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fix(inception): continued mitigation detection

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This commit is contained in:
Stéphane Lesimple 2023-08-25 11:42:57 +02:00
parent c94811e63d
commit 9b7b09ada3
1 changed files with 73 additions and 20 deletions
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91
spectre-meltdown-checker.sh
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@ -3535,7 +3535,7 @@ check_cpu()
if is_amd || is_hygon; then if is_amd || is_hygon; then
_info " * Selective Branch Predictor Barrier (SBPB)" _info " * Selective Branch Predictor Barrier (SBPB)"
_info_nol " * PRED_CMD MSR is available: " _info_nol " * PRED_CMD MSR supports SBPB bit write: "
if [ "$opt_allow_msr_write" = 1 ]; then if [ "$opt_allow_msr_write" = 1 ]; then
# the MSR PRED_SBPB is at offset 0x49, BIT(7), write-only # the MSR PRED_SBPB is at offset 0x49, BIT(7), write-only
@ -3545,6 +3545,7 @@ check_cpu()
cpuid_sbpb=1 cpuid_sbpb=1
elif [ $ret = $WRITE_MSR_RET_KO ]; then elif [ $ret = $WRITE_MSR_RET_KO ]; then
pstatus yellow NO pstatus yellow NO
cpuid_sbpb=2
else else
pstatus yellow UNKNOWN "$write_msr_msg" pstatus yellow UNKNOWN "$write_msr_msg"
cpuid_sbpb=3 cpuid_sbpb=3
@ -6359,44 +6360,72 @@ check_CVE_2023_20569_linux() {
pstatus yellow NO pstatus yellow NO
fi fi
_info_nol "* Kernel compiled with SRSO support " _info_nol "* Kernel compiled with SRSO support: "
if [ -r "$opt_config" ]; then if [ -r "$opt_config" ]; then
if grep -q '^CONFIG_CPU_SRSO=y' "$opt_config"; then if grep -q '^CONFIG_CPU_SRSO=y' "$opt_config"; then
pstatus green YES pstatus green YES
kernel_srso="CONFIG_CPU_SRSO=y found in kernel config"
else else
pstatus yellow NO "required for safe RET and ibpb_on_vmexit mitigations" pstatus yellow NO "required for safe RET and ibpb_on_vmexit mitigations"
fi fi
else else
pstatus yellow UNKNOWN "couldn't read your kernel configuration" # https://github.com/torvalds/linux/commit/138bcddb86d8a4f842e4ed6f0585abc9b1a764ff#diff-17bd24a7a7850613cced545790ac30646097e8d6207348c2bd1845f397acb390R2313
if [ -n "$kernel_err" ]; then
pstatus yellow UNKNOWN "$kernel_err"
elif grep -q 'WARNING: kernel not compiled with CPU_SRSO' "$kernel"; then
# this msg is optimized out at compile time if the option is not enabled, see commit referenced above
# if it's present, then SRSO is NOT compiled in
pstatus yellow NO "kernel not compiled with CPU_SRSO"
else
# if it's not present, then SRSO is compiled in IF kernel_sro==1, otherwise we're just
# in front of an old kernel that doesn't have the mitigation logic at all
if [ "$kernel_sro" = 1 ]; then
kernel_srso="SRSO mitigation logic is compiled in the kernel"
pstatus green OK "$kernel_srso"
else
pstatus yellow NO "your kernel is too old and doesn't have the mitigation logic"
fi
fi
fi fi
_info_nol "* Kernel compiled with IBPB support " _info_nol "* Kernel compiled with IBPB_ENTRY support: "
if [ -r "$opt_config" ]; then if [ -r "$opt_config" ]; then
if grep -q '^CONFIG_CPU_IBPB_ENTRY=y' "$opt_config"; then if grep -q '^CONFIG_CPU_IBPB_ENTRY=y' "$opt_config"; then
pstatus green YES pstatus green YES
kernel_ibpb_entry="CONFIG_CPU_IBPB_ENTRY=y found in kernel config"
else else
pstatus yellow NO "required for ibpb mitigation" pstatus yellow NO
fi fi
else else
pstatus yellow UNKNOWN "couldn't read your kernel configuration" # https://github.com/torvalds/linux/commit/138bcddb86d8a4f842e4ed6f0585abc9b1a764ff#diff-17bd24a7a7850613cced545790ac30646097e8d6207348c2bd1845f397acb390R2325
if [ -n "$kernel_err" ]; then
pstatus yellow UNKNOWN "$kernel_err"
elif grep -q 'WARNING: kernel not compiled with CPU_IBPB_ENTRY' "$kernel"; then
# this msg is optimized out at compile time if the option is not enabled, see commit referenced above
# if it's present, then IBPB_ENTRY is NOT compiled in
pstatus yellow NO "kernel not compiled with CPU_IBPB_ENTRY"
else
# if it's not present, then IBPB_ENTRY is compiled in IF kernel_sro==1, otherwise we're just
# in front of an old kernel that doesn't have the mitigation logic at all
if [ "$kernel_sro" = 1 ]; then
kernel_ibpb_entry="IBPB_ENTRY mitigation logic is compiled in the kernel"
pstatus green OK "$kernel_ibpb_entry"
else
pstatus yellow NO "your kernel is too old and doesn't have the mitigation logic"
fi
fi fi
if [ -n "$kernel_sro" ]; then
# TODO check mitigation
:
fi fi
# Zen & Zen2 : if the right IBPB microcode applied + SMT off --> not vuln # Zen & Zen2 : if the right IBPB microcode applied + SMT off --> not vuln
if [ "$cpu_family" = $(( 0x17 )) ]; then if [ "$cpu_family" = $(( 0x17 )) ]; then
_info_nol "* CPU supports IBPB : " _info_nol "* CPU supports IBPB: "
if [ -n "$cpuid_ibpb" ]; then if [ -n "$cpuid_ibpb" ]; then
pstatus green YES "$cpuid_ibpb" pstatus green YES "$cpuid_ibpb"
else else
pstatus red NO pstatus yellow NO
fi fi
_info_nol "* SMT is enabled: " _info_nol "* Hyper-Threading (SMT) is enabled: "
is_cpu_smt_enabled; smt_enabled=$? is_cpu_smt_enabled; smt_enabled=$?
if [ "$smt_enabled" = 0 ]; then if [ "$smt_enabled" = 0 ]; then
pstatus yellow YES pstatus yellow YES
@ -6409,7 +6438,7 @@ check_CVE_2023_20569_linux() {
if [ "$cpuid_sbpb" = 1 ]; then if [ "$cpuid_sbpb" = 1 ]; then
pstatus green YES pstatus green YES
elif [ "$cpuid_sbpb" = 3 ]; then elif [ "$cpuid_sbpb" = 3 ]; then
pstatus yellow UNKNOWN "cannot write MSR" pstatus yellow UNKNOWN "cannot write MSR, rerun with --allow-msr-write"
else else
pstatus yellow NO pstatus yellow NO
fi fi
@ -6425,11 +6454,35 @@ check_CVE_2023_20569_linux() {
# override status & msg in case CPU is not vulnerable after all # override status & msg in case CPU is not vulnerable after all
pvulnstatus "$cve" OK "your CPU vendor reported your CPU model as not affected" pvulnstatus "$cve" OK "your CPU vendor reported your CPU model as not affected"
elif [ -z "$msg" ]; then elif [ -z "$msg" ]; then
# if msg is empty, sysfs check didn't fill it. If the kernel does not bring the mitigation. # if msg is empty, sysfs check didn't fill it, so we rely on our own logic
if [ "$cpu_family" = $(( 0x17 )) ] && [ "$smt_enabled" = 1 ] && [ -n "$cpuid_ibpb" ]; then # Zen/Zen2
pvulnstatus "$cve" OK "IBPB supported and SMT is off" if [ "$cpu_family" = $(( 0x17 )) ]; then
if [ "$smt_enabled" = 0 ]; then
pvulnstatus "$cve" VULN "SMT is enabled on your Zen/Zen2 CPU, which makes mitigation ineffective"
explain "For Zen/Zen2 CPUs, proper mitigation needs an up to date microcode, and SMT needs to be disabled (this can be done by adding \`nosmt\` to your kernel command line)"
elif [ -z "$kernel_sro" ]; then
pvulnstatus "$cve" VULN "Your kernel is too old and doesn't have the SRSO mitigation logic"
elif [ -n "$cpuid_ibpb" ]; then
pvulnstatus "$cve" OK "SMT is disabled and both your kernel and microcode support mitigation"
else else
pvulnstatus $cve VULN "upgrade your kernel" pvulnstatus "$cve" VULN "Your microcode is too old"
fi
# Zen3/Zen4
elif [ "$cpu_family" = $(( 0x19 )) ]; then
if [ -z "$kernel_sro" ]; then
pvulnstatus "$cve" VULN "Your kernel is too old and doesn't have the SRSO mitigation logic"
elif [ -z "$kernel_srso" ] && [ -z "$kernel_ibpb_entry" ]; then
pvulnstatus "$cve" VULN "Your kernel doesn't have either SRSO or IBPB_ENTRY compiled-in"
elif [ "$cpuid_sbpb" = 3 ]; then
pvulnstatus "$cve" UNK "Couldn't verify if your microcode supports IBPB (rerun with --allow-msr-write)"
elif [ "$cpuid_sbpb" = 2 ]; then
pvulnstatus "$cve" VULN "Your microcode doesn't support SBPB"
else
pvulnstatus "$cve" OK "Your kernel and microcode both support mitigation"
fi
else
# not supposed to happen, as normally this CPU should not be affected and not run this code
pvulnstatus "$cve" OK "your CPU vendor reported your CPU model as not affected"
fi fi
else else
pvulnstatus $cve "$status" "$msg" pvulnstatus $cve "$status" "$msg"