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spectre-meltdown-checker/spectre-meltdown-checker.sh
Stéphane Lesimple 053f1613de fix(doc): use https:// URLs in the script comment header
2018-03-16 18:24:59 +01:00

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#! /bin/sh
# Spectre & Meltdown checker
#
# Check for the latest version at:
# https://github.com/speed47/spectre-meltdown-checker
# git clone https://github.com/speed47/spectre-meltdown-checker.git
# or wget https://meltdown.ovh -O spectre-meltdown-checker.sh
# or curl -L https://meltdown.ovh -o spectre-meltdown-checker.sh
#
# Stephane Lesimple
#
VERSION='0.35'
trap 'exit_cleanup' EXIT
trap '_warn "interrupted, cleaning up..."; exit_cleanup; exit 1' INT
exit_cleanup()
{
# cleanup the temp decompressed config & kernel image
[ -n "$dumped_config" ] && [ -f "$dumped_config" ] && rm -f "$dumped_config"
[ -n "$vmlinuxtmp" ] && [ -f "$vmlinuxtmp" ] && rm -f "$vmlinuxtmp"
[ "$mounted_debugfs" = 1 ] && umount /sys/kernel/debug 2>/dev/null
[ "$insmod_cpuid" = 1 ] && rmmod cpuid 2>/dev/null
[ "$insmod_msr" = 1 ] && rmmod msr 2>/dev/null
}
show_usage()
{
# shellcheck disable=SC2086
cat <<EOF
Usage:
Live mode: $(basename $0) [options] [--live]
Offline mode: $(basename $0) [options] [--kernel <vmlinux_file>] [--config <kernel_config>] [--map <kernel_map_file>]
Modes:
Two modes are available.
First mode is the "live" mode (default), it does its best to find information about the currently running kernel.
To run under this mode, just start the script without any option (you can also use --live explicitly)
Second mode is the "offline" mode, where you can inspect a non-running kernel.
You'll need to specify the location of the vmlinux file, config and System.map files:
--kernel vmlinux_file Specify a (possibly compressed) vmlinux file
--config kernel_config Specify a kernel config file
--map kernel_map_file Specify a kernel System.map file
Options:
--no-color Don't use color codes
--verbose, -v Increase verbosity level
--no-sysfs Don't use the /sys interface even if present
--sysfs-only Only use the /sys interface, don't run our own checks
--coreos Special mode for CoreOS (use an ephemeral toolbox to inspect kernel)
--batch text Produce machine readable output, this is the default if --batch is specified alone
--batch json Produce JSON output formatted for Puppet, Ansible, Chef...
--batch nrpe Produce machine readable output formatted for NRPE
--batch prometheus Produce output for consumption by prometheus-node-exporter
--variant [1,2,3] Specify which variant you'd like to check, by default all variants are checked
Can be specified multiple times (e.g. --variant 2 --variant 3)
Return codes:
0 (not vulnerable), 2 (vulnerable), 3 (unknown), 255 (error)
IMPORTANT:
A false sense of security is worse than no security at all.
Please use the --disclaimer option to understand exactly what this script does.
EOF
}
show_disclaimer()
{
cat <<EOF
Disclaimer:
This tool does its best to determine whether your system is immune (or has proper mitigations in place) for the
collectively named "speculative execution" vulnerabilities. It doesn't attempt to run any kind of exploit, and can't guarantee
that your system is secure, but rather helps you verifying whether your system has the known correct mitigations in place.
However, some mitigations could also exist in your kernel that this script doesn't know (yet) how to detect, or it might
falsely detect mitigations that in the end don't work as expected (for example, on backported or modified kernels).
Your system exposure also depends on your CPU. As of now, AMD and ARM processors are marked as immune to some or all of these
vulnerabilities (except some specific ARM models). All Intel processors manufactured since circa 1995 are thought to be vulnerable,
except some specific/old models, such as some early Atoms. Whatever processor one uses, one might seek more information
from the manufacturer of that processor and/or of the device in which it runs.
The nature of the discovered vulnerabilities being quite new, the landscape of vulnerable processors can be expected
to change over time, which is why this script makes the assumption that all CPUs are vulnerable, except if the manufacturer
explicitly stated otherwise in a verifiable public announcement.
Please also note that for Spectre vulnerabilities, all software can possibly be exploited, this tool only verifies that the
kernel (which is the core of the system) you're using has the proper protections in place. Verifying all the other software
is out of the scope of this tool. As a general measure, ensure you always have the most up to date stable versions of all
the softwares you use, especially for those who are exposed to the world, such as network daemons and browsers.
This tool has been released in the hope that it'll be useful, but don't use it to jump to conclusions about your security.
EOF
}
# parse options
opt_kernel=''
opt_config=''
opt_map=''
opt_live_explicit=0
opt_live=1
opt_no_color=0
opt_batch=0
opt_batch_format="text"
opt_verbose=1
opt_variant1=0
opt_variant2=0
opt_variant3=0
opt_allvariants=1
opt_no_sysfs=0
opt_sysfs_only=0
opt_coreos=0
global_critical=0
global_unknown=0
nrpe_vuln=""
# find a sane `echo` command
# we'll try to avoid using shell builtins that might not take options
if which echo >/dev/null 2>&1; then
echo_cmd=$(which echo)
else
[ -x /bin/echo ] && echo_cmd=/bin/echo
[ -x /system/bin/echo ] && echo_cmd=/system/bin/echo
fi
# still empty ? fallback to builtin
[ -z "$echo_cmd" ] && echo_cmd=echo
__echo()
{
opt="$1"
shift
_msg="$*"
if [ "$opt_no_color" = 1 ] ; then
# strip ANSI color codes
# some sed versions (i.e. toybox) can't seem to handle
# \033 aka \x1B correctly, so do it for them.
_ctrlchar=$($echo_cmd -e "\033")
_msg=$($echo_cmd -e "$_msg" | sed -r "s/$_ctrlchar\[([0-9][0-9]?(;[0-9][0-9]?)?)?m//g")
fi
# shellcheck disable=SC2086
$echo_cmd $opt -e "$_msg"
}
_echo()
{
if [ "$opt_verbose" -ge "$1" ]; then
shift
__echo '' "$*"
fi
}
_echo_nol()
{
if [ "$opt_verbose" -ge "$1" ]; then
shift
__echo -n "$*"
fi
}
_warn()
{
_echo 0 "\033[31m$*\033[0m" >&2
}
_info()
{
_echo 1 "$*"
}
_info_nol()
{
_echo_nol 1 "$*"
}
_verbose()
{
_echo 2 "$*"
}
_verbose_nol()
{
_echo_nol 2 "$*"
}
_debug()
{
_echo 3 "\033[34m(debug) $*\033[0m"
}
is_cpu_vulnerable_cached=0
_is_cpu_vulnerable_cached()
{
# shellcheck disable=SC2086
[ "$1" = 1 ] && return $variant1
# shellcheck disable=SC2086
[ "$1" = 2 ] && return $variant2
# shellcheck disable=SC2086
[ "$1" = 3 ] && return $variant3
echo "$0: error: invalid variant '$1' passed to is_cpu_vulnerable()" >&2
exit 255
}
is_cpu_vulnerable()
{
# param: 1, 2 or 3 (variant)
# returns 0 if vulnerable, 1 if not vulnerable
# (note that in shell, a return of 0 is success)
# by default, everything is vulnerable, we work in a "whitelist" logic here.
# usage: is_cpu_vulnerable 2 && do something if vulnerable
if [ "$is_cpu_vulnerable_cached" = 1 ]; then
_is_cpu_vulnerable_cached "$1"
return $?
fi
variant1=''
variant2=''
variant3=''
if is_cpu_specex_free; then
variant1=immune
variant2=immune
variant3=immune
elif [ "$cpu_vendor" = GenuineIntel ]; then
# Intel
# https://github.com/crozone/SpectrePoC/issues/1 ^F E5200 => spectre 2 not vulnerable
# https://github.com/paboldin/meltdown-exploit/issues/19 ^F E5200 => meltdown vulnerable
# model name : Pentium(R) Dual-Core CPU E5200 @ 2.50GHz
if grep -qE '^model name.+ Pentium\(R\) Dual-Core[[:space:]]+CPU[[:space:]]+E[0-9]{4}K? ' /proc/cpuinfo; then
variant1=vuln
[ -z "$variant2" ] && variant2=immune
variant3=vuln
fi
if [ "$capabilities_rdcl_no" = 1 ]; then
# capability bit for future Intel processor that will explicitly state
# that they're not vulnerable to Meltdown
# this var is set in check_cpu()
variant3=immune
_debug "is_cpu_vulnerable: RDCL_NO is set so not vuln to meltdown"
fi
elif [ "$cpu_vendor" = AuthenticAMD ]; then
# AMD revised their statement about variant2 => vulnerable
# https://www.amd.com/en/corporate/speculative-execution
variant1=vuln
variant2=vuln
[ -z "$variant3" ] && variant3=immune
elif [ "$cpu_vendor" = ARM ]; then
# ARM
# reference: https://developer.arm.com/support/security-update
# some devices (phones or other) have several ARMs and as such different part numbers,
# an example is "bigLITTLE". we shouldn't rely on the first CPU only, so we check the whole list
i=0
for cpupart in $cpu_part_list
do
i=$(( i + 1 ))
# do NOT quote $cpu_arch_list below
# shellcheck disable=SC2086
cpuarch=$(echo $cpu_arch_list | awk '{ print $'$i' }')
_debug "checking cpu$i: <$cpupart> <$cpuarch>"
# some kernels report AArch64 instead of 8
[ "$cpuarch" = "AArch64" ] && cpuarch=8
if [ -n "$cpupart" ] && [ -n "$cpuarch" ]; then
# Cortex-R7 and Cortex-R8 are real-time and only used in medical devices or such
# I can't find their CPU part number, but it's probably not that useful anyway
# model R7 R8 A9 A15 A17 A57 A72 A73 A75
# part ? ? 0xc09 0xc0f 0xc0e 0xd07 0xd08 0xd09 0xd0a
# arch 7? 7? 7 7 7 8 8 8 8
#
# variant 1 & variant 2
if [ "$cpuarch" = 7 ] && echo "$cpupart" | grep -Eq '^0x(c09|c0f|c0e)$'; then
# armv7 vulnerable chips
_debug "checking cpu$i: this armv7 vulnerable to spectre 1 & 2"
variant1=vuln
variant2=vuln
elif [ "$cpuarch" = 8 ] && echo "$cpupart" | grep -Eq '^0x(d07|d08|d09|d0a)$'; then
# armv8 vulnerable chips
_debug "checking cpu$i: this armv8 vulnerable to spectre 1 & 2"
variant1=vuln
variant2=vuln
else
_debug "checking cpu$i: this arm non vulnerable to 1 & 2"
# others are not vulnerable
[ -z "$variant1" ] && variant1=immune
[ -z "$variant2" ] && variant2=immune
fi
# for variant3, only A75 is vulnerable
if [ "$cpuarch" = 8 ] && [ "$cpupart" = 0xd0a ]; then
_debug "checking cpu$i: arm A75 vulnerable to meltdown"
variant3=vuln
else
_debug "checking cpu$i: this arm non vulnerable to meltdown"
[ -z "$variant3" ] && variant3=immune
fi
fi
_debug "is_cpu_vulnerable: for cpu$i and so far, we have <$variant1> <$variant2> <$variant3>"
done
fi
_debug "is_cpu_vulnerable: temp results are <$variant1> <$variant2> <$variant3>"
# if at least one of the cpu is vulnerable, then the system is vulnerable
[ "$variant1" = "immune" ] && variant1=1 || variant1=0
[ "$variant2" = "immune" ] && variant2=1 || variant2=0
[ "$variant3" = "immune" ] && variant3=1 || variant3=0
_debug "is_cpu_vulnerable: final results are <$variant1> <$variant2> <$variant3>"
is_cpu_vulnerable_cached=1
_is_cpu_vulnerable_cached "$1"
return $?
}
is_cpu_specex_free()
{
# return true (0) if the CPU doesn't do speculative execution, false (1) if it does.
# if it's not in the list we know, return false (1).
# source: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/x86/kernel/cpu/common.c#n882
# { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_CEDARVIEW, X86_FEATURE_ANY },
# { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_CLOVERVIEW, X86_FEATURE_ANY },
# { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_LINCROFT, X86_FEATURE_ANY },
# { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_PENWELL, X86_FEATURE_ANY },
# { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_PINEVIEW, X86_FEATURE_ANY },
# { X86_VENDOR_CENTAUR, 5 },
# { X86_VENDOR_INTEL, 5 },
# { X86_VENDOR_NSC, 5 },
# { X86_VENDOR_ANY, 4 },
parse_cpu_details
if [ "$cpu_vendor" = GenuineIntel ]; then
if [ "$cpu_family" = 6 ]; then
if [ "$cpu_model" = "$INTEL_FAM6_ATOM_CEDARVIEW" ] || \
[ "$cpu_model" = "$INTEL_FAM6_ATOM_CLOVERVIEW" ] || \
[ "$cpu_model" = "$INTEL_FAM6_ATOM_LINCROFT" ] || \
[ "$cpu_model" = "$INTEL_FAM6_ATOM_PENWELL" ] || \
[ "$cpu_model" = "$INTEL_FAM6_ATOM_PINEVIEW" ]; then
return 0
fi
elif [ "$cpu_family" = 5 ]; then
return 0
fi
fi
[ "$cpu_family" = 4 ] && return 0
return 1
}
show_header()
{
_info "Spectre and Meltdown mitigation detection tool v$VERSION"
_info
}
parse_opt_file()
{
# parse_opt_file option_name option_value
option_name="$1"
option_value="$2"
if [ -z "$option_value" ]; then
show_header
show_usage
echo "$0: error: --$option_name expects one parameter (a file)" >&2
exit 1
elif [ ! -e "$option_value" ]; then
show_header
echo "$0: error: couldn't find file $option_value" >&2
exit 1
elif [ ! -f "$option_value" ]; then
show_header
echo "$0: error: $option_value is not a file" >&2
exit 1
elif [ ! -r "$option_value" ]; then
show_header
echo "$0: error: couldn't read $option_value (are you root?)" >&2
exit 1
fi
echo "$option_value"
exit 0
}
while [ -n "$1" ]; do
if [ "$1" = "--kernel" ]; then
opt_kernel=$(parse_opt_file kernel "$2"); ret=$?
[ $ret -ne 0 ] && exit 255
shift 2
opt_live=0
elif [ "$1" = "--config" ]; then
opt_config=$(parse_opt_file config "$2"); ret=$?
[ $ret -ne 0 ] && exit 255
shift 2
opt_live=0
elif [ "$1" = "--map" ]; then
opt_map=$(parse_opt_file map "$2"); ret=$?
[ $ret -ne 0 ] && exit 255
shift 2
opt_live=0
elif [ "$1" = "--live" ]; then
opt_live_explicit=1
shift
elif [ "$1" = "--no-color" ]; then
opt_no_color=1
shift
elif [ "$1" = "--no-sysfs" ]; then
opt_no_sysfs=1
shift
elif [ "$1" = "--sysfs-only" ]; then
opt_sysfs_only=1
shift
elif [ "$1" = "--coreos" ]; then
opt_coreos=1
shift
elif [ "$1" = "--coreos-within-toolbox" ]; then
# don't use directly: used internally by --coreos
opt_coreos=0
shift
elif [ "$1" = "--batch" ]; then
opt_batch=1
opt_verbose=0
shift
case "$1" in
text|nrpe|json|prometheus) opt_batch_format="$1"; shift;;
--*) ;; # allow subsequent flags
'') ;; # allow nothing at all
*)
echo "$0: error: unknown batch format '$1'" >&2
echo "$0: error: --batch expects a format from: text, nrpe, json" >&2
exit 255
;;
esac
elif [ "$1" = "-v" ] || [ "$1" = "--verbose" ]; then
opt_verbose=$(( opt_verbose + 1 ))
shift
elif [ "$1" = "--variant" ]; then
if [ -z "$2" ]; then
echo "$0: error: option --variant expects a parameter (1, 2 or 3)" >&2
exit 255
fi
case "$2" in
1) opt_variant1=1; opt_allvariants=0;;
2) opt_variant2=1; opt_allvariants=0;;
3) opt_variant3=1; opt_allvariants=0;;
*)
echo "$0: error: invalid parameter '$2' for --variant, expected either 1, 2 or 3" >&2;
exit 255
;;
esac
shift 2
elif [ "$1" = "-h" ] || [ "$1" = "--help" ]; then
show_header
show_usage
exit 0
elif [ "$1" = "--version" ]; then
opt_no_color=1
show_header
exit 0
elif [ "$1" = "--disclaimer" ]; then
show_header
show_disclaimer
exit 0
else
show_header
show_usage
echo "$0: error: unknown option '$1'"
exit 255
fi
done
show_header
if [ "$opt_no_sysfs" = 1 ] && [ "$opt_sysfs_only" = 1 ]; then
_warn "Incompatible options specified (--no-sysfs and --sysfs-only), aborting"
exit 255
fi
# print status function
pstatus()
{
if [ "$opt_no_color" = 1 ]; then
_info_nol "$2"
else
case "$1" in
red) col="\033[41m\033[30m";;
green) col="\033[42m\033[30m";;
yellow) col="\033[43m\033[30m";;
blue) col="\033[44m\033[30m";;
*) col="";;
esac
_info_nol "$col $2 \033[0m"
fi
[ -n "$3" ] && _info_nol " ($3)"
_info
}
# Print the final status of a vulnerability (incl. batch mode)
# Arguments are: CVE UNK/OK/VULN description
pvulnstatus()
{
if [ "$opt_batch" = 1 ]; then
case "$1" in
CVE-2017-5753) aka="SPECTRE VARIANT 1";;
CVE-2017-5715) aka="SPECTRE VARIANT 2";;
CVE-2017-5754) aka="MELTDOWN";;
esac
case "$opt_batch_format" in
text) _echo 0 "$1: $2 ($3)";;
json)
case "$2" in
UNK) is_vuln="null";;
VULN) is_vuln="true";;
OK) is_vuln="false";;
esac
json_output="${json_output:-[}{\"NAME\":\"$aka\",\"CVE\":\"$1\",\"VULNERABLE\":$is_vuln,\"INFOS\":\"$3\"},"
;;
nrpe) [ "$2" = VULN ] && nrpe_vuln="$nrpe_vuln $1";;
prometheus)
prometheus_output="${prometheus_output:+$prometheus_output\n}specex_vuln_status{name=\"$aka\",cve=\"$1\",status=\"$2\",info=\"$3\"} 1"
;;
esac
fi
# always fill global_* vars because we use that do decide the program exit code
case "$2" in
UNK) global_unknown="1";;
VULN) global_critical="1";;
esac
# display info if we're not in quiet/batch mode
vulnstatus="$2"
shift 2
_info_nol "> \033[46m\033[30mSTATUS:\033[0m "
case "$vulnstatus" in
UNK) pstatus yellow 'UNKNOWN' "$@";;
VULN) pstatus red 'VULNERABLE' "$@";;
OK) pstatus green 'NOT VULNERABLE' "$@";;
esac
}
# The 3 below functions are taken from the extract-linux script, available here:
# https://github.com/torvalds/linux/blob/master/scripts/extract-vmlinux
# The functions have been modified for better integration to this script
# The original header of the file has been retained below
# ----------------------------------------------------------------------
# extract-vmlinux - Extract uncompressed vmlinux from a kernel image
#
# Inspired from extract-ikconfig
# (c) 2009,2010 Dick Streefland <dick@streefland.net>
#
# (c) 2011 Corentin Chary <corentin.chary@gmail.com>
#
# Licensed under the GNU General Public License, version 2 (GPLv2).
# ----------------------------------------------------------------------
vmlinux=''
vmlinux_err=''
check_vmlinux()
{
readelf -h "$1" >/dev/null 2>&1 && return 0
return 1
}
try_decompress()
{
# The obscure use of the "tr" filter is to work around older versions of
# "grep" that report the byte offset of the line instead of the pattern.
# Try to find the header ($1) and decompress from here
for pos in $(tr "$1\n$2" "\n$2=" < "$6" | grep -abo "^$2")
do
_debug "try_decompress: magic for $3 found at offset $pos"
if ! which "$3" >/dev/null 2>&1; then
vmlinux_err="missing '$3' tool, please install it, usually it's in the '$5' package"
return 0
fi
pos=${pos%%:*}
# shellcheck disable=SC2086
tail -c+$pos "$6" 2>/dev/null | $3 $4 > "$vmlinuxtmp" 2>/dev/null
if check_vmlinux "$vmlinuxtmp"; then
vmlinux="$vmlinuxtmp"
_debug "try_decompress: decompressed with $3 successfully!"
return 0
else
_debug "try_decompress: decompression with $3 did not work"
fi
done
return 1
}
extract_vmlinux()
{
[ -n "$1" ] || return 1
# Prepare temp files:
vmlinuxtmp="$(mktemp /tmp/vmlinux-XXXXXX)"
# Initial attempt for uncompressed images or objects:
if check_vmlinux "$1"; then
cat "$1" > "$vmlinuxtmp"
vmlinux=$vmlinuxtmp
return 0
fi
# That didn't work, so retry after decompression.
try_decompress '\037\213\010' xy gunzip '' gunzip "$1" && return 0
try_decompress '\3757zXZ\000' abcde unxz '' xz-utils "$1" && return 0
try_decompress 'BZh' xy bunzip2 '' bzip2 "$1" && return 0
try_decompress '\135\0\0\0' xxx unlzma '' xz-utils "$1" && return 0
try_decompress '\211\114\132' xy 'lzop' '-d' lzop "$1" && return 0
try_decompress '\002\041\114\030' xyy 'lz4' '-d -l' liblz4-tool "$1" && return 0
try_decompress '\177ELF' xxy 'cat' '' cat "$1" && return 0
return 1
}
# end of extract-vmlinux functions
mount_debugfs()
{
if [ ! -e /sys/kernel/debug/sched_features ]; then
# try to mount the debugfs hierarchy ourselves and remember it to umount afterwards
mount -t debugfs debugfs /sys/kernel/debug 2>/dev/null && mounted_debugfs=1
fi
}
load_msr()
{
modprobe msr 2>/dev/null && insmod_msr=1
_debug "attempted to load module msr, insmod_msr=$insmod_msr"
}
load_cpuid()
{
modprobe cpuid 2>/dev/null && insmod_cpuid=1
_debug "attempted to load module cpuid, insmod_cpuid=$insmod_cpuid"
}
read_cpuid()
{
_leaf="$1"
_bytenum="$2"
_and_operand="$3"
if [ ! -e /dev/cpu/0/cpuid ]; then
# try to load the module ourselves (and remember it so we can rmmod it afterwards)
load_cpuid
fi
if [ ! -e /dev/cpu/0/cpuid ]; then
return 2
fi
if [ "$opt_verbose" -ge 3 ]; then
dd if=/dev/cpu/0/cpuid bs=16 skip="$_leaf" iflag=skip_bytes count=1 >/dev/null 2>/dev/null
_debug "cpuid: reading leaf$_leaf of cpuid on cpu0, ret=$?"
_debug "cpuid: leaf$_leaf eax-ebx-ecx-edx: $( dd if=/dev/cpu/0/cpuid bs=16 skip="$_leaf" iflag=skip_bytes count=1 2>/dev/null | od -x -A n)"
_debug "cpuid: leaf$_leaf edx higher byte is: $(dd if=/dev/cpu/0/cpuid bs=16 skip="$_leaf" iflag=skip_bytes count=1 2>/dev/null | dd bs=1 skip="$_bytenum" count=1 2>/dev/null | od -x -A n)"
fi
# getting proper byte of edx on leaf$_leaf of cpuinfo in decimal
_reg_byte=$(dd if=/dev/cpu/0/cpuid bs=16 skip="$_leaf" iflag=skip_bytes count=1 2>/dev/null | dd bs=1 skip="$_bytenum" count=1 2>/dev/null | od -t u1 -A n | awk '{print $1}')
_debug "cpuid: leaf$_leaf byte $_bytenum: $_reg_byte (decimal)"
_reg_bit=$(( _reg_byte & _and_operand ))
_debug "cpuid: leaf$_leaf byte $_bytenum & $_and_operand = $_reg_bit"
[ "$_reg_bit" -eq 0 ] && return 1
# $_reg_bit is > 0, so the bit was found: return true (aka 0)
return 0
}
dmesg_grep()
{
# grep for something in dmesg, ensuring that the dmesg buffer
# has not been truncated
dmesg_grepped=''
if ! dmesg | grep -qE '(^|\] )Linux version [0-9]'; then
# dmesg truncated
return 2
fi
dmesg_grepped=$(dmesg | grep -E "$1" | head -1)
# not found:
[ -z "$dmesg_grepped" ] && return 1
# found, output is in $dmesg_grepped
return 0
}
is_coreos()
{
which coreos-install >/dev/null 2>&1 && which toolbox >/dev/null 2>&1 && return 0
return 1
}
parse_cpu_details()
{
[ "$parse_cpu_details_done" = 1 ] && return 0
cpu_vendor=$( grep '^vendor_id' /proc/cpuinfo | awk '{print $3}' | head -1)
cpu_friendly_name=$(grep '^model name' /proc/cpuinfo | cut -d: -f2- | head -1 | sed -e 's/^ *//')
# special case for ARM follows
if grep -qi 'CPU implementer[[:space:]]*:[[:space:]]*0x41' /proc/cpuinfo; then
cpu_vendor='ARM'
# some devices (phones or other) have several ARMs and as such different part numbers,
# an example is "bigLITTLE", so we need to store the whole list, this is needed for is_cpu_vulnerable
cpu_part_list=$(awk '/CPU part/ {print $4}' /proc/cpuinfo)
cpu_arch_list=$(awk '/CPU architecture/ {print $3}' /proc/cpuinfo)
# take the first one to fill the friendly name, do NOT quote the vars below
# shellcheck disable=SC2086
cpu_arch=$(echo $cpu_arch_list | awk '{ print $1 }')
# shellcheck disable=SC2086
cpu_part=$(echo $cpu_part_list | awk '{ print $1 }')
[ "$cpu_arch" = "AArch64" ] && cpu_arch=8
cpu_friendly_name="ARM"
[ -n "$cpu_arch" ] && cpu_friendly_name="$cpu_friendly_name v$cpu_arch"
[ -n "$cpu_part" ] && cpu_friendly_name="$cpu_friendly_name model $cpu_part"
fi
cpu_family=$( grep '^cpu family' /proc/cpuinfo | awk '{print $4}' | grep -E '^[0-9]+$' | head -1)
cpu_model=$( grep '^model' /proc/cpuinfo | awk '{print $3}' | grep -E '^[0-9]+$' | head -1)
cpu_stepping=$(grep '^stepping' /proc/cpuinfo | awk '{print $3}' | grep -E '^[0-9]+$' | head -1)
cpu_ucode=$( grep '^microcode' /proc/cpuinfo | awk '{print $3}' | head -1)
# also define those that we will need in other funcs
# taken from ttps://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/x86/include/asm/intel-family.h
# shellcheck disable=SC2034
{
INTEL_FAM6_CORE_YONAH=$(( 0x0E ))
INTEL_FAM6_CORE2_MEROM=$(( 0x0F ))
INTEL_FAM6_CORE2_MEROM_L=$(( 0x16 ))
INTEL_FAM6_CORE2_PENRYN=$(( 0x17 ))
INTEL_FAM6_CORE2_DUNNINGTON=$(( 0x1D ))
INTEL_FAM6_NEHALEM=$(( 0x1E ))
INTEL_FAM6_NEHALEM_G=$(( 0x1F ))
INTEL_FAM6_NEHALEM_EP=$(( 0x1A ))
INTEL_FAM6_NEHALEM_EX=$(( 0x2E ))
INTEL_FAM6_WESTMERE=$(( 0x25 ))
INTEL_FAM6_WESTMERE_EP=$(( 0x2C ))
INTEL_FAM6_WESTMERE_EX=$(( 0x2F ))
INTEL_FAM6_SANDYBRIDGE=$(( 0x2A ))
INTEL_FAM6_SANDYBRIDGE_X=$(( 0x2D ))
INTEL_FAM6_IVYBRIDGE=$(( 0x3A ))
INTEL_FAM6_IVYBRIDGE_X=$(( 0x3E ))
INTEL_FAM6_HASWELL_CORE=$(( 0x3C ))
INTEL_FAM6_HASWELL_X=$(( 0x3F ))
INTEL_FAM6_HASWELL_ULT=$(( 0x45 ))
INTEL_FAM6_HASWELL_GT3E=$(( 0x46 ))
INTEL_FAM6_BROADWELL_CORE=$(( 0x3D ))
INTEL_FAM6_BROADWELL_GT3E=$(( 0x47 ))
INTEL_FAM6_BROADWELL_X=$(( 0x4F ))
INTEL_FAM6_BROADWELL_XEON_D=$(( 0x56 ))
INTEL_FAM6_SKYLAKE_MOBILE=$(( 0x4E ))
INTEL_FAM6_SKYLAKE_DESKTOP=$(( 0x5E ))
INTEL_FAM6_SKYLAKE_X=$(( 0x55 ))
INTEL_FAM6_KABYLAKE_MOBILE=$(( 0x8E ))
INTEL_FAM6_KABYLAKE_DESKTOP=$(( 0x9E ))
# /* "Small Core" Processors (Atom) */
INTEL_FAM6_ATOM_PINEVIEW=$(( 0x1C ))
INTEL_FAM6_ATOM_LINCROFT=$(( 0x26 ))
INTEL_FAM6_ATOM_PENWELL=$(( 0x27 ))
INTEL_FAM6_ATOM_CLOVERVIEW=$(( 0x35 ))
INTEL_FAM6_ATOM_CEDARVIEW=$(( 0x36 ))
INTEL_FAM6_ATOM_SILVERMONT1=$(( 0x37 ))
INTEL_FAM6_ATOM_SILVERMONT2=$(( 0x4D ))
INTEL_FAM6_ATOM_AIRMONT=$(( 0x4C ))
INTEL_FAM6_ATOM_MERRIFIELD=$(( 0x4A ))
INTEL_FAM6_ATOM_MOOREFIELD=$(( 0x5A ))
INTEL_FAM6_ATOM_GOLDMONT=$(( 0x5C ))
INTEL_FAM6_ATOM_DENVERTON=$(( 0x5F ))
INTEL_FAM6_ATOM_GEMINI_LAKE=$(( 0x7A ))
# /* Xeon Phi */
INTEL_FAM6_XEON_PHI_KNL=$(( 0x57 ))
INTEL_FAM6_XEON_PHI_KNM=$(( 0x85 ))
}
parse_cpu_details_done=1
}
is_ucode_blacklisted()
{
parse_cpu_details
# if it's not an Intel, don't bother: it's not blacklisted
[ "$cpu_vendor" = GenuineIntel ] || return 1
# it also needs to be family=6
[ "$cpu_family" = 6 ] || return 1
# now, check each known bad microcode
# source: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/x86/kernel/cpu/intel.c#n105
# 2018-02-08 update: https://newsroom.intel.com/wp-content/uploads/sites/11/2018/02/microcode-update-guidance.pdf
# model,stepping,microcode
ucode_found="model $cpu_model stepping $cpu_stepping ucode $cpu_ucode"
for tuple in \
$INTEL_FAM6_KABYLAKE_DESKTOP,0x0B,0x80 \
$INTEL_FAM6_KABYLAKE_DESKTOP,0x0A,0x80 \
$INTEL_FAM6_KABYLAKE_DESKTOP,0x09,0x80 \
$INTEL_FAM6_KABYLAKE_MOBILE,0x0A,0x80 \
$INTEL_FAM6_KABYLAKE_MOBILE,0x09,0x80 \
$INTEL_FAM6_SKYLAKE_X,0x03,0x0100013e \
$INTEL_FAM6_SKYLAKE_X,0x04,0x02000036 \
$INTEL_FAM6_SKYLAKE_X,0x04,0x0200003a \
$INTEL_FAM6_SKYLAKE_X,0x04,0x0200003c \
$INTEL_FAM6_BROADWELL_CORE,0x04,0x28 \
$INTEL_FAM6_BROADWELL_GT3E,0x01,0x1b \
$INTEL_FAM6_BROADWELL_XEON_D,0x02,0x14 \
$INTEL_FAM6_BROADWELL_XEON_D,0x03,0x07000011 \
$INTEL_FAM6_BROADWELL_X,0x01,0x0b000023 \
$INTEL_FAM6_BROADWELL_X,0x01,0x0b000025 \
$INTEL_FAM6_HASWELL_ULT,0x01,0x21 \
$INTEL_FAM6_HASWELL_GT3E,0x01,0x18 \
$INTEL_FAM6_HASWELL_CORE,0x03,0x23 \
$INTEL_FAM6_HASWELL_X,0x02,0x3b \
$INTEL_FAM6_HASWELL_X,0x04,0x10 \
$INTEL_FAM6_IVYBRIDGE_X,0x04,0x42a \
$INTEL_FAM6_SANDYBRIDGE_X,0x06,0x61b \
$INTEL_FAM6_SANDYBRIDGE_X,0x07,0x712
do
model=$(echo $tuple | cut -d, -f1)
stepping=$(( $(echo $tuple | cut -d, -f2) ))
ucode=$(echo $tuple | cut -d, -f3)
if [ "$cpu_model" = "$model" ] && [ "$cpu_stepping" = "$stepping" ] && echo "$cpu_ucode" | grep -qi "^$ucode$"; then
_debug "is_ucode_blacklisted: we have a match! ($cpu_model/$cpu_stepping/$cpu_ucode)"
return 0
fi
done
_debug "is_ucode_blacklisted: no ($cpu_model/$cpu_stepping/$cpu_ucode)"
return 1
}
is_skylake_cpu()
{
# is this a skylake cpu?
# return 0 if yes, 1 otherwise
#if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
# boot_cpu_data.x86 == 6) {
# switch (boot_cpu_data.x86_model) {
# case INTEL_FAM6_SKYLAKE_MOBILE:
# case INTEL_FAM6_SKYLAKE_DESKTOP:
# case INTEL_FAM6_SKYLAKE_X:
# case INTEL_FAM6_KABYLAKE_MOBILE:
# case INTEL_FAM6_KABYLAKE_DESKTOP:
# return true;
parse_cpu_details
[ "$cpu_vendor" = GenuineIntel ] || return 1
[ "$cpu_family" = 6 ] || return 1
if [ "$cpu_model" = $INTEL_FAM6_SKYLAKE_MOBILE ] || \
[ "$cpu_model" = $INTEL_FAM6_SKYLAKE_DESKTOP ] || \
[ "$cpu_model" = $INTEL_FAM6_SKYLAKE_X ] || \
[ "$cpu_model" = $INTEL_FAM6_KABYLAKE_MOBILE ] || \
[ "$cpu_model" = $INTEL_FAM6_KABYLAKE_DESKTOP ]; then
return 0
fi
return 1
}
# check for mode selection inconsistency
if [ "$opt_live_explicit" = 1 ]; then
if [ -n "$opt_kernel" ] || [ -n "$opt_config" ] || [ -n "$opt_map" ]; then
show_usage
echo "$0: error: incompatible modes specified, use either --live or --kernel/--config/--map" >&2
exit 255
fi
fi
# coreos mode
if [ "$opt_coreos" = 1 ]; then
if ! is_coreos; then
_warn "CoreOS mode asked, but we're not under CoreOS!"
exit 255
fi
_warn "CoreOS mode, starting an ephemeral toolbox to launch the script"
load_msr
load_cpuid
mount_debugfs
toolbox --ephemeral --bind-ro /dev/cpu:/dev/cpu -- sh -c "dnf install -y binutils which && /media/root$PWD/$0 $* --coreos-within-toolbox"
exitcode=$?
exit $exitcode
else
if is_coreos; then
_warn "You seem to be running CoreOS, you might want to use the --coreos option for better results"
_warn
fi
fi
parse_cpu_details
if [ "$opt_live" = 1 ]; then
# root check (only for live mode, for offline mode, we already checked if we could read the files)
if [ "$(id -u)" -ne 0 ]; then
_warn "Note that you should launch this script with root privileges to get accurate information."
_warn "We'll proceed but you might see permission denied errors."
_warn "To run it as root, you can try the following command: sudo $0"
_warn
fi
_info "Checking for vulnerabilities on current system"
_info "Kernel is \033[35m$(uname -s) $(uname -r) $(uname -v) $(uname -m)\033[0m"
_info "CPU is \033[35m$cpu_friendly_name\033[0m"
# try to find the image of the current running kernel
# first, look for the BOOT_IMAGE hint in the kernel cmdline
if [ -r /proc/cmdline ] && grep -q 'BOOT_IMAGE=' /proc/cmdline; then
opt_kernel=$(grep -Eo 'BOOT_IMAGE=[^ ]+' /proc/cmdline | cut -d= -f2)
_debug "found opt_kernel=$opt_kernel in /proc/cmdline"
# if we have a dedicated /boot partition, our bootloader might have just called it /
# so try to prepend /boot and see if we find anything
[ -e "/boot/$opt_kernel" ] && opt_kernel="/boot/$opt_kernel"
# special case for CoreOS if we're inside the toolbox
[ -e "/media/root/boot/$opt_kernel" ] && opt_kernel="/media/root/boot/$opt_kernel"
_debug "opt_kernel is now $opt_kernel"
# else, the full path is already there (most probably /boot/something)
fi
# if we didn't find a kernel, default to guessing
if [ ! -e "$opt_kernel" ]; then
# Fedora:
[ -e "/lib/modules/$(uname -r)/vmlinuz" ] && opt_kernel="/lib/modules/$(uname -r)/vmlinuz"
# Slackare:
[ -e "/boot/vmlinuz" ] && opt_kernel="/boot/vmlinuz"
# Arch:
[ -e "/boot/vmlinuz-linux" ] && opt_kernel="/boot/vmlinuz-linux"
# Linux-Libre:
[ -e "/boot/vmlinuz-linux-libre" ] && opt_kernel="/boot/vmlinuz-linux-libre"
# pine64
[ -e "/boot/pine64/Image" ] && opt_kernel="/boot/pine64/Image"
# generic:
[ -e "/boot/vmlinuz-$(uname -r)" ] && opt_kernel="/boot/vmlinuz-$(uname -r)"
[ -e "/boot/kernel-$( uname -r)" ] && opt_kernel="/boot/kernel-$( uname -r)"
[ -e "/boot/bzImage-$(uname -r)" ] && opt_kernel="/boot/bzImage-$(uname -r)"
# Gentoo:
[ -e "/boot/kernel-genkernel-$(uname -m)-$(uname -r)" ] && opt_kernel="/boot/kernel-genkernel-$(uname -m)-$(uname -r)"
# NixOS:
[ -e "/run/booted-system/kernel" ] && opt_kernel="/run/booted-system/kernel"
# systemd kernel-install:
[ -e "/etc/machine-id" ] && [ -e "/boot/$(cat /etc/machine-id)/$(uname -r)/linux" ] && opt_kernel="/boot/$(cat /etc/machine-id)/$(uname -r)/linux"
fi
# system.map
if [ -e /proc/kallsyms ] ; then
opt_map=/proc/kallsyms
elif [ -e "/lib/modules/$(uname -r)/System.map" ] ; then
opt_map="/lib/modules/$(uname -r)/System.map"
elif [ -e "/boot/System.map-$(uname -r)" ] ; then
opt_map="/boot/System.map-$(uname -r)"
fi
# config
if [ -e /proc/config.gz ] ; then
dumped_config="$(mktemp /tmp/config-XXXXXX)"
gunzip -c /proc/config.gz > "$dumped_config"
# dumped_config will be deleted at the end of the script
opt_config="$dumped_config"
elif [ -e "/lib/modules/$(uname -r)/config" ]; then
opt_config="/lib/modules/$(uname -r)/config"
elif [ -e "/boot/config-$(uname -r)" ]; then
opt_config="/boot/config-$(uname -r)"
fi
else
_info "Checking for vulnerabilities against specified kernel"
_info "CPU is \033[35m$cpu_friendly_name\033[0m"
fi
if [ -n "$opt_kernel" ]; then
_verbose "Will use vmlinux image \033[35m$opt_kernel\033[0m"
else
_verbose "Will use no vmlinux image (accuracy might be reduced)"
bad_accuracy=1
fi
if [ -n "$opt_config" ] && ! grep -q '^CONFIG_' "$opt_config"; then
# given file is invalid!
_warn "The kernel config file seems invalid, was expecting a plain-text file, ignoring it!"
opt_config=''
fi
if [ -n "$dumped_config" ] && [ -n "$opt_config" ]; then
_verbose "Will use kconfig \033[35m/proc/config.gz (decompressed)\033[0m"
elif [ -n "$opt_config" ]; then
_verbose "Will use kconfig \033[35m$opt_config\033[0m"
else
_verbose "Will use no kconfig (accuracy might be reduced)"
bad_accuracy=1
fi
if [ -n "$opt_map" ]; then
_verbose "Will use System.map file \033[35m$opt_map\033[0m"
else
_verbose "Will use no System.map file (accuracy might be reduced)"
bad_accuracy=1
fi
if [ "$bad_accuracy" = 1 ]; then
_info "We're missing some kernel info (see -v), accuracy might be reduced"
fi
if [ -e "$opt_kernel" ]; then
if ! which readelf >/dev/null 2>&1; then
_debug "readelf not found"
vmlinux_err="missing 'readelf' tool, please install it, usually it's in the 'binutils' package"
elif [ "$opt_sysfs_only" = 1 ]; then
vmlinux_err='kernel image decompression skipped'
else
extract_vmlinux "$opt_kernel"
fi
else
_debug "no opt_kernel defined"
vmlinux_err="couldn't find your kernel image in /boot, if you used netboot, this is normal"
fi
if [ -z "$vmlinux" ] || [ ! -r "$vmlinux" ]; then
[ -z "$vmlinux_err" ] && vmlinux_err="couldn't extract your kernel from $opt_kernel"
else
vmlinux_version=$(strings "$vmlinux" 2>/dev/null | grep '^Linux version ' | head -1)
if [ -z "$vmlinux_version" ]; then
# try harder with some kernels (such as Red Hat) that don't have ^Linux version before their version string
vmlinux_version=$(strings "$vmlinux" 2>/dev/null | grep -E '^[[:alnum:]][^[:space:]]+ \([^[:space:]]+\) #[0-9]+ .+ (19|20)[0-9][0-9]$' | head -1)
fi
if [ -n "$vmlinux_version" ]; then
# in live mode, check if the img we found is the correct one
if [ "$opt_live" = 1 ]; then
_verbose "Kernel image is \033[35m$vmlinux_version"
if ! echo "$vmlinux_version" | grep -qF "$(uname -r)" || \
! echo "$vmlinux_version" | grep -qF "$(uname -v)"; then
_warn "Possible disrepancy between your running kernel and the image we found ($opt_kernel), results might be incorrect"
fi
else
_info "Kernel image is \033[35m$vmlinux_version"
fi
else
_verbose "Kernel image version is unknown"
fi
fi
_info
# end of header stuff
# now we define some util functions and the check_*() funcs, as
# the user can choose to execute only some of those
sys_interface_check()
{
[ "$opt_live" = 1 ] && [ "$opt_no_sysfs" = 0 ] && [ -r "$1" ] || return 1
_info_nol "* Mitigated according to the /sys interface: "
if grep -qi '^not affected' "$1"; then
# Not affected
status=OK
pstatus green YES "kernel confirms that your CPU is unaffected"
elif grep -qi '^mitigation' "$1"; then
# Mitigation: PTI
status=OK
pstatus green YES "kernel confirms that the mitigation is active"
elif grep -qi '^vulnerable' "$1"; then
# Vulnerable
status=VULN
pstatus red NO "kernel confirms your system is vulnerable"
else
status=UNK
pstatus yellow UNKNOWN "unknown value reported by kernel"
fi
msg=$(cat "$1")
_debug "sys_interface_check: $1=$msg"
return 0
}
check_cpu()
{
_info "\033[1;34mHardware check\033[0m"
_info "* Hardware support (CPU microcode) for mitigation techniques"
_info " * Indirect Branch Restricted Speculation (IBRS)"
_info_nol " * SPEC_CTRL MSR is available: "
if [ ! -e /dev/cpu/0/msr ]; then
# try to load the module ourselves (and remember it so we can rmmod it afterwards)
load_msr
fi
if [ ! -e /dev/cpu/0/msr ]; then
spec_ctrl_msr=-1
pstatus yellow UNKNOWN "couldn't read /dev/cpu/0/msr, is msr support enabled in your kernel?"
else
# the new MSR 'SPEC_CTRL' is at offset 0x48
# here we use dd, it's the same as using 'rdmsr 0x48' but without needing the rdmsr tool
# if we get a read error, the MSR is not there. bs has to be 8 for msr
# skip=9 because 8*9=72=0x48
dd if=/dev/cpu/0/msr of=/dev/null bs=8 count=1 skip=9 2>/dev/null; ret=$?
if [ $ret -eq 0 ]; then
spec_ctrl_msr=1
pstatus green YES
else
spec_ctrl_msr=0
pstatus red NO
fi
fi
_info_nol " * CPU indicates IBRS capability: "
# from kernel src: { X86_FEATURE_SPEC_CTRL, CPUID_EDX,26, 0x00000007, 0 },
read_cpuid 7 15 4; ret=$?
if [ $ret -eq 0 ]; then
pstatus green YES "SPEC_CTRL feature bit"
cpuid_spec_ctrl=1
elif [ $ret -eq 2 ]; then
pstatus yellow UNKNOWN "couldn't read /dev/cpu/0/cpuid, is cpuid support enabled in your kernel?"
else
pstatus red NO
fi
# hardware support according to kernel
if [ "$opt_verbose" -ge 2 ]; then
# the spec_ctrl flag in cpuinfo is set if and only if the kernel sees
# that the spec_ctrl cpuinfo bit set. we already check that ourselves above
# but let's check it anyway (in verbose mode only)
_verbose_nol " * Kernel has set the spec_ctrl flag in cpuinfo: "
if [ "$opt_live" = 1 ]; then
if grep ^flags /proc/cpuinfo | grep -qw spec_ctrl; then
pstatus green YES
else
pstatus blue NO
fi
else
pstatus blue N/A "not testable in offline mode"
fi
fi
# IBPB
_info " * Indirect Branch Prediction Barrier (IBPB)"
_info_nol " * PRED_CMD MSR is available: "
if [ ! -e /dev/cpu/0/msr ]; then
pstatus yellow UNKNOWN "couldn't read /dev/cpu/0/msr, is msr support enabled in your kernel?"
else
# the new MSR 'PRED_CTRL' is at offset 0x49, write-only
# here we use dd, it's the same as using 'wrmsr 0x49 0' but without needing the wrmsr tool
# if we get a write error, the MSR is not there
$echo_cmd -ne "\0\0\0\0\0\0\0\0" | dd of=/dev/cpu/0/msr bs=8 count=1 seek=73 oflag=seek_bytes 2>/dev/null; ret=$?
if [ $ret -eq 0 ]; then
pstatus green YES
else
pstatus red NO
fi
fi
_info_nol " * CPU indicates IBPB capability: "
# CPUID EAX=0x80000008, ECX=0x00 return EBX[12] indicates support for just IBPB.
read_cpuid 2147483656 5 16; ret=$?
if [ $ret -eq 0 ]; then
pstatus green YES "IBPB_SUPPORT feature bit"
elif [ "$cpuid_spec_ctrl" = 1 ]; then
pstatus green YES "SPEC_CTRL feature bit"
elif [ $ret -eq 2 ]; then
pstatus yellow UNKNOWN "couldn't read /dev/cpu/0/cpuid, is cpuid support enabled in your kernel?"
else
pstatus red NO
fi
# STIBP
_info " * Single Thread Indirect Branch Predictors (STIBP)"
_info_nol " * SPEC_CTRL MSR is available: "
if [ "$spec_ctrl_msr" = 1 ]; then
pstatus green YES
elif [ "$spec_ctrl_msr" = 0 ]; then
pstatus red NO
else
pstatus yellow UNKNOWN "couldn't read /dev/cpu/0/msr, is msr support enabled in your kernel?"
fi
_info_nol " * CPU indicates STIBP capability: "
# A processor supports STIBP if it enumerates CPUID (EAX=7H,ECX=0):EDX[27] as 1
read_cpuid 7 15 8; ret=$?
if [ $ret -eq 0 ]; then
pstatus green YES
elif [ $ret -eq 2 ]; then
pstatus yellow UNKNOWN "couldn't read /dev/cpu/0/cpuid, is cpuid support enabled in your kernel?"
else
pstatus red NO
fi
_info " * Enhanced IBRS (IBRS_ALL)"
_info_nol " * CPU indicates ARCH_CAPABILITIES MSR availability: "
cpuid_arch_capabilities=-1
# A processor supports STIBP if it enumerates CPUID (EAX=7H,ECX=0):EDX[27] as 1
read_cpuid 7 15 32; ret=$?
if [ $ret -eq 0 ]; then
pstatus green YES
cpuid_arch_capabilities=1
elif [ $ret -eq 2 ]; then
pstatus yellow UNKNOWN "couldn't read /dev/cpu/0/cpuid, is cpuid support enabled in your kernel?"
else
pstatus red NO
cpuid_arch_capabilities=0
fi
_info_nol " * ARCH_CAPABILITIES MSR advertises IBRS_ALL capability: "
capabilities_rdcl_no=-1
capabilities_ibrs_all=-1
if [ "$cpuid_arch_capabilities" = -1 ]; then
pstatus yellow UNKNOWN
elif [ "$cpuid_arch_capabilities" != 1 ]; then
capabilities_rdcl_no=0
capabilities_ibrs_all=0
pstatus red NO
elif [ ! -e /dev/cpu/0/msr ]; then
spec_ctrl_msr=-1
pstatus yellow UNKNOWN "couldn't read /dev/cpu/0/msr, is msr support enabled in your kernel?"
else
# the new MSR 'ARCH_CAPABILITIES' is at offset 0x10a
# here we use dd, it's the same as using 'rdmsr 0x10a' but without needing the rdmsr tool
# if we get a read error, the MSR is not there. bs has to be 8 for msr
capabilities=$(dd if=/dev/cpu/0/msr bs=8 count=1 skip=266 iflag=skip_bytes 2>/dev/null | od -t u1 -A n | awk '{print $8}'); ret=$?
capabilities_rdcl_no=0
capabilities_ibrs_all=0
if [ $ret -eq 0 ]; then
_debug "capabilities MSR lower byte is $capabilities (decimal)"
[ $(( capabilities & 1 )) -eq 1 ] && capabilities_rdcl_no=1
[ $(( capabilities & 2 )) -eq 2 ] && capabilities_ibrs_all=1
_debug "capabilities says rdcl_no=$capabilities_rdcl_no ibrs_all=$capabilities_ibrs_all"
if [ "$capabilities_ibrs_all" = 1 ]; then
pstatus green YES
else
pstatus red NO
fi
else
pstatus yellow UNKNOWN
fi
fi
_info_nol " * CPU explicitly indicates not being vulnerable to Meltdown (RDCL_NO): "
if [ "$capabilities_rdcl_no" = -1 ]; then
pstatus yellow UNKNOWN
elif [ "$capabilities_rdcl_no" = 1 ]; then
pstatus green YES
else
pstatus blue NO
fi
_info_nol " * CPU microcode is known to cause stability problems: "
if is_ucode_blacklisted; then
pstatus red YES "$ucode_found"
_warn
_warn "The microcode your CPU is running on is known to cause instability problems,"
_warn "such as intempestive reboots or random crashes."
_warn "You are advised to either revert to a previous microcode version (that might not have"
_warn "the mitigations for Spectre), or upgrade to a newer one if available."
_warn
else
pstatus blue NO "$ucode_found"
fi
_info "* CPU vulnerability to the three speculative execution attacks variants"
for v in 1 2 3; do
_info_nol " * Vulnerable to Variant $v: "
if is_cpu_vulnerable $v; then
pstatus red YES
else
pstatus green NO
fi
done
_info
}
check_redhat_canonical_spectre()
{
# if we were already called, don't do it again
[ -n "$redhat_canonical_spectre" ] && return
if ! which strings >/dev/null 2>&1; then
redhat_canonical_spectre=-1
elif [ -n "$vmlinux_err" ]; then
redhat_canonical_spectre=-2
else
# Red Hat / Ubuntu specific variant1 patch is difficult to detect,
# let's use the same way than the official Red Hat detection script,
# and detect their specific variant2 patch. If it's present, it means
# that the variant1 patch is also present (both were merged at the same time)
if strings "$vmlinux" | grep -qw noibrs && strings "$vmlinux" | grep -qw noibpb; then
_debug "found redhat/canonical version of the variant2 patch (implies variant1)"
redhat_canonical_spectre=1
else
redhat_canonical_spectre=0
fi
fi
}
###################
# SPECTRE VARIANT 1
check_variant1()
{
_info "\033[1;34mCVE-2017-5753 [bounds check bypass] aka 'Spectre Variant 1'\033[0m"
status=UNK
sys_interface_available=0
msg=''
if sys_interface_check "/sys/devices/system/cpu/vulnerabilities/spectre_v1"; then
# this kernel has the /sys interface, trust it over everything
# v0.33+: don't. some kernels have backported the array_index_mask_nospec() workaround without
# modifying the vulnerabilities/spectre_v1 file. that's bad. we can't trust it when it says Vulnerable :(
# see "silent backport" detection at the bottom of this func
sys_interface_available=1
fi
if [ "$opt_sysfs_only" != 1 ]; then
# no /sys interface (or offline mode), fallback to our own ways
_info_nol "* Kernel has array_index_mask_nospec: "
# vanilla: look for the Linus' mask aka array_index_mask_nospec()
# that is inlined at least in raw_copy_from_user (__get_user_X symbols)
#mov PER_CPU_VAR(current_task), %_ASM_DX
#cmp TASK_addr_limit(%_ASM_DX),%_ASM_AX
#jae bad_get_user
# /* array_index_mask_nospec() are the 2 opcodes that follow */
#+sbb %_ASM_DX, %_ASM_DX
#+and %_ASM_DX, %_ASM_AX
#ASM_STAC
# x86 64bits: jae(0x0f 0x83 0x?? 0x?? 0x?? 0x??) sbb(0x48 0x19 0xd2) and(0x48 0x21 0xd0)
# x86 32bits: cmp(0x3b 0x82 0x?? 0x?? 0x00 0x00) jae(0x73 0x??) sbb(0x19 0xd2) and(0x21 0xd0)
if [ -n "$vmlinux_err" ]; then
pstatus yellow UNKNOWN "couldn't check ($vmlinux_err)"
elif ! which perl >/dev/null 2>&1; then
pstatus yellow UNKNOWN "missing 'perl' binary, please install it"
else
perl -ne '/\x0f\x83....\x48\x19\xd2\x48\x21\xd0/ and $found++; END { exit($found) }' "$vmlinux"; ret=$?
if [ $ret -gt 0 ]; then
pstatus green YES "$ret occurence(s) found of 64 bits array_index_mask_nospec()"
v1_mask_nospec=1
else
perl -ne '/\x3b\x82..\x00\x00\x73.\x19\xd2\x21\xd0/ and $found++; END { exit($found) }' "$vmlinux"; ret=$?
if [ $ret -gt 0 ]; then
pstatus green YES "$ret occurence(s) found of 32 bits array_index_mask_nospec()"
v1_mask_nospec=1
else
pstatus red NO
fi
fi
fi
_info_nol "* Kernel has the Red Hat/Ubuntu patch: "
check_redhat_canonical_spectre
if [ "$redhat_canonical_spectre" = -1 ]; then
pstatus yellow UNKNOWN "missing 'strings' tool, please install it, usually it's in the binutils package"
elif [ "$redhat_canonical_spectre" = -2 ]; then
pstatus yellow UNKNOWN "couldn't check ($vmlinux_err)"
elif [ "$redhat_canonical_spectre" = 1 ]; then
pstatus green YES
else
pstatus red NO
fi
if [ "$opt_verbose" -ge 2 ] || ( [ "$v1_mask_nospec" != 1 ] && [ "$redhat_canonical_spectre" != 1 ] ); then
# this is a slow heuristic and we don't need it if we already know the kernel is patched
# but still show it in verbose mode
_info_nol "* Checking count of LFENCE instructions following a jump in kernel... "
if [ -n "$vmlinux_err" ]; then
pstatus yellow UNKNOWN "couldn't check ($vmlinux_err)"
else
if ! which objdump >/dev/null 2>&1; then
pstatus yellow UNKNOWN "missing 'objdump' tool, please install it, usually it's in the binutils package"
else
# here we disassemble the kernel and count the number of occurrences of the LFENCE opcode
# in non-patched kernels, this has been empirically determined as being around 40-50
# in patched kernels, this is more around 70-80, sometimes way higher (100+)
# v0.13: 68 found in a 3.10.23-xxxx-std-ipv6-64 (with lots of modules compiled-in directly), which doesn't have the LFENCE patches,
# so let's push the threshold to 70.
# v0.33+: now only count lfence opcodes after a jump, way less error-prone
# non patched kernel have between 0 and 20 matches, patched ones have at least 40-45
nb_lfence=$(objdump -d "$vmlinux" | grep -w -B1 lfence | grep -Ewc 'jmp|jne|je')
if [ "$nb_lfence" -lt 30 ]; then
pstatus red NO "only $nb_lfence jump-then-lfence instructions found, should be >= 30 (heuristic)"
else
v1_lfence=1
pstatus green YES "$nb_lfence jump-then-lfence instructions found, which is >= 30 (heuristic)"
fi
fi
fi
fi
else
# we have no sysfs but were asked to use it only!
msg="/sys vulnerability interface use forced, but it's not available!"
status=UNK
fi
# report status
cve='CVE-2017-5753'
if ! is_cpu_vulnerable 1; then
# override status & msg in case CPU is not vulnerable after all
pvulnstatus $cve OK "your CPU vendor reported your CPU model as not vulnerable"
elif [ -z "$msg" ]; then
# if msg is empty, sysfs check didn't fill it, rely on our own test
if [ "$v1_mask_nospec" = 1 ]; then
pvulnstatus $cve OK "Kernel source has been patched to mitigate the vulnerability (array_index_mask_nospec)"
elif [ "$redhat_canonical_spectre" = 1 ]; then
pvulnstatus $cve OK "Kernel source has been patched to mitigate the vulnerability (Red Hat/Ubuntu patch)"
elif [ "$v1_lfence" = 1 ]; then
pvulnstatus $cve OK "Kernel source has PROBABLY been patched to mitigate the vulnerability (jump-then-lfence instructions heuristic)"
elif [ "$vmlinux_err" ]; then
pvulnstatus $cve UNK "Couldn't find kernel image or tools missing to execute the checks"
else
pvulnstatus $cve VULN "Kernel source needs to be patched to mitigate the vulnerability"
fi
else
if [ "$msg" = "Vulnerable" ] && [ "$v1_mask_nospec" = 1 ]; then
pvulnstatus $cve OK "Kernel source has been patched to mitigate the vulnerability (silent backport of array_index_mask_nospec)"
else
[ "$msg" = "Vulnerable" ] && msg="Kernel source needs to be patched to mitigate the vulnerability"
pvulnstatus $cve "$status" "$msg"
fi
fi
}
###################
# SPECTRE VARIANT 2
check_variant2()
{
_info "\033[1;34mCVE-2017-5715 [branch target injection] aka 'Spectre Variant 2'\033[0m"
status=UNK
sys_interface_available=0
msg=''
if sys_interface_check "/sys/devices/system/cpu/vulnerabilities/spectre_v2"; then
# this kernel has the /sys interface, trust it over everything
sys_interface_available=1
fi
if [ "$opt_sysfs_only" != 1 ]; then
_info "* Mitigation 1"
_info_nol " * Kernel is compiled with IBRS/IBPB support: "
ibrs_can_tell=0
if [ "$opt_live" = 1 ]; then
ibrs_can_tell=1
mount_debugfs
for dir in \
/sys/kernel/debug \
/sys/kernel/debug/x86 \
/proc/sys/kernel; do
if [ -e "$dir/ibrs_enabled" ]; then
# if the file is there, we have IBRS compiled-in
# /sys/kernel/debug/ibrs_enabled: vanilla
# /sys/kernel/debug/x86/ibrs_enabled: Red Hat (see https://access.redhat.com/articles/3311301)
# /proc/sys/kernel/ibrs_enabled: OpenSUSE tumbleweed
pstatus green YES
ibrs_knob_dir=$dir
ibrs_supported=1
ibrs_enabled=$(cat "$dir/ibrs_enabled" 2>/dev/null)
_debug "ibrs: found $dir/ibrs_enabled=$ibrs_enabled"
if [ -e "$dir/ibpb_enabled" ]; then
ibpb_enabled=$(cat "$dir/ibpb_enabled" 2>/dev/null)
_debug "ibpb: found $dir/ibpb_enabled=$ibpb_enabled"
else
ibpb_enabled=-1
_debug "ibpb: no ibpb_enabled file in $dir"
fi
break
else
_debug "ibrs: $dir/ibrs_enabled file doesn't exist"
fi
done
# on some newer kernels, the spec_ctrl_ibrs flag in /proc/cpuinfo
# is set when ibrs has been administratively enabled (usually from cmdline)
# which in that case means ibrs is supported *and* enabled for kernel & user
# as per the ibrs patch series v3
if [ "$ibrs_supported" = 0 ]; then
if grep ^flags /proc/cpuinfo | grep -qw spec_ctrl_ibrs; then
_debug "ibrs: found spec_ctrl_ibrs flag in /proc/cpuinfo"
ibrs_supported=1
# enabled=2 -> kernel & user
ibrs_enabled=2
# XXX and what about ibpb ?
fi
fi
fi
if [ "$ibrs_supported" != 1 ] && [ -n "$opt_map" ]; then
ibrs_can_tell=1
if grep -q spec_ctrl "$opt_map"; then
pstatus green YES
ibrs_supported=1
_debug "ibrs: found '*spec_ctrl*' symbol in $opt_map"
fi
fi
if [ "$ibrs_supported" != 1 ]; then
check_redhat_canonical_spectre
if [ "$redhat_canonical_spectre" = 1 ]; then
pstatus green YES "Red Hat/Ubuntu patch"
ibrs_supported=1
fi
fi
if [ "$ibrs_supported" != 1 ]; then
if [ "$ibrs_can_tell" = 1 ]; then
pstatus red NO
else
# if we're in offline mode without System.map, we can't really know
pstatus yellow UNKNOWN "in offline mode, we need System.map to be able to tell"
fi
fi
_info " * Currently enabled features"
_info_nol " * IBRS enabled for Kernel space: "
if [ "$opt_live" = 1 ]; then
if [ "$ibpb_enabled" = 2 ]; then
# if ibpb=2, ibrs is forcefully=0
pstatus blue NO "IBPB used instead of IBRS in all kernel entrypoints"
else
# 0 means disabled
# 1 is enabled only for kernel space
# 2 is enabled for kernel and user space
case "$ibrs_enabled" in
"")
if [ "$ibrs_supported" = 1 ]; then
pstatus yellow UNKNOWN
else
pstatus red NO
fi
;;
0)
pstatus red NO
_verbose " - To enable, \`echo 1 > $ibrs_knob_dir/ibrs_enabled' as root. If you don't have hardware support, you'll get an error."
;;
1 | 2) pstatus green YES;;
*) pstatus yellow UNKNOWN;;
esac
fi
else
pstatus blue N/A "not testable in offline mode"
fi
_info_nol " * IBRS enabled for User space: "
if [ "$opt_live" = 1 ]; then
if [ "$ibpb_enabled" = 2 ]; then
# if ibpb=2, ibrs is forcefully=0
pstatus blue NO "IBPB used instead of IBRS in all kernel entrypoints"
else
case "$ibrs_enabled" in
"")
if [ "$ibrs_supported" = 1 ]; then
pstatus yellow UNKNOWN
else
pstatus red NO
fi
;;
0 | 1)
pstatus red NO
_verbose " - To enable, \`echo 2 > $ibrs_knob_dir/ibrs_enabled' as root. If you don't have hardware support, you'll get an error."
;;
2) pstatus green YES;;
*) pstatus yellow UNKNOWN;;
esac
fi
else
pstatus blue N/A "not testable in offline mode"
fi
_info_nol " * IBPB enabled: "
if [ "$opt_live" = 1 ]; then
case "$ibpb_enabled" in
"")
if [ "$ibrs_supported" = 1 ]; then
pstatus yellow UNKNOWN
else
pstatus red NO
fi
;;
0)
pstatus red NO
_verbose " - To enable, \`echo 1 > $ibrs_knob_dir/ibpb_enabled' as root. If you don't have hardware support, you'll get an error."
;;
1) pstatus green YES;;
2) pstatus green YES "IBPB used instead of IBRS in all kernel entrypoints";;
*) pstatus yellow UNKNOWN;;
esac
else
pstatus blue N/A "not testable in offline mode"
fi
_info "* Mitigation 2"
_info_nol " * Kernel compiled with retpoline option: "
# We check the RETPOLINE kernel options
if [ -r "$opt_config" ]; then
if grep -q '^CONFIG_RETPOLINE=y' "$opt_config"; then
pstatus green YES
retpoline=1
# shellcheck disable=SC2046
_debug 'retpoline: found '$(grep '^CONFIG_RETPOLINE' "$opt_config")" in $opt_config"
else
pstatus red NO
fi
else
pstatus yellow UNKNOWN "couldn't read your kernel configuration"
fi
_info_nol " * Kernel compiled with a retpoline-aware compiler: "
# Now check if the compiler used to compile the kernel knows how to insert retpolines in generated asm
# For gcc, this is -mindirect-branch=thunk-extern (detected by the kernel makefiles)
# See gcc commit https://github.com/hjl-tools/gcc/commit/23b517d4a67c02d3ef80b6109218f2aadad7bd79
# In latest retpoline LKML patches, the noretpoline_setup symbol exists only if CONFIG_RETPOLINE is set
# *AND* if the compiler is retpoline-compliant, so look for that symbol
if [ -e "/sys/devices/system/cpu/vulnerabilities/spectre_v2" ]; then
if grep -qw Minimal /sys/devices/system/cpu/vulnerabilities/spectre_v2; then
pstatus red NO "kernel reports minimal retpoline compilation"
elif grep -qw Full /sys/devices/system/cpu/vulnerabilities/spectre_v2; then
retpoline_compiler=1
pstatus green YES "kernel reports full retpoline compilation"
else
if [ "$retpoline" = 1 ]; then
pstatus yellow UNKNOWN
else
pstatus red NO
fi
fi
elif [ -n "$opt_map" ]; then
# look for the symbol
if grep -qw noretpoline_setup "$opt_map"; then
retpoline_compiler=1
pstatus green YES "noretpoline_setup symbol found in System.map"
else
if [ "$retpoline" = 1 ]; then
pstatus yellow UNKNOWN
else
pstatus red NO
fi
fi
elif [ -n "$vmlinux" ]; then
# look for the symbol
if which nm >/dev/null 2>&1; then
# the proper way: use nm and look for the symbol
if nm "$vmlinux" 2>/dev/null | grep -qw 'noretpoline_setup'; then
retpoline_compiler=1
pstatus green YES "noretpoline_setup found in vmlinux symbols"
else
if [ "$retpoline" = 1 ]; then
pstatus yellow UNKNOWN
else
pstatus red NO
fi
fi
elif grep -q noretpoline_setup "$vmlinux"; then
# if we don't have nm, nevermind, the symbol name is long enough to not have
# any false positive using good old grep directly on the binary
retpoline_compiler=1
pstatus green YES "noretpoline_setup found in vmlinux"
else
if [ "$retpoline" = 1 ]; then
pstatus yellow UNKNOWN
else
pstatus red NO
fi
fi
else
if [ "$retpoline" = 1 ]; then
pstatus yellow UNKNOWN "couldn't find your kernel image or System.map"
else
pstatus red NO
fi
fi
elif [ "$sys_interface_available" = 0 ]; then
# we have no sysfs but were asked to use it only!
msg="/sys vulnerability interface use forced, but it's not available!"
status=UNK
fi
cve='CVE-2017-5715'
if ! is_cpu_vulnerable 2; then
# override status & msg in case CPU is not vulnerable after all
pvulnstatus $cve OK "your CPU vendor reported your CPU model as not vulnerable"
elif [ -z "$msg" ]; then
# if msg is empty, sysfs check didn't fill it, rely on our own test
if [ "$retpoline" = 1 ] && [ "$retpoline_compiler" = 1 ]; then
pvulnstatus $cve OK "retpoline mitigates the vulnerability"
elif [ "$opt_live" = 1 ]; then
if ( [ "$ibrs_enabled" = 1 ] || [ "$ibrs_enabled" = 2 ] ) && [ "$ibpb_enabled" = 1 ]; then
pvulnstatus $cve OK "IBRS/IBPB are mitigating the vulnerability"
elif ( [ "$ibrs_enabled" = 1 ] || [ "$ibrs_enabled" = 2 ] ) && [ "$ibpb_enabled" = -1 ]; then
# IBPB doesn't seem here on this kernel
pvulnstatus $cve OK "IBRS is mitigating the vulnerability"
elif [ "$ibpb_enabled" = 2 ]; then
pvulnstatus $cve OK "Full IBPB is mitigating the vulnerability"
elif [ "$ibrs_supported" = 1 ] && [ "$cpuid_spec_ctrl" != 1 ]; then
pvulnstatus $cve VULN "Your kernel is compiled with IBRS but your CPU microcode is lacking support to successfully mitigate the vulnerability"
else
pvulnstatus $cve VULN "IBRS hardware + kernel support OR kernel with retpoline are needed to mitigate the vulnerability"
fi
else
if [ "$ibrs_supported" = 1 ]; then
pvulnstatus $cve OK "offline mode: IBRS/IBPB will mitigate the vulnerability if enabled at runtime"
elif [ "$ibrs_can_tell" = 1 ]; then
pvulnstatus $cve VULN "IBRS hardware + kernel support OR kernel with retpoline are needed to mitigate the vulnerability"
else
pvulnstatus $cve UNK "offline mode: not enough information"
fi
fi
else
[ "$msg" = "Vulnerable" ] && msg="IBRS hardware + kernel support OR kernel with retpoline are needed to mitigate the vulnerability"
pvulnstatus $cve "$status" "$msg"
fi
}
########################
# MELTDOWN aka VARIANT 3
check_variant3()
{
_info "\033[1;34mCVE-2017-5754 [rogue data cache load] aka 'Meltdown' aka 'Variant 3'\033[0m"
status=UNK
sys_interface_available=0
msg=''
if sys_interface_check "/sys/devices/system/cpu/vulnerabilities/meltdown"; then
# this kernel has the /sys interface, trust it over everything
sys_interface_available=1
fi
if [ "$opt_sysfs_only" != 1 ]; then
_info_nol "* Kernel supports Page Table Isolation (PTI): "
kpti_support=0
kpti_can_tell=0
if [ -n "$opt_config" ]; then
kpti_can_tell=1
if grep -Eq '^(CONFIG_PAGE_TABLE_ISOLATION|CONFIG_KAISER)=y' "$opt_config"; then
# shellcheck disable=SC2046
_debug 'kpti_support: found option '$(grep -E '^(CONFIG_PAGE_TABLE_ISOLATION|CONFIG_KAISER)=y' "$opt_config")" in $opt_config"
kpti_support=1
fi
fi
if [ "$kpti_support" = 0 ] && [ -n "$opt_map" ]; then
# it's not an elif: some backports don't have the PTI config but still include the patch
# so we try to find an exported symbol that is part of the PTI patch in System.map
kpti_can_tell=1
if grep -qw kpti_force_enabled "$opt_map"; then
_debug "kpti_support: found kpti_force_enabled in $opt_map"
kpti_support=1
fi
fi
if [ "$kpti_support" = 0 ] && [ -n "$vmlinux" ]; then
# same as above but in case we don't have System.map and only vmlinux, look for the
# nopti option that is part of the patch (kernel command line option)
kpti_can_tell=1
if ! which strings >/dev/null 2>&1; then
pstatus yellow UNKNOWN "missing 'strings' tool, please install it, usually it's in the binutils package"
else
if strings "$vmlinux" | grep -qw nopti; then
_debug "kpti_support: found nopti string in $vmlinux"
kpti_support=1
fi
fi
fi
if [ "$kpti_support" = 1 ]; then
pstatus green YES
elif [ "$kpti_can_tell" = 1 ]; then
pstatus red NO
else
pstatus yellow UNKNOWN "couldn't read your kernel configuration nor System.map file"
fi
mount_debugfs
_info_nol "* PTI enabled and active: "
if [ "$opt_live" = 1 ]; then
dmesg_grep="Kernel/User page tables isolation: enabled"
dmesg_grep="$dmesg_grep|Kernel page table isolation enabled"
dmesg_grep="$dmesg_grep|x86/pti: Unmapping kernel while in userspace"
if grep ^flags /proc/cpuinfo | grep -qw pti; then
# vanilla PTI patch sets the 'pti' flag in cpuinfo
_debug "kpti_enabled: found 'pti' flag in /proc/cpuinfo"
kpti_enabled=1
elif grep ^flags /proc/cpuinfo | grep -qw kaiser; then
# kernel line 4.9 sets the 'kaiser' flag in cpuinfo
_debug "kpti_enabled: found 'kaiser' flag in /proc/cpuinfo"
kpti_enabled=1
elif [ -e /sys/kernel/debug/x86/pti_enabled ]; then
# Red Hat Backport creates a dedicated file, see https://access.redhat.com/articles/3311301
kpti_enabled=$(cat /sys/kernel/debug/x86/pti_enabled 2>/dev/null)
_debug "kpti_enabled: file /sys/kernel/debug/x86/pti_enabled exists and says: $kpti_enabled"
fi
if [ -z "$kpti_enabled" ]; then
dmesg_grep "$dmesg_grep"; ret=$?
if [ $ret -eq 0 ]; then
_debug "kpti_enabled: found hint in dmesg: $dmesg_grepped"
kpti_enabled=1
elif [ $ret -eq 2 ]; then
_debug "kpti_enabled: dmesg truncated"
kpti_enabled=-1
fi
fi
if [ -z "$kpti_enabled" ]; then
_debug "kpti_enabled: couldn't find any hint that PTI is enabled"
kpti_enabled=0
fi
if [ "$kpti_enabled" = 1 ]; then
pstatus green YES
elif [ "$kpti_enabled" = -1 ]; then
pstatus yellow UNKNOWN "dmesg truncated, please reboot and relaunch this script"
else
pstatus red NO
fi
else
pstatus blue N/A "can't verify if PTI is enabled in offline mode"
fi
# no security impact but give a hint to the user in verbose mode
# about PCID/INVPCID cpuid features that must be present to avoid
# too big a performance impact with PTI
# refs:
# https://marc.info/?t=151532047900001&r=1&w=2
# https://groups.google.com/forum/m/#!topic/mechanical-sympathy/L9mHTbeQLNU
if [ "$opt_verbose" -ge 2 ]; then
_info "* Performance impact if PTI is enabled"
_info_nol " * CPU supports PCID: "
if grep ^flags /proc/cpuinfo | grep -qw pcid; then
pstatus green YES 'performance degradation with PTI will be limited'
else
pstatus blue NO 'no security impact but performance will be degraded with PTI'
fi
_info_nol " * CPU supports INVPCID: "
if grep ^flags /proc/cpuinfo | grep -qw invpcid; then
pstatus green YES 'performance degradation with PTI will be limited'
else
pstatus blue NO 'no security impact but performance will be degraded with PTI'
fi
fi
elif [ "$sys_interface_available" = 0 ]; then
# we have no sysfs but were asked to use it only!
msg="/sys vulnerability interface use forced, but it's not available!"
status=UNK
fi
# Test if the current host is a Xen PV Dom0 / DomU
if [ -d "/proc/xen" ]; then
# XXX do we have a better way that relying on dmesg?
dmesg_grep 'Booting paravirtualized kernel on Xen$'; ret=$?
if [ $ret -eq 2 ]; then
_warn "dmesg truncated, Xen detection will be unreliable. Please reboot and relaunch this script"
elif [ $ret -eq 0 ]; then
if [ -e /proc/xen/capabilities ] && grep -q "control_d" /proc/xen/capabilities; then
xen_pv_domo=1
else
xen_pv_domu=1
fi
fi
fi
if [ "$opt_live" = 1 ]; then
# checking whether we're running under Xen PV 64 bits. If yes, we are affected by variant3
# (unless we are a Dom0)
_info_nol "* Running as a Xen PV DomU: "
if [ "$xen_pv_domu" = 1 ]; then
pstatus red YES
else
pstatus green NO
fi
fi
cve='CVE-2017-5754'
if ! is_cpu_vulnerable 3; then
# override status & msg in case CPU is not vulnerable after all
pvulnstatus $cve OK "your CPU vendor reported your CPU model as not vulnerable"
elif [ -z "$msg" ]; then
# if msg is empty, sysfs check didn't fill it, rely on our own test
if [ "$opt_live" = 1 ]; then
if [ "$kpti_enabled" = 1 ]; then
pvulnstatus $cve OK "PTI mitigates the vulnerability"
elif [ "$xen_pv_domo" = 1 ]; then
pvulnstatus $cve OK "Xen Dom0s are safe and do not require PTI"
elif [ "$xen_pv_domu" = 1 ]; then
pvulnstatus $cve VULN "Xen PV DomUs are vulnerable and need to be run in HVM, PVHVM, PVH mode, or the Xen hypervisor must have the Xen's own PTI patch"
else
pvulnstatus $cve VULN "PTI is needed to mitigate the vulnerability"
fi
else
if [ "$kpti_support" = 1 ]; then
pvulnstatus $cve OK "offline mode: PTI will mitigate the vulnerability if enabled at runtime"
elif [ "$kpti_can_tell" = 1 ]; then
pvulnstatus $cve VULN "PTI is needed to mitigate the vulnerability"
else
pvulnstatus $cve UNK "offline mode: not enough information"
fi
fi
else
if [ "$xen_pv_domo" = 1 ]; then
msg="Xen Dom0s are safe and do not require PTI"
status="OK"
elif [ "$xen_pv_domu" = 1 ]; then
msg="Xen PV DomUs are vulnerable and need to be run in HVM, PVHVM or PVH mode"
status="VULN"
elif [ "$msg" = "Vulnerable" ]; then
msg="PTI is needed to mitigate the vulnerability"
fi
pvulnstatus $cve "$status" "$msg"
fi
# Warn the user about XSA-254 recommended mitigations
if [ "$xen_pv_domo" = 1 ]; then
_warn
_warn "This host is a Xen Dom0. Please make sure that you are running your DomUs"
_warn "in HVM, PVHVM or PVH mode to prevent any guest-to-host / host-to-guest attacks."
_warn
_warn "See https://blog.xenproject.org/2018/01/22/xen-project-spectre-meltdown-faq-jan-22-update/ and XSA-254 for details."
fi
}
check_cpu
# now run the checks the user asked for
if [ "$opt_variant1" = 1 ] || [ "$opt_allvariants" = 1 ]; then
check_variant1
_info
fi
if [ "$opt_variant2" = 1 ] || [ "$opt_allvariants" = 1 ]; then
check_variant2
_info
fi
if [ "$opt_variant3" = 1 ] || [ "$opt_allvariants" = 1 ]; then
check_variant3
_info
fi
_info "A false sense of security is worse than no security at all, see --disclaimer"
if [ "$opt_batch" = 1 ] && [ "$opt_batch_format" = "nrpe" ]; then
if [ ! -z "$nrpe_vuln" ]; then
echo "Vulnerable:$nrpe_vuln"
else
echo "OK"
fi
fi
if [ "$opt_batch" = 1 ] && [ "$opt_batch_format" = "json" ]; then
_echo 0 "${json_output%?}]"
fi
if [ "$opt_batch" = 1 ] && [ "$opt_batch_format" = "prometheus" ]; then
echo "# TYPE specex_vuln_status untyped"
echo "# HELP specex_vuln_status Exposure of system to speculative execution vulnerabilities"
echo "$prometheus_output"
fi
# exit with the proper exit code
[ "$global_critical" = 1 ] && exit 2 # critical
[ "$global_unknown" = 1 ] && exit 3 # unknown
exit 0 # ok
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