#!/bin/sh set -e EXITCODE=0 # rancher/k3s modified from # https://github.com/moby/moby/blob/c831882/contrib/check-config.sh # bits of this were adapted from lxc-checkconfig for moby # see also https://github.com/lxc/lxc/blob/lxc-1.0.2/src/lxc/lxc-checkconfig.in uname=$(uname -r) possibleConfigs=" /proc/config.gz /boot/config-${uname} /boot/config-${uname##*-} /usr/src/linux-${uname}/.config /usr/src/linux/.config " binDir=$(dirname "$0") configFormat=gz isError=0 if [ $# -gt 0 ]; then CONFIG="$1" fi if ! command -v zgrep >/dev/null 2>&1; then zgrep() { zcat "$2" | grep "$1" } fi dogrep() { if [ "$configFormat" = "gz" ]; then zgrep "$1" "$2" else grep "$1" "$2" fi } kernelVersion="$(uname -r)" kernelMajor="${kernelVersion%%.*}" kernelMinor="${kernelVersion#$kernelMajor.}" kernelMinor="${kernelMinor%%.*}" is_set() { dogrep "CONFIG_$1=[y|m]" "$CONFIG" > /dev/null } is_set_in_kernel() { dogrep "CONFIG_$1=y" "$CONFIG" > /dev/null } is_set_as_module() { dogrep "CONFIG_$1=m" "$CONFIG" > /dev/null } color() { codes= if [ "$1" = 'bold' ]; then codes=1 shift fi if [ "$#" -gt 0 ]; then code= case "$1" in # see https://en.wikipedia.org/wiki/ANSI_escape_code#Colors black) code=30 ;; red) code=31 ;; green) code=32 ;; yellow) code=33 ;; blue) code=34 ;; magenta) code=35 ;; cyan) code=36 ;; white) code=37 ;; esac if [ "$code" ]; then [ "$codes" ] && codes="${codes};" codes="${codes}${code}" fi fi printf '\033['"$codes"'m' } wrap_color() { text="$1" shift color "$@" echo -n "$text" color reset echo } wrap_good() { echo "$(wrap_color "$1" white): $(wrap_color "$2" green)" } wrap_bad() { echo "$(wrap_color "$1" bold): $(wrap_color "$2 (fail)" bold red)" EXITCODE=$(($EXITCODE+1)) } wrap_warn() { echo "$(wrap_color "$1" bold): $(wrap_color "$2" bold yellow)" } warning() { wrap_color >&2 "$*" yellow } check_flag() { if is_set_in_kernel "$1"; then wrap_good "CONFIG_$1" 'enabled' elif is_set_as_module "$1"; then wrap_good "CONFIG_$1" 'enabled (as module)' else if [ $isError -eq 1 ]; then wrap_bad "CONFIG_$1" 'missing' else wrap_warn "CONFIG_$1" 'missing' fi fi } check_flags() { for flag in "$@"; do echo -n "- "; check_flag "$flag" done } check_command() { if command -v "$1" >/dev/null 2>&1; then wrap_good "$1 command" 'available' else wrap_bad "$1 command" 'missing' fi } check_device() { if [ -c "$1" ]; then wrap_good "$1" 'present' else wrap_bad "$1" 'missing' fi } check_distro_userns() { [ -s /etc/os-release ] || return 0 source /etc/os-release 2>/dev/null || true if ( echo "${ID}" | grep -q -E '^(centos|rhel)$' ) && \ ( echo "${VERSION_ID}" | grep -q -E '^7' ); then # this is a CentOS7 or RHEL7 system if ! grep -q "user_namespace.enable=1" /proc/cmdline; then # no user namespace support enabled wrap_bad " (RHEL7/CentOS7" "User namespaces disabled; add 'user_namespace.enable=1' to boot command line)" fi fi } # --- echo { cd $binDir echo "Verifying binaries in $binDir:" if [ -s .sha256sums ]; then sumsTemp=$(mktemp) if sha256sum -c .sha256sums >$sumsTemp 2>&1; then wrap_good '- sha256sum' 'good' else wrap_bad '- sha256sum' 'does not match' cat $sumsTemp | sed 's/^/ ... /' fi rm -f $sumsTemp else wrap_warn '- sha256sum' 'sha256sums unavailable' fi linkFail=0 if [ -s .links ]; then while read file link; do if [ "$(readlink $file)" != "$link" ]; then wrap_bad '- links' "$file should link to $link" linkFail=1 fi done <.links if [ $linkFail -eq 0 ]; then wrap_good '- links' 'good' fi else wrap_warn '- links' 'link list unavailable' fi cd - >/dev/null } echo { version_ge() { [ "$1" = "$2" ] || [ "$(printf '%s\n' "$@" | sort -V | head -n 1)" != "$1" ] } version_less() { [ "$(printf '%s\n' "$@" | sort -rV | head -n 1)" != "$1" ] } which_iptables() { ( localIPtables=$(command -v iptables) PATH=$(printf "%s" "$(echo -n $PATH | tr ":" "\n" | grep -v -E "^$binDir$")" | tr "\n" ":") systemIPtables=$(command -v iptables) if [ -n "$systemIPtables" ]; then echo $systemIPtables return fi echo $localIPtables ) } echo "System:" iptablesCmd=$(which_iptables) iptablesVersion= if [ "$iptablesCmd" ]; then iptablesInfo=$($iptablesCmd --version 2>/dev/null) || true iptablesVersion=$(echo $iptablesInfo | awk '{ print $2 }') label="$(dirname $iptablesCmd) $iptablesInfo" fi if echo "$iptablesVersion" | grep -v -q -E '^v[0-9]'; then [ "$iptablesCmd" ] || iptablesCmd="unknown iptables" wrap_warn "- $iptablesCmd" "unknown version: $iptablesInfo" elif version_ge $iptablesVersion v1.8.0; then iptablesMode=$(echo $iptablesInfo | awk '{ print $3 }') if [ "$iptablesMode" != "(legacy)" ] && version_less $iptablesVersion v1.8.4; then wrap_bad "- $label" 'should be older than v1.8.0, newer than v1.8.3, or in legacy mode' else wrap_good "- $label" 'ok' fi else wrap_good "- $label" 'older than v1.8' fi totalSwap=$(free | grep -i '^swap:' | awk '{ print $2 }') if [ "$totalSwap" != "0" ]; then wrap_warn '- swap' 'should be disabled' else wrap_good '- swap' 'disabled' fi if ip route | grep -v cni0 | grep -q -E '^10\.(42|43)\.'; then wrap_warn '- routes' 'default CIDRs 10.42.0.0/16 or 10.43.0.0/16 already routed' else wrap_good '- routes' 'ok' fi } echo { check_limit_over() { if [ "$(cat "$1")" -le "$2" ]; then wrap_bad "- $1" "$(cat "$1")" wrap_color " This should be set to at least $2, for example set: sysctl -w kernel/keys/root_maxkeys=1000000" bold black else wrap_good "- $1" "$(cat "$1")" fi } echo 'Limits:' check_limit_over /proc/sys/kernel/keys/root_maxkeys 10000 } echo # --- SUDO= [ $(id -u) -ne 0 ] && SUDO=sudo lsmod | grep -q configs || $SUDO modprobe configs || true if [ -z "$CONFIG" ]; then for tryConfig in ${possibleConfigs}; do if [ -e "$tryConfig" ]; then CONFIG="$tryConfig" break fi done fi if [ ! -e "$CONFIG" ]; then case "$CONFIG" in -*) warning "error: argument $CONFIG" ;; *) warning "error: cannot find kernel config $CONFIG" ;; esac warning " try running this script again, specifying the kernel config:" warning " set CONFIG=/path/to/kernel/.config or add argument /path/to/kernel/.config" exit 1 fi wrap_color "info: reading kernel config from $CONFIG ..." cyan zcat $CONFIG >/dev/null 2>&1 || configFormat= echo echo 'Generally Necessary:' cgroupV2FsType='63677270' cgroupFsType="$(stat --file-system --format=%t /sys/fs/cgroup 2>/dev/null || :)" cgroupHybridFsType="$(stat --file-system --format=%t /sys/fs/cgroup/unified 2>/dev/null || :)" echo -n '- ' case "${cgroupFsType}:${cgroupHybridFsType}" in '':*) cgroupVariant='Nonexistent' ;; ${cgroupV2FsType}:*) cgroupVariant='V2' ;; *:${cgroupV2FsType}) cgroupVariant='Hybrid' ;; *) cgroupVariant='V1' ;; esac case "${cgroupVariant}" in Nonexistent) wrap_bad 'cgroup hierarchy' "cgroups ${cgroupVariant}" ;; *) case "${cgroupVariant}" in V2) cgroupMatch='cpu|cpuset|memory' cgroupMatchNum=3 cgroupFile='/sys/fs/cgroup/cgroup.controllers' ;; *) cgroupMatch='cpuset|memory' cgroupMatchNum=2 cgroupFile='/proc/self/cgroup' ;; esac if [ "$(tr -s ' ' '\n' <"${cgroupFile}" 2>/dev/null | grep -Ec "(^|:)(${cgroupMatch})(\$|:)")" -eq ${cgroupMatchNum} ]; then cgroupStatus='good' else cgroupStatus='bad' fi wrap_${cgroupStatus} 'cgroup hierarchy' "cgroups ${cgroupVariant} mounted, ${cgroupMatch} controllers status: ${cgroupStatus}" if [ "x${cgroupStatus}" = 'xbad' ]; then warning ' (for cgroups V1/Hybrid on non-Systemd init see https://github.com/tianon/cgroupfs-mount)' fi ;; esac if [ "$(cat /sys/module/apparmor/parameters/enabled 2>/dev/null)" = 'Y' ]; then echo -n '- ' if command -v apparmor_parser &> /dev/null; then wrap_good 'apparmor' 'enabled and tools installed' else wrap_bad 'apparmor' 'enabled, but apparmor_parser missing' echo -n ' ' if command -v apt-get &> /dev/null; then wrap_color '(use "apt-get install apparmor" to fix this)' elif command -v yum &> /dev/null; then wrap_color '(your best bet is "yum install apparmor-parser")' elif command -v zypper &> /dev/null; then wrap_color '(your best bet is "zypper install apparmor-parser")' else wrap_color '(look for an "apparmor" package for your distribution)' fi fi fi flags=" NAMESPACES NET_NS PID_NS IPC_NS UTS_NS CGROUPS CGROUP_CPUACCT CGROUP_DEVICE CGROUP_FREEZER CGROUP_SCHED CPUSETS MEMCG KEYS VETH BRIDGE BRIDGE_NETFILTER IP_NF_FILTER IP_NF_TARGET_MASQUERADE NETFILTER_XT_MATCH_ADDRTYPE NETFILTER_XT_MATCH_CONNTRACK NETFILTER_XT_MATCH_IPVS IP_NF_NAT NF_NAT POSIX_MQUEUE " isError=1 check_flags $flags && isError=0 if [ "$kernelMajor" -lt 4 ] || ( [ "$kernelMajor" -eq 4 ] && [ "$kernelMinor" -lt 8 ] ); then check_flags DEVPTS_MULTIPLE_INSTANCES fi echo echo 'Optional Features:' { check_flags USER_NS check_distro_userns } { check_flags SECCOMP } { check_flags CGROUP_PIDS } # { # check_flags MEMCG_SWAP MEMCG_SWAP_ENABLED # if [ -e /sys/fs/cgroup/memory/memory.memsw.limit_in_bytes ]; then # echo " $(wrap_color '(cgroup swap accounting is currently enabled)' bold black)" # elif is_set MEMCG_SWAP && ! is_set MEMCG_SWAP_ENABLED; then # echo " $(wrap_color '(cgroup swap accounting is currently not enabled, you can enable it by setting boot option "swapaccount=1")' bold black)" # fi # } # { # if is_set LEGACY_VSYSCALL_NATIVE; then # echo -n "- "; wrap_bad "CONFIG_LEGACY_VSYSCALL_NATIVE" 'enabled' # echo " $(wrap_color '(dangerous, provides an ASLR-bypassing target with usable ROP gadgets.)' bold black)" # elif is_set LEGACY_VSYSCALL_EMULATE; then # echo -n "- "; wrap_good "CONFIG_LEGACY_VSYSCALL_EMULATE" 'enabled' # elif is_set LEGACY_VSYSCALL_NONE; then # echo -n "- "; wrap_bad "CONFIG_LEGACY_VSYSCALL_NONE" 'enabled' # echo " $(wrap_color '(containers using eglibc <= 2.13 will not work. Switch to' bold black)" # echo " $(wrap_color ' "CONFIG_VSYSCALL_[NATIVE|EMULATE]" or use "vsyscall=[native|emulate]"' bold black)" # echo " $(wrap_color ' on kernel command line. Note that this will disable ASLR for the,' bold black)" # echo " $(wrap_color ' VDSO which may assist in exploiting security vulnerabilities.)' bold black)" # # else Older kernels (prior to 3dc33bd30f3e, released in v4.40-rc1) do # # not have these LEGACY_VSYSCALL options and are effectively # # LEGACY_VSYSCALL_EMULATE. Even older kernels are presumably # # effectively LEGACY_VSYSCALL_NATIVE. # fi # } if [ "$kernelMajor" -lt 4 ] || ( [ "$kernelMajor" -eq 4 ] && [ "$kernelMinor" -le 5 ] ); then check_flags MEMCG_KMEM fi if [ "$kernelMajor" -lt 3 ] || ( [ "$kernelMajor" -eq 3 ] && [ "$kernelMinor" -le 18 ] ); then check_flags RESOURCE_COUNTERS fi if [ "$kernelMajor" -lt 3 ] || ( [ "$kernelMajor" -eq 3 ] && [ "$kernelMinor" -le 13 ] ); then netprio=NETPRIO_CGROUP else netprio=CGROUP_NET_PRIO fi # IOSCHED_CFQ CFQ_GROUP_IOSCHED flags=" BLK_CGROUP BLK_DEV_THROTTLING CGROUP_PERF CGROUP_HUGETLB NET_CLS_CGROUP $netprio CFS_BANDWIDTH FAIR_GROUP_SCHED RT_GROUP_SCHED IP_NF_TARGET_REDIRECT IP_SET IP_VS IP_VS_NFCT IP_VS_PROTO_TCP IP_VS_PROTO_UDP IP_VS_RR " check_flags $flags # if ! is_set EXT4_USE_FOR_EXT2; then # check_flags EXT3_FS EXT3_FS_XATTR EXT3_FS_POSIX_ACL EXT3_FS_SECURITY # if ! is_set EXT3_FS || ! is_set EXT3_FS_XATTR || ! is_set EXT3_FS_POSIX_ACL || ! is_set EXT3_FS_SECURITY; then # echo " $(wrap_color '(enable these ext3 configs if you are using ext3 as backing filesystem)' bold black)" # fi # fi check_flags EXT4_FS EXT4_FS_POSIX_ACL EXT4_FS_SECURITY if ! is_set EXT4_FS || ! is_set EXT4_FS_POSIX_ACL || ! is_set EXT4_FS_SECURITY; then if is_set EXT4_USE_FOR_EXT2; then echo " $(wrap_color 'enable these ext4 configs if you are using ext3 or ext4 as backing filesystem' bold black)" else echo " $(wrap_color 'enable these ext4 configs if you are using ext4 as backing filesystem' bold black)" fi fi echo '- Network Drivers:' echo " - \"$(wrap_color 'overlay' blue)\":" check_flags VXLAN | sed 's/^/ /' # BRIDGE_VLAN_FILTERING echo ' Optional (for encrypted networks):' check_flags CRYPTO CRYPTO_AEAD CRYPTO_GCM CRYPTO_SEQIV CRYPTO_GHASH \ XFRM XFRM_USER XFRM_ALGO INET_ESP INET_XFRM_MODE_TRANSPORT | sed 's/^/ /' # echo " - \"$(wrap_color 'ipvlan' blue)\":" # check_flags IPVLAN | sed 's/^/ /' # echo " - \"$(wrap_color 'macvlan' blue)\":" # check_flags MACVLAN DUMMY | sed 's/^/ /' # echo " - \"$(wrap_color 'ftp,tftp client in container' blue)\":" # check_flags NF_NAT_FTP NF_CONNTRACK_FTP NF_NAT_TFTP NF_CONNTRACK_TFTP | sed 's/^/ /' echo '- Storage Drivers:' echo " - \"$(wrap_color 'overlay' blue)\":" check_flags OVERLAY_FS | sed 's/^/ /' # --- echo if [ $EXITCODE -eq 0 ]; then wrap_good 'STATUS' 'pass' else wrap_bad 'STATUS' $EXITCODE fi exit $EXITCODE