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mirror of https://github.com/speed47/spectre-meltdown-checker synced 2024-12-22 20:33:56 +01:00

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

This commit is contained in:
Stéphane Lesimple 2018-01-10 12:24:16 +01:00
parent 5389ac6844
commit 74bc7ba637

View File

@ -8,7 +8,7 @@
#
# Stephane Lesimple
#
VERSION=0.21
VERSION=0.22
# Script configuration
show_usage()
@ -34,8 +34,10 @@ show_usage()
Options:
--no-color Don't use color codes
-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
--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.
@ -79,6 +81,10 @@ 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
@ -255,6 +261,20 @@ while [ -n "$1" ]; do
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 "$1" = "--help" ]; then
show_header
show_usage
@ -467,15 +487,38 @@ fi
_info
###########
# SPECTRE 1
_info "\033[1;34mCVE-2017-5753 [bounds check bypass] aka 'Spectre Variant 1'\033[0m"
_info_nol "* Checking count of LFENCE opcodes in kernel: "
# end of header stuff
status=0
if [ -n "$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 "$vmlinux_err"
else
else
if ! which objdump >/dev/null 2>&1; then
pstatus yellow UNKNOWN "missing 'objdump' tool, please install it, usually it's in the binutils package"
else
@ -494,31 +537,33 @@ else
status=2
fi
fi
fi
fi
if ! is_cpu_vulnerable 1; then
if ! is_cpu_vulnerable 1; then
pvulnstatus CVE-2017-5753 OK "your CPU vendor reported your CPU model as not vulnerable"
else
else
case "$status" in
0) pvulnstatus CVE-2017-5753 UNK "impossible to check ${vmlinux}";;
1) pvulnstatus CVE-2017-5753 VULN 'heuristic to be improved when official patches become available';;
2) pvulnstatus CVE-2017-5753 OK 'heuristic to be improved when official patches become available';;
esac
fi
fi
}
###########
# VARIANT 2
_info
_info "\033[1;34mCVE-2017-5715 [branch target injection] aka 'Spectre Variant 2'\033[0m"
_info "* Mitigation 1"
_info_nol "* Hardware (CPU microcode) support for mitigation: "
if [ ! -e /dev/cpu/0/msr ]; then
###################
# SPECTRE VARIANT 2
check_variant2()
{
_info "\033[1;34mCVE-2017-5715 [branch target injection] aka 'Spectre Variant 2'\033[0m"
_info "* Mitigation 1"
_info_nol "* Hardware (CPU microcode) support for mitigation: "
if [ ! -e /dev/cpu/0/msr ]; then
# try to load the module ourselves (and remember it so we can rmmod it afterwards)
modprobe msr 2>/dev/null && insmod_msr=1
fi
if [ ! -e /dev/cpu/0/msr ]; then
fi
if [ ! -e /dev/cpu/0/msr ]; then
pstatus yellow UNKNOWN "couldn't read /dev/cpu/0/msr, is msr support enabled in your kernel?"
else
else
# the new MSR 'SPEC_CTRL' is at offset 0x48
# here we use dd, it's the same as using 'rdmsr 0x48' but without needing the rdmsr tool
# if we get a read error, the MSR is not there
@ -528,19 +573,16 @@ else
else
pstatus red NO
fi
fi
fi
if [ "$insmod_msr" = 1 ]; then
if [ "$insmod_msr" = 1 ]; then
# if we used modprobe ourselves, rmmod the module
rmmod msr 2>/dev/null
fi
_info_nol "* Kernel support for IBRS: "
if [ "$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 [ "$opt_live" = 1 ]; then
mount_debugfs
if [ -e /sys/kernel/debug/ibrs_enabled ]; then
# if the file is there, we have IBRS compiled-in
pstatus green YES
@ -552,19 +594,19 @@ if [ "$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
_info_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
@ -574,43 +616,43 @@ if [ "$opt_live" = 1 ]; then
1 | 2) pstatus green YES;;
*) pstatus yellow UNKNOWN;;
esac
else
else
pstatus blue N/A "not testable in offline mode"
fi
fi
_info_nol "* IBRS enabled for User space: "
if [ "$opt_live" = 1 ]; then
_info_nol "* IBRS enabled for User space: "
if [ "$opt_live" = 1 ]; then
case "$ibrs_enabled" in
"") [ "$ibrs_supported" = 1 ] && pstatus yellow UNKNOWN || pstatus red NO;;
0 | 1) pstatus red NO;;
2) pstatus green YES;;
*) pstatus yellow UNKNOWN;;
esac
else
else
pstatus blue N/A "not testable in offline mode"
fi
fi
_info "* Mitigation 2"
_info_nol "* Kernel compiled with retpoline option: "
# We check the RETPOLINE kernel options
if [ -r "$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
_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 "$opt_map" ]; then
_info_nol "* Kernel compiled with a retpoline-aware compiler: "
# Now check if the compiler used to compile the kernel knows how to insert retpolines in generated asm
# For gcc, this is -mindirect-branch=thunk-extern (detected by the kernel makefiles)
# See gcc commit https://github.com/hjl-tools/gcc/commit/23b517d4a67c02d3ef80b6109218f2aadad7bd79
# In latest retpoline LKML patches, the noretpoline_setup symbol exists only if CONFIG_RETPOLINE is set
# *AND* if the compiler is retpoline-compliant, so look for that symbol
if [ -n "$opt_map" ]; then
# look for the symbol
if grep -qw noretpoline_setup "$opt_map"; then
retpoline_compiler=1
@ -618,7 +660,7 @@ if [ -n "$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
@ -636,50 +678,52 @@ elif [ -n "$vmlinux" ]; then
else
pstatus red NO
fi
else
else
pstatus yellow UNKNOWN "couldn't find your kernel image or System.map"
fi
fi
if ! is_cpu_vulnerable 2; then
if ! is_cpu_vulnerable 2; then
pvulnstatus CVE-2017-5715 OK "your CPU vendor reported your CPU model as not vulnerable"
elif [ "$retpoline" = 1 -a "$retpoline_compiler" = 1 ]; then
elif [ "$retpoline" = 1 -a "$retpoline_compiler" = 1 ]; then
pvulnstatus CVE-2017-5715 OK "retpoline mitigate the vulnerability"
elif [ "$opt_live" = 1 ]; then
elif [ "$opt_live" = 1 ]; then
if [ "$ibrs_enabled" = 1 -o "$ibrs_enabled" = 2 ]; then
pvulnstatus CVE-2017-5715 OK "IBRS mitigates the vulnerability"
else
pvulnstatus CVE-2017-5715 VULN "IBRS hardware + kernel support OR kernel with retpoline are needed to mitigate the vulnerability"
fi
else
else
if [ "$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
fi
}
##########
# MELTDOWN
_info
_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 "$opt_config" ]; then
########################
# MELTDOWN aka VARIANT 3
check_variant3()
{
_info "\033[1;34mCVE-2017-5754 [rogue data cache load] aka 'Meltdown' aka 'Variant 3'\033[0m"
_info_nol "* Kernel supports Page Table Isolation (PTI): "
kpti_support=0
kpti_can_tell=0
if [ -n "$opt_config" ]; then
kpti_can_tell=1
if grep -Eq '^(CONFIG_PAGE_TABLE_ISOLATION|CONFIG_KAISER)=y' "$opt_config"; then
kpti_support=1
fi
fi
if [ "$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
@ -690,18 +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
_info_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
@ -725,35 +770,47 @@ 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
if ! is_cpu_vulnerable 3; then
if ! is_cpu_vulnerable 3; then
pvulnstatus CVE-2017-5754 OK "your CPU vendor reported your CPU model as not vulnerable"
elif [ "$opt_live" = 1 ]; then
elif [ "$opt_live" = 1 ]; then
if [ "$kpti_enabled" = 1 ]; then
pvulnstatus CVE-2017-5754 OK "PTI mitigates the vulnerability"
else
pvulnstatus CVE-2017-5754 VULN "PTI is needed to mitigate the vulnerability"
fi
else
else
if [ "$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
fi
}
_info
# 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