import re
import json
from .__about__ import __version__
-from .checks import add_kconfig_checks, add_cmdline_checks, normalize_cmdline_options
+from .checks import add_kconfig_checks, add_cmdline_checks, normalize_cmdline_options, add_sysctl_checks
from .engine import populate_with_data, perform_checks, override_expected_value
def detect_arch(fname, archs):
with _open(fname, 'rt', encoding='utf-8') as f:
- arch_pattern = re.compile("CONFIG_[a-zA-Z0-9_]*=y")
+ arch_pattern = re.compile("CONFIG_[a-zA-Z0-9_]+=y$")
arch = None
for line in f.readlines():
if arch_pattern.match(line):
if arch is None:
arch = option
else:
- return None, 'more than one supported microarchitecture is detected'
+ return None, 'detected more than one microarchitecture'
if arch is None:
return None, 'failed to detect microarchitecture'
return arch, 'OK'
def detect_kernel_version(fname):
with _open(fname, 'rt', encoding='utf-8') as f:
- ver_pattern = re.compile("# Linux/.* Kernel Configuration")
+ ver_pattern = re.compile("# Linux/.+ Kernel Configuration$")
for line in f.readlines():
if ver_pattern.match(line):
line = line.strip()
gcc_version = None
clang_version = None
with _open(fname, 'rt', encoding='utf-8') as f:
- gcc_version_pattern = re.compile("CONFIG_GCC_VERSION=[0-9]*")
- clang_version_pattern = re.compile("CONFIG_CLANG_VERSION=[0-9]*")
for line in f.readlines():
- if gcc_version_pattern.match(line):
+ if line.startswith('CONFIG_GCC_VERSION='):
gcc_version = line[19:-1]
- if clang_version_pattern.match(line):
+ if line.startswith('CONFIG_CLANG_VERSION='):
clang_version = line[21:-1]
if gcc_version is None or clang_version is None:
return None, 'no CONFIG_GCC_VERSION or CONFIG_CLANG_VERSION'
print(f'[+] Config check is finished: \'OK\' - {ok_count}{ok_suppressed} / \'FAIL\' - {fail_count}{fail_suppressed}')
-def parse_kconfig_file(parsed_options, fname):
+def parse_kconfig_file(mode, parsed_options, fname):
with _open(fname, 'rt', encoding='utf-8') as f:
- opt_is_on = re.compile("CONFIG_[a-zA-Z0-9_]*=[a-zA-Z0-9_\"]*")
- opt_is_off = re.compile("# CONFIG_[a-zA-Z0-9_]* is not set")
+ opt_is_on = re.compile("CONFIG_[a-zA-Z0-9_]+=.+$")
+ opt_is_off = re.compile("# CONFIG_[a-zA-Z0-9_]+ is not set$")
for line in f.readlines():
line = line.strip()
sys.exit(f'[!] ERROR: bad enabled Kconfig option "{line}"')
elif opt_is_off.match(line):
option, value = line[2:].split(' ', 1)
- if value != 'is not set':
- sys.exit(f'[!] ERROR: bad disabled Kconfig option "{line}"')
+ assert(value == 'is not set'), \
+ f'unexpected value of disabled Kconfig option "{line}"'
+ elif line != '' and not line.startswith('#') and mode != 'json':
+ print(f'[!] WARNING: strange line in Kconfig file: "{line}"')
if option in parsed_options:
- sys.exit(f'[!] ERROR: Kconfig option "{line}" exists multiple times')
+ sys.exit(f'[!] ERROR: Kconfig option "{line}" is found multiple times')
if option:
parsed_options[option] = value
-def parse_cmdline_file(parsed_options, fname):
+def parse_cmdline_file(mode, parsed_options, fname):
with open(fname, 'r', encoding='utf-8') as f:
line = f.readline()
opts = line.split()
else:
name = opt
value = '' # '' is not None
+ if name in parsed_options and mode != 'json':
+ print(f'[!] WARNING: cmdline option "{name}" is found multiple times')
value = normalize_cmdline_options(name, value)
parsed_options[name] = value
+def parse_sysctl_file(mode, parsed_options, fname):
+ with open(fname, 'r', encoding='utf-8') as f:
+ sysctl_pattern = re.compile("[a-zA-Z0-9/\._-]+ =.*$")
+ for line in f.readlines():
+ line = line.strip()
+ if not sysctl_pattern.match(line):
+ sys.exit(f'[!] ERROR: unexpected line in sysctl file: {line}')
+ option, value = line.split('=', 1)
+ option = option.strip()
+ value = value.strip()
+ # sysctl options may be found multiple times, let's save the last value:
+ parsed_options[option] = value
+
+ # let's check the presence of some ancient sysctl option
+ # to ensure that we are parsing the output of `sudo sysctl -a > file`
+ if 'kernel.printk' not in parsed_options:
+ sys.exit(f'[!] ERROR: {fname} doesn\'t look like a sysctl output file, please try `sudo sysctl -a > {fname}`')
+
+ # let's check the presence of a sysctl option available for root
+ if 'net.core.bpf_jit_harden' not in parsed_options and mode != 'json':
+ print(f'[!] WARNING: sysctl option "net.core.bpf_jit_harden" available for root is not found in {fname}, please try `sudo sysctl -a > {fname}`')
+
+
def main():
# Report modes:
# * verbose mode for
parser.add_argument('-c', '--config',
help='check the security hardening options in the kernel Kconfig file (also supports *.gz files)')
parser.add_argument('-l', '--cmdline',
- help='check the security hardening options in the kernel cmdline file')
+ help='check the security hardening options in the kernel cmdline file (contents of /proc/cmdline)')
+ parser.add_argument('-s', '--sysctl',
+ help='check the security hardening options in the sysctl output file (`sudo sysctl -a > file`)')
parser.add_argument('-p', '--print', choices=supported_archs,
help='print the security hardening recommendations for the selected microarchitecture')
parser.add_argument('-g', '--generate', choices=supported_archs,
print(f'[+] Kconfig file to check: {args.config}')
if args.cmdline:
print(f'[+] Kernel cmdline file to check: {args.cmdline}')
+ if args.sysctl:
+ print(f'[+] Sysctl output file to check: {args.sysctl}')
arch, msg = detect_arch(args.config, supported_archs)
if arch is None:
# add relevant cmdline checks to the checklist
add_cmdline_checks(config_checklist, arch)
+ if args.sysctl:
+ # add relevant sysctl checks to the checklist
+ add_sysctl_checks(config_checklist, arch)
+
# populate the checklist with the parsed Kconfig data
parsed_kconfig_options = OrderedDict()
- parse_kconfig_file(parsed_kconfig_options, args.config)
+ parse_kconfig_file(mode, parsed_kconfig_options, args.config)
populate_with_data(config_checklist, parsed_kconfig_options, 'kconfig')
# populate the checklist with the kernel version data
if args.cmdline:
# populate the checklist with the parsed cmdline data
parsed_cmdline_options = OrderedDict()
- parse_cmdline_file(parsed_cmdline_options, args.cmdline)
+ parse_cmdline_file(mode, parsed_cmdline_options, args.cmdline)
populate_with_data(config_checklist, parsed_cmdline_options, 'cmdline')
+ if args.sysctl:
+ # populate the checklist with the parsed sysctl data
+ parsed_sysctl_options = OrderedDict()
+ parse_sysctl_file(mode, parsed_sysctl_options, args.sysctl)
+ populate_with_data(config_checklist, parsed_sysctl_options, 'sysctl')
+
# hackish refinement of the CONFIG_ARCH_MMAP_RND_BITS check
mmap_rnd_bits_max = parsed_kconfig_options.get('CONFIG_ARCH_MMAP_RND_BITS_MAX', None)
if mmap_rnd_bits_max:
all_parsed_options = parsed_kconfig_options # assignment does not copy
if args.cmdline:
all_parsed_options.update(parsed_cmdline_options)
+ if args.sysctl:
+ all_parsed_options.update(parsed_sysctl_options)
print_unknown_options(config_checklist, all_parsed_options)
# finally print the results
sys.exit(0)
elif args.cmdline:
- sys.exit('[!] ERROR: checking cmdline doesn\'t work without checking Kconfig')
+ sys.exit('[!] ERROR: checking cmdline depends on checking Kconfig')
+ elif args.sysctl:
+ # TODO: sysctl check should also work separately
+ sys.exit('[!] ERROR: checking sysctl depends on checking Kconfig')
if args.print:
- assert(args.config is None and args.cmdline is None), 'unexpected args'
+ assert(args.config is None and args.cmdline is None and args.sysctl is None), 'unexpected args'
+ if args.generate:
+ sys.exit('[!] ERROR: --print and --generate can\'t be used together')
if mode and mode not in ('verbose', 'json'):
sys.exit(f'[!] ERROR: wrong mode "{mode}" for --print')
arch = args.print
add_kconfig_checks(config_checklist, arch)
add_cmdline_checks(config_checklist, arch)
+ add_sysctl_checks(config_checklist, arch)
if mode != 'json':
print(f'[+] Printing kernel security hardening options for {arch}...')
print_checklist(mode, config_checklist, False)
sys.exit(0)
if args.generate:
- assert(args.config is None and args.cmdline is None), 'unexpected args'
+ assert(args.config is None and args.cmdline is None and args.sysctl is None and args.print is None), 'unexpected args'
if mode:
sys.exit(f'[!] ERROR: wrong mode "{mode}" for --generate')
arch = args.generate
add_kconfig_checks(config_checklist, arch)
+ print(f'CONFIG_{arch}=y') # the Kconfig fragment should describe the microarchitecture
for opt in config_checklist:
if opt.name == 'CONFIG_ARCH_MMAP_RND_BITS':
continue # don't add CONFIG_ARCH_MMAP_RND_BITS because its value needs refinement
projects / kconfig-hardened-check.git / blobdiff