Files
SKELETONKEY/tools/verify-vm/verify.sh
T
leviathan f792a3c4a6 verify-vm: close the loop — first successful end-to-end VM verification
Five fixes that landed us at a working 'verify.sh <module> -> JSON
verification record' loop. Tested with pwnkit on
generic/ubuntu2004 / Ubuntu 20.04.6 LTS / 5.4.0-169-generic.

1. core/nft_compat.h — shim header that conditionally defines newer-
   kernel nft uapi constants that aren't in older distro headers:
     NFT_CHAIN_HW_OFFLOAD     kernel 5.5
     NFT_CHAIN_BINDING        kernel 5.9
     NFTA_VERDICT_CHAIN_ID    kernel 5.14
     NFTA_SET_DESC_CONCAT     kernel 5.6
     NFTA_SET_EXPR            kernel 5.12
     NFTA_SET_EXPRESSIONS     kernel 5.16
     NFTA_SET_ELEM_KEY_END    kernel 5.6
     NFTA_SET_ELEM_EXPRESSIONS kernel 5.16
   Numeric values are stable kernel ABI; the target vulnerable kernel
   understands them at runtime regardless of the build host's headers.
   Without this, nf_tables / nft_fwd_dup / nft_payload / nft_set_uaf
   modules fail to compile on Ubuntu 20.04's libc-dev (5.4 uapi).

2. modules/{nf_tables, nft_fwd_dup, nft_payload, nft_set_uaf}/
   skeletonkey_modules.c — each #includes the new compat shim after
   <linux/netfilter/nf_tables.h>.

3. tools/verify-vm/Vagrantfile — wrap config in 'c.vm.define host do
   |m| ... end' block so 'vagrant up <skk-MODULE>' finds the machine.
   (Earlier without define block, vagrant always treated the Vagrantfile
   as a single anonymous machine.) Also disable Parallels Tools auto-
   install — it fails on Ubuntu 20.04's 5.4 kernel ('current Linux
   kernel version is outdated and not supported by latest tools'); we
   use rsync sync_folder over plain SSH which doesn't need the tools.

4. tools/verify-vm/verify.sh — explicit 'vagrant rsync' before
   'vagrant provision build-and-verify' so the source tree gets synced
   even on already-running VMs (vagrant up runs rsync automatically;
   vagrant provision does not).

5. tools/verify-vm/verify.sh — fix verdict parser. Vagrant prefixes
   provisioner stdout with the VM name ('    skk-pwnkit: VERDICT:
   VULNERABLE'), so the previous '^VERDICT: ' regex never matched.
   New grep allows the prefix; added '|| true' so a grep miss doesn't
   trigger set-e+pipefail and silently exit the script before the JSON
   verification record gets emitted.

First successful verification record:
  {
    "module": "pwnkit",
    "verified_at": "2026-05-23T19:26:02Z",
    "host_kernel": "5.4.0-169-generic",
    "host_distro": "Ubuntu 20.04.6 LTS",
    "vm_box": "generic/ubuntu2004",
    "expect_detect": "VULNERABLE",
    "actual_detect": "VULNERABLE",
    "status": "match"
  }

SKELETONKEY correctly identifies polkit 0.105 on Ubuntu 20.04 as
vulnerable to CVE-2021-4034. The verifier pipeline is now ready for
sweep across the rest of the corpus.
2026-05-23 15:26:51 -04:00

213 lines
8.1 KiB
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#!/usr/bin/env bash
# tools/verify-vm/verify.sh — verify ONE module in the right pre-built VM.
#
# Usage:
# verify.sh <module> # provision, run --explain --active, suspend VM
# verify.sh <module> --keep # keep VM running after for inspection
# verify.sh <module> --destroy # destroy VM after (full reset; slow next run)
# verify.sh --list # show every module + the box it's mapped to
#
# What it does:
# 1. Reads tools/verify-vm/targets.yaml: <module> -> (box, kernel_pkg, kver,
# expect_detect).
# 2. Sets SKK_VM_* env vars + spins up the right Vagrant VM.
# 3. If a kernel pin is needed, installs it + reboots the VM.
# 4. Runs `skeletonkey --explain <module> --active` inside the VM via
# `vagrant provision --provision-with build-and-verify`.
# 5. Captures stdout, parses the VERDICT line, compares against expect_detect.
# 6. Emits a JSON verification record on stdout (timestamped) suitable for
# piping into the per-module verified-on table (separate follow-up).
#
# Requirements:
# - tools/verify-vm/setup.sh has been run successfully (Vagrant +
# vagrant-parallels + boxes cached).
# - Module name matches a key in targets.yaml.
set -euo pipefail
REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)"
VM_DIR="$REPO_ROOT/tools/verify-vm"
TARGETS="$VM_DIR/targets.yaml"
LOG_DIR="$VM_DIR/logs"
mkdir -p "$LOG_DIR"
# Minimal YAML field reader for targets.yaml's flat 2-level structure.
# Usage: yget <module> <field>
# yget af_packet box -> "ubuntu1804"
# Strips surrounding quotes and trailing whitespace; empty fields -> "".
yget() {
local module="$1"
local field="$2"
awk -v m="${module}:" -v f=" ${field}:" '
$0 ~ "^"m"[[:space:]]*$" { inmod=1; next }
inmod && /^[a-zA-Z]/ { inmod=0 } # next top-level key
inmod && $0 ~ "^"f {
sub("^[^:]+:[[:space:]]*", "")
sub("[[:space:]]+#.*$", "") # trim trailing comment
sub("^\"", ""); sub("\"$", "")
print; exit
}
' "$TARGETS"
}
# ── arg parsing ───────────────────────────────────────────────────────────
KEEP=0; DESTROY=0; LIST=0; MODULE=""
while [[ $# -gt 0 ]]; do
case "$1" in
--keep) KEEP=1 ;;
--destroy) DESTROY=1 ;;
--list) LIST=1 ;;
-h|--help)
sed -n '1,30p' "$0"; exit 0 ;;
--*)
echo "[-] unknown flag: $1" >&2; exit 2 ;;
*)
MODULE="$1" ;;
esac
shift
done
# ── --list mode ───────────────────────────────────────────────────────────
if [[ $LIST -eq 1 ]]; then
printf "%-22s %-14s %-18s %-14s %s\n" "MODULE" "BOX" "KERNEL" "EXPECT" "NOTES"
printf "%-22s %-14s %-18s %-14s %s\n" "------" "---" "------" "------" "-----"
# Iterate top-level keys (lines starting in column 0 with `something:`).
awk '/^[a-z_][a-zA-Z0-9_]*:[[:space:]]*$/ { sub(":", ""); print }' "$TARGETS" | \
while read -r mod; do
box=$(yget "$mod" box)
kv=$(yget "$mod" kernel_version)
exp=$(yget "$mod" expect_detect)
notes=$(yget "$mod" notes | head -c 60)
[[ -z "$box" ]] && box="(manual)"
[[ -z "$kv" ]] && kv="stock"
[[ -z "$exp" ]] && exp="?"
printf "%-22s %-14s %-18s %-14s %s\n" "$mod" "$box" "$kv" "$exp" "$notes"
done
exit 0
fi
if [[ -z "$MODULE" ]]; then
echo "[-] usage: verify.sh <module> [--keep|--destroy]"
echo " verify.sh --list # show all targets"
exit 2
fi
# ── load target ───────────────────────────────────────────────────────────
BOX=$(yget "$MODULE" box)
KERNEL_PKG=$(yget "$MODULE" kernel_pkg)
KERNEL_VER=$(yget "$MODULE" kernel_version)
EXPECT=$(yget "$MODULE" expect_detect)
MANUAL=$(yget "$MODULE" manual)
NOTES=$(yget "$MODULE" notes)
if ! grep -q "^${MODULE}:" "$TARGETS"; then
echo "[-] module not in targets.yaml: $MODULE" >&2
exit 3
fi
if [[ "$MANUAL" == "true" || -z "$BOX" ]]; then
echo "[-] $MODULE is marked manual: true (${NOTES:0:80})" >&2
exit 4
fi
BOX="generic/$BOX"
VM_HOSTNAME="skk-${MODULE}"
SHORT_NOTES="${NOTES:0:80}"
# ── kick off provisioning ─────────────────────────────────────────────────
echo
echo "════════════════════════════════════════════════════"
echo " SKELETONKEY VM verifier: $MODULE"
echo "════════════════════════════════════════════════════"
echo " box: $BOX"
echo " kernel: ${KERNEL_PKG:-(stock)}$KERNEL_VER"
echo " expect: $EXPECT"
echo " notes: $SHORT_NOTES"
echo
cd "$VM_DIR"
export SKK_VM_BOX="$BOX"
export SKK_VM_KERNEL_PKG="$KERNEL_PKG"
export SKK_VM_KERNEL_VERSION="$KERNEL_VER"
export SKK_VM_HOSTNAME="$VM_HOSTNAME"
export SKK_MODULE="$MODULE"
export VAGRANT_VAGRANTFILE="$VM_DIR/Vagrantfile"
# Spin up if not running.
if ! vagrant status "$VM_HOSTNAME" 2>&1 | grep -q "running"; then
echo "[*] vagrant up..."
vagrant up "$VM_HOSTNAME" --provider=parallels
fi
# Reboot if a kernel pin was applied (uname -r != target).
if [[ -n "$KERNEL_PKG" ]]; then
current_kver=$(vagrant ssh "$VM_HOSTNAME" -c "uname -r" 2>/dev/null | tr -d '\r')
if [[ "$current_kver" != *"$KERNEL_VER"* ]]; then
echo "[*] current kernel $current_kver != target $KERNEL_VER; rebooting..."
vagrant reload "$VM_HOSTNAME"
sleep 5
fi
fi
# Run the explain probe.
LOG="$LOG_DIR/verify-${MODULE}-$(date +%Y%m%d-%H%M%S).log"
# Force rsync the source tree in. vagrant up runs rsync automatically on
# first up but NOT on a resume/already-running VM, so we always rsync here
# to guarantee /vagrant/ inside the guest matches the host's source tree.
echo "[*] syncing source into VM..."
vagrant rsync "$VM_HOSTNAME" 2>&1 | tail -5
echo "[*] running verifier..."
vagrant provision "$VM_HOSTNAME" --provision-with build-and-verify 2>&1 | tee "$LOG"
# Parse verdict. Vagrant prefixes provisioner output with the VM name
# (e.g. " skk-pwnkit: VERDICT: VULNERABLE"), so anchor on the VERDICT
# keyword itself. `|| true` keeps pipefail+set-e from killing us on miss.
VERDICT=$(grep -E "VERDICT:" "$LOG" | tail -1 | awk '{print $NF}' || true)
[[ -z "$VERDICT" ]] && VERDICT="?"
# Compare.
if [[ "$VERDICT" == "$EXPECT" ]]; then
STATUS=match
else
STATUS=MISMATCH
fi
# Verification record (JSON).
NOW=$(date -u +%Y-%m-%dT%H:%M:%SZ)
HOST_KVER=$(vagrant ssh "$VM_HOSTNAME" -c "uname -r" 2>/dev/null | tr -d '\r')
HOST_DISTRO=$(vagrant ssh "$VM_HOSTNAME" -c \
"(. /etc/os-release && echo \"\$PRETTY_NAME\")" 2>/dev/null | tr -d '\r')
echo
echo "════════════════════════════════════════════════════"
echo " Verification record"
echo "════════════════════════════════════════════════════"
cat <<JSON
{
"module": "$MODULE",
"verified_at": "$NOW",
"host_kernel": "$HOST_KVER",
"host_distro": "$HOST_DISTRO",
"vm_box": "$BOX",
"expect_detect": "$EXPECT",
"actual_detect": "$VERDICT",
"status": "$STATUS",
"log": "$LOG"
}
JSON
echo
# Lifecycle.
if [[ $DESTROY -eq 1 ]]; then
echo "[*] --destroy: tearing down VM..."
vagrant destroy -f "$VM_HOSTNAME"
elif [[ $KEEP -eq 1 ]]; then
echo "[i] --keep: VM left running. Reconnect with:"
echo " cd tools/verify-vm && vagrant ssh $VM_HOSTNAME"
else
echo "[*] suspending VM (resume next time)..."
vagrant suspend "$VM_HOSTNAME"
fi
[[ "$STATUS" == "match" ]] && exit 0 || exit 5