From e23712129d678174068adf9e5658906badeb8d4a Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?St=C3=A9phane=20Lesimple?= Date: Wed, 1 Apr 2026 21:36:45 +0200 Subject: [PATCH] enh: rework is_cpu_affected() to enhance maintainability --- src/libs/200_cpu_affected.sh | 266 ++++++++++++++++++----------------- 1 file changed, 138 insertions(+), 128 deletions(-) diff --git a/src/libs/200_cpu_affected.sh b/src/libs/200_cpu_affected.sh index 503d2e4..4fb4f52 100644 --- a/src/libs/200_cpu_affected.sh +++ b/src/libs/200_cpu_affected.sh @@ -1,4 +1,32 @@ # vim: set ts=4 sw=4 sts=4 et: + +# Helpers for is_cpu_affected: encode the 4 patterns for setting affected_* variables. +# Each function takes the variable suffix as $1 (e.g. "variantl1tf", not "affected_variantl1tf"). +# Variables hold 1 (not affected / immune) or 0 (affected / vuln); empty = not yet decided. + +# Set affected_$1 to 1 (not affected) unconditionally. +# Use for: hardware capability bits (cap_rdcl_no, cap_ssb_no, cap_gds_no, cap_tsa_*_no), +# is_cpu_specex_free results, and vendor-wide immune facts (AMD/L1TF, Cavium, etc.). +# This always wins and cannot be overridden by _infer_vuln (which only fires on empty). +# Must not be followed by _set_vuln for the same variable in the same code path. +_set_immune() { eval "affected_$1=1"; } + +# Set affected_$1 to 0 (affected) unconditionally. +# Use for: confirmed-vuln model/erratum lists, ARM unknown-CPU fallback. +# Note: intentionally overrides a prior _infer_immune (1) — this is required for ARM +# big.LITTLE cumulative logic where a second vuln core must override a prior safe core. +# Must not be called after _set_immune for the same variable in the same code path. +_set_vuln() { eval "affected_$1=0"; } + +# Set affected_$1 to 1 (not affected) only if not yet decided (currently empty). +# Use for: model/family whitelists, per-part ARM immune inferences, +# AMD/ARM partial immunity (immune on this variant axis but not others). +_infer_immune() { eval "[ -z \"\$affected_$1\" ] && affected_$1=1 || :"; } + +# Set affected_$1 to 0 (affected) only if not yet decided (currently empty). +# Use for: family-level catch-all fallbacks (Intel L1TF non-whitelist, itlbmh non-whitelist). +_infer_vuln() { eval "[ -z \"\$affected_$1\" ] && affected_$1=0 || :"; } + # Return the cached affected_* status for a given CVE # Args: $1=cve_id # Returns: 0 if affected, 1 if not affected @@ -72,79 +100,79 @@ is_cpu_affected() { affected_itlbmh='' affected_srbds='' # Zenbleed and Inception are both AMD specific, look for "is_amd" below: - affected_zenbleed=immune - affected_inception=immune + _set_immune zenbleed + _set_immune inception # TSA is AMD specific (Zen 3/4), look for "is_amd" below: - affected_tsa=immune + _set_immune tsa # Downfall & Reptar are Intel specific, look for "is_intel" below: - affected_downfall=immune - affected_reptar=immune + _set_immune downfall + _set_immune reptar if is_cpu_mds_free; then - [ -z "$affected_msbds" ] && affected_msbds=immune - [ -z "$affected_mfbds" ] && affected_mfbds=immune - [ -z "$affected_mlpds" ] && affected_mlpds=immune - [ -z "$affected_mdsum" ] && affected_mdsum=immune + _infer_immune msbds + _infer_immune mfbds + _infer_immune mlpds + _infer_immune mdsum pr_debug "is_cpu_affected: cpu not affected by Microarchitectural Data Sampling" fi if is_cpu_taa_free; then - [ -z "$affected_taa" ] && affected_taa=immune + _infer_immune taa pr_debug "is_cpu_affected: cpu not affected by TSX Asynhronous Abort" fi if is_cpu_srbds_free; then - [ -z "$affected_srbds" ] && affected_srbds=immune + _infer_immune srbds pr_debug "is_cpu_affected: cpu not affected by Special Register Buffer Data Sampling" fi if is_cpu_specex_free; then - affected_variant1=immune - affected_variant2=immune - affected_variant3=immune - affected_variant3a=immune - affected_variant4=immune - affected_variantl1tf=immune - affected_msbds=immune - affected_mfbds=immune - affected_mlpds=immune - affected_mdsum=immune - affected_taa=immune - affected_srbds=immune + _set_immune variant1 + _set_immune variant2 + _set_immune variant3 + _set_immune variant3a + _set_immune variant4 + _set_immune variantl1tf + _set_immune msbds + _set_immune mfbds + _set_immune mlpds + _set_immune mdsum + _set_immune taa + _set_immune srbds elif is_intel; then # Intel # https://github.com/crozone/SpectrePoC/issues/1 ^F E5200 => spectre 2 not affected # https://github.com/paboldin/meltdown-exploit/issues/19 ^F E5200 => meltdown affected # model name : Pentium(R) Dual-Core CPU E5200 @ 2.50GHz if echo "$cpu_friendly_name" | grep -qE 'Pentium\(R\) Dual-Core[[:space:]]+CPU[[:space:]]+E[0-9]{4}K?'; then - affected_variant1=vuln - [ -z "$affected_variant2" ] && affected_variant2=immune - affected_variant3=vuln + _set_vuln variant1 + _infer_immune variant2 + _set_vuln variant3 fi if [ "$cap_rdcl_no" = 1 ]; then # capability bit for future Intel processor that will explicitly state # that they're not affected to Meltdown # this var is set in check_cpu() - [ -z "$affected_variant3" ] && affected_variant3=immune - [ -z "$affected_variantl1tf" ] && affected_variantl1tf=immune + _set_immune variant3 + _set_immune variantl1tf pr_debug "is_cpu_affected: RDCL_NO is set so not vuln to meltdown nor l1tf" fi if [ "$cap_ssb_no" = 1 ]; then # capability bit for future Intel processor that will explicitly state # that they're not affected to Variant 4 # this var is set in check_cpu() - [ -z "$affected_variant4" ] && affected_variant4=immune + _set_immune variant4 pr_debug "is_cpu_affected: SSB_NO is set so not vuln to affected_variant4" fi if is_cpu_ssb_free; then - [ -z "$affected_variant4" ] && affected_variant4=immune + _infer_immune variant4 pr_debug "is_cpu_affected: cpu not affected by speculative store bypass so not vuln to affected_variant4" fi # variant 3a if [ "$cpu_family" = 6 ]; then if [ "$cpu_model" = "$INTEL_FAM6_XEON_PHI_KNL" ] || [ "$cpu_model" = "$INTEL_FAM6_XEON_PHI_KNM" ]; then pr_debug "is_cpu_affected: xeon phi immune to variant 3a" - [ -z "$affected_variant3a" ] && affected_variant3a=immune + _infer_immune variant3a elif [ "$cpu_model" = "$INTEL_FAM6_ATOM_SILVERMONT" ] || [ "$cpu_model" = "$INTEL_FAM6_ATOM_SILVERMONT_MID" ] || [ "$cpu_model" = "$INTEL_FAM6_ATOM_SILVERMONT_D" ]; then @@ -153,10 +181,10 @@ is_cpu_affected() { # => silvermont CPUs (aka cherry lake for tablets and brawsell for mobile/desktop) don't seem to be affected # => goldmont ARE affected pr_debug "is_cpu_affected: silvermont immune to variant 3a" - [ -z "$affected_variant3a" ] && affected_variant3a=immune + _infer_immune variant3a fi fi - # L1TF (RDCL_NO already checked above) + # L1TF (cap_rdcl_no already checked above) if [ "$cpu_family" = 6 ]; then if [ "$cpu_model" = "$INTEL_FAM6_ATOM_SALTWELL" ] || [ "$cpu_model" = "$INTEL_FAM6_ATOM_SALTWELL_TABLET" ] || @@ -177,14 +205,14 @@ is_cpu_affected() { [ "$cpu_model" = "$INTEL_FAM6_XEON_PHI_KNM" ]; then pr_debug "is_cpu_affected: intel family 6 but model known to be immune to l1tf" - [ -z "$affected_variantl1tf" ] && affected_variantl1tf=immune + _infer_immune variantl1tf else pr_debug "is_cpu_affected: intel family 6 is vuln to l1tf" - [ -z "$affected_variantl1tf" ] && affected_variantl1tf=vuln + _infer_vuln variantl1tf fi elif [ "$cpu_family" -lt 6 ]; then pr_debug "is_cpu_affected: intel family < 6 is immune to l1tf" - [ -z "$affected_variantl1tf" ] && affected_variantl1tf=immune + _infer_immune variantl1tf fi # Downfall if [ "$cap_gds_no" = 1 ]; then @@ -192,7 +220,7 @@ is_cpu_affected() { # that they're unaffected by GDS. Also set by hypervisors on virtual CPUs # so that the guest kernel doesn't try to mitigate GDS when it's already mitigated on the host pr_debug "is_cpu_affected: downfall: not affected (GDS_NO)" - affected_downfall=immune + _set_immune downfall elif [ "$cpu_family" = 6 ]; then # list from https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=64094e7e3118aff4b0be8ff713c242303e139834 set -u @@ -208,7 +236,7 @@ is_cpu_affected() { [ "$cpu_model" = "$INTEL_FAM6_TIGERLAKE" ] || [ "$cpu_model" = "$INTEL_FAM6_ROCKETLAKE" ]; then pr_debug "is_cpu_affected: downfall: affected" - affected_downfall=vuln + _set_vuln downfall elif [ "$cap_avx2" = 0 ] && [ "$cap_avx512" = 0 ]; then pr_debug "is_cpu_affected: downfall: no avx; immune" else @@ -267,7 +295,7 @@ is_cpu_affected() { ) if [ "$cpu_cpuid" = "$affected_cpuid" ] && [ $((cpu_platformid & ucode_platformid_mask)) -gt 0 ]; then # this is not perfect as Intel never tells about their EOL CPUs, so more CPUs might be affected but there's no way to tell - affected_reptar=vuln + _set_vuln reptar g_reptar_fixed_ucode_version=$fixed_ucode_ver break fi @@ -276,26 +304,26 @@ is_cpu_affected() { elif is_amd || is_hygon; then # AMD revised their statement about affected_variant2 => affected # https://www.amd.com/en/corporate/speculative-execution - affected_variant1=vuln - affected_variant2=vuln - [ -z "$affected_variant3" ] && affected_variant3=immune + _set_vuln variant1 + _set_vuln variant2 + _infer_immune variant3 # https://www.amd.com/en/corporate/security-updates # "We have not identified any AMD x86 products susceptible to the Variant 3a vulnerability in our analysis to-date." - [ -z "$affected_variant3a" ] && affected_variant3a=immune + _infer_immune variant3a if is_cpu_ssb_free; then - [ -z "$affected_variant4" ] && affected_variant4=immune + _infer_immune variant4 pr_debug "is_cpu_affected: cpu not affected by speculative store bypass so not vuln to affected_variant4" fi - affected_variantl1tf=immune + _set_immune variantl1tf # Zenbleed - amd_legacy_erratum "$(amd_model_range 0x17 0x30 0x0 0x4f 0xf)" && affected_zenbleed=vuln - amd_legacy_erratum "$(amd_model_range 0x17 0x60 0x0 0x7f 0xf)" && affected_zenbleed=vuln - amd_legacy_erratum "$(amd_model_range 0x17 0xa0 0x0 0xaf 0xf)" && affected_zenbleed=vuln + amd_legacy_erratum "$(amd_model_range 0x17 0x30 0x0 0x4f 0xf)" && _set_vuln zenbleed + amd_legacy_erratum "$(amd_model_range 0x17 0x60 0x0 0x7f 0xf)" && _set_vuln zenbleed + amd_legacy_erratum "$(amd_model_range 0x17 0xa0 0x0 0xaf 0xf)" && _set_vuln zenbleed # Inception (according to kernel, zen 1 to 4) if [ "$cpu_family" = $((0x17)) ] || [ "$cpu_family" = $((0x19)) ]; then - affected_inception=vuln + _set_vuln inception fi # TSA (Zen 3/4 are affected, unless CPUID says otherwise) @@ -304,19 +332,19 @@ is_cpu_affected() { # they're not affected to TSA-SQ and TSA-L1 # these vars are set in check_cpu() pr_debug "is_cpu_affected: TSA_SQ_NO and TSA_L1_NO are set so not vuln to TSA" - affected_tsa=immune + _set_immune tsa elif [ "$cpu_family" = $((0x19)) ]; then - affected_tsa=vuln + _set_vuln tsa fi elif [ "$cpu_vendor" = CAVIUM ]; then - affected_variant3=immune - affected_variant3a=immune - affected_variantl1tf=immune + _set_immune variant3 + _set_immune variant3a + _set_immune variantl1tf elif [ "$cpu_vendor" = PHYTIUM ]; then - affected_variant3=immune - affected_variant3a=immune - affected_variantl1tf=immune + _set_immune variant3 + _set_immune variant3a + _set_immune variantl1tf elif [ "$cpu_vendor" = ARM ]; then # ARM # reference: https://developer.arm.com/support/security-update @@ -348,73 +376,73 @@ is_cpu_affected() { # Maintain cumulative check of vulnerabilities - # if at least one of the cpu is affected, then the system is affected if [ "$cpuarch" = 7 ] && echo "$cpupart" | grep -q -w -e 0xc08 -e 0xc09 -e 0xc0d -e 0xc0e; then - affected_variant1=vuln - affected_variant2=vuln - [ -z "$affected_variant3" ] && affected_variant3=immune - [ -z "$affected_variant3a" ] && affected_variant3a=immune - [ -z "$affected_variant4" ] && affected_variant4=immune + _set_vuln variant1 + _set_vuln variant2 + _infer_immune variant3 + _infer_immune variant3a + _infer_immune variant4 pr_debug "checking cpu$i: armv7 A8/A9/A12/A17 non affected to variants 3, 3a & 4" elif [ "$cpuarch" = 7 ] && echo "$cpupart" | grep -q -w -e 0xc0f; then - affected_variant1=vuln - affected_variant2=vuln - [ -z "$affected_variant3" ] && affected_variant3=immune - affected_variant3a=vuln - [ -z "$affected_variant4" ] && affected_variant4=immune + _set_vuln variant1 + _set_vuln variant2 + _infer_immune variant3 + _set_vuln variant3a + _infer_immune variant4 pr_debug "checking cpu$i: armv7 A15 non affected to variants 3 & 4" elif [ "$cpuarch" = 8 ] && echo "$cpupart" | grep -q -w -e 0xd07 -e 0xd08; then - affected_variant1=vuln - affected_variant2=vuln - [ -z "$affected_variant3" ] && affected_variant3=immune - affected_variant3a=vuln - affected_variant4=vuln + _set_vuln variant1 + _set_vuln variant2 + _infer_immune variant3 + _set_vuln variant3a + _set_vuln variant4 pr_debug "checking cpu$i: armv8 A57/A72 non affected to variants 3" elif [ "$cpuarch" = 8 ] && echo "$cpupart" | grep -q -w -e 0xd09; then - affected_variant1=vuln - affected_variant2=vuln - [ -z "$affected_variant3" ] && affected_variant3=immune - [ -z "$affected_variant3a" ] && affected_variant3a=immune - affected_variant4=vuln + _set_vuln variant1 + _set_vuln variant2 + _infer_immune variant3 + _infer_immune variant3a + _set_vuln variant4 pr_debug "checking cpu$i: armv8 A73 non affected to variants 3 & 3a" elif [ "$cpuarch" = 8 ] && echo "$cpupart" | grep -q -w -e 0xd0a; then - affected_variant1=vuln - affected_variant2=vuln - affected_variant3=vuln - [ -z "$affected_variant3a" ] && affected_variant3a=immune - affected_variant4=vuln + _set_vuln variant1 + _set_vuln variant2 + _set_vuln variant3 + _infer_immune variant3a + _set_vuln variant4 pr_debug "checking cpu$i: armv8 A75 non affected to variant 3a" elif [ "$cpuarch" = 8 ] && echo "$cpupart" | grep -q -w -e 0xd0b -e 0xd0c -e 0xd0d; then - affected_variant1=vuln - [ -z "$affected_variant2" ] && affected_variant2=immune - [ -z "$affected_variant3" ] && affected_variant3=immune - [ -z "$affected_variant3a" ] && affected_variant3a=immune - affected_variant4=vuln + _set_vuln variant1 + _infer_immune variant2 + _infer_immune variant3 + _infer_immune variant3a + _set_vuln variant4 pr_debug "checking cpu$i: armv8 A76/A77/NeoverseN1 non affected to variant 2, 3 & 3a" elif [ "$cpuarch" = 8 ] && echo "$cpupart" | grep -q -w -e 0xd40 -e 0xd49 -e 0xd4f; then - affected_variant1=vuln - [ -z "$affected_variant2" ] && affected_variant2=immune - [ -z "$affected_variant3" ] && affected_variant3=immune - [ -z "$affected_variant3a" ] && affected_variant3a=immune - [ -z "$affected_variant4" ] && affected_variant4=immune + _set_vuln variant1 + _infer_immune variant2 + _infer_immune variant3 + _infer_immune variant3a + _infer_immune variant4 pr_debug "checking cpu$i: armv8 NeoverseN2/V1/V2 non affected to variant 2, 3, 3a & 4" elif [ "$cpuarch" -le 7 ] || { [ "$cpuarch" = 8 ] && [ $((cpupart)) -lt $((0xd07)) ]; }; then - [ -z "$affected_variant1" ] && affected_variant1=immune - [ -z "$affected_variant2" ] && affected_variant2=immune - [ -z "$affected_variant3" ] && affected_variant3=immune - [ -z "$affected_variant3a" ] && affected_variant3a=immune - [ -z "$affected_variant4" ] && affected_variant4=immune + _infer_immune variant1 + _infer_immune variant2 + _infer_immune variant3 + _infer_immune variant3a + _infer_immune variant4 pr_debug "checking cpu$i: arm arch$cpuarch, all immune (v7 or v8 and model < 0xd07)" else - affected_variant1=vuln - affected_variant2=vuln - affected_variant3=vuln - affected_variant3a=vuln - affected_variant4=vuln + _set_vuln variant1 + _set_vuln variant2 + _set_vuln variant3 + _set_vuln variant3a + _set_vuln variant4 pr_debug "checking cpu$i: arm unknown arch$cpuarch part$cpupart, considering vuln" fi fi pr_debug "is_cpu_affected: for cpu$i and so far, we have <$affected_variant1> <$affected_variant2> <$affected_variant3> <$affected_variant3a> <$affected_variant4>" done - affected_variantl1tf=immune + _set_immune variantl1tf fi # we handle iTLB Multihit here (not linked to is_specex_free) @@ -437,43 +465,25 @@ is_cpu_affected() { [ "$cpu_model" = "$INTEL_FAM6_ATOM_GOLDMONT_D" ] || [ "$cpu_model" = "$INTEL_FAM6_ATOM_GOLDMONT_PLUS" ]; then pr_debug "is_cpu_affected: intel family 6 but model known to be immune to itlbmh" - [ -z "$affected_itlbmh" ] && affected_itlbmh=immune + _infer_immune itlbmh else pr_debug "is_cpu_affected: intel family 6 is vuln to itlbmh" - affected_itlbmh=vuln + _infer_vuln itlbmh fi elif [ "$cpu_family" -lt 6 ]; then pr_debug "is_cpu_affected: intel family < 6 is immune to itlbmh" - [ -z "$affected_itlbmh" ] && affected_itlbmh=immune + _infer_immune itlbmh fi else pr_debug "is_cpu_affected: non-intel not affected to itlbmh" - [ -z "$affected_itlbmh" ] && affected_itlbmh=immune + _infer_immune itlbmh fi - pr_debug "is_cpu_affected: temp results are <$affected_variant1> <$affected_variant2> <$affected_variant3> <$affected_variant3a> <$affected_variant4> <$affected_variantl1tf>" - [ "$affected_variant1" = "immune" ] && affected_variant1=1 || affected_variant1=0 - [ "$affected_variant2" = "immune" ] && affected_variant2=1 || affected_variant2=0 - [ "$affected_variant3" = "immune" ] && affected_variant3=1 || affected_variant3=0 - [ "$affected_variant3a" = "immune" ] && affected_variant3a=1 || affected_variant3a=0 - [ "$affected_variant4" = "immune" ] && affected_variant4=1 || affected_variant4=0 - [ "$affected_variantl1tf" = "immune" ] && affected_variantl1tf=1 || affected_variantl1tf=0 - [ "$affected_msbds" = "immune" ] && affected_msbds=1 || affected_msbds=0 - [ "$affected_mfbds" = "immune" ] && affected_mfbds=1 || affected_mfbds=0 - [ "$affected_mlpds" = "immune" ] && affected_mlpds=1 || affected_mlpds=0 - [ "$affected_mdsum" = "immune" ] && affected_mdsum=1 || affected_mdsum=0 - [ "$affected_taa" = "immune" ] && affected_taa=1 || affected_taa=0 - [ "$affected_itlbmh" = "immune" ] && affected_itlbmh=1 || affected_itlbmh=0 - [ "$affected_srbds" = "immune" ] && affected_srbds=1 || affected_srbds=0 - [ "$affected_zenbleed" = "immune" ] && affected_zenbleed=1 || affected_zenbleed=0 - [ "$affected_downfall" = "immune" ] && affected_downfall=1 || affected_downfall=0 - [ "$affected_inception" = "immune" ] && affected_inception=1 || affected_inception=0 - [ "$affected_reptar" = "immune" ] && affected_reptar=1 || affected_reptar=0 - [ "$affected_tsa" = "immune" ] && affected_tsa=1 || affected_tsa=0 + pr_debug "is_cpu_affected: final results are <$affected_variant1> <$affected_variant2> <$affected_variant3> <$affected_variant3a> <$affected_variant4> <$affected_variantl1tf>" affected_variantl1tf_sgx="$affected_variantl1tf" # even if we are affected to L1TF, if there's no SGX, we're not affected to the original foreshadow - [ "$cap_sgx" = 0 ] && affected_variantl1tf_sgx=1 - pr_debug "is_cpu_affected: final results are <$affected_variant1> <$affected_variant2> <$affected_variant3> <$affected_variant3a> <$affected_variant4> <$affected_variantl1tf> <$affected_variantl1tf_sgx>" + [ "$cap_sgx" = 0 ] && _set_immune variantl1tf_sgx + pr_debug "is_cpu_affected: variantl1tf_sgx=<$affected_variantl1tf_sgx>" g_is_cpu_affected_cached=1 _is_cpu_affected_cached "$1" return $?