Added support for MDS related vulnerabilities (#282)

This commit is contained in:
Agata Gruza 2019-05-14 10:21:20 -07:00 committed by Stéphane Lesimple
parent d547ce4ab4
commit 8e870db4f5
2 changed files with 242 additions and 24 deletions

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@ -1,7 +1,7 @@
Spectre & Meltdown Checker
==========================
A shell script to tell if your system is vulnerable against the several "speculative execution" CVEs that were made public in 2018.
A shell script to tell if your system is vulnerable against the several "speculative execution" CVEs that were made public since 2018.
- CVE-2017-5753 [bounds check bypass] aka 'Spectre Variant 1'
- CVE-2017-5715 [branch target injection] aka 'Spectre Variant 2'
- CVE-2017-5754 [rogue data cache load] aka 'Meltdown' aka 'Variant 3'
@ -10,6 +10,10 @@ A shell script to tell if your system is vulnerable against the several "specula
- CVE-2018-3615 [L1 terminal fault] aka 'Foreshadow (SGX)'
- CVE-2018-3620 [L1 terminal fault] aka 'Foreshadow-NG (OS)'
- CVE-2018-3646 [L1 terminal fault] aka 'Foreshadow-NG (VMM)'
- CVE-2018-12126 [MSBDS] Microarchitectural Store Buffer Data Sampling
- CVE-2018-12130 [MFBDS] Microarchitectural Fill Buffer Data Sampling
- CVE-2018-12127 [MLPDS] Microarchitectural Load Port Data Sampling
- CVE-2019-11091 [MDSUM] Microarchitectural Data Sampling Uncacheable Memory
Supported operating systems:
- Linux (all versions, flavors and distros)
@ -129,6 +133,14 @@ docker run --rm --privileged -v /boot:/boot:ro -v /dev/cpu:/dev/cpu:ro -v /lib/m
updated kernel (with L1d flush)
- Performance impact of the mitigation: low to significant
**CVE-2018-12126** [MSBDS] Microarchitectural Store Buffer Data Sampling
**CVE-2018-12130** [MFBDS] Microarchitectural Fill Buffer Data Sampling
**CVE-2018-12127** [MLPDS] Microarchitectural Load Port Data Sampling
**CVE-2019-11091** [MDSUM] Microarchitectural Data Sampling Uncacheable Memory
- Impact: Kernel
- Mitigation: microcode update + kernel update making possible to protect various CPU internal buffers from unprivilaged speculative access to data
## Understanding what this script does and doesn't
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.

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@ -76,7 +76,7 @@ show_usage()
--batch nrpe produce machine readable output formatted for NRPE
--batch prometheus produce output for consumption by prometheus-node-exporter
--variant [1,2,3,3a,4,l1tf] specify which variant you'd like to check, by default all variants are checked
--variant [1,2,3,3a,4,l1tf,msbds,mfbds,mlpds,mdsum] specify which variant you'd like to check, by default all variants are checked
--cve [cve1,cve2,...] specify which CVE you'd like to check, by default all supported CVEs are checked
can be specified multiple times (e.g. --variant 2 --variant 3)
--hw-only only check for CPU information, don't check for any variant
@ -153,7 +153,7 @@ global_critical=0
global_unknown=0
nrpe_vuln=''
supported_cve_list='CVE-2017-5753 CVE-2017-5715 CVE-2017-5754 CVE-2018-3640 CVE-2018-3639 CVE-2018-3615 CVE-2018-3620 CVE-2018-3646'
supported_cve_list='CVE-2017-5753 CVE-2017-5715 CVE-2017-5754 CVE-2018-3640 CVE-2018-3639 CVE-2018-3615 CVE-2018-3620 CVE-2018-3646 CVE-2018-12126 CVE-2018-12130 CVE-2018-12127 CVE-2019-11091'
# find a sane command to print colored messages, we prefer `printf` over `echo`
# because `printf` behavior is more standard across Linux/BSD
@ -271,6 +271,10 @@ cve2name()
CVE-2018-3615) echo "Foreshadow (SGX), L1 terminal fault";;
CVE-2018-3620) echo "Foreshadow-NG (OS), L1 terminal fault";;
CVE-2018-3646) echo "Foreshadow-NG (VMM), L1 terminal fault";;
CVE-2018-12126) echo "Microarchitectural Store Buffer Data Sampling (MSBDS)";;
CVE-2018-12130) echo "Microarchitectural Fill Buffer Data Sampling (MFBDS)";;
CVE-2018-12127) echo "Microarchitectural Load Port Data Sampling (MLPDS)";;
CVE-2019-11091) echo "Microarchitectural Data Sampling Uncacheable Memory (MDSUM)";;
*) echo "$0: error: invalid CVE '$1' passed to cve2name()" >&2; exit 255;;
esac
}
@ -288,6 +292,10 @@ _is_cpu_vulnerable_cached()
CVE-2018-3615) return $variantl1tf_sgx;;
CVE-2018-3620) return $variantl1tf;;
CVE-2018-3646) return $variantl1tf;;
CVE-2018-12126) return $variant_msbds;;
CVE-2018-12130) return $variant_mfbds;;
CVE-2018-12127) return $variant_mlpds;;
CVE-2019-11091) return $variant_mdsum;;
*) echo "$0: error: invalid variant '$1' passed to is_cpu_vulnerable()" >&2; exit 255;;
esac
}
@ -310,6 +318,10 @@ is_cpu_vulnerable()
variant3a=''
variant4=''
variantl1tf=''
variant_msbds=''
variant_mfbds=''
variant_mlpds=''
variant_mdsum=''
if is_cpu_specex_free; then
variant1=immune
@ -318,6 +330,10 @@ is_cpu_vulnerable()
variant3a=immune
variant4=immune
variantl1tf=immune
variant_msbds=immune
variant_mfbds=immune
variant_mlpds=immune
variant_mdsum=immune
elif is_intel; then
# Intel
# https://github.com/crozone/SpectrePoC/issues/1 ^F E5200 => spectre 2 not vulnerable
@ -347,6 +363,13 @@ is_cpu_vulnerable()
[ -z "$variant4" ] && variant4=immune
_debug "is_cpu_vulnerable: cpu not affected by speculative store bypass so not vuln to variant4"
fi
if is_cpu_mds_free; then
[ -z "$variant_msbds" ] && variant_msbds=immune
[ -z "$variant_mfbds" ] && variant_mfbds=immune
[ -z "$variant_mlpds" ] && variant_mlpds=immune
[ -z "$variant_mdsum" ] && variant_mdsum=immune
_debug "is_cpu_vulnerable: cpu not affected by Microarchitectural Data Sampling"
fi
# variant 4a for xeon phi
if [ "$cpu_family" = 6 ]; then
if [ "$cpu_model" = "$INTEL_FAM6_XEON_PHI_KNL" ] || [ "$cpu_model" = "$INTEL_FAM6_XEON_PHI_KNM" ]; then
@ -395,6 +418,13 @@ is_cpu_vulnerable()
[ -z "$variant4" ] && variant4=immune
_debug "is_cpu_vulnerable: cpu not affected by speculative store bypass so not vuln to variant4"
fi
if is_cpu_mds_free; then
[ -z "$variant_msbds" ] && variant_msbds=immune
[ -z "$variant_mfbds" ] && variant_mfbds=immune
[ -z "$variant_mlpds" ] && variant_mlpds=immune
[ -z "$variant_mdsum" ] && variant_mdsum=immune
_debug "is_cpu_vulnerable: cpu not affected by Microarchitectural Data Sampling"
fi
variantl1tf=immune
elif [ "$cpu_vendor" = CAVIUM ]; then
variant3=immune
@ -496,6 +526,10 @@ is_cpu_vulnerable()
[ "$variant3a" = "immune" ] && variant3a=1 || variant3a=0
[ "$variant4" = "immune" ] && variant4=1 || variant4=0
[ "$variantl1tf" = "immune" ] && variantl1tf=1 || variantl1tf=0
[ "$variant_msbds" = "immune" ] && variant_msbds=1 || variant_msbds=0
[ "$variant_mfbds" = "immune" ] && variant_mfbds=1 || variant_mfbds=0
[ "$variant_mlpds" = "immune" ] && variant_mlpds=1 || variant_mlpds=0
[ "$variant_mdsum" = "immune" ] && variant_mdsum=1 || variant_mdsum=0
variantl1tf_sgx="$variantl1tf"
# even if we are vulnerable to L1TF, if there's no SGX, we're safe for the original foreshadow
[ "$cpuid_sgx" = 0 ] && variantl1tf_sgx=1
@ -538,6 +572,51 @@ is_cpu_specex_free()
return 1
}
is_cpu_mds_free()
{
# return true (0) if the CPU isn't affected by microarchitectural data sampling, false (1) if it does.
# if it's not in the list we know, return false (1).
# source: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/x86/kernel/cpu/common.c
#VULNWL_INTEL(ATOM_GOLDMONT, NO_MDS | NO_L1TF),
#VULNWL_INTEL(ATOM_GOLDMONT_X, NO_MDS | NO_L1TF),
#VULNWL_INTEL(ATOM_GOLDMONT_PLUS, NO_MDS | NO_L1TF),
#/* AMD Family 0xf - 0x12 */
#VULNWL_AMD(0x0f, NO_MELTDOWN | NO_SSB | NO_L1TF | NO_MDS),
#VULNWL_AMD(0x10, NO_MELTDOWN | NO_SSB | NO_L1TF | NO_MDS),
#VULNWL_AMD(0x11, NO_MELTDOWN | NO_SSB | NO_L1TF | NO_MDS),
#VULNWL_AMD(0x12, NO_MELTDOWN | NO_SSB | NO_L1TF | NO_MDS),
#/* FAMILY_ANY must be last, otherwise 0x0f - 0x12 matches won't work */
#VULNWL_AMD(X86_FAMILY_ANY, NO_MELTDOWN | NO_L1TF | NO_MDS),
#VULNWL_HYGON(X86_FAMILY_ANY, NO_MELTDOWN | NO_L1TF | NO_MDS),
parse_cpu_details
if is_intel; then
if [ "$cpu_family" = 6 ]; then
if [ "$cpu_model" = "$INTEL_FAM6_ATOM_GOLDMONT" ] || \
[ "$cpu_model" = "$INTEL_FAM6_ATOM_GOLDMONT_X" ] || \
[ "$cpu_model" = "$INTEL_FAM6_ATOM_GOLDMONT_PLUS" ]; then
return 0
fi
fi
fi
if is_amd; then
if [ "$cpu_family" = "18" ] || \
[ "$cpu_family" = "17" ] || \
[ "$cpu_family" = "16" ] || \
[ "$cpu_family" = "15" ]; then
return 0
fi
fi
if is_hygon; then
return 0
fi
return 1
}
is_cpu_ssb_free()
{
# return true (0) if the CPU isn't affected by speculative store bypass, false (1) if it does.
@ -798,6 +877,10 @@ while [ -n "$1" ]; do
3) opt_cve_list="$opt_cve_list CVE-2017-5754"; opt_cve_all=0;;
3a) opt_cve_list="$opt_cve_list CVE-2018-3640"; opt_cve_all=0;;
4) opt_cve_list="$opt_cve_list CVE-2018-3639"; opt_cve_all=0;;
msbds) opt_cve_list="$opt_cve_list CVE-2018-12126"; opt_cve_all=0;;
mfbds) opt_cve_list="$opt_cve_list CVE-2018-12130"; opt_cve_all=0;;
mlpds) opt_cve_list="$opt_cve_list CVE-2018-12127"; opt_cve_all=0;;
mdsum) opt_cve_list="$opt_cve_list CVE-2019-11091"; opt_cve_all=0;;
l1tf) opt_cve_list="$opt_cve_list CVE-2018-3615 CVE-2018-3620 CVE-2018-3646"; opt_cve_all=0;;
*)
echo "$0: error: invalid parameter '$2' for --variant, expected either 1, 2, 3, 3a, 4 or l1tf" >&2;
@ -872,6 +955,10 @@ pvulnstatus()
CVE-2018-3615) aka="L1TF SGX";;
CVE-2018-3620) aka="L1TF OS";;
CVE-2018-3646) aka="L1TF VMM";;
CVE-2018-12126) aka="MSBDS";;
CVE-2018-12130) aka="MFBDS";;
CVE-2018-12127) aka="MLPDS";;
CVE-2019-11091) aka="MDSUM";;
*) echo "$0: error: invalid CVE '$1' passed to pvulnstatus()" >&2; exit 255;;
esac
@ -2267,6 +2354,8 @@ check_cpu()
fi
_info_nol " * ARCH_CAPABILITIES MSR advertises IBRS_ALL capability: "
mds_no=-1
capabilities_mds_no=-1
capabilities_rdcl_no=-1
capabilities_ibrs_all=-1
capabilities_rsba=-1
@ -2276,6 +2365,7 @@ check_cpu()
pstatus yellow UNKNOWN
elif [ "$cpuid_arch_capabilities" != 1 ]; then
capabilities_rdcl_no=0
capabilities_mds_no=0
capabilities_ibrs_all=0
capabilities_rsba=0
capabilities_l1dflush_no=0
@ -2307,6 +2397,7 @@ check_cpu()
done
capabilities=$val_cap_msr
capabilities_rdcl_no=0
capabilities_mds_no=0
capabilities_ibrs_all=0
capabilities_rsba=0
capabilities_l1dflush_no=0
@ -2318,7 +2409,8 @@ check_cpu()
[ $(( capabilities >> 2 & 1 )) -eq 1 ] && capabilities_rsba=1
[ $(( capabilities >> 3 & 1 )) -eq 1 ] && capabilities_l1dflush_no=1
[ $(( capabilities >> 4 & 1 )) -eq 1 ] && capabilities_ssb_no=1
_debug "capabilities says rdcl_no=$capabilities_rdcl_no ibrs_all=$capabilities_ibrs_all rsba=$capabilities_rsba l1dflush_no=$capabilities_l1dflush_no ssb_no=$capabilities_ssb_no"
[ $(( capabilities >> 5 & 1 )) -eq 1 ] && capabilities_mds_no=1
_debug "capabilities says rdcl_no=$capabilities_rdcl_no ibrs_all=$capabilities_ibrs_all rsba=$capabilities_rsba l1dflush_no=$capabilities_l1dflush_no ssb_no=$capabilities_ssb_no mds_no=$capabilities_mds_no"
if [ "$capabilities_ibrs_all" = 1 ]; then
if [ $cpu_mismatch -eq 0 ]; then
pstatus green YES
@ -2372,6 +2464,15 @@ check_cpu()
else
pstatus blue NO
fi
_info_nol " * CPU explicitly indicates not being vulnerable to Microarchitectural Data Sampling (MDC_NO): "
if [ "$capabilities_mds_no" = -1 ]; then
pstatus yellow UNKNOWN
elif [ "$capabilities_mds_no" = 1 ]; then
pstatus green YES
else
pstatus yellow NO
fi
fi
_info_nol " * CPU supports Software Guard Extensions (SGX): "
@ -4114,6 +4215,111 @@ check_CVE_2018_3646_bsd()
fi
}
###################
# MSBDS SECTION
# Microarchitectural Store Buffer Data Sampling
check_CVE_2018_12126()
{
cve='CVE-2018-12126'
check_mds $cve
}
###################
# MFBDS SECTION
# Microarchitectural Fill Buffer Data Sampling
check_CVE_2018_12130()
{
cve='CVE-2018-12130'
check_mds $cve
}
###################
# MLPDS SECTION
# Microarchitectural Load Port Data Sampling
check_CVE_2018_12127()
{
cve='CVE-2018-12127'
check_mds $cve
}
###################
# MDSUM SECTION
# Microarchitectural Data Sampling Uncacheable Memory
check_CVE_2019_11091()
{
cve='CVE-2019-11091'
check_mds $cve
}
# Microarchitectural Data Sampling
check_mds()
{
sys_interface_available=0
cve=$1
_info "\033[1;34m$cve aka '$(cve2name "$cve")'\033[0m"
if [ "$opt_live" != 1 ]; then
pstatus blue N/A "not testable in offline mode"
pvulnstatus $cve UNK
return
fi
if ! is_cpu_vulnerable "$cve" ; then
# override status & msg in case CPU is not vulnerable after all
pvulnstatus $cve OK "your CPU vendor reported your CPU model as not vulnerable"
return
fi
if sys_interface_check '/sys/devices/system/cpu/vulnerabilities/mds'; then
# this kernel has the /sys interface, trust it over everything
sys_interface_available=1
fi
if [ "$sys_interface_available" = 1 ]; then
if grep -Eq 'Not affected' "/sys/devices/system/cpu/vulnerabilities/mds"; then
mds_mitigated=1
elif grep -Eq '(Mitigation: Clear CPU buffers)' "/sys/devices/system/cpu/vulnerabilities/mds"; then
if grep -Eq '(SMT mitigated|disabled)' "/sys/devices/system/cpu/vulnerabilities/mds"; then
mds_mitigated=1
else
#Simultaneous multi-threading (aka SMT or HyperThreading) is enabled. System may be vulnerable in some environments.
mds_mitigated=0
_info_nol "* Disable SMT to have complete mitigation\n"
fi
elif grep -Eq 'Vulnerable' "/sys/devices/system/cpu/vulnerabilities/mds"; then
mds_mitigated=0
_info_nol "* For more info check Linux kernel Documentation/admin-guide/hw-vuln/mds.rst\n"
else
mds_mitigated=-1
fi
if grep -Eq 'no microcode' "/sys/devices/system/cpu/vulnerabilities/mds"; then
mds_mitigated=0
_info_nol "* CPU microcode is needed to mitigate the vulnerability\n"
fi
else
pstatus yellow UNKNOWN "can't find or interpret /sys/devices/system/cpu/vulnerabilities/mds"
mds_mitigated=-1
fi
if [ $mds_mitigated = 0 ];then
pvulnstatus $cve VULN
elif [ $mds_mitigated = 1 ]; then
pvulnstatus $cve OK
else
pvulnstatus $cve UNK "further action may be needed to mitigate this vulnerability. For more info check Linux kernel Documentation/admin-guide/hw-vuln/mds.rst"
fi
}
if [ "$opt_no_hw" = 0 ] && [ -z "$opt_arch_prefix" ]; then
check_cpu
check_cpu_vulnerabilities