mirror of
https://github.com/speed47/spectre-meltdown-checker
synced 2024-08-29 23:33:41 +02:00
986 lines
31 KiB
Bash
Executable File
986 lines
31 KiB
Bash
Executable File
#! /bin/sh
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# Spectre & Meltdown checker
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#
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# Check for the latest version at:
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# https://github.com/speed47/spectre-meltdown-checker
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# git clone https://github.com/speed47/spectre-meltdown-checker.git
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# or wget https://raw.githubusercontent.com/speed47/spectre-meltdown-checker/master/spectre-meltdown-checker.sh
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#
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# Stephane Lesimple
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#
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VERSION=0.29
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show_usage()
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{
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cat <<EOF
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Usage:
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Live mode: `basename $0` [options] [--live]
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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.
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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.
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You'll need to specify the location of the vmlinux file, and if possible, the corresponding config and System.map files:
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--kernel vmlinux_file Specify a (possibly compressed) vmlinux file
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--config kernel_config Specify a kernel config file
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--map kernel_map_file Specify a kernel System.map file
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Options:
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--no-color Don't use color codes
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--verbose, -v Increase verbosity level
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--no-sysfs Don't use the /sys interface even if present
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--batch text Produce machine readable output, this is the default if --batch is specified alone
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--batch json Produce JSON output formatted for Puppet, Ansible, Chef...
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--batch nrpe Produce machine readable output formatted for NRPE
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--variant [1,2,3] Specify which variant you'd like to check, by default all variants are checked
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Can be specified multiple times (e.g. --variant 2 --variant 3)
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IMPORTANT:
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A false sense of security is worse than no security at all.
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Please use the --disclaimer option to understand exactly what this script does.
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EOF
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}
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show_disclaimer()
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{
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cat <<EOF
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Disclaimer:
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This tool does its best to determine whether your system is immune (or has proper mitigations in place) for the
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collectively named "speculative execution" vulnerabilities. It doesn't attempt to run any kind of exploit, and can't guarantee
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that your system is secure, but rather helps you verifying whether your system has the known correct mitigations in place.
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However, some mitigations could also exist in your kernel that this script doesn't know (yet) how to detect, or it might
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falsely detect mitigations that in the end don't work as expected (for example, on backported or modified kernels).
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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
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vulnerabilities (except some specific ARM models). All Intel processors manufactured since circa 1995 are thought to be vulnerable.
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Whatever processor one uses, one might seek more information from the manufacturer of that processor and/or of the device
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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
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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
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}
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# parse options
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opt_kernel=''
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opt_config=''
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opt_map=''
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opt_live_explicit=0
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opt_live=1
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opt_no_color=0
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opt_batch=0
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opt_batch_format="text"
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opt_verbose=1
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opt_variant1=0
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opt_variant2=0
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opt_variant3=0
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opt_allvariants=1
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opt_no_sysfs=0
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global_critical=0
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global_unknown=0
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nrpe_vuln=""
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__echo()
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{
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opt="$1"
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shift
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_msg="$@"
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if [ "$opt_no_color" = 1 ] ; then
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# strip ANSI color codes
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_msg=$(/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
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/bin/echo $opt -e "$_msg"
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}
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_echo()
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{
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if [ $opt_verbose -ge $1 ]; then
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shift
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__echo '' "$@"
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fi
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}
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_echo_nol()
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{
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if [ $opt_verbose -ge $1 ]; then
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shift
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__echo -n "$@"
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fi
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}
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_warn()
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{
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_echo 0 "\033[31m${@}\033[0m" >&2
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}
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_info()
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{
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_echo 1 "$@"
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}
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_info_nol()
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{
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_echo_nol 1 "$@"
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}
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_verbose()
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{
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_echo 2 "$@"
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}
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_debug()
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{
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_echo 3 "\033[34m(debug) $@\033[0m"
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}
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is_cpu_vulnerable()
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{
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# param: 1, 2 or 3 (variant)
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# returns 0 if vulnerable, 1 if not vulnerable
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# (note that in shell, a return of 0 is success)
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# by default, everything is vulnerable, we work in a "whitelist" logic here.
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# usage: is_cpu_vulnerable 2 && do something if vulnerable
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variant1=0
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variant2=0
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variant3=0
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if grep -q AMD /proc/cpuinfo; then
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# AMD revised their statement about variant2 => vulnerable
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# https://www.amd.com/en/corporate/speculative-execution
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variant3=1
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elif grep -qi 'CPU implementer\s*:\s*0x41' /proc/cpuinfo; then
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# ARM
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# reference: https://developer.arm.com/support/security-update
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cpupart=$(awk '/CPU part/ {print $4;exit}' /proc/cpuinfo)
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cpuarch=$(awk '/CPU architecture/ {print $3;exit}' /proc/cpuinfo)
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if [ -n "$cpupart" -a -n "$cpuarch" ]; then
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# Cortex-R7 and Cortex-R8 are real-time and only used in medical devices or such
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# I can't find their CPU part number, but it's probably not that useful anyway
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# model R7 R8 A9 A15 A17 A57 A72 A73 A75
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# part ? ? 0xc09 0xc0f 0xc0e 0xd07 0xd08 0xd09 0xd0a
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# arch 7? 7? 7 7 7 8 8 8 8
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if [ "$cpuarch" = 7 ] && echo "$cpupart" | grep -Eq '^0x(c09|c0f|c0e)$'; then
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# armv7 vulnerable chips
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:
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elif [ "$cpuarch" = 8 ] && echo "$cpupart" | grep -Eq '^0x(d07|d08|d09|d0a)$'; then
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# armv8 vulnerable chips
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:
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else
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variant1=1
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variant2=1
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fi
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# for variant3, only A75 is vulnerable
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if ! [ "$cpuarch" = 8 -a "$cpupart" = 0xd0a ]; then
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variant3=1
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fi
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fi
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fi
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[ "$1" = 1 ] && return $variant1
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[ "$1" = 2 ] && return $variant2
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[ "$1" = 3 ] && return $variant3
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echo "$0: error: invalid variant '$1' passed to is_cpu_vulnerable()" >&2
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exit 255
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}
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show_header()
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{
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_info "\033[1;34mSpectre and Meltdown mitigation detection tool v$VERSION\033[0m"
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_info
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}
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parse_opt_file()
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{
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# parse_opt_file option_name option_value
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option_name="$1"
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option_value="$2"
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if [ -z "$option_value" ]; then
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show_header
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show_usage
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echo "$0: error: --$option_name expects one parameter (a file)" >&2
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exit 1
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elif [ ! -e "$option_value" ]; then
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show_header
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echo "$0: error: couldn't find file $option_value" >&2
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exit 1
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elif [ ! -f "$option_value" ]; then
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show_header
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echo "$0: error: $option_value is not a file" >&2
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exit 1
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elif [ ! -r "$option_value" ]; then
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show_header
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echo "$0: error: couldn't read $option_value (are you root?)" >&2
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exit 1
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fi
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echo "$option_value"
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exit 0
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}
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while [ -n "$1" ]; do
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if [ "$1" = "--kernel" ]; then
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opt_kernel=$(parse_opt_file kernel "$2")
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[ $? -ne 0 ] && exit 255
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shift 2
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opt_live=0
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elif [ "$1" = "--config" ]; then
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opt_config=$(parse_opt_file config "$2")
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[ $? -ne 0 ] && exit 255
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shift 2
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opt_live=0
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elif [ "$1" = "--map" ]; then
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opt_map=$(parse_opt_file map "$2")
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[ $? -ne 0 ] && exit 255
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shift 2
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opt_live=0
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elif [ "$1" = "--live" ]; then
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opt_live_explicit=1
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shift
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elif [ "$1" = "--no-color" ]; then
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opt_no_color=1
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shift
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elif [ "$1" = "--no-sysfs" ]; then
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opt_no_sysfs=1
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shift
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elif [ "$1" = "--batch" ]; then
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opt_batch=1
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opt_verbose=0
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shift
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case "$1" in
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text|nrpe|json) opt_batch_format="$1"; shift;;
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--*) ;; # allow subsequent flags
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'') ;; # allow nothing at all
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*)
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echo "$0: error: unknown batch format '$1'" >&2
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echo "$0: error: --batch expects a format from: text, nrpe, json" >&2
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exit 255
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;;
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esac
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elif [ "$1" = "-v" -o "$1" = "--verbose" ]; then
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opt_verbose=$(expr $opt_verbose + 1)
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shift
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elif [ "$1" = "--variant" ]; then
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if [ -z "$2" ]; then
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echo "$0: error: option --variant expects a parameter (1, 2 or 3)" >&2
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exit 255
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fi
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case "$2" in
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1) opt_variant1=1; opt_allvariants=0;;
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2) opt_variant2=1; opt_allvariants=0;;
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3) opt_variant3=1; opt_allvariants=0;;
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*)
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echo "$0: error: invalid parameter '$2' for --variant, expected either 1, 2 or 3" >&2;
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exit 255
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;;
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esac
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shift 2
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elif [ "$1" = "-h" -o "$1" = "--help" ]; then
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show_header
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show_usage
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exit 0
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elif [ "$1" = "--version" ]; then
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opt_no_color=1
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show_header
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exit 0
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elif [ "$1" = "--disclaimer" ]; then
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show_header
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show_disclaimer
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exit 0
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else
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show_header
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show_usage
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echo "$0: error: unknown option '$1'"
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exit 255
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fi
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done
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show_header
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# print status function
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pstatus()
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{
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if [ "$opt_no_color" = 1 ]; then
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_info_nol "$2"
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else
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case "$1" in
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red) col="\033[101m\033[30m";;
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green) col="\033[102m\033[30m";;
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yellow) col="\033[103m\033[30m";;
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blue) col="\033[104m\033[30m";;
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*) col="";;
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esac
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_info_nol "$col $2 \033[0m"
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fi
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[ -n "$3" ] && _info_nol " ($3)"
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_info
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}
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# Print the final status of a vulnerability (incl. batch mode)
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# Arguments are: CVE UNK/OK/VULN description
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pvulnstatus()
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{
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if [ "$opt_batch" = 1 ]; then
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case "$opt_batch_format" in
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text) _echo 0 "$1: $2 ($3)";;
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json)
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case "$1" in
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CVE-2017-5753) aka="SPECTRE VARIANT 1";;
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CVE-2017-5715) aka="SPECTRE VARIANT 2";;
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CVE-2017-5754) aka="MELTDOWN";;
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esac
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case "$2" in
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UNK) is_vuln="null";;
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VULN) is_vuln="true";;
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OK) is_vuln="false";;
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esac
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json_output="${json_output:-[}{\"NAME\":\""$aka"\",\"CVE\":\""$1"\",\"VULNERABLE\":$is_vuln,\"INFOS\":\""$3"\"},"
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;;
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nrpe) [ "$2" = VULN ] && nrpe_vuln="$nrpe_vuln $1";;
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esac
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fi
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# always fill global_* vars because we use that do decide the program exit code
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case "$2" in
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UNK) global_unknown="1";;
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VULN) global_critical="1";;
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esac
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# display info if we're not in quiet/batch mode
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_info_nol "> \033[46m\033[30mSTATUS:\033[0m "
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case "$2" in
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UNK) pstatus yellow 'UNKNOWN' "$@";;
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VULN) pstatus red 'VULNERABLE' "$@";;
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OK) pstatus green 'NOT VULNERABLE' "$@";;
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esac
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}
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# The 3 below functions are taken from the extract-linux script, available here:
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# https://github.com/torvalds/linux/blob/master/scripts/extract-vmlinux
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# The functions have been modified for better integration to this script
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# The original header of the file has been retained below
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# ----------------------------------------------------------------------
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# extract-vmlinux - Extract uncompressed vmlinux from a kernel image
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#
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# Inspired from extract-ikconfig
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# (c) 2009,2010 Dick Streefland <dick@streefland.net>
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#
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# (c) 2011 Corentin Chary <corentin.chary@gmail.com>
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#
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# Licensed under the GNU General Public License, version 2 (GPLv2).
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# ----------------------------------------------------------------------
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vmlinux=''
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vmlinux_err=''
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check_vmlinux()
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{
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readelf -h "$1" > /dev/null 2>&1 || return 1
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return 0
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}
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try_decompress()
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{
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# The obscure use of the "tr" filter is to work around older versions of
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# "grep" that report the byte offset of the line instead of the pattern.
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# Try to find the header ($1) and decompress from here
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for pos in `tr "$1\n$2" "\n$2=" < "$6" | grep -abo "^$2"`
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do
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_debug "try_decompress: magic for $3 found at offset $pos"
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if ! which "$3" >/dev/null 2>&1; then
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vmlinux_err="missing '$3' tool, please install it, usually it's in the '$5' package"
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return 0
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fi
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pos=${pos%%:*}
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tail -c+$pos "$6" 2>/dev/null | $3 $4 > $vmlinuxtmp 2>/dev/null
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if check_vmlinux "$vmlinuxtmp"; then
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vmlinux="$vmlinuxtmp"
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_debug "try_decompress: decompressed with $3 successfully!"
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return 0
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else
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_debug "try_decompress: decompression with $3 did not work"
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fi
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done
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return 1
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}
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extract_vmlinux()
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{
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[ -n "$1" ] || return 1
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# Prepare temp files:
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vmlinuxtmp="$(mktemp /tmp/vmlinux-XXXXXX)"
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trap "rm -f $vmlinuxtmp" EXIT
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# Initial attempt for uncompressed images or objects:
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if check_vmlinux "$1"; then
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cat "$1" > "$vmlinuxtmp"
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vmlinux=$vmlinuxtmp
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return 0
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fi
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# That didn't work, so retry after decompression.
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try_decompress '\037\213\010' xy gunzip '' gunzip "$1" && return 0
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try_decompress '\3757zXZ\000' abcde unxz '' xz-utils "$1" && return 0
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try_decompress 'BZh' xy bunzip2 '' bzip2 "$1" && return 0
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try_decompress '\135\0\0\0' xxx unlzma '' xz-utils "$1" && return 0
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try_decompress '\211\114\132' xy 'lzop' '-d' lzop "$1" && return 0
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try_decompress '\002\041\114\030' xyy 'lz4' '-d -l' liblz4-tool "$1" && return 0
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return 1
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}
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# end of extract-vmlinux functions
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# check for mode selection inconsistency
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if [ "$opt_live_explicit" = 1 ]; then
|
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if [ -n "$opt_kernel" -o -n "$opt_config" -o -n "$opt_map" ]; then
|
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show_usage
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echo "$0: error: incompatible modes specified, use either --live or --kernel/--config/--map" >&2
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exit 255
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fi
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fi
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# root check (only for live mode, for offline mode, we already checked if we could read the files)
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if [ "$opt_live" = 1 ]; then
|
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if [ "$(id -u)" -ne 0 ]; then
|
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_warn "Note that you should launch this script with root privileges to get accurate information."
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_warn "We'll proceed but you might see permission denied errors."
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_warn "To run it as root, you can try the following command: sudo $0"
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_warn
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fi
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_info "Checking for vulnerabilities against running kernel \033[35m"$(uname -s) $(uname -r) $(uname -v) $(uname -m)"\033[0m"
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_info "CPU is\033[35m"$(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
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# first, look for the BOOT_IMAGE hint in the kernel cmdline
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if [ -r /proc/cmdline ] && grep -q 'BOOT_IMAGE=' /proc/cmdline; then
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opt_kernel=$(grep -Eo 'BOOT_IMAGE=[^ ]+' /proc/cmdline | cut -d= -f2)
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_debug "found opt_kernel=$opt_kernel in /proc/cmdline"
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# if we have a dedicated /boot partition, our bootloader might have just called it /
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# so try to prepend /boot and see if we find anything
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[ -e "/boot/$opt_kernel" ] && opt_kernel="/boot/$opt_kernel"
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_debug "opt_kernel is now $opt_kernel"
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# else, the full path is already there (most probably /boot/something)
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fi
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# if we didn't find a kernel, default to guessing
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if [ ! -e "$opt_kernel" ]; then
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[ -e /boot/vmlinuz-linux ] && opt_kernel=/boot/vmlinuz-linux
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[ -e /boot/vmlinuz-linux-libre ] && opt_kernel=/boot/vmlinuz-linux-libre
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|
[ -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)
|
|
fi
|
|
|
|
# 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
|
|
|
|
# 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 /boot/config-$(uname -r) ]; then
|
|
opt_config=/boot/config-$(uname -r)
|
|
fi
|
|
else
|
|
_info "Checking for vulnerabilities against specified kernel"
|
|
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 "$dumped_config" ]; then
|
|
_verbose "Will use kconfig \033[35m/proc/config.gz\033[0m"
|
|
elif [ -n "$opt_config" ]; then
|
|
_verbose "Will use kconfig \033[35m$opt_config\033[0m"
|
|
else
|
|
_verbose "Will use no kconfig (accuracy might be reduced)"
|
|
bad_accuracy=1
|
|
fi
|
|
if [ -n "$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 "$opt_kernel" ]; then
|
|
if ! which readelf >/dev/null 2>&1; then
|
|
vmlinux_err="missing 'readelf' tool, please install it, usually it's in the 'binutils' package"
|
|
else
|
|
extract_vmlinux "$opt_kernel"
|
|
fi
|
|
else
|
|
vmlinux_err="couldn't find your kernel image in /boot, if you used netboot, this is normal"
|
|
fi
|
|
if [ -z "$vmlinux" -o ! -r "$vmlinux" ]; then
|
|
[ -z "$vmlinux_err" ] && vmlinux_err="couldn't extract your kernel from $opt_kernel"
|
|
fi
|
|
|
|
_info
|
|
|
|
# end of header stuff
|
|
|
|
# now we define some util functions and the check_*() funcs, as
|
|
# the user can choose to execute only some of those
|
|
|
|
mount_debugfs()
|
|
{
|
|
if [ ! -e /sys/kernel/debug/sched_features ]; then
|
|
# try to mount the debugfs hierarchy ourselves and remember it to umount afterwards
|
|
mount -t debugfs debugfs /sys/kernel/debug 2>/dev/null && mounted_debugfs=1
|
|
fi
|
|
}
|
|
|
|
umount_debugfs()
|
|
{
|
|
if [ "$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
|
|
_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")
|
|
_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
|
|
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
|
|
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
|
|
# 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
|
|
fi
|
|
fi
|
|
|
|
# if we have the /sys interface, don't even check is_cpu_vulnerable ourselves, the kernel already does it
|
|
if [ "$sys_interface_available" = 0 ] && ! is_cpu_vulnerable 1; then
|
|
# override status & msg in case CPU is not vulnerable after all
|
|
msg="your CPU vendor reported your CPU model as not vulnerable"
|
|
status=OK
|
|
fi
|
|
|
|
# report status
|
|
pvulnstatus CVE-2017-5753 "$status" "$msg"
|
|
}
|
|
|
|
###################
|
|
# SPECTRE VARIANT 2
|
|
check_variant2()
|
|
{
|
|
_info "\033[1;34mCVE-2017-5715 [branch target injection] aka 'Spectre Variant 2'\033[0m"
|
|
|
|
status=UNK
|
|
sys_interface_available=0
|
|
msg=''
|
|
if sys_interface_check "/sys/devices/system/cpu/vulnerabilities/spectre_v2"; then
|
|
# this kernel has the /sys interface, trust it over everything
|
|
sys_interface_available=1
|
|
else
|
|
_info "* Mitigation 1"
|
|
_info_nol "* Hardware (CPU microcode) support for mitigation: "
|
|
if [ ! -e /dev/cpu/0/msr ]; then
|
|
# try to load the module ourselves (and remember it so we can rmmod it afterwards)
|
|
modprobe msr 2>/dev/null && insmod_msr=1
|
|
_debug "attempted to load module msr, ret=$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 [ $? -eq 0 ]; then
|
|
pstatus green YES
|
|
else
|
|
pstatus red NO
|
|
fi
|
|
fi
|
|
|
|
if [ "$insmod_msr" = 1 ]; then
|
|
# if we used modprobe ourselves, rmmod the module
|
|
rmmod msr 2>/dev/null
|
|
_debug "attempted to unload module msr, ret=$?"
|
|
fi
|
|
|
|
_info_nol "* Kernel support for IBRS: "
|
|
if [ "$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)
|
|
_debug "ibrs: found $ibrs_file=$ibrs_enabled"
|
|
break
|
|
else
|
|
_debug "ibrs: file $ibrs_file doesn't exist"
|
|
fi
|
|
done
|
|
fi
|
|
if [ "$ibrs_supported" != 1 -a -n "$opt_map" ]; then
|
|
if grep -q spec_ctrl "$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
|
|
pstatus red NO
|
|
fi
|
|
|
|
_info_nol "* IBRS enabled for Kernel space: "
|
|
if [ "$opt_live" = 1 ]; then
|
|
# 0 means disabled
|
|
# 1 is enabled only for kernel space
|
|
# 2 is enabled for kernel and user space
|
|
case "$ibrs_enabled" in
|
|
"") [ "$ibrs_supported" = 1 ] && pstatus yellow UNKNOWN || pstatus red NO;;
|
|
0) pstatus red NO;;
|
|
1 | 2) pstatus green YES;;
|
|
*) pstatus yellow UNKNOWN;;
|
|
esac
|
|
else
|
|
pstatus blue N/A "not testable in offline mode"
|
|
fi
|
|
|
|
_info_nol "* IBRS enabled for User space: "
|
|
if [ "$opt_live" = 1 ]; then
|
|
case "$ibrs_enabled" in
|
|
"") [ "$ibrs_supported" = 1 ] && pstatus yellow UNKNOWN || pstatus red NO;;
|
|
0 | 1) pstatus red NO;;
|
|
2) pstatus green YES;;
|
|
*) 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
|
|
_debug "retpoline: found "$(grep '^CONFIG_RETPOLINE' "$opt_config")" in $opt_config"
|
|
else
|
|
pstatus red NO
|
|
fi
|
|
else
|
|
pstatus yellow UNKNOWN "couldn't read your kernel configuration"
|
|
fi
|
|
|
|
_info_nol "* Kernel compiled with a retpoline-aware compiler: "
|
|
# Now check if the compiler used to compile the kernel knows how to insert retpolines in generated asm
|
|
# For gcc, this is -mindirect-branch=thunk-extern (detected by the kernel makefiles)
|
|
# See gcc commit https://github.com/hjl-tools/gcc/commit/23b517d4a67c02d3ef80b6109218f2aadad7bd79
|
|
# In latest retpoline LKML patches, the noretpoline_setup symbol exists only if CONFIG_RETPOLINE is set
|
|
# *AND* if the compiler is retpoline-compliant, so look for that symbol
|
|
if [ -n "$opt_map" ]; then
|
|
# look for the symbol
|
|
if grep -qw noretpoline_setup "$opt_map"; then
|
|
retpoline_compiler=1
|
|
pstatus green YES "noretpoline_setup symbol found in System.map"
|
|
else
|
|
pstatus red NO
|
|
fi
|
|
elif [ -n "$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 "$vmlinux" 2>/dev/null | grep -qw 'noretpoline_setup'; then
|
|
retpoline_compiler=1
|
|
pstatus green YES "noretpoline_setup found in vmlinux symbols"
|
|
else
|
|
pstatus red NO
|
|
fi
|
|
elif grep -q noretpoline_setup "$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
|
|
pstatus red NO
|
|
fi
|
|
else
|
|
pstatus yellow UNKNOWN "couldn't find your kernel image or System.map"
|
|
fi
|
|
fi
|
|
|
|
# if we have the /sys interface, don't even check is_cpu_vulnerable ourselves, the kernel already does it
|
|
if [ "$sys_interface_available" = 0 ] && ! is_cpu_vulnerable 2; then
|
|
# override status & msg in case CPU is not vulnerable after all
|
|
pvulnstatus CVE-2017-5715 OK "your CPU vendor reported your CPU model as not vulnerable"
|
|
elif [ -z "$msg" ]; then
|
|
# if msg is empty, sysfs check didn't fill it, rely on our own test
|
|
if [ "$retpoline" = 1 -a "$retpoline_compiler" = 1 ]; then
|
|
pvulnstatus CVE-2017-5715 OK "retpoline mitigate the vulnerability"
|
|
elif [ "$opt_live" = 1 ]; then
|
|
if [ "$ibrs_enabled" = 1 -o "$ibrs_enabled" = 2 ]; then
|
|
pvulnstatus CVE-2017-5715 OK "IBRS mitigates the vulnerability"
|
|
else
|
|
pvulnstatus CVE-2017-5715 VULN "IBRS hardware + kernel support OR kernel with retpoline are needed to mitigate the vulnerability"
|
|
fi
|
|
else
|
|
if [ "$ibrs_supported" = 1 ]; then
|
|
pvulnstatus CVE-2017-5715 OK "offline mode: IBRS will mitigate the vulnerability if enabled at runtime"
|
|
else
|
|
pvulnstatus CVE-2017-5715 VULN "IBRS hardware + kernel support OR kernel with retpoline are needed to mitigate the vulnerability"
|
|
fi
|
|
fi
|
|
else
|
|
pvulnstatus CVE-2017-5715 "$status" "$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
|
|
else
|
|
_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
|
|
_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 -a -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 -a -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
|
|
# RedHat 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: $kpti_enabled"
|
|
elif dmesg | grep -Eq "$dmesg_grep"; then
|
|
# if we can't find the flag, grep dmesg output
|
|
_debug "kpti_enabled: found hint in dmesg: "$(dmesg | grep -E "$dmesg_grep")
|
|
kpti_enabled=1
|
|
elif [ -r /var/log/dmesg ] && grep -Eq "$dmesg_grep" /var/log/dmesg; then
|
|
# if we can't find the flag in dmesg output, grep in /var/log/dmesg when readable
|
|
_debug "kpti_enabled: found hint in /var/log/dmesg: "$(grep -E "$dmesg_grep" /var/log/dmesg)
|
|
kpti_enabled=1
|
|
else
|
|
_debug "kpti_enabled: couldn't find any hint that PTI is enabled"
|
|
kpti_enabled=0
|
|
fi
|
|
if [ "$kpti_enabled" = 1 ]; then
|
|
pstatus green YES
|
|
else
|
|
pstatus red NO
|
|
fi
|
|
else
|
|
pstatus blue N/A "can't verify if PTI is enabled in offline mode"
|
|
fi
|
|
fi
|
|
|
|
# if we have the /sys interface, don't even check is_cpu_vulnerable ourselves, the kernel already does it
|
|
cve='CVE-2017-5754'
|
|
if [ "$sys_interface_available" = 0 ] && ! 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"
|
|
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"
|
|
else
|
|
pvulnstatus $cve VULN "PTI is needed to mitigate the vulnerability"
|
|
fi
|
|
fi
|
|
else
|
|
pvulnstatus $cve "$status" "$msg"
|
|
fi
|
|
}
|
|
|
|
# now run the checks the user asked for
|
|
if [ "$opt_variant1" = 1 -o "$opt_allvariants" = 1 ]; then
|
|
check_variant1
|
|
_info
|
|
fi
|
|
if [ "$opt_variant2" = 1 -o "$opt_allvariants" = 1 ]; then
|
|
check_variant2
|
|
_info
|
|
fi
|
|
if [ "$opt_variant3" = 1 -o "$opt_allvariants" = 1 ]; then
|
|
check_variant3
|
|
_info
|
|
fi
|
|
|
|
_info "A false sense of security is worse than no security at all, see --disclaimer"
|
|
|
|
# this'll umount only if we mounted debugfs ourselves
|
|
umount_debugfs
|
|
|
|
# cleanup the temp decompressed config
|
|
[ -n "$dumped_config" ] && rm -f "$dumped_config"
|
|
|
|
if [ "$opt_batch" = 1 -a "$opt_batch_format" = "nrpe" ]; then
|
|
if [ ! -z "$nrpe_vuln" ]; then
|
|
echo "Vulnerable:$nrpe_vuln"
|
|
else
|
|
echo "OK"
|
|
fi
|
|
fi
|
|
|
|
if [ "$opt_batch" = 1 -a "$opt_batch_format" = "json" ]; then
|
|
_echo 0 ${json_output%?}']'
|
|
fi
|
|
|
|
# exit with the proper exit code
|
|
[ "$global_critical" = 1 ] && exit 2 # critical
|
|
[ "$global_unknown" = 1 ] && exit 3 # unknown
|
|
exit 0 # ok
|