-hardened-check.py__ helps me to check the Linux kernel Kconfig option list
12 against my hardening preferences for `x86_64`, which are based on the
13 [KSPP recommended settings][1] and last public [grsecurity][2] patch (options
16 Please don't cry if my Python code looks like C. I'm just a kernel developer.
18 __TODO:__ add hardening preferences for ARM.
20 ## Script output examples
24 #./kconfig-hardened-check.py
25 usage: kconfig-hardened-check.py [-h] [-p] [-c CONFIG] [--debug]
27 Checks the hardening options in the Linux kernel config
30 -h, --help show this help message and exit
31 -p, --print print hardening preferences
32 -c CONFIG, --config CONFIG
33 check the config_file against these preferences
34 --debug enable internal debug mode
37 ### Script output for `Ubuntu 18.04 (Bionic Beaver)` kernel config
39 #./kconfig-hardened-check.py -c config_files/ubuntu-bionic-generic.config
40 [+] Checking "config_files/ubuntu-bionic-generic.config" against hardening preferences...
41 option name | desired val | decision | reason || check result
42 ===================================================================================================================
43 CONFIG_BUG | y | ubuntu18 | self_protection || OK
44 CONFIG_PAGE_TABLE_ISOLATION | y | ubuntu18 | self_protection || OK
45 CONFIG_RETPOLINE | y | ubuntu18 | self_protection || OK
46 CONFIG_X86_64 | y | ubuntu18 | self_protection || OK
47 CONFIG_X86_SMAP | y | ubuntu18 | self_protection || OK
48 CONFIG_X86_INTEL_UMIP | y | ubuntu18 | self_protection || OK
49 CONFIG_STRICT_KERNEL_RWX | y | ubuntu18 | self_protection || OK
50 CONFIG_DEBUG_WX | y | ubuntu18 | self_protection || OK
51 CONFIG_RANDOMIZE_BASE | y | ubuntu18 | self_protection || OK
52 CONFIG_RANDOMIZE_MEMORY | y | ubuntu18 | self_protection || OK
53 CONFIG_STACKPROTECTOR_STRONG | y | ubuntu18 | self_protection ||CONFIG_CC_STACKPROTECTOR_STRONG: OK ("y")
54 CONFIG_VMAP_STACK | y | ubuntu18 | self_protection || OK
55 CONFIG_THREAD_INFO_IN_TASK | y | ubuntu18 | self_protection || OK
56 CONFIG_SCHED_STACK_END_CHECK | y | ubuntu18 | self_protection || OK
57 CONFIG_SLUB_DEBUG | y | ubuntu18 | self_protection || OK
58 CONFIG_SLAB_FREELIST_HARDENED | y | ubuntu18 | self_protection || OK
59 CONFIG_SLAB_FREELIST_RANDOM | y | ubuntu18 | self_protection || OK
60 CONFIG_HARDENED_USERCOPY | y | ubuntu18 | self_protection || OK
61 CONFIG_FORTIFY_SOURCE | y | ubuntu18 | self_protection || OK
62 CONFIG_LOCK_DOWN_KERNEL | y | ubuntu18 | self_protection || OK
63 CONFIG_STRICT_MODULE_RWX | y | ubuntu18 | self_protection || OK
64 CONFIG_MODULE_SIG | y | ubuntu18 | self_protection || OK
65 CONFIG_MODULE_SIG_ALL | y | ubuntu18 | self_protection || OK
66 CONFIG_MODULE_SIG_SHA512 | y | ubuntu18 | self_protection || OK
67 CONFIG_SYN_COOKIES | y | ubuntu18 | self_protection || OK
68 CONFIG_DEFAULT_MMAP_MIN_ADDR | 65536 | ubuntu18 | self_protection || OK
69 CONFIG_BUG_ON_DATA_CORRUPTION | y | kspp | self_protection || FAIL: "is not set"
70 CONFIG_PAGE_POISONING | y | kspp | self_protection || FAIL: "is not set"
71 CONFIG_GCC_PLUGINS | y | kspp | self_protection || FAIL: "is not set"
72 CONFIG_GCC_PLUGIN_RANDSTRUCT | y | kspp | self_protection || FAIL: not found
73 CONFIG_GCC_PLUGIN_STRUCTLEAK | y | kspp | self_protection || FAIL: not found
74 CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL | y | kspp | self_protection || FAIL: not found
75 CONFIG_GCC_PLUGIN_LATENT_ENTROPY | y | kspp | self_protection || FAIL: not found
76 CONFIG_REFCOUNT_FULL | y | kspp | self_protection || FAIL: "is not set"
77 CONFIG_DEBUG_LIST | y | kspp | self_protection || FAIL: "is not set"
78 CONFIG_DEBUG_SG | y | kspp | self_protection || FAIL: "is not set"
79 CONFIG_DEBUG_CREDENTIALS | y | kspp | self_protection || FAIL: "is not set"
80 CONFIG_DEBUG_NOTIFIERS | y | kspp | self_protection || FAIL: "is not set"
81 CONFIG_MODULE_SIG_FORCE | y | kspp | self_protection || FAIL: "is not set"
82 CONFIG_HARDENED_USERCOPY_FALLBACK | is not set | kspp | self_protection || OK: not found
83 CONFIG_GCC_PLUGIN_STACKLEAK | y | my | self_protection || FAIL: not found
84 CONFIG_SLUB_DEBUG_ON | y | my | self_protection || FAIL: "is not set"
85 CONFIG_SECURITY_DMESG_RESTRICT | y | my | self_protection || FAIL: "is not set"
86 CONFIG_STATIC_USERMODEHELPER | y | my | self_protection || FAIL: "is not set"
87 CONFIG_SECURITY_LOADPIN | y | my | self_protection || FAIL: "is not set"
88 CONFIG_PAGE_POISONING_NO_SANITY | is not set | my | self_protection || OK: not found
89 CONFIG_PAGE_POISONING_ZERO | is not set | my | self_protection || OK: not found
90 CONFIG_SLAB_MERGE_DEFAULT | is not set | my | self_protection || FAIL: "y"
91 CONFIG_SECURITY | y | ubuntu18 | security_policy || OK
92 CONFIG_SECURITY_YAMA | y | ubuntu18 | security_policy || OK
93 CONFIG_SECURITY_SELINUX_DISABLE | is not set | ubuntu18 | security_policy || OK
94 CONFIG_SECCOMP | y | ubuntu18 | cut_attack_surface || OK
95 CONFIG_SECCOMP_FILTER | y | ubuntu18 | cut_attack_surface || OK
96 CONFIG_STRICT_DEVMEM | y | ubuntu18 | cut_attack_surface || OK
97 CONFIG_ACPI_CUSTOM_METHOD | is not set | ubuntu18 | cut_attack_surface || OK
98 CONFIG_COMPAT_BRK | is not set | ubuntu18 | cut_attack_surface || OK
99 CONFIG_DEVKMEM | is not set | ubuntu18 | cut_attack_surface || OK
100 CONFIG_COMPAT_VDSO | is not set | ubuntu18 | cut_attack_surface || OK
101 CONFIG_X86_PTDUMP | is not set | ubuntu18 | cut_attack_surface || OK
102 CONFIG_ZSMALLOC_STAT | is not set | ubuntu18 | cut_attack_surface || OK
103 CONFIG_PAGE_OWNER | is not set | ubuntu18 | cut_attack_surface || OK
104 CONFIG_DEBUG_KMEMLEAK | is not set | ubuntu18 | cut_attack_surface || OK
105 CONFIG_BINFMT_AOUT | is not set | ubuntu18 | cut_attack_surface || OK: not found
106 CONFIG_MMIOTRACE_TEST | is not set | ubuntu18 | cut_attack_surface || OK
107 CONFIG_IO_STRICT_DEVMEM | y | kspp | cut_attack_surface || FAIL: "is not set"
108 CONFIG_LEGACY_VSYSCALL_NONE | y | kspp | cut_attack_surface || FAIL: "is not set"
109 CONFIG_BINFMT_MISC | is not set | kspp | cut_attack_surface || FAIL: "m"
110 CONFIG_INET_DIAG | is not set | kspp | cut_attack_surface || FAIL: "m"
111 CONFIG_KEXEC | is not set | kspp | cut_attack_surface || FAIL: "y"
112 CONFIG_PROC_KCORE | is not set | kspp | cut_attack_surface || FAIL: "y"
113 CONFIG_LEGACY_PTYS | is not set | kspp | cut_attack_surface || FAIL: "y"
114 CONFIG_IA32_EMULATION | is not set | kspp | cut_attack_surface || FAIL: "y"
115 CONFIG_X86_X32 | is not set | kspp | cut_attack_surface || FAIL: "y"
116 CONFIG_MODIFY_LDT_SYSCALL | is not set | kspp | cut_attack_surface || FAIL: "y"
117 CONFIG_HIBERNATION | is not set | kspp | cut_attack_surface || FAIL: "y"
118 CONFIG_KPROBES | is not set |grsecurity| cut_attack_surface || FAIL: "y"
119 CONFIG_UPROBES | is not set |grsecurity| cut_attack_surface || FAIL: "y"
120 CONFIG_GENERIC_TRACER | is not set |grsecurity| cut_attack_surface || FAIL: "y"
121 CONFIG_PROC_VMCORE | is not set |grsecurity| cut_attack_surface || FAIL: "y"
122 CONFIG_PROC_PAGE_MONITOR | is not set |grsecurity| cut_attack_surface || FAIL: "y"
123 CONFIG_USELIB | is not set |grsecurity| cut_attack_surface || FAIL: "y"
124 CONFIG_CHECKPOINT_RESTORE | is not set |grsecurity| cut_attack_surface || FAIL: "y"
125 CONFIG_USERFAULTFD | is not set |grsecurity| cut_attack_surface || FAIL: "y"
126 CONFIG_HWPOISON_INJECT | is not set |grsecurity| cut_attack_surface || FAIL: "m"
127 CONFIG_MEM_SOFT_DIRTY | is not set |grsecurity| cut_attack_surface || FAIL: "y"
128 CONFIG_DEVPORT | is not set |grsecurity| cut_attack_surface || FAIL: "y"
129 CONFIG_DEBUG_FS | is not set |grsecurity| cut_attack_surface || FAIL: "y"
130 CONFIG_NOTIFIER_ERROR_INJECTION | is not set |grsecurity| cut_attack_surface || FAIL: "m"
131 CONFIG_ACPI_TABLE_UPGRADE | is not set | lockdown | cut_attack_surface || FAIL: "y"
132 CONFIG_ACPI_APEI_EINJ | is not set | lockdown | cut_attack_surface || FAIL: "m"
133 CONFIG_PROFILING | is not set | lockdown | cut_attack_surface || FAIL: "y"
134 CONFIG_BPF_SYSCALL | is not set | lockdown | cut_attack_surface || FAIL: "y"
135 CONFIG_MMIOTRACE | is not set | my | cut_attack_surface || FAIL: "y"
136 CONFIG_KEXEC_FILE | is not set | my | cut_attack_surface || FAIL: "y"
137 CONFIG_LIVEPATCH | is not set | my | cut_attack_surface || FAIL: "y"
138 CONFIG_USER_NS | is not set | my | cut_attack_surface || FAIL: "y"
139 CONFIG_IP_DCCP | is not set | my | cut_attack_surface || FAIL: "m"
140 CONFIG_IP_SCTP | is not set | my | cut_attack_surface || FAIL: "m"
141 CONFIG_FTRACE | is not set | my | cut_attack_surface || FAIL: "y"
142 CONFIG_BPF_JIT | is not set | my | cut_attack_surface || FAIL: "y"
143 CONFIG_ARCH_MMAP_RND_BITS | 32 | my |userspace_protection|| FAIL: "28"
145 [-] config check is NOT PASSED: 56 errors
149 N.B. If `CONFIG_GCC_PLUGIN*` options are automatically disabled during your kernel compilation,
150 that means that your gcc doesn't support plugins. For example, if you have `gcc-7` on Ubuntu,
151 try to install `gcc-7-plugin-dev` package, it should help.
154 __Go and fix them all!__
156 [1]: http://kernsec.org/wiki/index.php/Kernel_Self_Protection_Project/Recommended_Settings
157 [2]: https://grsecurity.net/