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fix(inception): Zen1/2 results based on kernel mitigations

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Sébastien Mériot 2023-08-16 15:54:13 +00:00 committed by Stéphane Lesimple
parent 3e67047c73
commit c94811e63d
1 changed files with 11 additions and 18 deletions
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27
spectre-meltdown-checker.sh
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@ -2783,10 +2783,10 @@ write_msr_one_core()
# or fallback to dd if it supports seek_bytes, we prefer it over perl because we can tell the difference between EPERM and EIO
elif dd if=/dev/null of=/dev/null bs=8 count=1 seek="$_msr_dec" oflag=seek_bytes 2>/dev/null && [ "${SMC_NO_DD:-}" != 1 ]; then
_debug "write_msr: using dd"
awk "BEGIN{printf \"\%c\", $_value_dec}" | dd of=/dev/cpu/"$_core"/msr bs=8 count=1 seek="$_msr_dec" oflag=seek_bytes 2>/dev/null; ret=$?
awk "BEGIN{printf \"%c\", $_value_dec}" | dd of=/dev/cpu/"$_core"/msr bs=8 count=1 seek="$_msr_dec" oflag=seek_bytes 2>/dev/null; ret=$?
# if it failed, inspect stderrto look for EPERM
if [ "$ret" != 0 ]; then
if aws "BEGIN{printf \"%c\", $_value_dec}" | dd of=/dev/cpu/"$_core"/msr bs=8 count=1 seek="$_msr_dec" oflag=seek_bytes 2>&1 | grep -qF 'Operation not permitted'; then
if awk "BEGIN{printf \"%c\", $_value_dec}" | dd of=/dev/cpu/"$_core"/msr bs=8 count=1 seek="$_msr_dec" oflag=seek_bytes 2>&1 | grep -qF 'Operation not permitted'; then
_write_denied=1
fi
fi
@ -6389,17 +6389,17 @@ check_CVE_2023_20569_linux() {
# Zen & Zen2 : if the right IBPB microcode applied + SMT off --> not vuln
if [ "$cpu_family" = $(( 0x17 )) ]; then
_info_nol " * IBPB support: "
_info_nol "* CPU supports IBPB : "
if [ -n "$cpuid_ibpb" ]; then
pstatus green YES "$cpuid_ibpb"
else
pstatus red NO
fi
_info_nol " * SMT is enabled: "
_info_nol "* SMT is enabled: "
is_cpu_smt_enabled; smt_enabled=$?
if [ "$smt_enabled" = 0 ]; then
pstatus red YES
pstatus yellow YES
else
pstatus green NO
fi
@ -6424,20 +6424,13 @@ check_CVE_2023_20569_linux() {
if ! is_cpu_affected "$cve" ; then
# override status & msg in case CPU is not vulnerable after all
pvulnstatus "$cve" OK "your CPU vendor reported your CPU model as not affected"
elif [ "$cpu_family" = $(( 0x17 )) ]; then
if [ "$smt_enabled" = 1 ] && [ -n "$cpuid_ibpb" ]; then
pvulnstatus "$cve" OK "IBPB supported and SMT is off"
elif [ "$smt_enabled" != 1 ] && [ -n "$cpuid_ibpb" ]; then
pvulnstatus "$cve" VULN "SMT is enabled"
elif [ "$smt_enabled" = 1 ]; then
pvulnstatus "$cve" VULN "IBPB is not supported by your current microcode"
else
pvulnstatus "$cve" VULN "SMT is enabled and IBPB is not support by your current microcode"
fi
explain "Zen1/2 with SMT off aren't vulnerable after the right IBPB microcode has been applied. (https://github.com/torvalds/linux/commit/138bcddb86d8a4f842e4ed6f0585abc9b1a764ff#diff-17bd24a7a7850613cced545790ac30646097e8d6207348c2bd1845f397acb390R2272)"
elif [ -z "$msg" ]; then
# if msg is empty, sysfs check didn't fill it. If the kernel does not bring the mitigation, system vuln.
# if msg is empty, sysfs check didn't fill it. If the kernel does not bring the mitigation.
if [ "$cpu_family" = $(( 0x17 )) ] && [ "$smt_enabled" = 1 ] && [ -n "$cpuid_ibpb" ]; then
pvulnstatus "$cve" OK "IBPB supported and SMT is off"
else
pvulnstatus $cve VULN "upgrade your kernel"
fi
else
pvulnstatus $cve "$status" "$msg"
fi