spectre-meltdown-checker/spectre-meltdown-checker.sh

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#! /bin/sh
# Spectre & Meltdown checker
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#
# 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
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#
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# Stephane Lesimple
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#
VERSION='0.36+'
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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 "$dumped_config"
[ -n "$kerneltmp" ] && [ -f "$kerneltmp" ] && rm -f "$kerneltmp"
[ -n "$kerneltmp2" ] && [ -f "$kerneltmp2" ] && rm -f "$kerneltmp2"
[ "$mounted_debugfs" = 1 ] && umount /sys/kernel/debug 2>/dev/null
[ "$mounted_procfs" = 1 ] && umount "$procfs" 2>/dev/null
[ "$insmod_cpuid" = 1 ] && rmmod cpuid 2>/dev/null
[ "$insmod_msr" = 1 ] && rmmod msr 2>/dev/null
[ "$kldload_cpuctl" = 1 ] && kldunload cpuctl 2>/dev/null
}
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show_usage()
{
# shellcheck disable=SC2086
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cat <<EOF
Usage:
Live mode: $(basename $0) [options] [--live]
Offline mode: $(basename $0) [options] [--kernel <kernel_file>] [--config <kernel_config>] [--map <kernel_map_file>]
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Modes:
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Two modes are available.
First mode is the "live" mode (default), it does its best to find information about the currently running kernel.
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To run under this mode, just start the script without any option (you can also use --live explicitly)
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Second mode is the "offline" mode, where you can inspect a non-running kernel.
You'll need to specify the location of the kernel file, config and System.map files:
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--kernel kernel_file specify a (possibly compressed) Linux or BSD kernel file
--config kernel_config specify a kernel config file (Linux only)
--map kernel_map_file specify a kernel System.map file (Linux only)
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Options:
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--no-color don't use color codes
--verbose, -v increase verbosity level, possibly several times
--no-sysfs don't use the /sys interface even if present [Linux]
--sysfs-only only use the /sys interface, don't run our own checks [Linux]
--coreos special mode for CoreOS (use an ephemeral toolbox to inspect kernel) [Linux]
--arch-prefix PREFIX specify a prefix for cross-inspecting a kernel of a different arch, for example "aarch64-linux-gnu-",
so that invoked tools will be prefixed with this (i.e. aarch64-linux-gnu-objdump)
--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)
--hw-only only check for CPU informations, don't check for any variant
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Return codes:
0 (not vulnerable), 2 (vulnerable), 3 (unknown), 255 (error)
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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.
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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
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explicitly stated otherwise in a verifiable public announcement.
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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.
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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.
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EOF
}
os=$(uname -s)
# parse options
opt_kernel=''
opt_config=''
opt_map=''
opt_live_explicit=0
opt_live=1
opt_no_color=0
opt_batch=0
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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
opt_arch_prefix=''
opt_hw_only=0
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global_critical=0
global_unknown=0
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nrpe_vuln=""
# find a sane command to print colored messages, we prefer `printf` over `echo`
# because `printf` behavior is more standard across Linux/BSD
# we'll try to avoid using shell builtins that might not take options
echo_cmd_type=echo
if which printf >/dev/null 2>&1; then
echo_cmd=$(which printf)
echo_cmd_type=printf
elif which echo >/dev/null 2>&1; then
echo_cmd=$(which echo)
else
# which command is broken?
[ -x /bin/echo ] && echo_cmd=/bin/echo
# for Android
[ -x /system/bin/echo ] && echo_cmd=/system/bin/echo
fi
# still empty ? fallback to builtin
[ -z "$echo_cmd" ] && echo_cmd=echo
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__echo()
{
opt="$1"
shift
_msg="$*"
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if [ "$opt_no_color" = 1 ] ; then
# strip ANSI color codes
# some sed versions (i.e. toybox) can't seem to handle
# \033 aka \x1B correctly, so do it for them.
if [ "$echo_cmd_type" = printf ]; then
_interpret_chars=''
else
_interpret_chars='-e'
fi
_ctrlchar=$($echo_cmd $_interpret_chars "\033")
_msg=$($echo_cmd $_interpret_chars "$_msg" | sed -r "s/$_ctrlchar\[([0-9][0-9]?(;[0-9][0-9]?)?)?m//g")
fi
if [ "$echo_cmd_type" = printf ]; then
if [ "$opt" = "-n" ]; then
$echo_cmd "$_msg"
else
$echo_cmd "$_msg\n"
fi
else
# shellcheck disable=SC2086
$echo_cmd $opt -e "$_msg"
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fi
}
_echo()
{
if [ "$opt_verbose" -ge "$1" ]; then
shift
__echo '' "$*"
fi
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}
_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 "$*"
}
_verbose()
{
_echo 2 "$*"
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}
_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 '$1' passed to is_cpu_vulnerable()" >&2
exit 255
}
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is_cpu_vulnerable()
{
# param: 1, 2 or 3 (variant)
# returns 0 if vulnerable, 1 if not vulnerable
# (note that in shell, a return of 0 is success)
# by default, everything is vulnerable, we work in a "whitelist" logic here.
# usage: is_cpu_vulnerable 2 && do something if vulnerable
if [ "$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? ' "$procfs/cpuinfo"; then
variant1=vuln
[ -z "$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
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# 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
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fi
_debug "is_cpu_vulnerable: for cpu$i and so far, we have <$variant1> <$variant2> <$variant3>"
done
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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 $?
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}
is_cpu_specex_free()
{
# return true (0) if the CPU doesn't do speculative execution, false (1) if it does.
# if it's not in the list we know, return false (1).
# source: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/x86/kernel/cpu/common.c#n882
# { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_CEDARVIEW, X86_FEATURE_ANY },
# { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_CLOVERVIEW, X86_FEATURE_ANY },
# { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_LINCROFT, X86_FEATURE_ANY },
# { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_PENWELL, X86_FEATURE_ANY },
# { X86_VENDOR_INTEL, 6, INTEL_FAM6_ATOM_PINEVIEW, X86_FEATURE_ANY },
# { X86_VENDOR_CENTAUR, 5 },
# { X86_VENDOR_INTEL, 5 },
# { X86_VENDOR_NSC, 5 },
# { X86_VENDOR_ANY, 4 },
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parse_cpu_details
if [ "$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
[ "$cpu_family" = 4 ] && return 0
return 1
}
show_header()
{
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_info "Spectre and Meltdown mitigation detection tool v$VERSION"
_info
}
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parse_opt_file()
{
# parse_opt_file option_name option_value
option_name="$1"
option_value="$2"
if [ -z "$option_value" ]; then
show_header
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show_usage
echo "$0: error: --$option_name expects one parameter (a file)" >&2
exit 1
elif [ ! -e "$option_value" ]; then
show_header
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echo "$0: error: couldn't find file $option_value" >&2
exit 1
elif [ ! -f "$option_value" ]; then
show_header
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echo "$0: error: $option_value is not a file" >&2
exit 1
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elif [ ! -r "$option_value" ]; then
show_header
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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
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shift 2
opt_live=0
elif [ "$1" = "--config" ]; then
opt_config=$(parse_opt_file config "$2"); ret=$?
[ $ret -ne 0 ] && exit 255
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shift 2
opt_live=0
elif [ "$1" = "--map" ]; then
opt_map=$(parse_opt_file map "$2"); ret=$?
[ $ret -ne 0 ] && exit 255
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shift 2
opt_live=0
elif [ "$1" = "--arch-prefix" ]; then
opt_arch_prefix="$2"
shift 2
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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" = "--hw-only" ]; then
opt_hw_only=1
shift
elif [ "$1" = "--batch" ]; then
opt_batch=1
opt_verbose=0
shift
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case "$1" in
text|nrpe|json|prometheus) opt_batch_format="$1"; shift;;
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--*) ;; # 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
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;;
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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
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show_usage
exit 0
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elif [ "$1" = "--version" ]; then
opt_no_color=1
show_header
exit 0
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elif [ "$1" = "--disclaimer" ]; then
show_header
show_disclaimer
exit 0
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else
show_header
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show_usage
echo "$0: error: unknown option '$1'"
exit 255
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fi
done
show_header
if [ "$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 " ($3)"
_info
}
# Print the final status of a vulnerability (incl. batch mode)
# Arguments are: CVE UNK/OK/VULN description
pvulnstatus()
{
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if [ "$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"
;;
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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
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vulnstatus="$2"
shift 2
_info_nol "> \033[46m\033[30mSTATUS:\033[0m "
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case "$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).
# ----------------------------------------------------------------------
kernel=''
kernel_err=''
check_kernel()
{
_file="$1"
_desperate_mode="$2"
# checking the return code of readelf -h is not enough, we could get
# a damaged ELF file and validate it, check for stderr warnings too
_readelf_warnings=$("${opt_arch_prefix}readelf" -S "$_file" 2>&1 >/dev/null | tr "\n" "/"); ret=$?
_readelf_sections=$("${opt_arch_prefix}readelf" -S "$_file" 2>/dev/null | grep -c -e data -e text -e init)
_kernel_size=$(stat -c %s "$_file" 2>/dev/null || stat -f %z "$_file" 2>/dev/null || echo 10000)
_debug "check_kernel: ret=$? size=$_kernel_size sections=$_readelf_sections warnings=$_readelf_warnings"
if [ -n "$_desperate_mode" ]; then
if "${opt_arch_prefix}strings" "$_file" | grep -Eq '^Linux version '; then
_debug "check_kernel (desperate): ... matched!"
return 0
else
_debug "check_kernel (desperate): ... invalid"
fi
else
if [ $ret -eq 0 ] && [ -z "$_readelf_warnings" ] && [ "$_readelf_sections" -gt 0 ]; then
if [ "$_kernel_size" -ge 100000 ]; then
_debug "check_kernel: ... file is valid"
return 0
else
_debug "check_kernel: ... file seems valid but is too small, ignoring"
fi
else
_debug "check_kernel: ... file is invalid"
fi
fi
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
_debug "try_decompress: looking for $3 magic in $6"
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
kernel_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 $4 > "$kerneltmp" 2>/dev/null; ret=$?
if [ ! -s "$kerneltmp" ]; then
# don't rely on $ret, sometimes it's != 0 but worked
# (e.g. gunzip ret=2 just means there was trailing garbage)
_debug "try_decompress: decompression with $3 failed (err=$ret)"
elif check_kernel "$kerneltmp" "$7"; then
kernel="$kerneltmp"
_debug "try_decompress: decompressed with $3 successfully!"
return 0
elif [ "$3" != "cat" ]; then
_debug "try_decompress: decompression with $3 worked but result is not a kernel, trying with an offset"
[ -z "$kerneltmp2" ] && kerneltmp2=$(mktemp /tmp/kernel-XXXXXX)
cat "$kerneltmp" > "$kerneltmp2"
try_decompress '\177ELF' xxy 'cat' '' cat "$kerneltmp2" && return 0
else
_debug "try_decompress: decompression with $3 worked but result is not a kernel"
fi
done
return 1
}
extract_kernel()
{
[ -n "$1" ] || return 1
# Prepare temp files:
kerneltmp="$(mktemp /tmp/kernel-XXXXXX)"
# Initial attempt for uncompressed images or objects:
if check_kernel "$1"; then
cat "$1" > "$kerneltmp"
kernel=$kerneltmp
return 0
fi
# That didn't work, so retry after decompression.
for mode in '' 'desperate'; do
try_decompress '\037\213\010' xy gunzip '' gunzip "$1" "$mode" && return 0
try_decompress '\3757zXZ\000' abcde unxz '' xz-utils "$1" "$mode" && return 0
try_decompress 'BZh' xy bunzip2 '' bzip2 "$1" "$mode" && return 0
try_decompress '\135\0\0\0' xxx unlzma '' xz-utils "$1" "$mode" && return 0
try_decompress '\211\114\132' xy 'lzop' '-d' lzop "$1" "$mode" && return 0
try_decompress '\002\041\114\030' xyy 'lz4' '-d -l' liblz4-tool "$1" "$mode" && return 0
try_decompress '\177ELF' xxy 'cat' '' cat "$1" "$mode" && return 0
done
_verbose "Couldn't extract the kernel image, accuracy might be reduced"
return 1
}
# end of extract-vmlinux functions