diff --git a/spectre-meltdown-checker.sh b/spectre-meltdown-checker.sh index d84f05e..3545fed 100755 --- a/spectre-meltdown-checker.sh +++ b/spectre-meltdown-checker.sh @@ -8,7 +8,7 @@ # # Stephane Lesimple # -VERSION=0.25 +VERSION=0.26 # Script configuration show_usage() @@ -33,7 +33,8 @@ show_usage() Options: --no-color Don't use color codes - -v, --verbose Increase verbosity level + --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... --batch nrpe Produce machine readable output formatted for NRPE @@ -86,6 +87,7 @@ opt_variant1=0 opt_variant2=0 opt_variant3=0 opt_allvariants=1 +opt_no_sysfs=0 nrpe_critical=0 nrpe_unknown=0 @@ -95,13 +97,13 @@ __echo() { opt="$1" shift - msg="$@" + _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") + _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" + /bin/echo $opt -e "$_msg" } _echo() @@ -250,6 +252,9 @@ while [ -n "$1" ]; do elif [ "$1" = "--no-color" ]; then opt_no_color=1 shift + elif [ "$1" = "--no-sysfs" ]; then + opt_no_sysfs=1 + shift elif [ "$1" = "--batch" ]; then opt_batch=1 opt_verbose=0 @@ -548,46 +553,83 @@ umount_debugfs() fi } +sys_interface_check() +{ + [ "$opt_live" = 1 -a "$opt_no_sysfs" = 0 -a -r "$1" ] || return 1 + _info_nol "* Checking wheter 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 "$1") + return 0 +} + ################### # SPECTRE VARIANT 1 check_variant1() { _info "\033[1;34mCVE-2017-5753 [bounds check bypass] aka 'Spectre Variant 1'\033[0m" - _info_nol "* Checking count of LFENCE opcodes in kernel: " - status=0 - if [ -n "$vmlinux_err" ]; then - pstatus yellow UNKNOWN "$vmlinux_err" + status=UNK + sys_interface_available=0 + msg='' + if sys_interface_check "/sys/devices/system/cpu/vulnerabilities/spectre_v1"; then + # this kernel has the /sys interface, trust it over everything + sys_interface_available=1 else - if ! which objdump >/dev/null 2>&1; then - pstatus yellow UNKNOWN "missing 'objdump' tool, please install it, usually it's in the binutils package" + # no /sys interface (or offline mode), fallback to our own ways + _info_nol "* Checking count of LFENCE opcodes in kernel: " + if [ -n "$vmlinux_err" ]; then + msg="couldn't check ($vmlinux_err)" + status=UNK + pstatus yellow UNKNOWN else - # here we disassemble the kernel and count the number of occurences of the LFENCE opcode - # in non-patched kernels, this has been empirically determined as being around 40-50 - # in patched kernels, this is more around 70-80, sometimes way higher (100+) - # v0.13: 68 found in a 3.10.23-xxxx-std-ipv6-64 (with lots of modules compiled-in directly), which doesn't have the LFENCE patches, - # so let's push the threshold to 70. - # TODO LKML patch is starting to dump LFENCE in favor of the PAUSE opcode, we might need to check that (patch not stabilized yet) - nb_lfence=$(objdump -D "$vmlinux" | grep -wc lfence) - if [ "$nb_lfence" -lt 70 ]; then - pstatus red NO "only $nb_lfence opcodes found, should be >= 70" - status=1 + if ! which objdump >/dev/null 2>&1; then + msg="missing 'objdump' tool, please install it, usually it's in the binutils package" + status=UNK + pstatus yellow UNKNOWN else - pstatus green YES "$nb_lfence opcodes found, which is >= 70" - status=2 + # here we disassemble the kernel and count the number of occurences 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 $nb_lfence opcodes found, should be >= 70, heuristic to be improved when official patches become available" + status=VULN + pstatus yellow UNKNOWN + else + msg="$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 ! 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 ${vmlinux}";; - 1) pvulnstatus CVE-2017-5753 VULN 'heuristic to be improved when official patches become available';; - 2) pvulnstatus CVE-2017-5753 OK 'heuristic to be improved when official patches become available';; - esac + # if we have the /sys interface, don't even check is_cpu_vulnerable ourselves, the kernel already does it + if [ "$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" } ################### @@ -595,153 +637,169 @@ check_variant1() 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 - pstatus yellow UNKNOWN "couldn't read /dev/cpu/0/msr, is msr support enabled in your kernel?" + + 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 - # 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 [ $? -eq 0 ]; then - pstatus green YES - else - pstatus red NO + _info "* Mitigation 1" + _info_nol "* Hardware (CPU microcode) support for mitigation: " + if [ ! -e /dev/cpu/0/msr ]; then + # try to load the module ourselves (and remember it so we can rmmod it afterwards) + modprobe msr 2>/dev/null && insmod_msr=1 fi - fi - - if [ "$insmod_msr" = 1 ]; then - # if we used modprobe ourselves, rmmod the module - rmmod msr 2>/dev/null - 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 + 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 [ $? -eq 0 ]; then pstatus green YES - ibrs_supported=1 - ibrs_enabled=$(cat "$ibrs_file" 2>/dev/null) - break - fi - done - fi - if [ "$ibrs_supported" != 1 -a -n "$opt_map" ]; then - if grep -q spec_ctrl "$opt_map"; then - pstatus green YES - ibrs_supported=1 - 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' "$opt_config"; then - pstatus green YES - retpoline=1 - else - pstatus red NO - fi - else - pstatus yellow UNKNOWN "couldn't read your kernel configuration" - fi - - _info_nol "* Kernel compiled with a retpoline-aware compiler: " - # Now check if the compiler used to compile the kernel knows how to insert retpolines in generated asm - # For gcc, this is -mindirect-branch=thunk-extern (detected by the kernel makefiles) - # See gcc commit https://github.com/hjl-tools/gcc/commit/23b517d4a67c02d3ef80b6109218f2aadad7bd79 - # In latest retpoline LKML patches, the noretpoline_setup symbol exists only if CONFIG_RETPOLINE is set - # *AND* if the compiler is retpoline-compliant, so look for that symbol - if [ -n "$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 + fi + + if [ "$insmod_msr" = 1 ]; then + # if we used modprobe ourselves, rmmod the module + rmmod msr 2>/dev/null + fi + + _info_nol "* Kernel support for IBRS: " + if [ "$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 "$ibrs_file" 2>/dev/null) + break + fi + done + fi + if [ "$ibrs_supported" != 1 -a -n "$opt_map" ]; then + if grep -q spec_ctrl "$opt_map"; then + pstatus green YES + ibrs_supported=1 + fi + fi + if [ "$ibrs_supported" != 1 ]; then pstatus red NO fi - else - pstatus yellow UNKNOWN "couldn't find your kernel image or System.map" + + _info_nol "* IBRS enabled for Kernel space: " + if [ "$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' "$opt_config"; then + pstatus green YES + retpoline=1 + else + pstatus red NO + fi + else + pstatus yellow UNKNOWN "couldn't read your kernel configuration" + fi + + _info_nol "* Kernel compiled with a retpoline-aware compiler: " + # Now check if the compiler used to compile the kernel knows how to insert retpolines in generated asm + # For gcc, this is -mindirect-branch=thunk-extern (detected by the kernel makefiles) + # See gcc commit https://github.com/hjl-tools/gcc/commit/23b517d4a67c02d3ef80b6109218f2aadad7bd79 + # In latest retpoline LKML patches, the noretpoline_setup symbol exists only if CONFIG_RETPOLINE is set + # *AND* if the compiler is retpoline-compliant, so look for that symbol + if [ -n "$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 ! is_cpu_vulnerable 2; then + # if we have the /sys interface, don't even check is_cpu_vulnerable ourselves, the kernel already does it + if [ "$sys_interface_available" = 0 ] && ! is_cpu_vulnerable 2; then + # override status & msg in case CPU is not vulnerable after all pvulnstatus CVE-2017-5715 OK "your CPU vendor reported your CPU model as not vulnerable" - elif [ "$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" + 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 - pvulnstatus CVE-2017-5715 VULN "IBRS hardware + kernel support OR kernel with retpoline are needed to mitigate the vulnerability" + if [ "$ibrs_supported" = 1 ]; then + pvulnstatus CVE-2017-5715 OK "offline mode: IBRS will mitigate the vulnerability if enabled at runtime" + else + pvulnstatus CVE-2017-5715 VULN "IBRS hardware + kernel support OR kernel with retpoline are needed to mitigate the vulnerability" + fi fi else - if [ "$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 + pvulnstatus CVE-2017-5715 "$status" "$msg" fi } @@ -750,88 +808,105 @@ check_variant2() 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 - 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 "$opt_map"; then - kpti_support=1 - fi - fi - if [ "$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 + + 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 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 [ "$opt_live" = 1 ]; then - if grep ^flags /proc/cpuinfo | grep -qw pti; then - # vanilla PTI patch sets the 'pti' flag in cpuinfo - kpti_enabled=1 - elif grep ^flags /proc/cpuinfo | grep -qw kaiser; then - # kernel line 4.9 sets the 'kaiser' flag in cpuinfo - kpti_enabled=1 - elif [ -e /sys/kernel/debug/x86/pti_enabled ]; then - # RedHat Backport creates a dedicated file, see https://access.redhat.com/articles/3311301 - kpti_enabled=$(cat /sys/kernel/debug/x86/pti_enabled 2>/dev/null) - elif dmesg | grep -Eq 'Kernel/User page tables isolation: enabled|Kernel page table isolation enabled'; then - # 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 + 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_enabled" = 1 ]; then - pstatus green YES - else - pstatus red NO + 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 "$vmlinux" | grep -qw nopti; then + kpti_support=1 + fi + fi fi - else - pstatus blue N/A "can't verify if PTI is enabled in offline mode" - fi - if ! is_cpu_vulnerable 3; then - pvulnstatus CVE-2017-5754 OK "your CPU vendor reported your CPU model as not vulnerable" - elif [ "$opt_live" = 1 ]; then - if [ "$kpti_enabled" = 1 ]; then - pvulnstatus CVE-2017-5754 OK "PTI mitigates the vulnerability" - else - pvulnstatus CVE-2017-5754 VULN "PTI is needed to mitigate the vulnerability" - fi - else if [ "$kpti_support" = 1 ]; then - pvulnstatus CVE-2017-5754 OK "offline mode: PTI will mitigate the vulnerability if enabled at runtime" + pstatus green YES + elif [ "$kpti_can_tell" = 1 ]; then + pstatus red NO else - pvulnstatus CVE-2017-5754 VULN "PTI is needed to mitigate the vulnerability" + pstatus yellow UNKNOWN "couldn't read your kernel configuration nor System.map file" fi + + mount_debugfs + _info_nol "* PTI enabled and active: " + if [ "$opt_live" = 1 ]; then + if grep ^flags /proc/cpuinfo | grep -qw pti; then + # vanilla PTI patch sets the 'pti' flag in cpuinfo + kpti_enabled=1 + elif grep ^flags /proc/cpuinfo | grep -qw kaiser; then + # kernel line 4.9 sets the 'kaiser' flag in 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=$(cat /sys/kernel/debug/x86/pti_enabled 2>/dev/null) + elif dmesg | grep -Eq 'Kernel/User page tables isolation: enabled|Kernel page table isolation enabled'; then + # if we can't find the flag, grep dmesg output + kpti_enabled=1 + elif [ -r /var/log/dmesg ] && grep -Eq 'Kernel/User page tables isolation: enabled|Kernel page table isolation enabled' /var/log/dmesg; then + # if we can't find the flag in dmesg output, grep in /var/log/dmesg when readable + kpti_enabled=1 + else + kpti_enabled=0 + fi + if [ "$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 }