Added support for TAA related vulnerabilities

This commit is contained in:
Agata Gruza 2019-11-12 09:30:36 -08:00 committed by Stéphane Lesimple
parent f5ec320fe5
commit d623524342
2 changed files with 143 additions and 4 deletions

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@ -14,6 +14,7 @@ A shell script to tell if your system is vulnerable against the several "specula
- CVE-2018-12130 [microarchitectural fill buffer data sampling (MFBDS)] aka 'ZombieLoad'
- CVE-2018-12127 [microarchitectural load port data sampling (MLPDS)] aka 'RIDL'
- CVE-2019-11091 [microarchitectural data sampling uncacheable memory (MDSUM)] aka 'RIDL'
- CVE-2019-11135 [TSX asynchronous abort] aka 'TAA'
Supported operating systems:
- Linux (all versions, flavors and distros)
@ -145,6 +146,12 @@ docker run --rm --privileged -v /boot:/boot:ro -v /dev/cpu:/dev/cpu:ro -v /lib/m
- Mitigation: microcode update + kernel update making possible to protect various CPU internal buffers from unprivileged speculative access to data
- Performance impact of the mitigation: low to significant
**CVE-2019-11135** TSX Asynchronous Abort (TAA)
- Impact: Kernel
- Mitigation: microcode update + kernel update making possible to protect various CPU internal buffers from unprivileged speculative access to data
- Performance impact of the mitigation: low to significant
## 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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@ -78,7 +78,7 @@ show_usage()
--batch prometheus produce output for consumption by prometheus-node-exporter
--variant VARIANT specify which variant you'd like to check, by default all variants are checked
VARIANT can be one of 1, 2, 3, 3a, 4, l1tf, msbds, mfbds, mlpds, mdsum
VARIANT can be one of 1, 2, 3, 3a, 4, l1tf, msbds, mfbds, mlpds, mdsum, taa
can be specified multiple times (e.g. --variant 2 --variant 3)
--cve [cve1,cve2,...] specify which CVE you'd like to check, by default all supported CVEs are checked
--hw-only only check for CPU information, don't check for any variant
@ -157,7 +157,7 @@ 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 CVE-2018-12126 CVE-2018-12130 CVE-2018-12127 CVE-2019-11091'
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 CVE-2019-11135'
# find a sane command to print colored messages, we prefer `printf` over `echo`
# because `printf` behavior is more standard across Linux/BSD
@ -279,6 +279,7 @@ cve2name()
CVE-2018-12130) echo "ZombieLoad, microarchitectural fill buffer data sampling (MFBDS)";;
CVE-2018-12127) echo "RIDL, microarchitectural load port data sampling (MLPDS)";;
CVE-2019-11091) echo "RIDL, microarchitectural data sampling uncacheable memory (MDSUM)";;
CVE-2019-11135) echo "Transactional Synchronization Extensions (TSX) Asynchronous Abort (TAA)";;
*) echo "$0: error: invalid CVE '$1' passed to cve2name()" >&2; exit 255;;
esac
}
@ -300,6 +301,7 @@ _is_cpu_vulnerable_cached()
CVE-2018-12130) return $variant_mfbds;;
CVE-2018-12127) return $variant_mlpds;;
CVE-2019-11091) return $variant_mdsum;;
CVE-2019-11135) return $variant_taa;;
*) echo "$0: error: invalid variant '$1' passed to is_cpu_vulnerable()" >&2; exit 255;;
esac
}
@ -326,6 +328,7 @@ is_cpu_vulnerable()
variant_mfbds=''
variant_mlpds=''
variant_mdsum=''
variant_taa=''
if is_cpu_mds_free; then
[ -z "$variant_msbds" ] && variant_msbds=immune
@ -335,6 +338,11 @@ is_cpu_vulnerable()
_debug "is_cpu_vulnerable: cpu not affected by Microarchitectural Data Sampling"
fi
if is_cpu_taa_free; then
[ -z "$variant_taa" ] && variant_taa=immune
_debug "is_cpu_vulnerable: cpu not affected by TSX Asynhronous Abort"
fi
if is_cpu_specex_free; then
variant1=immune
variant2=immune
@ -346,6 +354,7 @@ is_cpu_vulnerable()
variant_mfbds=immune
variant_mlpds=immune
variant_mdsum=immune
variant_taa=immune
elif is_intel; then
# Intel
# https://github.com/crozone/SpectrePoC/issues/1 ^F E5200 => spectre 2 not vulnerable
@ -528,6 +537,7 @@ is_cpu_vulnerable()
[ "$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
[ "$variant_taa" = "immune" ] && variant_taa=1 || variant_taa=0
variantl1tf_sgx="$variantl1tf"
# even if we are vulnerable to L1TF, if there's no SGX, we're safe for the original foreshadow
[ "$cpuid_sgx" = 0 ] && variantl1tf_sgx=1
@ -616,6 +626,27 @@ is_cpu_mds_free()
return 1
}
is_cpu_taa_free()
{
# return true (0) if the CPU isn't affected by tsx asynchronnous aborts, false (1) if it does.
# There are three types of processors that do not require additional mitigations.
# 1. CPUs that do not support Intel TSX are not affected.
# 2. CPUs that enumerate IA32_ARCH_CAPABILITIES[TAA_NO] (bit 8)=1 are not affected.
# 3. CPUs that support Intel TSX and do not enumerate IA32_ARCH_CAPABILITIES[MDS_NO] (bit 5)=1
# do not need additional mitigations beyond what is already required to mitigate MDS.
if ! is_intel; then
return 0
# is intel
elif [ "$capabilities_taa_no" = 0 ] || \
[ "$rtm" = 0]; 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.
@ -885,8 +916,9 @@ while [ -n "$1" ]; do
mlpds) opt_cve_list="$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;;
taa) opt_cve_list="$opt_cve_list CVE-2019-11135"; opt_cve_all=0;;
*)
echo "$0: error: invalid parameter '$2' for --variant, expected either 1, 2, 3, 3a, 4, msbds, mfbds, mlpds, mdsum, or l1tf" >&2;
echo "$0: error: invalid parameter '$2' for --variant, expected either 1, 2, 3, 3a, 4, msbds, mfbds, mlpds, mdsum, taa or l1tf" >&2;
exit 255
;;
esac
@ -2477,6 +2509,22 @@ check_cpu()
fi
fi
if is_intel; then
_info " * TSX Asynchronous Abort"
_info_nol " * TSX support is available: "
read_cpuid 0x7 $EDX 11 1 1; ret=$?
if [ $ret -eq 0 ]; then
rtm=1
pstatus green YES "TSX RTM feature bit"
elif [ $ret -eq 2 ]; then
rtm=-1
pstatus yellow UNKNOWN "is cpuid kernel module available?"
else
rtm=0
pstatus yellow NO
fi
fi
if is_intel; then
_info " * Enhanced IBRS (IBRS_ALL)"
_info_nol " * CPU indicates ARCH_CAPABILITIES MSR availability: "
@ -2494,6 +2542,7 @@ check_cpu()
fi
_info_nol " * ARCH_CAPABILITIES MSR advertises IBRS_ALL capability: "
capabilities_taa_no=-1
capabilities_mds_no=-1
capabilities_rdcl_no=-1
capabilities_ibrs_all=-1
@ -2504,6 +2553,7 @@ check_cpu()
pstatus yellow UNKNOWN
elif [ "$cpuid_arch_capabilities" != 1 ]; then
capabilities_rdcl_no=0
capabilities_taa_no=0
capabilities_mds_no=0
capabilities_ibrs_all=0
capabilities_rsba=0
@ -2536,6 +2586,7 @@ check_cpu()
done
capabilities=$val_cap_msr
capabilities_rdcl_no=0
capabilities_taa_no=0
capabilities_mds_no=0
capabilities_ibrs_all=0
capabilities_rsba=0
@ -2549,7 +2600,8 @@ check_cpu()
[ $(( capabilities >> 3 & 1 )) -eq 1 ] && capabilities_l1dflush_no=1
[ $(( capabilities >> 4 & 1 )) -eq 1 ] && capabilities_ssb_no=1
[ $(( capabilities >> 5 & 1 )) -eq 1 ] && capabilities_mds_no=1
_debug "capabilities says rdcl_no=$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"
[ $(( capabilities >> 8 & 1 )) -eq 1 ] && capabilities_taa_no=1
_debug "capabilities says rdcl_no=$capabilities_rdcl_no ibrs_all=$capabilities_ibrs_all rsba=$capabilities_rsba l1dflush_no=$capabilities_l1dflush_no ssb_no=$capabilities_ssb_no mds_no=$capabilities_mds_no taa_no=$capabilities_taa_no"
if [ "$capabilities_ibrs_all" = 1 ]; then
if [ $cpu_mismatch -eq 0 ]; then
pstatus green YES
@ -2612,6 +2664,15 @@ check_cpu()
else
pstatus yellow NO
fi
_info_nol " * CPU explicitly indicates not being vulnerable to TSX Asynchrnonous Abort (TAA_NO): "
if [ "$capabilities_taa_no" = -1 ]; then
pstatus yellow UNKNOWN
elif [ "$capabilities_taa_no" = 1 ]; then
pstatus green YES
else
pstatus yellow NO
fi
fi
_info_nol " * CPU supports Software Guard Extensions (SGX): "
@ -4650,6 +4711,77 @@ check_mds_linux()
fi
}
###################
# TAA SECTION
# Transactional Synchronization Extension (TSX) Asynchronous Abort
check_CVE_2019_11135()
{
cve='CVE-2019-11135'
check_taa $cve
}
# TSX Asynchronous Abort
check_taa()
{
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 $cve OK "your CPU vendor reported your CPU model as not vulnerable"
return
fi
if sys_interface_check '/sys/devices/system/cpu/vulnerabilities/tsx_async_abort'; then
# this kernel has the /sys interface, trust it over everything
sys_interface_available=1
fi
if [ "$sys_interface_available" = 1 ]; then
if grep -Eq 'Not affected' "/sys/devices/system/cpu/vulnerabilities/tsx_async_abort"; then
taa_mitigated=1
elif grep -Eq 'Mitigation:' "/sys/devices/system/cpu/vulnerabilities/tsx_async_abort"; then
if grep -Eq '(SMT mitigated|disabled)' "/sys/devices/system/cpu/vulnerabilities/tsx_async_abort"; then
taa_mitigated=1
else
#Simultaneous multi-threading (aka SMT or HyperThreading) is enabled. System may be vulnerable in some environments.
taa_mitigated=1
_info_nol "* Disable SMT to have complete mitigation\n"
fi
elif grep -Eq 'Vulnerable' "/sys/devices/system/cpu/vulnerabilities/tsx_async_abort"; then
taa_mitigated=0
_info_nol "* For more info check Linux kernel Documentation/admin-guide/hw-vuln/tsx_async_abort.rst\n"
else
taa_mitigated=-1
fi
if grep -Eq 'no microcode' "/sys/devices/system/cpu/vulnerabilities/tsx_async_abort"; then
taa_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/tsx_async_abort"
taa_mitigated=-1
fi
if [ $taa_mitigated = 0 ];then
pvulnstatus $cve VULN
elif [ $taa_mitigated = 1 ]; then
pvulnstatus $cve OK
else
pvulnstatus $cve UNK "further action may be needed to mitigate this vulnerability. For more info check Linux kernel Documentation/admin-guide/hw-vuln/tsx_async_abort.rst"
fi
}
if [ "$opt_no_hw" = 0 ] && [ -z "$opt_arch_prefix" ]; then
check_cpu
check_cpu_vulnerabilities