enh: use g_mode to explicitly save/load the current running mode

This commit is contained in:
Stéphane Lesimple
2026-04-10 19:26:46 +02:00
parent f7ba617e16
commit e67c9e4265
24 changed files with 218 additions and 210 deletions
+88 -98
View File
@@ -101,60 +101,48 @@ check_CVE_2017_5753_linux() {
# For no-runtime analysis of these old kernels, match the specific instruction patterns.
if [ -z "$v1_kernel_mitigated" ]; then
pr_info_nol "* Kernel has array_index_mask_nospec (v4.15 binary pattern): "
# vanilla: look for the Linus' mask aka array_index_mask_nospec()
# that is inlined at least in raw_copy_from_user (__get_user_X symbols)
#mov PER_CPU_VAR(current_task), %_ASM_DX
#cmp TASK_addr_limit(%_ASM_DX),%_ASM_AX
#jae bad_get_user
# /* array_index_mask_nospec() are the 2 opcodes that follow */
#+sbb %_ASM_DX, %_ASM_DX
#+and %_ASM_DX, %_ASM_AX
#ASM_STAC
# x86 64bits: jae(0x0f 0x83 0x?? 0x?? 0x?? 0x??) sbb(0x48 0x19 0xd2) and(0x48 0x21 0xd0)
# x86 32bits: cmp(0x3b 0x82 0x?? 0x?? 0x00 0x00) jae(0x73 0x??) sbb(0x19 0xd2) and(0x21 0xd0)
#
# arm32
##ifdef CONFIG_THUMB2_KERNEL
##define CSDB ".inst.w 0xf3af8014"
##else
##define CSDB ".inst 0xe320f014" e320f014
##endif
#asm volatile(
# "cmp %1, %2\n" e1500003
#" sbc %0, %1, %1\n" e0c03000
#CSDB
#: "=r" (mask)
#: "r" (idx), "Ir" (sz)
#: "cc");
#
# http://git.arm.linux.org.uk/cgit/linux-arm.git/commit/?h=spectre&id=a78d156587931a2c3b354534aa772febf6c9e855
v1_mask_nospec=''
if [ -n "$g_kernel_err" ]; then
pstatus yellow UNKNOWN "couldn't check ($g_kernel_err)"
elif ! command -v perl >/dev/null 2>&1; then
pstatus yellow UNKNOWN "missing 'perl' binary, please install it"
else
perl -ne '/\x0f\x83....\x48\x19\xd2\x48\x21\xd0/ and $found++; END { exit($found ? 0 : 1) }' "$g_kernel"
ret=$?
if [ "$ret" -eq 0 ]; then
pstatus green YES "x86 64 bits array_index_mask_nospec()"
v1_mask_nospec="x86 64 bits array_index_mask_nospec"
elif is_x86_kernel; then
# x86: binary pattern matching for array_index_mask_nospec()
# x86 64bits: jae(0x0f 0x83 ....) sbb(0x48 0x19 0xd2) and(0x48 0x21 0xd0)
# x86 32bits: cmp(0x3b 0x82 .. .. 0x00 0x00) jae(0x73 ..) sbb(0x19 0xd2) and(0x21 0xd0)
if ! command -v perl >/dev/null 2>&1; then
pstatus yellow UNKNOWN "missing 'perl' binary, please install it"
else
perl -ne '/\x3b\x82..\x00\x00\x73.\x19\xd2\x21\xd0/ and $found++; END { exit($found ? 0 : 1) }' "$g_kernel"
perl -ne '/\x0f\x83....\x48\x19\xd2\x48\x21\xd0/ and $found++; END { exit($found ? 0 : 1) }' "$g_kernel"
ret=$?
if [ "$ret" -eq 0 ]; then
pstatus green YES "x86 32 bits array_index_mask_nospec()"
v1_mask_nospec="x86 32 bits array_index_mask_nospec"
pstatus green YES "x86 64 bits array_index_mask_nospec()"
v1_mask_nospec="x86 64 bits array_index_mask_nospec"
else
ret=$("${opt_arch_prefix}objdump" "$g_objdump_options" "$g_kernel" | grep -w -e f3af8014 -e e320f014 -B2 | grep -B1 -w sbc | grep -w -c cmp)
if [ "$ret" -gt 0 ]; then
pstatus green YES "$ret occurrence(s) found of arm 32 bits array_index_mask_nospec()"
v1_mask_nospec="arm 32 bits array_index_mask_nospec"
perl -ne '/\x3b\x82..\x00\x00\x73.\x19\xd2\x21\xd0/ and $found++; END { exit($found ? 0 : 1) }' "$g_kernel"
ret=$?
if [ "$ret" -eq 0 ]; then
pstatus green YES "x86 32 bits array_index_mask_nospec()"
v1_mask_nospec="x86 32 bits array_index_mask_nospec"
else
pstatus yellow NO
fi
fi
fi
elif is_arm_kernel; then
# arm32: match CSDB instruction (0xf3af8014 Thumb2 or 0xe320f014 ARM) preceded by sbc+cmp
# http://git.arm.linux.org.uk/cgit/linux-arm.git/commit/?h=spectre&id=a78d156587931a2c3b354534aa772febf6c9e855
if ! command -v "${opt_arch_prefix}objdump" >/dev/null 2>&1; then
pstatus yellow UNKNOWN "missing '${opt_arch_prefix}objdump' tool, please install it, usually it's in the binutils package"
else
ret=$("${opt_arch_prefix}objdump" "$g_objdump_options" "$g_kernel" | grep -w -e f3af8014 -e e320f014 -B2 | grep -B1 -w sbc | grep -w -c cmp)
if [ "$ret" -gt 0 ]; then
pstatus green YES "$ret occurrence(s) found of arm 32 bits array_index_mask_nospec()"
v1_mask_nospec="arm 32 bits array_index_mask_nospec"
else
pstatus yellow NO
fi
fi
else
pstatus yellow NO
fi
fi
@@ -172,67 +160,69 @@ check_CVE_2017_5753_linux() {
pstatus yellow NO
fi
pr_info_nol "* Kernel has mask_nospec64 (arm64): "
#.macro mask_nospec64, idx, limit, tmp
#sub \tmp, \idx, \limit
#bic \tmp, \tmp, \idx
#and \idx, \idx, \tmp, asr #63
#csdb
#.endm
#$ aarch64-linux-gnu-objdump -d vmlinux | grep -w bic -A1 -B1 | grep -w sub -A2 | grep -w and -B2
#ffffff8008082e44: cb190353 sub x19, x26, x25
#ffffff8008082e48: 8a3a0273 bic x19, x19, x26
#ffffff8008082e4c: 8a93ff5a and x26, x26, x19, asr #63
#ffffff8008082e50: d503229f hint #0x14
# /!\ can also just be "csdb" instead of "hint #0x14" for native objdump
#
# if we already have a detection, don't bother disassembling the kernel, the answer is no.
if [ -n "$v1_kernel_mitigated" ] || [ -n "$v1_mask_nospec" ] || [ "$g_redhat_canonical_spectre" -gt 0 ]; then
pstatus yellow NO
elif [ -n "$g_kernel_err" ]; then
pstatus yellow UNKNOWN "couldn't check ($g_kernel_err)"
elif ! command -v perl >/dev/null 2>&1; then
pstatus yellow UNKNOWN "missing 'perl' binary, please install it"
elif ! command -v "${opt_arch_prefix}objdump" >/dev/null 2>&1; then
pstatus yellow UNKNOWN "missing '${opt_arch_prefix}objdump' tool, please install it, usually it's in the binutils package"
else
"${opt_arch_prefix}objdump" "$g_objdump_options" "$g_kernel" | perl -ne 'push @r, $_; /\s(hint|csdb)\s/ && $r[0]=~/\ssub\s+(x\d+)/ && $r[1]=~/\sbic\s+$1,\s+$1,/ && $r[2]=~/\sand\s/ && exit(9); shift @r if @r>3'
ret=$?
if [ "$ret" -eq 9 ]; then
pstatus green YES "mask_nospec64 macro is present and used"
v1_mask_nospec="arm64 mask_nospec64"
else
if is_arm_kernel; then
pr_info_nol "* Kernel has mask_nospec64 (arm64): "
#.macro mask_nospec64, idx, limit, tmp
#sub \tmp, \idx, \limit
#bic \tmp, \tmp, \idx
#and \idx, \idx, \tmp, asr #63
#csdb
#.endm
#$ aarch64-linux-gnu-objdump -d vmlinux | grep -w bic -A1 -B1 | grep -w sub -A2 | grep -w and -B2
#ffffff8008082e44: cb190353 sub x19, x26, x25
#ffffff8008082e48: 8a3a0273 bic x19, x19, x26
#ffffff8008082e4c: 8a93ff5a and x26, x26, x19, asr #63
#ffffff8008082e50: d503229f hint #0x14
# /!\ can also just be "csdb" instead of "hint #0x14" for native objdump
#
# if we already have a detection, don't bother disassembling the kernel, the answer is no.
if [ -n "$v1_kernel_mitigated" ] || [ -n "$v1_mask_nospec" ] || [ "$g_redhat_canonical_spectre" -gt 0 ]; then
pstatus yellow NO
elif [ -n "$g_kernel_err" ]; then
pstatus yellow UNKNOWN "couldn't check ($g_kernel_err)"
elif ! command -v perl >/dev/null 2>&1; then
pstatus yellow UNKNOWN "missing 'perl' binary, please install it"
elif ! command -v "${opt_arch_prefix}objdump" >/dev/null 2>&1; then
pstatus yellow UNKNOWN "missing '${opt_arch_prefix}objdump' tool, please install it, usually it's in the binutils package"
else
"${opt_arch_prefix}objdump" "$g_objdump_options" "$g_kernel" | perl -ne 'push @r, $_; /\s(hint|csdb)\s/ && $r[0]=~/\ssub\s+(x\d+)/ && $r[1]=~/\sbic\s+$1,\s+$1,/ && $r[2]=~/\sand\s/ && exit(9); shift @r if @r>3'
ret=$?
if [ "$ret" -eq 9 ]; then
pstatus green YES "mask_nospec64 macro is present and used"
v1_mask_nospec="arm64 mask_nospec64"
else
pstatus yellow NO
fi
fi
fi
pr_info_nol "* Kernel has array_index_nospec (arm64): "
# in 4.19+ kernels, the mask_nospec64 asm64 macro is replaced by array_index_nospec, defined in nospec.h, and used in invoke_syscall()
# ffffff8008090a4c: 2a0203e2 mov w2, w2
# ffffff8008090a50: eb0200bf cmp x5, x2
# ffffff8008090a54: da1f03e2 ngc x2, xzr
# ffffff8008090a58: d503229f hint #0x14
# /!\ can also just be "csdb" instead of "hint #0x14" for native objdump
#
# if we already have a detection, don't bother disassembling the kernel, the answer is no.
if [ -n "$v1_kernel_mitigated" ] || [ -n "$v1_mask_nospec" ] || [ "$g_redhat_canonical_spectre" -gt 0 ]; then
pstatus yellow NO
elif [ -n "$g_kernel_err" ]; then
pstatus yellow UNKNOWN "couldn't check ($g_kernel_err)"
elif ! command -v perl >/dev/null 2>&1; then
pstatus yellow UNKNOWN "missing 'perl' binary, please install it"
elif ! command -v "${opt_arch_prefix}objdump" >/dev/null 2>&1; then
pstatus yellow UNKNOWN "missing '${opt_arch_prefix}objdump' tool, please install it, usually it's in the binutils package"
else
"${opt_arch_prefix}objdump" "$g_objdump_options" "$g_kernel" | perl -ne 'push @r, $_; /\s(hint|csdb)\s/ && $r[0]=~/\smov\s+(w\d+),\s+(w\d+)/ && $r[1]=~/\scmp\s+(x\d+),\s+(x\d+)/ && $r[2]=~/\sngc\s+$2,/ && exit(9); shift @r if @r>3'
ret=$?
if [ "$ret" -eq 9 ]; then
pstatus green YES "array_index_nospec macro is present and used"
v1_mask_nospec="arm64 array_index_nospec"
else
pr_info_nol "* Kernel has array_index_nospec (arm64): "
# in 4.19+ kernels, the mask_nospec64 asm64 macro is replaced by array_index_nospec, defined in nospec.h, and used in invoke_syscall()
# ffffff8008090a4c: 2a0203e2 mov w2, w2
# ffffff8008090a50: eb0200bf cmp x5, x2
# ffffff8008090a54: da1f03e2 ngc x2, xzr
# ffffff8008090a58: d503229f hint #0x14
# /!\ can also just be "csdb" instead of "hint #0x14" for native objdump
#
# if we already have a detection, don't bother disassembling the kernel, the answer is no.
if [ -n "$v1_kernel_mitigated" ] || [ -n "$v1_mask_nospec" ] || [ "$g_redhat_canonical_spectre" -gt 0 ]; then
pstatus yellow NO
elif [ -n "$g_kernel_err" ]; then
pstatus yellow UNKNOWN "couldn't check ($g_kernel_err)"
elif ! command -v perl >/dev/null 2>&1; then
pstatus yellow UNKNOWN "missing 'perl' binary, please install it"
elif ! command -v "${opt_arch_prefix}objdump" >/dev/null 2>&1; then
pstatus yellow UNKNOWN "missing '${opt_arch_prefix}objdump' tool, please install it, usually it's in the binutils package"
else
"${opt_arch_prefix}objdump" "$g_objdump_options" "$g_kernel" | perl -ne 'push @r, $_; /\s(hint|csdb)\s/ && $r[0]=~/\smov\s+(w\d+),\s+(w\d+)/ && $r[1]=~/\scmp\s+(x\d+),\s+(x\d+)/ && $r[2]=~/\sngc\s+$2,/ && exit(9); shift @r if @r>3'
ret=$?
if [ "$ret" -eq 9 ]; then
pstatus green YES "array_index_nospec macro is present and used"
v1_mask_nospec="arm64 array_index_nospec"
else
pstatus yellow NO
fi
fi
fi
fi # is_arm_kernel
elif [ "$sys_interface_available" = 0 ]; then
msg="/sys vulnerability interface use forced, but it's not available!"