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add --variant to specify what check we want to run

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This commit is contained in:
Stéphane Lesimple 2018-01-10 12:24:16 +01:00
parent 5389ac6844
commit 74bc7ba637
1 changed files with 309 additions and 252 deletions
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561
spectre-meltdown-checker.sh
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@ -8,7 +8,7 @@
# #
# Stephane Lesimple # Stephane Lesimple
# #
VERSION=0.21 VERSION=0.22
# Script configuration # Script configuration
show_usage() show_usage()
@ -34,8 +34,10 @@ show_usage()
Options: Options:
--no-color Don't use color codes --no-color Don't use color codes
-v, --verbose Increase verbosity level -v, --verbose Increase verbosity level
--batch Produce machine readable output --batch text Produce machine readable output, this is the default if --batch is specified alone
--batch nrpe Produce machine readable output formatted for NRPE --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: IMPORTANT:
A false sense of security is worse than no security at all. A false sense of security is worse than no security at all.
@ -79,6 +81,10 @@ opt_no_color=0
opt_batch=0 opt_batch=0
opt_batch_format="text" opt_batch_format="text"
opt_verbose=1 opt_verbose=1
opt_variant1=0
opt_variant2=0
opt_variant3=0
opt_allvariants=1
nrpe_critical=0 nrpe_critical=0
nrpe_unknown=0 nrpe_unknown=0
@ -255,6 +261,20 @@ while [ -n "$1" ]; do
elif [ "$1" = "-v" -o "$1" = "--verbose" ]; then elif [ "$1" = "-v" -o "$1" = "--verbose" ]; then
opt_verbose=$(expr $opt_verbose + 1) opt_verbose=$(expr $opt_verbose + 1)
shift 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 elif [ "$1" = "-h" -o "$1" = "--help" ]; then
show_header show_header
show_usage show_usage
@ -467,293 +487,330 @@ fi
_info _info
########### # end of header stuff
# SPECTRE 1
_info "\033[1;34mCVE-2017-5753 [bounds check bypass] aka 'Spectre Variant 1'\033[0m"
_info_nol "* Checking count of LFENCE opcodes in kernel: "
status=0 # now we define some util functions and the check_*() funcs, as
if [ -n "$vmlinux_err" ]; then # the user can choose to execute only some of those
pstatus yellow UNKNOWN "$vmlinux_err"
else
if ! which objdump >/dev/null 2>&1; then
pstatus yellow UNKNOWN "missing 'objdump' tool, please install it, usually it's in the binutils package"
else
# here we disassemble the kernel and count the number of occurences of the LFENCE opcode
# in non-patched kernels, this has been empirically determined as being around 40-50
# in patched kernels, this is more around 70-80, sometimes way higher (100+)
# v0.13: 68 found in a 3.10.23-xxxx-std-ipv6-64 (with lots of modules compiled-in directly), which doesn't have the LFENCE patches,
# so let's push the threshold to 70.
# TODO LKML patch is starting to dump LFENCE in favor of the PAUSE opcode, we might need to check that (patch not stabilized yet)
nb_lfence=$(objdump -D "$vmlinux" | grep -wc lfence)
if [ "$nb_lfence" -lt 70 ]; then
pstatus red NO "only $nb_lfence opcodes found, should be >= 70"
status=1
else
pstatus green YES "$nb_lfence opcodes found, which is >= 70"
status=2
fi
fi
fi
if ! is_cpu_vulnerable 1; then mount_debugfs()
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
_info
_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?"
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
fi
_info_nol "* Kernel support for IBRS: "
if [ "$opt_live" = 1 ]; then
if [ ! -e /sys/kernel/debug/sched_features ]; then if [ ! -e /sys/kernel/debug/sched_features ]; then
# try to mount the debugfs hierarchy ourselves and remember it to umount afterwards # try to mount the debugfs hierarchy ourselves and remember it to umount afterwards
mount -t debugfs debugfs /sys/kernel/debug 2>/dev/null && mounted_debugfs=1 mount -t debugfs debugfs /sys/kernel/debug 2>/dev/null && mounted_debugfs=1
fi fi
if [ -e /sys/kernel/debug/ibrs_enabled ]; then }
# if the file is there, we have IBRS compiled-in
pstatus green YES umount_debugfs()
ibrs_supported=1 {
ibrs_enabled=$(cat /sys/kernel/debug/ibrs_enabled 2>/dev/null) if [ "$mounted_debugfs" = 1 ]; then
elif [ -e /sys/kernel/debug/x86/ibrs_enabled ]; then # umount debugfs if we did mount it ourselves
# RedHat uses a different path (see https://access.redhat.com/articles/3311301) umount /sys/kernel/debug
pstatus green YES
ibrs_supported=1
ibrs_enabled=$(cat /sys/kernel/debug/x86/ibrs_enabled 2>/dev/null)
fi fi
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 [ "$opt_live" = 1 ]; then # SPECTRE VARIANT 1
# 0 means disabled check_variant1()
# 1 is enabled only for kernel space {
# 2 is enabled for kernel and user space _info "\033[1;34mCVE-2017-5753 [bounds check bypass] aka 'Spectre Variant 1'\033[0m"
case "$ibrs_enabled" in _info_nol "* Checking count of LFENCE opcodes in kernel: "
"") [ "$ibrs_supported" = 1 ] && pstatus yellow UNKNOWN || pstatus red NO;;
0) pstatus red NO;;
1 | 2) pstatus green YES;;
*) pstatus yellow UNKNOWN;;
esac
else
pstatus blue N/A "not testable in offline mode"
fi
_info_nol "* IBRS enabled for User space: " status=0
if [ "$opt_live" = 1 ]; then if [ -n "$vmlinux_err" ]; then
case "$ibrs_enabled" in pstatus yellow UNKNOWN "$vmlinux_err"
"") [ "$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 else
pstatus red NO 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
# 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 $nb_lfence opcodes found, should be >= 70"
status=1
else
pstatus green YES "$nb_lfence opcodes found, which is >= 70"
status=2
fi
fi
fi fi
else
pstatus yellow UNKNOWN "couldn't read your kernel configuration"
fi
_info_nol "* Kernel compiled with a retpoline-aware compiler: " if ! is_cpu_vulnerable 1; then
# Now check if the compiler used to compile the kernel knows how to insert retpolines in generated asm pvulnstatus CVE-2017-5753 OK "your CPU vendor reported your CPU model as not vulnerable"
# 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 else
pstatus red NO case "$status" in
0) pvulnstatus CVE-2017-5753 UNK "impossible to check ${vmlinux}";;
1) pvulnstatus CVE-2017-5753 VULN 'heuristic to be improved when official patches become available';;
2) pvulnstatus CVE-2017-5753 OK 'heuristic to be improved when official patches become available';;
esac
fi fi
elif [ -n "$vmlinux" ]; then }
# look for the symbol
if which nm >/dev/null 2>&1; then ###################
# the proper way: use nm and look for the symbol # SPECTRE VARIANT 2
if nm "$vmlinux" 2>/dev/null | grep -qw 'noretpoline_setup'; then check_variant2()
retpoline_compiler=1 {
pstatus green YES "noretpoline_setup found in vmlinux symbols" _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?"
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 [ $? -eq 0 ]; then
pstatus green YES
else else
pstatus red NO pstatus red NO
fi fi
elif grep -q noretpoline_setup "$vmlinux"; then fi
# 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 if [ "$insmod_msr" = 1 ]; then
retpoline_compiler=1 # if we used modprobe ourselves, rmmod the module
pstatus green YES "noretpoline_setup found in vmlinux" rmmod msr 2>/dev/null
else fi
_info_nol "* Kernel support for IBRS: "
if [ "$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
ibrs_supported=1
ibrs_enabled=$(cat /sys/kernel/debug/ibrs_enabled 2>/dev/null)
elif [ -e /sys/kernel/debug/x86/ibrs_enabled ]; then
# RedHat uses a different path (see https://access.redhat.com/articles/3311301)
pstatus green YES
ibrs_supported=1
ibrs_enabled=$(cat /sys/kernel/debug/x86/ibrs_enabled 2>/dev/null)
fi
fi
if [ "$ibrs_supported" != 1 -a -n "$opt_map" ]; then
if grep -q spec_ctrl "$opt_map"; then
pstatus green YES
ibrs_supported=1
fi
fi
if [ "$ibrs_supported" != 1 ]; then
pstatus red NO pstatus red NO
fi fi
else
pstatus yellow UNKNOWN "couldn't find your kernel image or System.map"
fi
if ! is_cpu_vulnerable 2; then _info_nol "* IBRS enabled for Kernel space: "
pvulnstatus CVE-2017-5715 OK "your CPU vendor reported your CPU model as not vulnerable" if [ "$opt_live" = 1 ]; then
elif [ "$retpoline" = 1 -a "$retpoline_compiler" = 1 ]; then # 0 means disabled
pvulnstatus CVE-2017-5715 OK "retpoline mitigate the vulnerability" # 1 is enabled only for kernel space
elif [ "$opt_live" = 1 ]; then # 2 is enabled for kernel and user space
if [ "$ibrs_enabled" = 1 -o "$ibrs_enabled" = 2 ]; then case "$ibrs_enabled" in
pvulnstatus CVE-2017-5715 OK "IBRS mitigates the vulnerability" "") [ "$ibrs_supported" = 1 ] && pstatus yellow UNKNOWN || pstatus red NO;;
0) pstatus red NO;;
1 | 2) pstatus green YES;;
*) pstatus yellow UNKNOWN;;
esac
else else
pvulnstatus CVE-2017-5715 VULN "IBRS hardware + kernel support OR kernel with retpoline are needed to mitigate the vulnerability" pstatus blue N/A "not testable in offline mode"
fi fi
else
if [ "$ibrs_supported" = 1 ]; then
pvulnstatus CVE-2017-5715 OK "offline mode: IBRS will mitigate the vulnerability if enabled at runtime"
else
pvulnstatus CVE-2017-5715 VULN "IBRS hardware + kernel support OR kernel with retpoline are needed to mitigate the vulnerability"
fi
fi
########## _info_nol "* IBRS enabled for User space: "
# MELTDOWN if [ "$opt_live" = 1 ]; then
_info case "$ibrs_enabled" in
_info "\033[1;34mCVE-2017-5754 [rogue data cache load] aka 'Meltdown' aka 'Variant 3'\033[0m" "") [ "$ibrs_supported" = 1 ] && pstatus yellow UNKNOWN || pstatus red NO;;
_info_nol "* Kernel supports Page Table Isolation (PTI): " 0 | 1) pstatus red NO;;
kpti_support=0 2) pstatus green YES;;
kpti_can_tell=0 *) pstatus yellow UNKNOWN;;
if [ -n "$opt_config" ]; then esac
kpti_can_tell=1
if grep -Eq '^(CONFIG_PAGE_TABLE_ISOLATION|CONFIG_KAISER)=y' "$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 "$vmlinux" ]; then
# same as above but in case we don't have System.map and only vmlinux, look for the
# nopti option that is part of the patch (kernel command line option)
kpti_can_tell=1
if ! which strings >/dev/null 2>&1; then
pstatus yellow UNKNOWN "missing 'strings' tool, please install it, usually it's in the binutils package"
else else
if strings "$vmlinux" | grep -qw nopti; then 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 "$vmlinux"; then
# if we don't have nm, nevermind, the symbol name is long enough to not have
# any false positive using good old grep directly on the binary
retpoline_compiler=1
pstatus green YES "noretpoline_setup found in vmlinux"
else
pstatus red NO
fi
else
pstatus yellow UNKNOWN "couldn't find your kernel image or System.map"
fi
if ! is_cpu_vulnerable 2; then
pvulnstatus CVE-2017-5715 OK "your CPU vendor reported your CPU model as not vulnerable"
elif [ "$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
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 [ "$ibrs_supported" = 1 ]; then
pvulnstatus CVE-2017-5715 OK "offline mode: IBRS will mitigate the vulnerability if enabled at runtime"
else
pvulnstatus CVE-2017-5715 VULN "IBRS hardware + kernel support OR kernel with retpoline are needed to mitigate the vulnerability"
fi
fi
}
########################
# MELTDOWN aka VARIANT 3
check_variant3()
{
_info "\033[1;34mCVE-2017-5754 [rogue data cache load] aka 'Meltdown' aka 'Variant 3'\033[0m"
_info_nol "* Kernel supports Page Table Isolation (PTI): "
kpti_support=0
kpti_can_tell=0
if [ -n "$opt_config" ]; then
kpti_can_tell=1
if grep -Eq '^(CONFIG_PAGE_TABLE_ISOLATION|CONFIG_KAISER)=y' "$opt_config"; then
kpti_support=1 kpti_support=1
fi fi
fi fi
fi if [ "$kpti_support" = 0 -a -n "$opt_map" ]; then
# it's not an elif: some backports don't have the PTI config but still include the patch
if [ "$kpti_support" = 1 ]; then # so we try to find an exported symbol that is part of the PTI patch in System.map
pstatus green YES kpti_can_tell=1
elif [ "$kpti_can_tell" = 1 ]; then if grep -qw kpti_force_enabled "$opt_map"; then
pstatus red NO kpti_support=1
else fi
pstatus yellow UNKNOWN "couldn't read your kernel configuration nor System.map file"
fi
_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 fi
if [ "$kpti_enabled" = 1 ]; then if [ "$kpti_support" = 0 -a -n "$vmlinux" ]; then
pstatus green YES # same as above but in case we don't have System.map and only vmlinux, look for the
else # nopti option that is part of the patch (kernel command line option)
pstatus red NO kpti_can_tell=1
if ! which strings >/dev/null 2>&1; then
pstatus yellow UNKNOWN "missing 'strings' tool, please install it, usually it's in the binutils package"
else
if strings "$vmlinux" | grep -qw nopti; then
kpti_support=1
fi
fi
fi fi
else
pstatus blue N/A "can't verify if PTI is enabled in offline mode"
fi
if [ "$mounted_debugfs" = 1 ]; then
# umount debugfs if we did mount it ourselves
umount /sys/kernel/debug
fi
if ! is_cpu_vulnerable 3; then
pvulnstatus CVE-2017-5754 OK "your CPU vendor reported your CPU model as not vulnerable"
elif [ "$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 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 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 fi
fi
_info 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 [ "$kpti_enabled" = 1 ]; then
pstatus green YES
else
pstatus red NO
fi
else
pstatus blue N/A "can't verify if PTI is enabled in offline mode"
fi
if ! is_cpu_vulnerable 3; then
pvulnstatus CVE-2017-5754 OK "your CPU vendor reported your CPU model as not vulnerable"
elif [ "$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"
else
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
_info "A false sense of security is worse than no security at all, see --disclaimer" _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" [ -n "$dumped_config" ] && rm -f "$dumped_config"
if [ "$opt_batch" = 1 -a "$opt_batch_format" = "nrpe" ]; then if [ "$opt_batch" = 1 -a "$opt_batch_format" = "nrpe" ]; then