mirror of
https://github.com/speed47/spectre-meltdown-checker.git
synced 2026-04-03 05:37:11 +02:00
enh: CVE-2022-40982 (Downfall) overhaul
built from commit c4c4ea8c0a5f2ffde852a22f26b9801bca61139a dated 2026-04-02 19:55:25 +0200 by Stéphane Lesimple (speed47_github@speed47.net) - added `--kernel-config` support for all three Kconfig variants seen over all kernel versions up to now - added `--kernel-map` support for `gds_select_mitigation` in `System.map` - fixed the `--sysfs-only` mode - added verbose information about remediation when `--explain` is used - implemented `--paranoid mode`, requiring `GDS_MITIGATION_LOCKED` so that mitigation can't be disabled at runtime - fixed offline mode (was wrongly looking at the system `dmesg`) - better microcode status reporting (enabled, disabled, unsupported, unknown) - fixed unknown (EOL) AVX-capable Intel family 6 CPUs now defaulting to affected - fixed 2 missing known affected CPU models: INTEL_FAM6_SKYLAKE_L and INTEL_FAM6_SKYLAKE
This commit is contained in:
github-actions[bot]
@@ -13,7 +13,7 @@
|
|||||||
#
|
#
|
||||||
# Stephane Lesimple
|
# Stephane Lesimple
|
||||||
#
|
#
|
||||||
VERSION='26.21.0402699'
|
VERSION='26.21.0402751'
|
||||||
|
|
||||||
# --- Common paths and basedirs ---
|
# --- Common paths and basedirs ---
|
||||||
readonly VULN_SYSFS_BASE="/sys/devices/system/cpu/vulnerabilities"
|
readonly VULN_SYSFS_BASE="/sys/devices/system/cpu/vulnerabilities"
|
||||||
@@ -588,9 +588,12 @@ is_cpu_affected() {
|
|||||||
pr_debug "is_cpu_affected: downfall: not affected (GDS_NO)"
|
pr_debug "is_cpu_affected: downfall: not affected (GDS_NO)"
|
||||||
_set_immune downfall
|
_set_immune downfall
|
||||||
elif [ "$cpu_family" = 6 ]; then
|
elif [ "$cpu_family" = 6 ]; then
|
||||||
# list from https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=64094e7e3118aff4b0be8ff713c242303e139834
|
# model blacklist from the kernel (arch/x86/kernel/cpu/common.c cpu_vuln_blacklist):
|
||||||
|
# 8974eb588283 (initial list) + c9f4c45c8ec3 (added Skylake/Skylake_L client)
|
||||||
set -u
|
set -u
|
||||||
if [ "$cpu_model" = "$INTEL_FAM6_SKYLAKE_X" ] ||
|
if [ "$cpu_model" = "$INTEL_FAM6_SKYLAKE_L" ] ||
|
||||||
|
[ "$cpu_model" = "$INTEL_FAM6_SKYLAKE" ] ||
|
||||||
|
[ "$cpu_model" = "$INTEL_FAM6_SKYLAKE_X" ] ||
|
||||||
[ "$cpu_model" = "$INTEL_FAM6_KABYLAKE_L" ] ||
|
[ "$cpu_model" = "$INTEL_FAM6_KABYLAKE_L" ] ||
|
||||||
[ "$cpu_model" = "$INTEL_FAM6_KABYLAKE" ] ||
|
[ "$cpu_model" = "$INTEL_FAM6_KABYLAKE" ] ||
|
||||||
[ "$cpu_model" = "$INTEL_FAM6_ICELAKE_L" ] ||
|
[ "$cpu_model" = "$INTEL_FAM6_ICELAKE_L" ] ||
|
||||||
@@ -605,10 +608,12 @@ is_cpu_affected() {
|
|||||||
_set_vuln downfall
|
_set_vuln downfall
|
||||||
elif [ "$cap_avx2" = 0 ] && [ "$cap_avx512" = 0 ]; then
|
elif [ "$cap_avx2" = 0 ] && [ "$cap_avx512" = 0 ]; then
|
||||||
pr_debug "is_cpu_affected: downfall: no avx; immune"
|
pr_debug "is_cpu_affected: downfall: no avx; immune"
|
||||||
|
_infer_immune downfall
|
||||||
else
|
else
|
||||||
# old Intel CPU (not in their DB), not listed as being affected by the Linux kernel,
|
# Intel family 6 CPU with AVX2 or AVX512, not in the known-affected list
|
||||||
# but with AVX2 or AVX512: unclear for now
|
# and GDS_NO not set: assume affected (whitelist principle)
|
||||||
pr_debug "is_cpu_affected: downfall: unclear, defaulting to non-affected for now"
|
pr_debug "is_cpu_affected: downfall: unknown AVX-capable CPU, defaulting to affected"
|
||||||
|
_infer_vuln downfall
|
||||||
fi
|
fi
|
||||||
set +u
|
set +u
|
||||||
fi
|
fi
|
||||||
@@ -7475,6 +7480,90 @@ check_CVE_2022_40982_linux() {
|
|||||||
if sys_interface_check "$VULN_SYSFS_BASE/gather_data_sampling"; then
|
if sys_interface_check "$VULN_SYSFS_BASE/gather_data_sampling"; then
|
||||||
# this kernel has the /sys interface, trust it over everything
|
# this kernel has the /sys interface, trust it over everything
|
||||||
sys_interface_available=1
|
sys_interface_available=1
|
||||||
|
#
|
||||||
|
# Kernel source inventory for gather_data_sampling (GDS/Downfall)
|
||||||
|
#
|
||||||
|
# --- sysfs messages ---
|
||||||
|
# all versions:
|
||||||
|
# "Not affected" (cpu_show_common, pre-existing)
|
||||||
|
#
|
||||||
|
# --- mainline ---
|
||||||
|
# 8974eb588283 (v6.5-rc6, initial GDS sysfs):
|
||||||
|
# "Vulnerable" (GDS_MITIGATION_OFF)
|
||||||
|
# "Vulnerable: No microcode" (GDS_MITIGATION_UCODE_NEEDED)
|
||||||
|
# "Mitigation: Microcode" (GDS_MITIGATION_FULL)
|
||||||
|
# "Mitigation: Microcode (locked)" (GDS_MITIGATION_FULL_LOCKED)
|
||||||
|
# "Unknown: Dependent on hypervisor status" (GDS_MITIGATION_HYPERVISOR)
|
||||||
|
# 553a5c03e90a (v6.5-rc6, added force option):
|
||||||
|
# "Mitigation: AVX disabled, no microcode" (GDS_MITIGATION_FORCE)
|
||||||
|
# 53cf5797f114 (v6.5-rc6, added CONFIG_GDS_FORCE_MITIGATION):
|
||||||
|
# no string changes; default becomes FORCE when Kconfig enabled
|
||||||
|
# 81ac7e5d7417 (v6.5-rc6, KVM GDS_NO plumbing):
|
||||||
|
# no string changes
|
||||||
|
# be83e809ca67 (v6.9-rc1, Kconfig rename):
|
||||||
|
# no string changes; CONFIG_GDS_FORCE_MITIGATION => CONFIG_MITIGATION_GDS_FORCE
|
||||||
|
# 03267a534bb3 (v6.12-rc1, removed force Kconfig):
|
||||||
|
# no string changes; CONFIG_MITIGATION_GDS_FORCE removed
|
||||||
|
# 225f2bd064c3 (v6.12-rc1, added on/off Kconfig):
|
||||||
|
# no string changes; added CONFIG_MITIGATION_GDS (default y)
|
||||||
|
# 9dcad2fb31bd (v6.16-rc1, restructured select/apply):
|
||||||
|
# no string changes; added GDS_MITIGATION_AUTO (internal, resolved before display)
|
||||||
|
# split gds_select_mitigation() + gds_apply_mitigation()
|
||||||
|
# d4932a1b148b (v6.17-rc3, bug fix):
|
||||||
|
# no string changes; CPUs without ARCH_CAP_GDS_CTRL were incorrectly classified
|
||||||
|
# as OFF ("Vulnerable") instead of UCODE_NEEDED ("Vulnerable: No microcode"),
|
||||||
|
# and locked-mitigation detection was skipped.
|
||||||
|
# NOT backported to any stable or RHEL branch as of 2026-04.
|
||||||
|
#
|
||||||
|
# --- stable backports ---
|
||||||
|
# 5.4.y, 5.10.y, 5.15.y, 6.1.y, 6.6.y: same 7 strings as mainline.
|
||||||
|
# use CONFIG_GDS_FORCE_MITIGATION; no GDS_MITIGATION_AUTO enum;
|
||||||
|
# missing d4932a1b148b bug fix (UCODE_NEEDED vs OFF misclassification).
|
||||||
|
# 6.12.y: same 7 strings as mainline.
|
||||||
|
# uses CONFIG_MITIGATION_GDS; no GDS_MITIGATION_AUTO enum;
|
||||||
|
# missing d4932a1b148b bug fix.
|
||||||
|
#
|
||||||
|
# --- RHEL/CentOS ---
|
||||||
|
# centos7 (3.10), rocky8 (4.18): same 7 strings; CONFIG_GDS_FORCE_MITIGATION.
|
||||||
|
# centos7 uses sprintf (not sysfs_emit) and __read_mostly.
|
||||||
|
# rocky9 (5.14): same 7 strings; CONFIG_MITIGATION_GDS (skipped FORCE rename).
|
||||||
|
# rocky10 (6.12): same 7 strings; CONFIG_MITIGATION_GDS; has gds_apply_mitigation().
|
||||||
|
#
|
||||||
|
# --- Kconfig symbols ---
|
||||||
|
# 53cf5797f114 (v6.5-rc6): CONFIG_GDS_FORCE_MITIGATION (default n)
|
||||||
|
# be83e809ca67 (v6.9-rc1): renamed to CONFIG_MITIGATION_GDS_FORCE
|
||||||
|
# 03267a534bb3 (v6.12-rc1): CONFIG_MITIGATION_GDS_FORCE removed
|
||||||
|
# 225f2bd064c3 (v6.12-rc1): CONFIG_MITIGATION_GDS (default y)
|
||||||
|
# vendor kernels: rocky9 uses CONFIG_MITIGATION_GDS on 5.14-based kernel
|
||||||
|
#
|
||||||
|
# --- kernel functions (for $opt_map / System.map) ---
|
||||||
|
# 8974eb588283 (v6.5-rc6): gds_select_mitigation(), update_gds_msr(),
|
||||||
|
# gds_parse_cmdline(), gds_show_state()
|
||||||
|
# 81ac7e5d7417 (v6.5-rc6): gds_ucode_mitigated() (exported for KVM)
|
||||||
|
# 9dcad2fb31bd (v6.16-rc1): split into gds_select_mitigation() + gds_apply_mitigation()
|
||||||
|
# stable 5.4.y-6.12.y: same 5 functions (no gds_apply_mitigation)
|
||||||
|
# rocky10 (6.12): has gds_apply_mitigation()
|
||||||
|
#
|
||||||
|
# --- CPU affection logic (for is_cpu_affected) ---
|
||||||
|
# X86_BUG_GDS is set when ALL three conditions are true:
|
||||||
|
# 1. CPU matches model blacklist (cpu_vuln_blacklist[] in common.c)
|
||||||
|
# 2. ARCH_CAP_GDS_NO (bit 26 of IA32_ARCH_CAPABILITIES) is NOT set
|
||||||
|
# 3. X86_FEATURE_AVX is present (GATHER instructions require AVX)
|
||||||
|
# 8974eb588283 (v6.5-rc6, initial model list):
|
||||||
|
# Intel: SKYLAKE_X, KABYLAKE_L, KABYLAKE, ICELAKE_L, ICELAKE_D,
|
||||||
|
# ICELAKE_X, COMETLAKE, COMETLAKE_L, TIGERLAKE_L, TIGERLAKE,
|
||||||
|
# ROCKETLAKE (all steppings)
|
||||||
|
# c9f4c45c8ec3 (v6.5-rc6, added missing client Skylake):
|
||||||
|
# Intel: + SKYLAKE_L, SKYLAKE
|
||||||
|
# 159013a7ca18 (v6.10-rc1, ITS stepping splits):
|
||||||
|
# no GDS model changes; some entries split by stepping for ITS but
|
||||||
|
# GDS flag remains on all stepping ranges for these models
|
||||||
|
# immunity: ARCH_CAP_GDS_NO (bit 26 of IA32_ARCH_CAPABILITIES)
|
||||||
|
# feature dependency: requires AVX (if AVX absent, CPU is immune)
|
||||||
|
# vendor scope: Intel only
|
||||||
|
#
|
||||||
|
# all messages start with either "Not affected", "Vulnerable", "Mitigation",
|
||||||
|
# or "Unknown"
|
||||||
status=$ret_sys_interface_check_status
|
status=$ret_sys_interface_check_status
|
||||||
fi
|
fi
|
||||||
|
|
||||||
@@ -7482,15 +7571,34 @@ check_CVE_2022_40982_linux() {
|
|||||||
pr_info_nol "* GDS is mitigated by microcode: "
|
pr_info_nol "* GDS is mitigated by microcode: "
|
||||||
if [ "$cap_gds_ctrl" = 1 ] && [ "$cap_gds_mitg_dis" = 0 ]; then
|
if [ "$cap_gds_ctrl" = 1 ] && [ "$cap_gds_mitg_dis" = 0 ]; then
|
||||||
pstatus green OK "microcode mitigation is supported and enabled"
|
pstatus green OK "microcode mitigation is supported and enabled"
|
||||||
|
elif [ "$cap_gds_ctrl" = 1 ] && [ "$cap_gds_mitg_dis" = 1 ]; then
|
||||||
|
pstatus yellow NO "microcode mitigation is supported but disabled"
|
||||||
|
elif [ "$cap_gds_ctrl" = 0 ]; then
|
||||||
|
pstatus yellow NO "microcode doesn't support GDS mitigation"
|
||||||
else
|
else
|
||||||
pstatus yellow NO
|
pstatus yellow UNKNOWN "couldn't read MSR for GDS capability"
|
||||||
fi
|
fi
|
||||||
|
|
||||||
pr_info_nol "* Kernel supports software mitigation by disabling AVX: "
|
pr_info_nol "* Kernel supports software mitigation by disabling AVX: "
|
||||||
|
kernel_gds=''
|
||||||
|
kernel_gds_err=''
|
||||||
if [ -n "$g_kernel_err" ]; then
|
if [ -n "$g_kernel_err" ]; then
|
||||||
kernel_gds_err="$g_kernel_err"
|
kernel_gds_err="$g_kernel_err"
|
||||||
elif grep -q 'gather_data_sampling' "$g_kernel"; then
|
elif grep -q 'gather_data_sampling' "$g_kernel"; then
|
||||||
kernel_gds="found gather_data_sampling in kernel image"
|
kernel_gds="found gather_data_sampling in kernel image"
|
||||||
fi
|
fi
|
||||||
|
if [ -z "$kernel_gds" ] && [ -r "$opt_config" ]; then
|
||||||
|
if grep -q '^CONFIG_GDS_FORCE_MITIGATION=y' "$opt_config" ||
|
||||||
|
grep -q '^CONFIG_MITIGATION_GDS_FORCE=y' "$opt_config" ||
|
||||||
|
grep -q '^CONFIG_MITIGATION_GDS=y' "$opt_config"; then
|
||||||
|
kernel_gds="GDS mitigation config option found enabled in kernel config"
|
||||||
|
fi
|
||||||
|
fi
|
||||||
|
if [ -z "$kernel_gds" ] && [ -n "$opt_map" ]; then
|
||||||
|
if grep -q 'gds_select_mitigation' "$opt_map"; then
|
||||||
|
kernel_gds="found gds_select_mitigation in System.map"
|
||||||
|
fi
|
||||||
|
fi
|
||||||
if [ -n "$kernel_gds" ]; then
|
if [ -n "$kernel_gds" ]; then
|
||||||
pstatus green YES "$kernel_gds"
|
pstatus green YES "$kernel_gds"
|
||||||
elif [ -n "$kernel_gds_err" ]; then
|
elif [ -n "$kernel_gds_err" ]; then
|
||||||
@@ -7502,30 +7610,34 @@ check_CVE_2022_40982_linux() {
|
|||||||
if [ -n "$kernel_gds" ]; then
|
if [ -n "$kernel_gds" ]; then
|
||||||
pr_info_nol "* Kernel has disabled AVX as a mitigation: "
|
pr_info_nol "* Kernel has disabled AVX as a mitigation: "
|
||||||
|
|
||||||
# Check dmesg message to see whether AVX has been disabled
|
if [ "$opt_live" = 1 ]; then
|
||||||
dmesg_grep 'Microcode update needed! Disabling AVX as mitigation'
|
# Check dmesg message to see whether AVX has been disabled
|
||||||
dmesgret=$?
|
dmesg_grep 'Microcode update needed! Disabling AVX as mitigation'
|
||||||
if [ "$dmesgret" -eq 0 ]; then
|
dmesgret=$?
|
||||||
kernel_avx_disabled="AVX disabled by the kernel (dmesg)"
|
if [ "$dmesgret" -eq 0 ]; then
|
||||||
pstatus green YES "$kernel_avx_disabled"
|
kernel_avx_disabled="AVX disabled by the kernel (dmesg)"
|
||||||
elif [ "$cap_avx2" = 0 ]; then
|
|
||||||
# Find out by ourselves
|
|
||||||
# cpuinfo says we don't have AVX2, query
|
|
||||||
# the CPU directly about AVX2 support
|
|
||||||
read_cpuid 0x7 0x0 "$EBX" 5 1 1
|
|
||||||
ret=$?
|
|
||||||
if [ "$ret" -eq "$READ_CPUID_RET_OK" ]; then
|
|
||||||
kernel_avx_disabled="AVX disabled by the kernel (cpuid)"
|
|
||||||
pstatus green YES "$kernel_avx_disabled"
|
pstatus green YES "$kernel_avx_disabled"
|
||||||
elif [ "$ret" -eq "$READ_CPUID_RET_KO" ]; then
|
elif [ "$cap_avx2" = 0 ]; then
|
||||||
pstatus yellow NO "CPU doesn't support AVX"
|
# Find out by ourselves
|
||||||
elif [ "$dmesgret" -eq 2 ]; then
|
# cpuinfo says we don't have AVX2, query
|
||||||
pstatus yellow UNKNOWN "dmesg truncated, can't tell whether mitigation is active, please reboot and relaunch this script"
|
# the CPU directly about AVX2 support
|
||||||
|
read_cpuid 0x7 0x0 "$EBX" 5 1 1
|
||||||
|
ret=$?
|
||||||
|
if [ "$ret" -eq "$READ_CPUID_RET_OK" ]; then
|
||||||
|
kernel_avx_disabled="AVX disabled by the kernel (cpuid)"
|
||||||
|
pstatus green YES "$kernel_avx_disabled"
|
||||||
|
elif [ "$ret" -eq "$READ_CPUID_RET_KO" ]; then
|
||||||
|
pstatus yellow NO "CPU doesn't support AVX"
|
||||||
|
elif [ "$dmesgret" -eq 2 ]; then
|
||||||
|
pstatus yellow UNKNOWN "dmesg truncated, can't tell whether mitigation is active, please reboot and relaunch this script"
|
||||||
|
else
|
||||||
|
pstatus yellow UNKNOWN "No sign of mitigation in dmesg and couldn't read cpuid info"
|
||||||
|
fi
|
||||||
else
|
else
|
||||||
pstatus yellow UNKNOWN "No sign of mitigation in dmesg and couldn't read cpuid info"
|
pstatus yellow NO "AVX support is enabled"
|
||||||
fi
|
fi
|
||||||
else
|
else
|
||||||
pstatus yellow NO "AVX support is enabled"
|
pstatus blue N/A "not testable in offline mode"
|
||||||
fi
|
fi
|
||||||
fi
|
fi
|
||||||
|
|
||||||
@@ -7540,16 +7652,33 @@ check_CVE_2022_40982_linux() {
|
|||||||
pvulnstatus "$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 "$msg" ]; then
|
||||||
# if msg is empty, sysfs check didn't fill it, rely on our own test
|
# if msg is empty, sysfs check didn't fill it, rely on our own test
|
||||||
if [ "$cap_gds_ctrl" = 1 ] && [ "$cap_gds_mitg_dis" = 0 ]; then
|
if [ "$opt_sysfs_only" != 1 ]; then
|
||||||
pvulnstatus "$cve" OK "Your microcode is up to date and mitigation is enabled"
|
if [ "$cap_gds_ctrl" = 1 ] && [ "$cap_gds_mitg_dis" = 0 ]; then
|
||||||
elif [ "$cap_gds_ctrl" = 1 ] && [ "$cap_gds_mitg_dis" = 1 ]; then
|
if [ "$opt_paranoid" = 1 ] && [ "$cap_gds_mitg_lock" != 1 ]; then
|
||||||
pvulnstatus "$cve" VULN "Your microcode is up to date but mitigation is disabled"
|
pvulnstatus "$cve" VULN "Microcode mitigation is enabled but not locked"
|
||||||
elif [ -z "$kernel_gds" ]; then
|
explain "In paranoid mode, the GDS mitigation must be locked to prevent a privileged attacker\n " \
|
||||||
pvulnstatus "$cve" VULN "Your microcode doesn't mitigate the vulnerability, and your kernel doesn't support mitigation"
|
"(e.g. in a guest VM) from disabling it. Check your firmware/BIOS for an option to lock the\n " \
|
||||||
elif [ -z "$kernel_avx_disabled" ]; then
|
"GDS mitigation, or update your microcode."
|
||||||
pvulnstatus "$cve" VULN "Your microcode doesn't mitigate the vulnerability, your kernel support the mitigation but the script did not detect AVX as disabled by the kernel"
|
else
|
||||||
|
pvulnstatus "$cve" OK "Your microcode is up to date and mitigation is enabled"
|
||||||
|
fi
|
||||||
|
elif [ "$cap_gds_ctrl" = 1 ] && [ "$cap_gds_mitg_dis" = 1 ]; then
|
||||||
|
pvulnstatus "$cve" VULN "Your microcode is up to date but mitigation is disabled"
|
||||||
|
explain "The GDS mitigation has been explicitly disabled (gather_data_sampling=off or mitigations=off).\n " \
|
||||||
|
"Remove the kernel parameter to re-enable it."
|
||||||
|
elif [ -z "$kernel_gds" ]; then
|
||||||
|
pvulnstatus "$cve" VULN "Your microcode doesn't mitigate the vulnerability, and your kernel doesn't support mitigation"
|
||||||
|
explain "Update both your CPU microcode (via BIOS/firmware update from your OEM) and your kernel\n " \
|
||||||
|
"to a version that supports GDS mitigation (Linux 6.5+, or check if your distro has a backport)."
|
||||||
|
elif [ -z "$kernel_avx_disabled" ]; then
|
||||||
|
pvulnstatus "$cve" VULN "Your microcode doesn't mitigate the vulnerability, your kernel supports the mitigation but AVX was not disabled"
|
||||||
|
explain "Update your CPU microcode (via BIOS/firmware update from your OEM). If no microcode update\n " \
|
||||||
|
"is available, use gather_data_sampling=force on the kernel command line to disable AVX as a workaround."
|
||||||
|
else
|
||||||
|
pvulnstatus "$cve" OK "Your microcode doesn't mitigate the vulnerability, but your kernel has disabled AVX support"
|
||||||
|
fi
|
||||||
else
|
else
|
||||||
pvulnstatus "$cve" OK "Your microcode doesn't mitigate the vulnerability, but your kernel has disabled AVX support"
|
pvulnstatus "$cve" "$status" "$ret_sys_interface_check_fullmsg"
|
||||||
fi
|
fi
|
||||||
else
|
else
|
||||||
pvulnstatus "$cve" "$status" "$msg"
|
pvulnstatus "$cve" "$status" "$msg"
|
||||||
|
|||||||
Reference in New Issue
Block a user