feat(cpu) add STIBP, RDCL_NO, IBRS_ALL checks

Move all the CPU checks to their own section,
for clarity. We now check for IBRS, IBPB, STIBP,
RDCL_NO and IBRS_ALL. We also show whether the
system CPU is vulnerable to the three variants,
regardless of the fact that mitigations are in
place or not, which is determined in each vuln-
specific section.
This commit is contained in:
Stéphane Lesimple 2018-01-24 14:44:16 +01:00
parent b45e40bec8
commit acf12a6d2d
1 changed files with 235 additions and 149 deletions

View File

@ -199,6 +199,8 @@ is_cpu_vulnerable()
variant3=''
# we also set a friendly name for the CPU to be used in the script if needed
cpu_friendly_name=$(grep '^model name' /proc/cpuinfo | cut -d: -f2- | head -1 | sed -e 's/^ *//')
# variant 0 is just for us to fill the cpu_friendly_name var
[ "$1" = 0 ] && return 0
if grep -q GenuineIntel /proc/cpuinfo; then
# Intel
@ -217,6 +219,13 @@ is_cpu_vulnerable()
[ -z "$variant2" ] && variant2=immune
[ -z "$variant3" ] && variant3=immune
fi
if [ "$capabilities_rdcl_no" = 1 ]; then
# capability bit for future Intel processor that will explicitly state
# that they're not vulnerable to Meltdown
# this var is set in check_cpu()
[ -z "$variant3" ] && variant3=immune
_debug "is_cpu_vulnerable: RDCL_NO is set so not vuln to meltdown"
fi
elif grep -q AuthenticAMD /proc/cpuinfo; then
# AMD revised their statement about variant2 => vulnerable
# https://www.amd.com/en/corporate/speculative-execution
@ -664,7 +673,7 @@ if [ "$opt_live" = 1 ]; then
_info "Checking for vulnerabilities on current system"
_info "Kernel is \033[35m"$(uname -s) $(uname -r) $(uname -v) $(uname -m)"\033[0m"
# call is_cpu_vulnerable to fill the cpu_friendly_name var
is_cpu_vulnerable 1
is_cpu_vulnerable 0
_info "CPU is \033[35m$cpu_friendly_name\033[0m"
# try to find the image of the current running kernel
@ -804,6 +813,230 @@ sys_interface_check()
return 0
}
check_cpu()
{
_info "\033[1;34mHardware check\033[0m"
_info "* Hardware support (CPU microcode) for mitigation techniques"
_info " * Indirect Branch Restricted Speculation (IBRS)"
_info_nol " * SPEC_CTRL MSR is available: "
if [ ! -e /dev/cpu/0/msr ]; then
# try to load the module ourselves (and remember it so we can rmmod it afterwards)
load_msr
fi
if [ ! -e /dev/cpu/0/msr ]; then
spec_ctrl_msr=-1
pstatus yellow UNKNOWN "couldn't read /dev/cpu/0/msr, is msr support enabled in your kernel?"
else
# the new MSR 'SPEC_CTRL' is at offset 0x48
# here we use dd, it's the same as using 'rdmsr 0x48' but without needing the rdmsr tool
# if we get a read error, the MSR is not there. bs has to be 8 for msr
# skip=9 because 8*9=72=0x48
dd if=/dev/cpu/0/msr of=/dev/null bs=8 count=1 skip=9 2>/dev/null
if [ $? -eq 0 ]; then
spec_ctrl_msr=1
pstatus green YES
else
spec_ctrl_msr=0
pstatus red NO
fi
fi
_info_nol " * CPU indicates IBRS capability: "
if [ ! -e /dev/cpu/0/cpuid ]; then
# try to load the module ourselves (and remember it so we can rmmod it afterwards)
load_cpuid
fi
if [ ! -e /dev/cpu/0/cpuid ]; then
pstatus yellow UNKNOWN "couldn't read /dev/cpu/0/cpuid, is cpuid support enabled in your kernel?"
else
# from kernel src: { X86_FEATURE_SPEC_CTRL, CPUID_EDX,26, 0x00000007, 0 },
if [ "$opt_verbose" -ge 3 ]; then
dd if=/dev/cpu/0/cpuid bs=16 skip=7 iflag=skip_bytes count=1 >/dev/null 2>/dev/null
_debug "cpuid: reading leaf7 of cpuid on cpu0, ret=$?"
_debug "cpuid: leaf7 eax-ebx-ecx-edx: "$(dd if=/dev/cpu/0/cpuid bs=16 skip=7 iflag=skip_bytes count=1 2>/dev/null | od -x -A n)
_debug "cpuid: leaf7 edx higher byte is: "$(dd if=/dev/cpu/0/cpuid bs=16 skip=7 iflag=skip_bytes count=1 2>/dev/null | dd bs=1 skip=15 count=1 2>/dev/null | od -x -A n)
fi
# getting high byte of edx on leaf7 of cpuinfo in decimal
edx_hb=$(dd if=/dev/cpu/0/cpuid bs=16 skip=7 iflag=skip_bytes count=1 2>/dev/null | dd bs=1 skip=15 count=1 2>/dev/null | od -t u -A n | awk '{print $1}')
_debug "cpuid: leaf7 edx higher byte: $edx_hb (decimal)"
edx_bit26=$(( edx_hb & 4 ))
_debug "cpuid: edx_bit26=$edx_bit26"
if [ "$edx_bit26" -eq 4 ]; then
pstatus green YES "SPEC_CTRL feature bit"
cpuid_spec_ctrl=1
else
pstatus red NO
fi
fi
# hardware support according to kernel
if [ "$opt_verbose" -ge 2 ]; then
# the spec_ctrl flag in cpuinfo is set if and only if the kernel sees
# that the spec_ctrl cpuinfo bit set. we already check that ourselves above
# but let's check it anyway (in verbose mode only)
_verbose_nol " * Kernel has set the spec_ctrl flag in cpuinfo: "
if [ "$opt_live" = 1 ]; then
if grep ^flags /proc/cpuinfo | grep -qw spec_ctrl; then
pstatus green YES
else
pstatus blue NO
fi
else
pstatus blue N/A "not testable in offline mode"
fi
fi
# IBPB
_info " * Indirect Branch Prediction Barrier (IBPB)"
_info_nol " * PRED_CMD MSR is available: "
if [ ! -e /dev/cpu/0/msr ]; then
pstatus yellow UNKNOWN "couldn't read /dev/cpu/0/msr, is msr support enabled in your kernel?"
else
# the new MSR 'PRED_CTRL' is at offset 0x49, write-only
# here we use dd, it's the same as using 'wrmsr 0x49 0' but without needing the wrmsr tool
# if we get a write error, the MSR is not there
$echo_cmd -ne "\0\0\0\0\0\0\0\0" | dd of=/dev/cpu/0/msr bs=8 count=1 seek=73 oflag=seek_bytes 2>/dev/null
if [ $? -eq 0 ]; then
pstatus green YES
else
pstatus red NO
fi
fi
_info_nol " * CPU indicates IBPB capability: "
if [ ! -e /dev/cpu/0/cpuid ]; then
pstatus yellow UNKNOWN "couldn't read /dev/cpu/0/cpuid, is cpuid support enabled in your kernel?"
else
# CPUID EAX=0x80000008, ECX=0x00 return EBX[12] indicates support for just IBPB.
if [ "$opt_verbose" -ge 3 ]; then
dd if=/dev/cpu/0/cpuid bs=16 skip=2147483656 iflag=skip_bytes count=1 >/dev/null 2>/dev/null
_debug "cpuid: reading leaf80000008 of cpuid on cpu0, ret=$?"
_debug "cpuid: leaf80000008 eax-ebx-ecx-edx: "$(dd if=/dev/cpu/0/cpuid bs=16 skip=2147483656 iflag=skip_bytes count=1 2>/dev/null | od -x -A n)
_debug "cpuid: leaf80000008 ebx 3rd byte is: "$(dd if=/dev/cpu/0/cpuid bs=16 skip=2147483656 iflag=skip_bytes count=1 2>/dev/null | dd bs=1 skip=5 count=1 2>/dev/null | od -x -A n)
fi
# getting high byte of edx on leaf7 of cpuinfo in decimal
ebx_b3=$(dd if=/dev/cpu/0/cpuid bs=16 skip=2147483656 iflag=skip_bytes count=1 2>/dev/null | dd bs=1 skip=5 count=1 2>/dev/null | od -t u -A n | awk '{print $1}')
_debug "cpuid: leaf80000008 ebx 3rd byte: $ebx_b3 (decimal)"
ebx_bit12=$(( ebx_b3 & 16 ))
_debug "cpuid: ebx_bit12=$ebx_bit12"
if [ "$ebx_bit12" -eq 16 ]; then
pstatus green YES "IBPB_SUPPORT feature bit"
cpuid_ibpb=1
elif [ "$cpuid_spec_ctrl" = 1 ]; then
pstatus green YES "SPEC_CTRL feature bit"
else
pstatus red NO
fi
fi
# STIBP
_info " * Single Thread Indirect Branch Predictors (STIBP)"
_info_nol " * SPEC_CTRL MSR is available: "
if [ "$spec_ctrl_msr" = 1 ]; then
pstatus green YES
elif [ "$spec_ctrl_msr" = 0 ]; then
pstatus red NO
else
pstatus yellow UNKNOWN "couldn't read /dev/cpu/0/msr, is msr support enabled in your kernel?"
fi
_info_nol " * CPU indicates STIBP capability: "
if [ ! -e /dev/cpu/0/cpuid ]; then
pstatus yellow UNKNOWN "couldn't read /dev/cpu/0/cpuid, is cpuid support enabled in your kernel?"
else
# A processor supports STIBP if it enumerates CPUID (EAX=7H,ECX=0):EDX[27] as 1
if [ "$opt_verbose" -ge 3 ]; then
dd if=/dev/cpu/0/cpuid bs=16 skip=7 iflag=skip_bytes count=1 >/dev/null 2>/dev/null
_debug "cpuid: reading leaf7 of cpuid on cpu0, ret=$?"
_debug "cpuid: leaf7 eax-ebx-ecx-edx: "$(dd if=/dev/cpu/0/cpuid bs=16 skip=7 iflag=skip_bytes count=1 2>/dev/null | od -x -A n)
_debug "cpuid: leaf7 edx higher byte is: "$(dd if=/dev/cpu/0/cpuid bs=16 skip=7 iflag=skip_bytes count=1 2>/dev/null | dd bs=1 skip=15 count=1 2>/dev/null | od -x -A n)
fi
# getting high byte of edx on leaf7 of cpuinfo in decimal
edx_hb=$(dd if=/dev/cpu/0/cpuid bs=16 skip=7 iflag=skip_bytes count=1 2>/dev/null | dd bs=1 skip=15 count=1 2>/dev/null | od -t u -A n | awk '{print $1}')
_debug "cpuid: leaf7 edx higher byte: $edx_hb (decimal)"
edx_bit27=$(( edx_hb & 8 ))
_debug "cpuid: edx_bit27=$edx_bit27"
if [ "$edx_bit27" -eq 8 ]; then
pstatus green YES
cpuid_stibp=1
else
pstatus red NO
fi
fi
_info " * Enhanced IBRS (IBRS_ALL)"
_info_nol " * CPU indicates ARCH_CAPABILITIES MSR availability: "
if [ ! -e /dev/cpu/0/cpuid ]; then
pstatus yellow UNKNOWN "couldn't read /dev/cpu/0/cpuid, is cpuid support enabled in your kernel?"
else
# A processor supports STIBP if it enumerates CPUID (EAX=7H,ECX=0):EDX[27] as 1
if [ "$opt_verbose" -ge 3 ]; then
dd if=/dev/cpu/0/cpuid bs=16 skip=7 iflag=skip_bytes count=1 >/dev/null 2>/dev/null
_debug "cpuid: reading leaf7 of cpuid on cpu0, ret=$?"
_debug "cpuid: leaf7 eax-ebx-ecx-edx: "$(dd if=/dev/cpu/0/cpuid bs=16 skip=7 iflag=skip_bytes count=1 2>/dev/null | od -x -A n)
_debug "cpuid: leaf7 edx higher byte is: "$(dd if=/dev/cpu/0/cpuid bs=16 skip=7 iflag=skip_bytes count=1 2>/dev/null | dd bs=1 skip=15 count=1 2>/dev/null | od -x -A n)
fi
# getting high byte of edx on leaf7 of cpuinfo in decimal
edx_hb=$(dd if=/dev/cpu/0/cpuid bs=16 skip=7 iflag=skip_bytes count=1 2>/dev/null | dd bs=1 skip=15 count=1 2>/dev/null | od -t u -A n | awk '{print $1}')
_debug "cpuid: leaf7 edx higher byte: $edx_hb (decimal)"
edx_bit29=$(( edx_hb & 32 ))
_debug "cpuid: edx_bit29=$edx_bit29"
if [ "$edx_bit27" -eq 32 ]; then
pstatus green YES
cpuid_arch_capabilities=1
else
pstatus red NO
fi
fi
_info_nol " * ARCH_CAPABILITIES MSR advertises IBRS_ALL capability: "
if [ "$cpuid_arch_capabilities" != 1 ]; then
pstatus red NO
elif [ ! -e /dev/cpu/0/msr ]; then
spec_ctrl_msr=-1
pstatus yellow UNKNOWN "couldn't read /dev/cpu/0/msr, is msr support enabled in your kernel?"
else
# the new MSR 'ARCH_CAPABILITIES' is at offset 0x10a
# here we use dd, it's the same as using 'rdmsr 0x10a' but without needing the rdmsr tool
# if we get a read error, the MSR is not there. bs has to be 8 for msr
capabilities=$(dd if=/dev/cpu/0/msr bs=8 count=1 skip=266 iflag=skip_bytes 2>/dev/null | od -t u1 -A n | awk '{print $8}')
if [ $? -eq 0 ]; then
_debug "capabilities MSR lower byte is $capabilities (decimal)"
capabilities_rdcl_no=0
[ $(( capabilities & 1 )) -eq 1 ] && capabilities_rdcl_no=1
[ $(( capabilities & 2 )) -eq 2 ] && capabilities_ibrs_all=1
_debug "capabilities says rdcl_no=$capabilities_rdcl_no ibrs_all=$capabilities_ibrs_all"
if [ "$capabilities_ibrs_all" = 1 ]; then
pstatus green YES
else
pstatus red NO
fi
else
pstatus yellow UNKNOWN
fi
fi
_info_nol " * CPU explicitly indicates not being vulnerable to Meltdown (RDCL_NO): "
if [ "$capabilities_rdcl_no" = 1 ]; then
pstatus green YES
else
pstatus blue NO
fi
_info "* CPU vulnerability to the three speculative execution attacks variants"
for v in 1 2 3; do
_info_nol " * Vulnerable to Variant $v: "
if is_cpu_vulnerable $v; then
pstatus red YES
else
pstatus green NO
fi
done
_info
}
###################
# SPECTRE VARIANT 1
check_variant1()
@ -877,154 +1110,6 @@ check_variant2()
fi
if [ "$opt_sysfs_only" != 1 ]; then
_info "* Mitigation 1"
_info " * Hardware support (CPU microcode)"
_info " * Indirect Branch Restricted Speculation (IBRS)"
_info_nol " * SPEC_CTRL MSR is available: "
if [ ! -e /dev/cpu/0/msr ]; then
# try to load the module ourselves (and remember it so we can rmmod it afterwards)
load_msr
fi
if [ ! -e /dev/cpu/0/msr ]; then
spec_ctrl_msr=-1
pstatus yellow UNKNOWN "couldn't read /dev/cpu/0/msr, is msr support enabled in your kernel?"
else
# the new MSR 'SPEC_CTRL' is at offset 0x48
# here we use dd, it's the same as using 'rdmsr 0x48' but without needing the rdmsr tool
# if we get a read error, the MSR is not there. bs has to be 8 for msr
# skip=9 because 8*9=72=0x48
dd if=/dev/cpu/0/msr of=/dev/null bs=8 count=1 skip=9 2>/dev/null
if [ $? -eq 0 ]; then
spec_ctrl_msr=1
pstatus green YES
else
spec_ctrl_msr=0
pstatus red NO
fi
fi
_info_nol " * CPU indicates IBRS capability: "
if [ ! -e /dev/cpu/0/cpuid ]; then
# try to load the module ourselves (and remember it so we can rmmod it afterwards)
load_cpuid
fi
if [ ! -e /dev/cpu/0/cpuid ]; then
pstatus yellow UNKNOWN "couldn't read /dev/cpu/0/cpuid, is cpuid support enabled in your kernel?"
else
# from kernel src: { X86_FEATURE_SPEC_CTRL, CPUID_EDX,26, 0x00000007, 0 },
if [ "$opt_verbose" -ge 3 ]; then
dd if=/dev/cpu/0/cpuid bs=16 skip=7 iflag=skip_bytes count=1 >/dev/null 2>/dev/null
_debug "cpuid: reading leaf7 of cpuid on cpu0, ret=$?"
_debug "cpuid: leaf7 eax-ebx-ecx-edx: "$(dd if=/dev/cpu/0/cpuid bs=16 skip=7 iflag=skip_bytes count=1 2>/dev/null | od -x -A n)
_debug "cpuid: leaf7 edx higher byte is: "$(dd if=/dev/cpu/0/cpuid bs=16 skip=7 iflag=skip_bytes count=1 2>/dev/null | dd bs=1 skip=15 count=1 2>/dev/null | od -x -A n)
fi
# getting high byte of edx on leaf7 of cpuinfo in decimal
edx_hb=$(dd if=/dev/cpu/0/cpuid bs=16 skip=7 iflag=skip_bytes count=1 2>/dev/null | dd bs=1 skip=15 count=1 2>/dev/null | od -t u -A n | awk '{print $1}')
_debug "cpuid: leaf7 edx higher byte: $edx_hb (decimal)"
edx_bit26=$(( edx_hb & 4 ))
_debug "cpuid: edx_bit26=$edx_bit26"
if [ "$edx_bit26" -eq 4 ]; then
pstatus green YES "SPEC_CTRL feature bit"
cpuid_spec_ctrl=1
else
pstatus red NO
fi
fi
# hardware support according to kernel
if [ "$opt_verbose" -ge 2 ]; then
# the spec_ctrl flag in cpuinfo is set if and only if the kernel sees
# that the spec_ctrl cpuinfo bit set. we already check that ourselves above
# but let's check it anyway (in verbose mode only)
_verbose_nol " * Kernel has set the spec_ctrl flag in cpuinfo: "
if [ "$opt_live" = 1 ]; then
if grep ^flags /proc/cpuinfo | grep -qw spec_ctrl; then
pstatus green YES
else
pstatus blue NO
fi
else
pstatus blue N/A "not testable in offline mode"
fi
fi
# IBPB
_info " * Indirect Branch Prediction Barrier (IBPB)"
_info_nol " * PRED_CMD MSR is available: "
if [ ! -e /dev/cpu/0/msr ]; then
pstatus yellow UNKNOWN "couldn't read /dev/cpu/0/msr, is msr support enabled in your kernel?"
else
# the new MSR 'PRED_CTRL' is at offset 0x49, write-only
# here we use dd, it's the same as using 'wrmsr 0x49 0' but without needing the wrmsr tool
# if we get a write error, the MSR is not there
$echo_cmd -ne "\0\0\0\0\0\0\0\0" | dd of=/dev/cpu/0/msr bs=8 count=1 seek=73 oflag=seek_bytes 2>/dev/null
if [ $? -eq 0 ]; then
pstatus green YES
else
pstatus red NO
fi
fi
_info_nol " * CPU indicates IBPB capability: "
if [ ! -e /dev/cpu/0/cpuid ]; then
pstatus yellow UNKNOWN "couldn't read /dev/cpu/0/cpuidr, is cpuid support enabled in your kernel?"
else
# CPUID EAX=0x80000008, ECX=0x00 return EBX[12] indicates support for just IBPB.
if [ "$opt_verbose" -ge 3 ]; then
dd if=/dev/cpu/0/cpuid bs=16 skip=2147483656 iflag=skip_bytes count=1 >/dev/null 2>/dev/null
_debug "cpuid: reading leaf80000008 of cpuid on cpu0, ret=$?"
_debug "cpuid: leaf80000008 eax-ebx-ecx-edx: "$(dd if=/dev/cpu/0/cpuid bs=16 skip=2147483656 iflag=skip_bytes count=1 2>/dev/null | od -x -A n)
_debug "cpuid: leaf80000008 ebx 3rd byte is: "$(dd if=/dev/cpu/0/cpuid bs=16 skip=2147483656 iflag=skip_bytes count=1 2>/dev/null | dd bs=1 skip=5 count=1 2>/dev/null | od -x -A n)
fi
# getting high byte of edx on leaf7 of cpuinfo in decimal
ebx_b3=$(dd if=/dev/cpu/0/cpuid bs=16 skip=2147483656 iflag=skip_bytes count=1 2>/dev/null | dd bs=1 skip=5 count=1 2>/dev/null | od -t u -A n | awk '{print $1}')
_debug "cpuid: leaf80000008 ebx 3rd byte: $ebx_b3 (decimal)"
ebx_bit12=$(( ebx_b3 & 16 ))
_debug "cpuid: ebx_bit12=$ebx_bit12"
if [ "$ebx_bit12" -eq 16 ]; then
pstatus green YES "IBPB_SUPPORT feature bit"
cpuid_ibpb=1
elif [ "$cpuid_spec_ctrl" = 1 ]; then
pstatus green YES "SPEC_CTRL feature bit"
else
pstatus red NO
fi
fi
# STIBP
_info " * Single Thread Indirect Branch Predictors (STIBP)"
_info_nol " * SPEC_CTRL MSR is available: "
if [ "$spec_ctrl_msr" = 1 ]; then
pstatus green YES
elif [ "$spec_ctrl_msr" = 0 ]; then
pstatus red NO
else
pstatus yellow UNKNOWN "couldn't read /dev/cpu/0/msr, is msr support enabled in your kernel?"
fi
_info_nol " * CPU indicates STIBP capability: "
if [ ! -e /dev/cpu/0/cpuid ]; then
pstatus yellow UNKNOWN "couldn't read /dev/cpu/0/cpuidr, is cpuid support enabled in your kernel?"
else
# A processor supports STIBP if it enumerates CPUID (EAX=7H,ECX=0):EDX[27] as 1
if [ "$opt_verbose" -ge 3 ]; then
dd if=/dev/cpu/0/cpuid bs=16 skip=7 iflag=skip_bytes count=1 >/dev/null 2>/dev/null
_debug "cpuid: reading leaf7 of cpuid on cpu0, ret=$?"
_debug "cpuid: leaf7 eax-ebx-ecx-edx: "$(dd if=/dev/cpu/0/cpuid bs=16 skip=7 iflag=skip_bytes count=1 2>/dev/null | od -x -A n)
_debug "cpuid: leaf7 edx higher byte is: "$(dd if=/dev/cpu/0/cpuid bs=16 skip=7 iflag=skip_bytes count=1 2>/dev/null | dd bs=1 skip=15 count=1 2>/dev/null | od -x -A n)
fi
# getting high byte of edx on leaf7 of cpuinfo in decimal
edx_hb=$(dd if=/dev/cpu/0/cpuid bs=16 skip=7 iflag=skip_bytes count=1 2>/dev/null | dd bs=1 skip=15 count=1 2>/dev/null | od -t u -A n | awk '{print $1}')
_debug "cpuid: leaf7 edx higher byte: $edx_hb (decimal)"
edx_bit27=$(( edx_hb & 8 ))
_debug "cpuid: edx_bit27=$edx_bit27"
if [ "$edx_bit27" -eq 8 ]; then
pstatus green YES "STIBP feature bit"
cpuid_stibp=1
else
pstatus red NO
fi
fi
_info_nol " * Kernel is compiled with IBRS/IBPB support: "
ibrs_can_tell=0
@ -1429,6 +1514,7 @@ check_variant3()
fi
}
check_cpu
# now run the checks the user asked for
if [ "$opt_variant1" = 1 -o "$opt_allvariants" = 1 ]; then
check_variant1