bump to v0.23 to reflect changes

NRPE mode

README.md

@@ -8,6 +8,10 @@ You can also specify a kernel image on the command line, if you'd like to inspec
 
 The script will do its best to detect mitigations, including backported non-vanilla patches, regardless of the advertised kernel version number.
 
+## Example of script output
+
+![checker](https://framapic.org/FjroIZximyoM/EO5msoSMKb6L.png)
+
 ## Quick summary of the CVEs
 
 **CVE-2017-5753** bounds check bypass (Spectre Variant 1)
@@ -28,69 +32,3 @@ The script will do its best to detect mitigations, including backported non-vani
    - Impact: Kernel
    - Mitigation: updated kernel (with PTI/KPTI patches), updating the kernel is enough
    - Performance impact of the mitigation: low to medium
-
-## Example of script output
-
-### Ubuntu LTS (before official patches)
-
-```
-$ sudo ./spectre-and-meltdown.sh
-Spectre and Meltdown mitigation detection tool v0.16
-
-Checking for vulnerabilities against live running kernel Linux 4.4.0-104-generic #127-Ubuntu SMP Mon Dec 11 12:16:42 UTC 2017 x86_64
-Will use vmlinux image /boot/vmlinuz-4.4.0-104-generic
-Will use kconfig /boot/config-4.4.0-104-generic
-Will use System.map file /boot/System.map-4.4.0-104-generic
-
-CVE-2017-5753 [bounds check bypass] aka 'Spectre Variant 1'
-* Kernel compiled with LFENCE opcode inserted at the proper places:  NO  (only 38 opcodes found, should be >= 70)
-> STATUS:  VULNERABLE 
-
-CVE-2017-5715 [branch target injection] aka 'Spectre Variant 2'
-* Mitigation 1
-*   Hardware (CPU microcode) support for mitigation:  NO 
-*   Kernel support for IBRS:  NO 
-*   IBRS enabled for Kernel space:  NO 
-*   IBRS enabled for User space:  NO 
-* Mitigation 2
-*   Kernel compiled with retpoline option:  NO 
-*   Kernel compiled with a retpoline-aware compiler:  NO 
-> STATUS:  VULNERABLE  (IBRS hardware + kernel support OR kernel with retpoline are needed to mitigate the vulnerability)
-
-CVE-2017-5754 [rogue data cache load] aka 'Meltdown' aka 'Variant 3'
-* Kernel supports Page Table Isolation (PTI):  NO 
-* PTI enabled and active:  NO 
-> STATUS:  VULNERABLE  (PTI is needed to mitigate the vulnerability)
-```
-
-### First patched kernel of RHEL6
-
-```
-$ sudo ./spectre-meltdown-checker.sh --kernel /tmp/vmlinuz-2.6.32-696.18.7.el6.x86_64 --config /tmp/config-2.6.32-696.18.7.el6.x86_64 --map /tmp/System.map-2.6.32-696.18.7.el6.x86_64
-Spectre and Meltdown mitigation detection tool v0.16
-
-Checking for vulnerabilities against specified kernel
-Will use vmlinux image /tmp/vmlinuz-2.6.32-696.18.7.el6.x86_64
-Will use kconfig /tmp/config-2.6.32-696.18.7.el6.x86_64
-Will use System.map file /tmp/System.map-2.6.32-696.18.7.el6.x86_64
-
-CVE-2017-5753 [bounds check bypass] aka 'Spectre Variant 1'
-* Kernel compiled with LFENCE opcode inserted at the proper places:  YES  (84 opcodes found, which is >= 70)
-> STATUS:  NOT VULNERABLE 
-
-CVE-2017-5715 [branch target injection] aka 'Spectre Variant 2'
-* Mitigation 1
-*   Hardware (CPU microcode) support for mitigation:  NO 
-*   Kernel support for IBRS:  YES 
-*   IBRS enabled for Kernel space:  N/A  (not testable in offline mode)
-*   IBRS enabled for User space:  N/A  (not testable in offline mode)
-* Mitigation 2
-*   Kernel compiled with retpoline option:  NO 
-*   Kernel compiled with a retpoline-aware compiler:  NO 
-> STATUS:  NOT VULNERABLE  (offline mode: IBRS will mitigate the vulnerability if enabled at runtime)
-
-CVE-2017-5754 [rogue data cache load] aka 'Meltdown' aka 'Variant 3'
-* Kernel supports Page Table Isolation (PTI):  YES 
-* PTI enabled and active:  N/A  (can't verify if PTI is enabled in offline mode)
-> STATUS:  NOT VULNERABLE  (offline mode: PTI will mitigate the vulnerability if enabled at runtime)
-```

spectre-meltdown-checker.sh

@@ -8,13 +8,296 @@
 #
 # Stephane Lesimple
 #
-VERSION=0.19
+VERSION=0.23
+
+# Script configuration
+show_usage()
+{
+	cat <<EOF
+	Usage:
+		Live mode:    $0 [options] [--live]
+		Offline mode: $0 [options] [--kernel <vmlinux_file>] [--config <kernel_config>] [--map <kernel_map_file>]
+
+	Modes:
+		Two modes are available.
+
+		First mode is the "live" mode (default), it does its best to find information about the currently running kernel.
+		To run under this mode, just start the script without any option (you can also use --live explicitely)
+
+		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
+
+	Options:
+		--no-color			Don't use color codes
+		-v, --verbose			Increase verbosity level
+		--batch text			Produce machine readable output, this is the default if --batch is specified alone
+		--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)
+
+	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
+explicitely stated otherwise in a verifiable public announcement.
+
+This tool has been released in the hope that it'll be useful, but don't use it to jump to conclusions about your security.
+
+EOF
+}
+
+# parse options
+opt_kernel=''
+opt_config=''
+opt_map=''
+opt_live_explicit=0
+opt_live=1
+opt_no_color=0
+opt_batch=0
+opt_batch_format="text"
+opt_verbose=1
+opt_variant1=0
+opt_variant2=0
+opt_variant3=0
+opt_allvariants=1
+
+nrpe_critical=0
+nrpe_unknown=0
+nrpe_vuln=""
+
+__echo()
+{
+	opt="$1"
+	shift
+	msg="$@"
+	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")
+	fi
+	# explicitely call /bin/echo to avoid shell builtins that might not take options
+	/bin/echo $opt -e "$msg"
+}
+
+_echo()
+{
+	if [ $opt_verbose -ge $1 ]; then
+		shift
+		__echo '' "$@"
+	fi
+}
+
+_echo_nol()
+{
+	if [ $opt_verbose -ge $1 ]; then
+		shift
+		__echo -n "$@"
+	fi
+}
+
+_warn()
+{
+	_echo 0 "\033[31m${@}\033[0m"
+}
+
+_info()
+{
+	_echo 1 "$@"
+}
+
+_info_nol()
+{
+	_echo_nol 1 "$@"
+}
+
+_verbose()
+{
+	_echo 2 "$@"
+}
+
+is_cpu_vulnerable()
+{
+	# param: 1, 2 or 3 (variant)
+	# returns 1 if vulnerable, 0 if not vulnerable, 255 on error
+	# 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 AMD /proc/cpuinfo; then
+		variant1=0
+		variant2=1
+		variant3=1
+	elif grep -qi 'CPU implementer\s*:\s*0x41' /proc/cpuinfo; then
+		# ARM
+		# reference: https://developer.arm.com/support/security-update
+		cpupart=$(awk '/CPU part/         {print $4;exit}' /proc/cpuinfo)
+		cpuarch=$(awk '/CPU architecture/ {print $3;exit}' /proc/cpuinfo)
+		if [ -n "$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
+				variant1=0
+				variant2=0
+			elif [ "$cpuarch" = 8 ] && echo "$cpupart" | grep -Eq '^0x(d07|d08|d09|d0a)$'; then
+				# armv8 vulnerable chips
+				variant1=0
+				variant2=0
+			else
+				variant1=1
+				variant2=1
+			fi
+			# for variant3, only A75 is vulnerable
+			if [ "$cpuarch" = 8 -a "$cpupart" = 0xd0a ]; then
+				variant3=0
+			else
+				variant3=1
+			fi
+		fi
+	fi
+	[ "$1" = 1 ] && return $variant1
+	[ "$1" = 2 ] && return $variant2
+	[ "$1" = 3 ] && return $variant3
+	return 255
+}
+
+show_header()
+{
+	_info "\033[1;34mSpectre and Meltdown mitigation detection tool v$VERSION\033[0m"
+	_info
+}
+
+parse_opt_file()
+{
+	# parse_opt_file option_name option_value
+	option_name="$1"
+	option_value="$2"
+	if [ -z "$option_value" ]; then
+		show_header
+		show_usage
+		echo "$0: error: --$option_name expects one parameter (a file)" >&2
+		exit 1
+	elif [ ! -e "$option_value" ]; then
+		show_header
+		echo "$0: error: couldn't find file $option_value" >&2
+		exit 1
+	elif [ ! -f "$option_value" ]; then
+		show_header
+		echo "$0: error: $option_value is not a file" >&2
+		exit 1
+	elif [ ! -e "$option_value" ]; then
+		show_header
+		echo "$0: error: couldn't read $option_value (are you root?)" >&2
+		exit 1
+	fi
+	echo "$option_value"
+	exit 0
+}
+
+while [ -n "$1" ]; do
+	if [ "$1" = "--kernel" ]; then
+		opt_kernel=$(parse_opt_file kernel "$2")
+		[ $? -ne 0 ] && exit $?
+		shift 2
+		opt_live=0
+	elif [ "$1" = "--config" ]; then
+		opt_config=$(parse_opt_file config "$2")
+		[ $? -ne 0 ] && exit $?
+		shift 2
+		opt_live=0
+	elif [ "$1" = "--map" ]; then
+		opt_map=$(parse_opt_file map "$2")
+		[ $? -ne 0 ] && exit $?
+		shift 2
+		opt_live=0
+	elif [ "$1" = "--live" ]; then
+		opt_live_explicit=1
+		shift
+	elif [ "$1" = "--no-color" ]; then
+		opt_no_color=1
+		shift
+	elif [ "$1" = "--batch" ]; then
+		opt_batch=1
+		opt_verbose=0
+		shift
+		case "$1" in
+			text|nrpe) opt_batch_format="$1"; shift;;
+			--*) ;;    # allow subsequent flags
+			'') ;;     # allow nothing at all
+			*)
+				echo "$0: error: unknown batch format '$1'"
+				echo "$0: error: --batch expects a format from: text, nrpe"
+				exit 1 >&2
+				;;
+		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 1
+		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 1;;
+		esac
+		shift 2
+	elif [ "$1" = "-h" -o "$1" = "--help" ]; then
+		show_header
+		show_usage
+		exit 0
+	elif [ "$1" = "--disclaimer" ]; then
+		show_header
+		show_disclaimer
+		exit 0
+	else
+		show_header
+		show_usage
+		echo "$0: error: unknown option '$1'"
+		exit 1
+	fi
+done
+
+show_header
 
 # print status function
 pstatus()
 {
 	if [ "$opt_no_color" = 1 ]; then
-		_echo_nol "$2"
+		_info_nol "$2"
 	else
 		case "$1" in
 			red)    col="\033[101m\033[30m";;
@@ -23,12 +306,39 @@ pstatus()
 			blue)   col="\033[104m\033[30m";;
 			*)      col="";;
 		esac
-		_echo_nol "$col $2 \033[0m"
+		_info_nol "$col $2 \033[0m"
 	fi
-	[ -n "$3" ] && _echo_nol " ($3)"
-	_echo
+	[ -n "$3" ] && _info_nol " ($3)"
+	_info
 }
 
+# Print the final status of a vulnerability (incl. batch mode)
+# Arguments are: CVE UNK/OK/VULN description
+pvulnstatus()
+{
+	if [ "$opt_batch" = 1 ]; then
+		case "$opt_batch_format" in
+			text) _echo 0 "$1: $2 ($3)";;
+			nrpe)
+				case "$2" in
+					UKN) nrpe_unknown="1";;
+					VULN) nrpe_critical="1"; nrpe_vuln="$nrpe_vuln $1";;
+				esac
+				;;
+		esac
+	fi
+
+	_info_nol "> \033[46m\033[30mSTATUS:\033[0m "
+	vulnstatus="$2"
+	shift 2
+	case "$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
@@ -97,121 +407,6 @@ extract_vmlinux()
 
 # end of extract-vmlinux functions
 
-show_usage()
-{
-	cat <<EOF
-	Usage:
-		Live mode:    $0 [options] [--live]
-		Offline mode: $0 [options] [--kernel <vmlinux_file>] [--config <kernel_config>] [--map <kernel_map_file>]
-
-	Modes:
-		Two modes are available.
-
-		First mode is the "live" mode (default), it does its best to find information about the currently running kernel.
-		To run under this mode, just start the script without any option (you can also use --live explicitely)
-
-		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
-
-	Options:
-		--no-color			Don't use color codes
-
-EOF
-}
-
-__echo()
-{
-	opt="$1"
-	shift
-	msg="$@"
-	if [ "$opt_no_color" = 1 ] ; then
-		# strip ANSI color codes
-		msg=$(echo "$msg" | sed -r "s/\x1B\[([0-9]{1,2}(;[0-9]{1,2})?)?[m|K]//g")
-	fi
-	# explicitely call /bin/echo to avoid shell builtins that might not take options
-	/bin/echo $opt -e "$msg"
-}
-
-_echo()
-{
-	__echo '' "$@"
-}
-
-_echo_nol()
-{
-	__echo -n "$@"
-}
-
-_echo "\033[1;34mSpectre and Meltdown mitigation detection tool v$VERSION\033[0m"
-_echo
-
-# parse options
-opt_kernel=''
-opt_config=''
-opt_map=''
-opt_live_explicit=0
-opt_live=1
-opt_no_color=0
-
-parse_opt_file()
-{
-	# parse_opt_file option_name option_value
-	option_name="$1"
-	option_value="$2"
-	if [ -z "$option_value" ]; then
-		show_usage
-		echo "$0: error: --$option_name expects one parameter (a file)" >&2
-		exit 1
-	elif [ ! -e "$option_value" ]; then
-		echo "$0: error: couldn't find file $option_value" >&2
-		exit 1
-	elif [ ! -f "$option_value" ]; then
-		echo "$0: error: $option_value is not a file" >&2
-		exit 1
-	elif [ ! -e "$option_value" ]; then
-		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 $?
-		shift 2
-		opt_live=0
-	elif [ "$1" = "--config" ]; then
-		opt_config=$(parse_opt_file config "$2")
-		[ $? -ne 0 ] && exit $?
-		shift 2
-		opt_live=0
-	elif [ "$1" = "--map" ]; then
-		opt_map=$(parse_opt_file map "$2")
-		[ $? -ne 0 ] && exit $?
-		shift 2
-		opt_live=0
-	elif [ "$1" = "--live" ]; then
-		opt_live_explicit=1
-		shift
-	elif [ "$1" = "--no-color" ]; then
-		opt_no_color=1
-		shift
-	elif [ "$1" = "-h" -o "$1" = "--help" ]; then
-		show_usage
-		exit 0
-	else
-		show_usage
-		echo "$0: error: unknown option '$1'"
-		exit 1
-	fi
-done
-
 # check for mode selection inconsistency
 if [ "$opt_live_explicit" = 1 ]; then
 	if [ -n "$opt_kernel" -o -n "$opt_config" -o -n "$opt_map" ]; then
@@ -225,12 +420,12 @@ fi
 
 if [ "$opt_live" = 1 ]; then
 	if [ "$(id -u)" -ne 0 ]; then
-		_echo "\033[31mNote that you should launch this script with root privileges to get accurate information.\033[0m"
-		_echo "\033[31mWe'll proceed but you might see permission denied errors.\033[0m"
-		_echo "\033[31mTo run it as root, you can try the following command: sudo $0\033[0m"
-		_echo
+		_warn "Note that you should launch this script with root privileges to get accurate information."
+		_warn "We'll proceed but you might see permission denied errors."
+		_warn "To run it as root, you can try the following command: sudo $0"
+		_warn
 	fi
-	_echo "Checking for vulnerabilities against live running kernel \033[35m"$(uname -s) $(uname -r) $(uname -v) $(uname -m)"\033[0m"
+	_info "Checking for vulnerabilities against live running kernel \033[35m"$(uname -s) $(uname -r) $(uname -v) $(uname -m)"\033[0m"
 
 	# try to find the image of the current running kernel
 	[ -e /boot/vmlinuz-linux       ] && opt_kernel=/boot/vmlinuz-linux
@@ -257,24 +452,24 @@ if [ "$opt_live" = 1 ]; then
 		opt_config=/boot/config-$(uname -r)
 	fi
 else
-	_echo "Checking for vulnerabilities against specified kernel"
+	_info "Checking for vulnerabilities against specified kernel"
 fi
 if [ -n "$opt_kernel" ]; then
-	_echo "Will use vmlinux image \033[35m$opt_kernel\033[0m"
+	_verbose "Will use vmlinux image \033[35m$opt_kernel\033[0m"
 else
-	_echo "Will use no vmlinux image (accuracy might be reduced)"
+	_verbose "Will use no vmlinux image (accuracy might be reduced)"
 fi
 if [ -n "$dumped_config" ]; then
-	_echo "Will use kconfig \033[35m/proc/config.gz\033[0m"
+	_verbose "Will use kconfig \033[35m/proc/config.gz\033[0m"
 elif [ -n "$opt_config" ]; then
-	_echo "Will use kconfig \033[35m$opt_config\033[0m"
+	_verbose "Will use kconfig \033[35m$opt_config\033[0m"
 else
-	_echo "Will use no kconfig (accuracy might be reduced)"
+	_verbose "Will use no kconfig (accuracy might be reduced)"
 fi
 if [ -n "$opt_map" ]; then
-	_echo "Will use System.map file \033[35m$opt_map\033[0m"
+	_verbose "Will use System.map file \033[35m$opt_map\033[0m"
 else
-	_echo "Will use no System.map file (accuracy might be reduced)"
+	_verbose "Will use no System.map file (accuracy might be reduced)"
 fi
 
 if [ -e "$opt_kernel" ]; then
@@ -284,23 +479,46 @@ if [ -e "$opt_kernel" ]; then
 		extract_vmlinux "$opt_kernel"
 	fi
 else
-	vmlinux_err="couldn't find your kernel image in /boot, if you used neboot, this is normal"
+	vmlinux_err="couldn't find your kernel image in /boot, if you used netboot, this is normal"
 fi
 if [ -z "$vmlinux" -o ! -r "$vmlinux" ]; then
 	[ -z "$vmlinux_err" ] && vmlinux_err="couldn't extract your kernel from $opt_kernel"
 fi
 
-_echo
+_info
 
-###########
-# SPECTRE 1
-_echo "\033[1;34mCVE-2017-5753 [bounds check bypass] aka 'Spectre Variant 1'\033[0m"
-_echo_nol "* Checking count of LFENCE opcodes in kernel: "
+# end of header stuff
 
-status=0
-if [ -n "$vmlinux_err" ]; then
+# now we define some util functions and the check_*() funcs, as
+# the user can choose to execute only some of those
+
+mount_debugfs()
+{
+	if [ ! -e /sys/kernel/debug/sched_features ]; then
+		# try to mount the debugfs hierarchy ourselves and remember it to umount afterwards
+		mount -t debugfs debugfs /sys/kernel/debug 2>/dev/null && mounted_debugfs=1
+	fi
+}
+
+umount_debugfs()
+{
+	if [ "$mounted_debugfs" = 1 ]; then
+		# umount debugfs if we did mount it ourselves
+		umount /sys/kernel/debug
+	fi
+}
+
+###################
+# SPECTRE VARIANT 1
+check_variant1()
+{
+	_info "\033[1;34mCVE-2017-5753 [bounds check bypass] aka 'Spectre Variant 1'\033[0m"
+	_info_nol "* Checking count of LFENCE opcodes in kernel: "
+
+	status=0
+	if [ -n "$vmlinux_err" ]; then
 		pstatus yellow UNKNOWN "$vmlinux_err"
-else
+	else
 		if ! which objdump >/dev/null 2>&1; then
 			pstatus yellow UNKNOWN "missing 'objdump' tool, please install it, usually it's in the binutils package"
 		else
@@ -319,26 +537,33 @@ else
 				status=2
 			fi
 		fi
-fi
+	fi
 
-_echo_nol "> \033[46m\033[30mSTATUS:\033[0m "
-[ "$status" = 0 ] && pstatus yellow UNKNOWN
-[ "$status" = 1 ] && pstatus red   'VULNERABLE'     'heuristic to be improved when official patches become available'
-[ "$status" = 2 ] && pstatus green 'NOT VULNERABLE' 'heuristic to be improved when official patches become available'
+	if ! is_cpu_vulnerable 1; then
+		pvulnstatus CVE-2017-5753 OK "your CPU vendor reported your CPU model as not vulnerable"
+	else
+		case "$status" in
+			0) pvulnstatus CVE-2017-5753 UNK "impossible to check ${vmlinux}";;
+			1) pvulnstatus CVE-2017-5753 VULN 'heuristic to be improved when official patches become available';;
+			2) pvulnstatus CVE-2017-5753 OK 'heuristic to be improved when official patches become available';;
+		esac
+	fi
+}
 
-###########
-# VARIANT 2
-_echo
-_echo "\033[1;34mCVE-2017-5715 [branch target injection] aka 'Spectre Variant 2'\033[0m"
-_echo "* Mitigation 1"
-_echo_nol "*   Hardware (CPU microcode) support for mitigation: "
-if [ ! -e /dev/cpu/0/msr ]; then
+###################
+# SPECTRE VARIANT 2
+check_variant2()
+{
+	_info "\033[1;34mCVE-2017-5715 [branch target injection] aka 'Spectre Variant 2'\033[0m"
+	_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
-fi
-if [ ! -e /dev/cpu/0/msr ]; then
+	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
+	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
@@ -348,19 +573,16 @@ else
 		else
 			pstatus red NO
 		fi
-fi
+	fi
 
-if [ "$insmod_msr" = 1 ]; then
+	if [ "$insmod_msr" = 1 ]; then
 		# if we used modprobe ourselves, rmmod the module
 		rmmod msr 2>/dev/null
-fi
-
-_echo_nol "*   Kernel support for IBRS: "
-if [ "$opt_live" = 1 ]; then
-	if [ ! -e /sys/kernel/debug/sched_features ]; then
-		# try to mount the debugfs hierarchy ourselves and remember it to umount afterwards
-		mount -t debugfs debugfs /sys/kernel/debug 2>/dev/null && mounted_debugfs=1
 	fi
+
+	_info_nol "*   Kernel support for IBRS: "
+	if [ "$opt_live" = 1 ]; then
+		mount_debugfs
 		if [ -e /sys/kernel/debug/ibrs_enabled ]; then
 			# if the file is there, we have IBRS compiled-in
 			pstatus green YES
@@ -372,19 +594,19 @@ if [ "$opt_live" = 1 ]; then
 			ibrs_supported=1
 			ibrs_enabled=$(cat /sys/kernel/debug/x86/ibrs_enabled 2>/dev/null)
 		fi
-fi
-if [ "$ibrs_supported" != 1 -a -n "$opt_map" ]; then
+	fi
+	if [ "$ibrs_supported" != 1 -a -n "$opt_map" ]; then
 		if grep -q spec_ctrl "$opt_map"; then
 			pstatus green YES
 			ibrs_supported=1
 		fi
-fi
-if [ "$ibrs_supported" != 1 ]; then
+	fi
+	if [ "$ibrs_supported" != 1 ]; then
 		pstatus red NO
-fi
+	fi
 
-_echo_nol "*   IBRS enabled for Kernel space: "
-if [ "$opt_live" = 1 ]; then
+	_info_nol "*   IBRS enabled for Kernel space: "
+	if [ "$opt_live" = 1 ]; then
 		# 0 means disabled
 		# 1 is enabled only for kernel space
 		# 2 is enabled for kernel and user space
@@ -394,43 +616,43 @@ if [ "$opt_live" = 1 ]; then
 			1 | 2) pstatus green YES;;
 			*)     pstatus yellow UNKNOWN;;
 		esac
-else
+	else
 		pstatus blue N/A "not testable in offline mode"
-fi
+	fi
 
-_echo_nol "*   IBRS enabled for User space: "
-if [ "$opt_live" = 1 ]; then
+	_info_nol "*   IBRS enabled for User space: "
+	if [ "$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
+	else
 		pstatus blue N/A "not testable in offline mode"
-fi
+	fi
 
-_echo "* Mitigation 2"
-_echo_nol "*   Kernel compiled with retpoline option: "
-# We check the RETPOLINE kernel options
-if [ -r "$opt_config" ]; then
+	_info "* Mitigation 2"
+	_info_nol "*   Kernel compiled with retpoline option: "
+	# We check the RETPOLINE kernel options
+	if [ -r "$opt_config" ]; then
 		if grep -q '^CONFIG_RETPOLINE=y' "$opt_config"; then
 			pstatus green YES
 			retpoline=1
 		else
 			pstatus red NO
 		fi
-else
+	else
 		pstatus yellow UNKNOWN "couldn't read your kernel configuration"
-fi
+	fi
 
-_echo_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 "$opt_map" ]; then
+	_info_nol "*   Kernel compiled with a retpoline-aware compiler: "
+	# Now check if the compiler used to compile the kernel knows how to insert retpolines in generated asm
+	# For gcc, this is -mindirect-branch=thunk-extern (detected by the kernel makefiles)
+	# See gcc commit https://github.com/hjl-tools/gcc/commit/23b517d4a67c02d3ef80b6109218f2aadad7bd79
+	# In latest retpoline LKML patches, the noretpoline_setup symbol exists only if CONFIG_RETPOLINE is set
+	# *AND* if the compiler is retpoline-compliant, so look for that symbol
+	if [ -n "$opt_map" ]; then
 		# look for the symbol
 		if grep -qw noretpoline_setup "$opt_map"; then
 			retpoline_compiler=1
@@ -438,7 +660,7 @@ if [ -n "$opt_map" ]; then
 		else
 			pstatus red NO
 		fi
-elif [ -n "$vmlinux" ]; then
+	elif [ -n "$vmlinux" ]; then
 		# look for the symbol
 		if which nm >/dev/null 2>&1; then
 			# the proper way: use nm and look for the symbol
@@ -456,51 +678,52 @@ elif [ -n "$vmlinux" ]; then
 		else
 			pstatus red NO
 		fi
-else
+	else
 		pstatus yellow UNKNOWN "couldn't find your kernel image or System.map"
-fi
+	fi
 
-_echo_nol "> \033[46m\033[30mSTATUS:\033[0m "
-if grep -q AMD /proc/cpuinfo; then
-	pstatus green "NOT VULNERABLE" "your CPU is not vulnerable as per the vendor"
-elif [ "$retpoline" = 1 -a "$retpoline_compiler" = 1 ]; then
-	pstatus green "NOT VULNERABLE" "retpoline mitigate the vulnerability"
-elif [ "$opt_live" = 1 ]; then
+	if ! is_cpu_vulnerable 2; then
+		pvulnstatus CVE-2017-5715 OK "your CPU vendor reported your CPU model as not vulnerable"
+	elif [ "$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
-		pstatus green "NOT VULNERABLE" "IBRS mitigates the vulnerability"
+			pvulnstatus CVE-2017-5715 OK "IBRS mitigates the vulnerability"
 		else
-		pstatus red VULNERABLE "IBRS hardware + kernel support OR kernel with retpoline are needed to mitigate the vulnerability"
+			pvulnstatus CVE-2017-5715 VULN "IBRS hardware + kernel support OR kernel with retpoline are needed to mitigate the vulnerability"
 		fi
-else
+	else
 		if [ "$ibrs_supported" = 1 ]; then
-		pstatus green "NOT VULNERABLE" "offline mode: IBRS will mitigate the vulnerability if enabled at runtime"
+			pvulnstatus CVE-2017-5715 OK "offline mode: IBRS will mitigate the vulnerability if enabled at runtime"
 		else
-		pstatus red VULNERABLE "IBRS hardware + kernel support OR kernel with retpoline are needed to mitigate the vulnerability"
+			pvulnstatus CVE-2017-5715 VULN "IBRS hardware + kernel support OR kernel with retpoline are needed to mitigate the vulnerability"
 		fi
-fi
+	fi
+}
 
-##########
-# MELTDOWN
-_echo
-_echo "\033[1;34mCVE-2017-5754 [rogue data cache load] aka 'Meltdown' aka 'Variant 3'\033[0m"
-_echo_nol "* Kernel supports Page Table Isolation (PTI): "
-kpti_support=0
-kpti_can_tell=0
-if [ -n "$opt_config" ]; then
+########################
+# MELTDOWN aka VARIANT 3
+check_variant3()
+{
+	_info "\033[1;34mCVE-2017-5754 [rogue data cache load] aka 'Meltdown' aka 'Variant 3'\033[0m"
+	_info_nol "* Kernel supports Page Table Isolation (PTI): "
+	kpti_support=0
+	kpti_can_tell=0
+	if [ -n "$opt_config" ]; then
 		kpti_can_tell=1
-	if grep -Eq '^\(CONFIG_PAGE_TABLE_ISOLATION\|CONFIG_KAISER\)=y' "$opt_config"; then
+		if grep -Eq '^(CONFIG_PAGE_TABLE_ISOLATION|CONFIG_KAISER)=y' "$opt_config"; then
 			kpti_support=1
 		fi
-fi
-if [ "$kpti_support" = 0 -a -n "$opt_map" ]; then
+	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 "$opt_map"; then
 			kpti_support=1
 		fi
-fi
-if [ "$kpti_support" = 0 -a -n "$vmlinux" ]; then
+	fi
+	if [ "$kpti_support" = 0 -a -n "$vmlinux" ]; then
 		# same as above but in case we don't have System.map and only vmlinux, look for the
 		# nopti option that is part of the patch (kernel command line option)
 		kpti_can_tell=1
@@ -511,18 +734,19 @@ if [ "$kpti_support" = 0 -a -n "$vmlinux" ]; then
 				kpti_support=1
 			fi
 		fi
-fi
+	fi
 
-if [ "$kpti_support" = 1 ]; then
+	if [ "$kpti_support" = 1 ]; then
 		pstatus green YES
-elif [ "$kpti_can_tell" = 1 ]; then
+	elif [ "$kpti_can_tell" = 1 ]; then
 		pstatus red NO
-else
+	else
 		pstatus yellow UNKNOWN "couldn't read your kernel configuration nor System.map file"
-fi
+	fi
 
-_echo_nol "* PTI enabled and active: "
-if [ "$opt_live" = 1 ]; then
+	mount_debugfs
+	_info_nol "* PTI enabled and active: "
+	if [ "$opt_live" = 1 ]; then
 		if grep ^flags /proc/cpuinfo | grep -qw pti; then
 			# vanilla PTI patch sets the 'pti' flag in cpuinfo
 			kpti_enabled=1
@@ -533,7 +757,10 @@ if [ "$opt_live" = 1 ]; then
 			# RedHat Backport creates a dedicated file, see https://access.redhat.com/articles/3311301
 			kpti_enabled=$(cat /sys/kernel/debug/x86/pti_enabled 2>/dev/null)
 		elif dmesg | grep -Eq 'Kernel/User page tables isolation: enabled|Kernel page table isolation enabled'; then
-		# if we can't find the flag, grep in dmesg
+			# if we can't find the flag, grep dmesg output
+			kpti_enabled=1
+		elif [ -r /var/log/dmesg ] && grep -Eq 'Kernel/User page tables isolation: enabled|Kernel page table isolation enabled' /var/log/dmesg; then
+			# if we can't find the flag in dmesg output, grep in /var/log/dmesg when readable
 			kpti_enabled=1
 		else
 			kpti_enabled=0
@@ -543,32 +770,56 @@ if [ "$opt_live" = 1 ]; then
 		else
 			pstatus red NO
 		fi
-else
+	else
 		pstatus blue N/A "can't verify if PTI is enabled in offline mode"
-fi
+	fi
 
-if [ "$mounted_debugfs" = 1 ]; then
-	# umount debugfs if we did mount it ourselves
-	umount /sys/kernel/debug
-fi
-
-_echo_nol "> \033[46m\033[30mSTATUS:\033[0m "
-if grep -q AMD /proc/cpuinfo; then
-	pstatus green "NOT VULNERABLE" "your CPU is not vulnerable as per the vendor"
-elif [ "$opt_live" = 1 ]; then
+	if ! is_cpu_vulnerable 3; then
+		pvulnstatus CVE-2017-5754 OK "your CPU vendor reported your CPU model as not vulnerable"
+	elif [ "$opt_live" = 1 ]; then
 		if [ "$kpti_enabled" = 1 ]; then
-		pstatus green "NOT VULNERABLE" "PTI mitigates the vulnerability"
+			pvulnstatus CVE-2017-5754 OK "PTI mitigates the vulnerability"
 		else
-		pstatus red "VULNERABLE" "PTI is needed to mitigate the vulnerability"
+			pvulnstatus CVE-2017-5754 VULN "PTI is needed to mitigate the vulnerability"
 		fi
-else
+	else
 		if [ "$kpti_support" = 1 ]; then
-		pstatus green "NOT VULNERABLE" "offline mode: PTI will mitigate the vulnerability if enabled at runtime"
+			pvulnstatus CVE-2017-5754 OK "offline mode: PTI will mitigate the vulnerability if enabled at runtime"
 		else
-		pstatus red "VULNERABLE" "PTI is needed to mitigate the vulnerability"
+			pvulnstatus CVE-2017-5754 VULN "PTI is needed to mitigate the vulnerability"
 		fi
+	fi
+}
+
+# now run the checks the user asked for
+if [ "$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
 
-_echo
+_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
+	[ "$nrpe_critical" = 1 ] && exit 2  # critical
+	[ "$nrpe_unknown" = 1 ] && exit 3  # unknown
+	exit 0  # ok
+fi