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://raw.githubusercontent.com/speed47/spectre-meltdown-checker/master/spectre-meltdown-checker.sh
#
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# Stephane Lesimple
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#
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VERSION=0.31
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show_usage()
{
cat <<EOF
Usage:
Live mode: `basename $0` [options] [--live]
Offline mode: `basename $0` [options] [--kernel <vmlinux_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 vmlinux file, and if possible, the corresponding 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
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Options:
--no-color Don't use color codes
--verbose, -v Increase verbosity level
--no-sysfs Don't use the /sys interface even if present
--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...
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--batch nrpe Produce machine readable output formatted for NRPE
--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)
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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.
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
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explicitly stated otherwise in a verifiable public announcement.
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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
}
# 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
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global_critical=0
global_unknown=0
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nrpe_vuln=""
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__echo()
{
opt="$1"
shift
_msg="$@"
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if [ "$opt_no_color" = 1 ] ; then
# strip ANSI color codes
_msg=$(/bin/echo -e "$_msg" | sed -r "s/\x1B\[([0-9]{1,2}(;[0-9]{1,2})?)?[m|K]//g")
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fi
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# explicitly call /bin/echo to avoid shell builtins that might not take options
/bin/echo $opt -e "$_msg"
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}
_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()
{
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_echo 3 "\033[34m(debug) $@\033[0m"
}
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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
variant1=0
variant2=0
variant3=0
if grep -q GenuineIntel /proc/cpuinfo; then
# Intel
# Old Atoms are not vulnerable to spectre 2 nor meltdown
# https://security-center.intel.com/advisory.aspx?intelid=INTEL-SA-00088&languageid=en-fr
if grep -qE '^model name.+ Atom\(TM\) CPU +(S|D|N|230|330)' /proc/cpuinfo; then
variant2=1
variant3=1
fi
elif grep -q AuthenticAMD /proc/cpuinfo; then
# AMD revised their statement about variant2 => vulnerable
# https://www.amd.com/en/corporate/speculative-execution
variant3=1
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elif grep -qi 'CPU implementer\s*:\s*0x41' /proc/cpuinfo; then
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# ARM
# reference: https://developer.arm.com/support/security-update
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cpupart=$(awk '/CPU part/ {print $4;exit}' /proc/cpuinfo)
cpuarch=$(awk '/CPU architecture/ {print $3;exit}' /proc/cpuinfo)
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if [ -n "$cpupart" -a -n "$cpuarch" ]; then
# Cortex-R7 and Cortex-R8 are real-time and only used in medical devices or such
# I can't find their CPU part number, but it's probably not that useful anyway
# model R7 R8 A9 A15 A17 A57 A72 A73 A75
# part ? ? 0xc09 0xc0f 0xc0e 0xd07 0xd08 0xd09 0xd0a
# arch 7? 7? 7 7 7 8 8 8 8
if [ "$cpuarch" = 7 ] && echo "$cpupart" | grep -Eq '^0x(c09|c0f|c0e)$'; then
# armv7 vulnerable chips
:
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elif [ "$cpuarch" = 8 ] && echo "$cpupart" | grep -Eq '^0x(d07|d08|d09|d0a)$'; then
# armv8 vulnerable chips
:
else
# others are not vulnerable
variant1=1
variant2=1
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fi
# for variant3, only A75 is vulnerable
if ! [ "$cpuarch" = 8 -a "$cpupart" = 0xd0a ]; then
variant3=1
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fi
fi
fi
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[ "$1" = 1 ] && return $variant1
[ "$1" = 2 ] && return $variant2
[ "$1" = 3 ] && return $variant3
echo "$0: error: invalid variant '$1' passed to is_cpu_vulnerable()" >&2
exit 255
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}
show_header()
{
_info "\033[1;34mSpectre and Meltdown mitigation detection tool v$VERSION\033[0m"
_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")
[ $? -ne 0 ] && exit 255
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shift 2
opt_live=0
elif [ "$1" = "--config" ]; then
opt_config=$(parse_opt_file config "$2")
[ $? -ne 0 ] && exit 255
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shift 2
opt_live=0
elif [ "$1" = "--map" ]; then
opt_map=$(parse_opt_file map "$2")
[ $? -ne 0 ] && exit 255
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shift 2
opt_live=0
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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" = "--batch" ]; then
opt_batch=1
opt_verbose=0
shift
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case "$1" in
text|nrpe|json) 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" -o "$1" = "--verbose" ]; then
opt_verbose=$(expr $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
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elif [ "$1" = "-h" -o "$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 '$1'"
exit 255
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fi
done
show_header
# print status function
pstatus()
{
if [ "$opt_no_color" = 1 ]; then
_info_nol "$2"
else
case "$1" in
red) col="\033[101m\033[30m";;
green) col="\033[102m\033[30m";;
yellow) col="\033[103m\033[30m";;
blue) col="\033[104m\033[30m";;
*) col="";;
esac
_info_nol "$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 "$opt_batch_format" in
text) _echo 0 "$1: $2 ($3)";;
json)
case "$1" in
CVE-2017-5753) aka="SPECTRE VARIANT 1";;
CVE-2017-5715) aka="SPECTRE VARIANT 2";;
CVE-2017-5754) aka="MELTDOWN";;
esac
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";;
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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).
# ----------------------------------------------------------------------
vmlinux=''
vmlinux_err=''
check_vmlinux()
{
readelf -h "$1" > /dev/null 2>&1 || return 1
return 0
}
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%%:*}
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)"
trap "rm -f $vmlinuxtmp" EXIT
# 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 "$1" && return 0
return 1
}
# end of extract-vmlinux functions
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# check for mode selection inconsistency
if [ "$opt_live_explicit" = 1 ]; then
if [ -n "$opt_kernel" -o -n "$opt_config" -o -n "$opt_map" ]; then
show_usage
echo "$0: error: incompatible modes specified, use either --live or --kernel/--config/--map" >&2
exit 255
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fi
fi
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# root check (only for live mode, for offline mode, we already checked if we could read the files)
if [ "$opt_live" = 1 ]; then
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 $0"
_warn
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fi
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_info "Checking for vulnerabilities against running kernel \033[35m"$(uname -s) $(uname -r) $(uname -v) $(uname -m)"\033[0m"
_info "CPU is\033[35m"$(grep '^model name' /proc/cpuinfo | cut -d: -f2 | head -1)"\033[0m"
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# 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"
_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
[ -e /boot/vmlinuz-linux ] && opt_kernel=/boot/vmlinuz-linux
[ -e /boot/vmlinuz-linux-libre ] && opt_kernel=/boot/vmlinuz-linux-libre
[ -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)
[ -e /boot/kernel-genkernel-$(uname -m)-$(uname -r) ] && opt_kernel=/boot/kernel-genkernel-$(uname -m)-$(uname -r)
[ -e /run/booted-system/kernel ] && opt_kernel=/run/booted-system/kernel
fi
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# system.map
if [ -e /proc/kallsyms ] ; then
opt_map="/proc/kallsyms"
elif [ -e /boot/System.map-$(uname -r) ] ; then
opt_map=/boot/System.map-$(uname -r)
fi
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# config
if [ -e /proc/config.gz ] ; then
dumped_config="$(mktemp /tmp/config-XXXXXX)"
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gunzip -c /proc/config.gz > $dumped_config
# dumped_config will be deleted at the end of the script
opt_config=$dumped_config
elif [ -e /boot/config-$(uname -r) ]; then
opt_config=/boot/config-$(uname -r)
fi
else
_info "Checking for vulnerabilities against specified kernel"
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fi
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if [ -n "$opt_kernel" ]; then
_verbose "Will use vmlinux image \033[35m$opt_kernel\033[0m"
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else
_verbose "Will use no vmlinux image (accuracy might be reduced)"
bad_accuracy=1
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fi
if [ -n "$dumped_config" ]; then
_verbose "Will use kconfig \033[35m/proc/config.gz\033[0m"
elif [ -n "$opt_config" ]; then
_verbose "Will use kconfig \033[35m$opt_config\033[0m"
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else
_verbose "Will use no kconfig (accuracy might be reduced)"
bad_accuracy=1
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fi
if [ -n "$opt_map" ]; then
_verbose "Will use System.map file \033[35m$opt_map\033[0m"
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else
_verbose "Will use no System.map file (accuracy might be reduced)"
bad_accuracy=1
fi
if [ "$bad_accuracy" = 1 ]; then
_info "We're missing some kernel info (see -v), accuracy might be reduced"
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fi
if [ -e "$opt_kernel" ]; then
if ! which readelf >/dev/null 2>&1; then
vmlinux_err="missing 'readelf' tool, please install it, usually it's in the 'binutils' package"
else
extract_vmlinux "$opt_kernel"
fi
else
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vmlinux_err="couldn't find your kernel image in /boot, if you used netboot, this is normal"
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fi
if [ -z "$vmlinux" -o ! -r "$vmlinux" ]; then
[ -z "$vmlinux_err" ] && vmlinux_err="couldn't extract your kernel from $opt_kernel"
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fi
_info
# end of header stuff
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# now we define some util functions and the check_*() funcs, as
# the user can choose to execute only some of those
mount_debugfs()
{
if [ ! -e /sys/kernel/debug/sched_features ]; then
# try to mount the debugfs hierarchy ourselves and remember it to umount afterwards
mount -t debugfs debugfs /sys/kernel/debug 2>/dev/null && mounted_debugfs=1
fi
}
umount_debugfs()
{
if [ "$mounted_debugfs" = 1 ]; then
# umount debugfs if we did mount it ourselves
umount /sys/kernel/debug
fi
}
sys_interface_check()
{
[ "$opt_live" = 1 -a "$opt_no_sysfs" = 0 -a -r "$1" ] || return 1
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_info_nol "* Checking whether we're safe 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")
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_debug "sys_interface_check: $1=$msg"
return 0
}
###################
# 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
sys_interface_available=1
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else
# no /sys interface (or offline mode), fallback to our own ways
_info_nol "* Checking count of LFENCE opcodes in kernel: "
if [ -n "$vmlinux_err" ]; then
msg="couldn't check ($vmlinux_err)"
status=UNK
pstatus yellow UNKNOWN
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else
if ! which objdump >/dev/null 2>&1; then
msg="missing 'objdump' tool, please install it, usually it's in the binutils package"
status=UNK
pstatus yellow UNKNOWN
else
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# 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.
nb_lfence=$(objdump -d "$vmlinux" | grep -wc lfence)
if [ "$nb_lfence" -lt 70 ]; then
msg="only $nb_lfence opcodes found, should be >= 70, heuristic to be improved when official patches become available"
status=VULN
pstatus red NO
else
msg="$nb_lfence opcodes found, which is >= 70, heuristic to be improved when official patches become available"
status=OK
pstatus green YES
fi
fi
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fi
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fi
# if we have the /sys interface, don't even check is_cpu_vulnerable ourselves, the kernel already does it
if [ "$sys_interface_available" = 0 ] && ! is_cpu_vulnerable 1; then
# override status & msg in case CPU is not vulnerable after all
msg="your CPU vendor reported your CPU model as not vulnerable"
status=OK
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fi
# report status
pvulnstatus CVE-2017-5753 "$status" "$msg"
}
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###################
# SPECTRE VARIANT 2
check_variant2()
{
_info "\033[1;34mCVE-2017-5715 [branch target injection] aka 'Spectre Variant 2'\033[0m"
status=UNK
sys_interface_available=0
msg=''
if sys_interface_check "/sys/devices/system/cpu/vulnerabilities/spectre_v2"; then
# this kernel has the /sys interface, trust it over everything
sys_interface_available=1
else
_info "* Mitigation 1"
_info "* Hardware (CPU microcode) support for mitigation"
_info_nol "* The SPEC_CTRL MSR is available: "
if [ ! -e /dev/cpu/0/msr ]; then
# try to load the module ourselves (and remember it so we can rmmod it afterwards)
modprobe msr 2>/dev/null && insmod_msr=1
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_debug "attempted to load module msr, insmod_msr=$insmod_msr"
fi
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 '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
dd if=/dev/cpu/0/msr of=/dev/null bs=8 count=1 skip=9 2>/dev/null
if [ $? -eq 0 ]; then
pstatus green YES
else
pstatus red NO
fi
fi
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if [ "$insmod_msr" = 1 ]; then
# if we used modprobe ourselves, rmmod the module
rmmod msr 2>/dev/null
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_debug "attempted to unload module msr, ret=$?"
fi
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# CPUID test
_info_nol "* The SPEC_CTRL CPUID feature bit is set: "
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if [ ! -e /dev/cpu/0/cpuid ]; then
# try to load the module ourselves (and remember it so we can rmmod it afterwards)
modprobe cpuid 2>/dev/null && insmod_cpuid=1
_debug "attempted to load module cpuid, insmod_cpuid=$insmod_cpuid"
fi
if [ ! -e /dev/cpu/0/cpuid ]; then
pstatus yellow UNKNOWN "couldn't read /dev/cpu/0/cpuidr, is cpuid support enabled in your kernel?"
else
# from kernel src: { X86_FEATURE_SPEC_CTRL, CPUID_EDX,26, 0x00000007, 0 },
if [ "$opt_verbose" -ge 3 ]; then
dd if=/dev/cpu/0/cpuid bs=16 skip=7 iflag=skip_bytes count=1 >/dev/null 2>/dev/null
_debug "cpuid: reading leaf7 of cpuid on cpu0, ret=$?"
_debug "cpuid: leaf7 eax-ebx-ecd-edx: "$(dd if=/dev/cpu/0/cpuid bs=16 skip=7 iflag=skip_bytes count=1 2>/dev/null | od -x -A n)
_debug "cpuid: leaf7 edx higher-half is: "$(dd if=/dev/cpu/0/cpuid bs=16 skip=7 iflag=skip_bytes count=1 2>/dev/null | dd bs=1 skip=15 count=1 2>/dev/null | od -x -A n)
fi
# getting high byte of edx on leaf7 of cpuinfo in decimal
edx_hb=$(dd if=/dev/cpu/0/cpuid bs=16 skip=7 iflag=skip_bytes count=1 2>/dev/null | dd bs=1 skip=15 count=1 2>/dev/null | od -t u -A n | awk '{print $1}')
_debug "cpuid: leaf7 edx higher byte: $edx_hb (decimal)"
edx_bit26=$(( edx_hb & 8 ))
_debug "cpuid: edx_bit26=$edx_bit26"
if [ "$edx_bit26" -eq 8 ]; then
pstatus green YES
else
pstatus red NO
fi
fi
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# hardware support according to kernel
if [ "$opt_verbose" -ge 2 ]; then
_verbose_nol "* The kernel has set the spec_ctrl flag in cpuinfo: "
if [ "$opt_live" = 1 ]; then
if grep ^flags /proc/cpuinfo | grep -qw spec_ctrl; then
pstatus green YES
else
pstatus red NO
fi
else
pstatus blue N/A "not testable in offline mode"
fi
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fi
_info_nol "* Kernel support for IBRS: "
if [ "$opt_live" = 1 ]; then
mount_debugfs
for ibrs_file in \
/sys/kernel/debug/ibrs_enabled \
/sys/kernel/debug/x86/ibrs_enabled \
/proc/sys/kernel/ibrs_enabled; do
if [ -e "$ibrs_file" ]; then
# if the file is there, we have IBRS compiled-in
# /sys/kernel/debug/ibrs_enabled: vanilla
# /sys/kernel/debug/x86/ibrs_enabled: RedHat (see https://access.redhat.com/articles/3311301)
# /proc/sys/kernel/ibrs_enabled: OpenSUSE tumbleweed
pstatus green YES
ibrs_supported=1
ibrs_enabled=$(cat "$ibrs_file" 2>/dev/null)
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_debug "ibrs: found $ibrs_file=$ibrs_enabled"
break
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else
_debug "ibrs: file $ibrs_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