diff options
| -rwxr-xr-x | spectre-meltdown-checker.sh | 77 |
1 files changed, 73 insertions, 4 deletions
diff --git a/spectre-meltdown-checker.sh b/spectre-meltdown-checker.sh index 22bab38..6b052d0 100755 --- a/spectre-meltdown-checker.sh +++ b/spectre-meltdown-checker.sh @@ -16,15 +16,85 @@ pstatus() /bin/echo } +# ---------------------------------------------------------------------- +# extract-vmlinux - Extract uncompressed vmlinux from a kernel image +# +# Inspired from extract-ikconfig +# (c) 2009,2010 Dick Streefland <dick@streefland.net> +# +# (c) 2011 Corentin Chary <corentin.chary@gmail.com> +# +# Licensed under the GNU General Public License, version 2 (GPLv2). +# ---------------------------------------------------------------------- + +check_vmlinux() +{ + file "$1" 2>/dev/null | grep -q ELF || return 1 + return 0 +} + +try_decompress() +{ + # The obscure use of the "tr" filter is to work around older versions of + # "grep" that report the byte offset of the line instead of the pattern. + + # Try to find the header ($1) and decompress from here + for pos in `tr "$1\n$2" "\n$2=" < "$img" | grep -abo "^$2"` + do + pos=${pos%%:*} + tail -c+$pos "$img" | $3 > $vmlinuxtmp 2> /dev/null + check_vmlinux $vmlinuxtmp && echo $vmlinuxtmp || rm -f $vmlinuxtmp + done +} + +extract_vmlinux() +{ + img="$1" + + # Prepare temp files: + vmlinuxtmp=$(mktemp /tmp/vmlinux-XXX) + + # Initial attempt for uncompressed images or objects: + check_vmlinux $img + + # That didn't work, so retry after decompression. + try_decompress '\037\213\010' xy gunzip || \ + try_decompress '\3757zXZ\000' abcde unxz || \ + try_decompress 'BZh' xy bunzip2 || \ + try_decompress '\135\0\0\0' xxx unlzma || \ + try_decompress '\211\114\132' xy 'lzop -d' +} + + /bin/echo "Spectre and Meltdown mitigation detection tool v$VERSION" /bin/echo # SPECTRE 1 /bin/echo -e "\033[1;34mCVE-2017-5753 [bounds check bypass] aka 'Spectre Variant 1'\033[0m" -/bin/echo -n "* Kernel recompiled with LFENCE opcode insertion: " -pstatus yellow UNKNOWN "check not yet implemented" +/bin/echo -n "* Kernel compiled with LFENCE opcode inserted at the proper places: " + +vmlinux=$(extract_vmlinux /boot/vmlinuz-4.4.110) +status=0 +if [ -z "$vmlinux" -o ! -r "$vmlinux" ]; then + pstatus yellow UNKNOWN "couldn't extract your kernel" +elif ! which objdump >/dev/null 2>&1; then + pstatus yellow UNKNOWN "missing 'objdump' tool, please install it, usually it's in the binutils package" +else + nb_lfence=$(objdump -D "$vmlinux" | grep -wc lfence) + if [ "$nb_lfence" -lt 50 ]; then + pstatus red NO "only $nb_lfence lfence opcodes found, should be >= 50" + status=1 + else + pstatus green YES "$nb_lfence opcodes found, which is >= 50" + status=2 + fi + rm -f $vmlinux +fi + /bin/echo -ne "> \033[46m\033[30mSTATUS:\033[0m " -pstatus yellow UNKNOWN "not implemented, but real answer is most probably VULNERABLE at this stage" +[ "$status" = 0 ] && pstatus yellow UNKNOWN +[ "$status" = 1 ] && pstatus red VULNERABLE +[ "$status" = 2 ] && pstatus green 'NOT VULNERABLE' # VARIANT 2 @@ -153,4 +223,3 @@ if [ "$USER" != root ]; then /bin/echo "You can try the following command: sudo $0" fi - |