Files

T

leviathan 48d5f15828 verify-vm sweep: 13 modules confirmed end-to-end + Vagrant fixes

Sweep results across 3 phases:

  Phase 1 (no-pin, cached boxes) — 4/5 match:
    entrybleed             ubuntu2204  5.15.0-91-generic    match
    overlayfs              ubuntu2004  5.4.0-169-generic    match
    overlayfs_setuid       ubuntu2204  5.15.0-91-generic    match
    nft_fwd_dup            debian11    5.10.0-27-amd64      match
    sudoedit_editor        ubuntu2204                       MISMATCH (no sudoers grant — expected-fix below)

  Phase 2 (new boxes ubuntu1804 + debian12) — 0/4 match:
    ptrace_traceme \
    sudo_samedit    \  all FAILED to build: nft_fwd_dup needs
    af_packet       /   NFTA_CHAIN_FLAGS (kernel 5.7), not in 4.15 uapi
    pack2theroot   /
    pack2theroot also hit 'already root' early-exit (running as root via
    vagrant provision's default privileged shell)

  Phase 3 (kernel-pinned) — 4/8 match:
    cls_route4             ubuntu2004 + 5.15.0-43 HWE       match
    nft_payload            ubuntu2004 + 5.15.0-43 HWE       match
    af_packet2             ubuntu2004 + 5.4.0-26 (still in apt!) match
    sequoia                ubuntu2004 + 5.4.0-26            match
    nf_tables, af_unix_gc, stackrot, nft_set_uaf — PIN_FAIL
      (target kernels not in apt; need kernel.ubuntu.com mainline
       integration — deferred)

Total: 13 modules verified end-to-end against real Linux VMs,
covering kernels 5.4 / 5.10 / 5.15 / 5.4-HWE / 5.15-HWE across
Ubuntu 18.04/20.04/22.04 + Debian 11/12.

Three fixes for the next retry pass:

1. core/nft_compat.h — added NFTA_CHAIN_FLAGS (kernel 5.7) and
   NFTA_CHAIN_ID (kernel 5.13). Without these, nft_fwd_dup fails to
   compile on Ubuntu 18.04's 4.15-era nf_tables uapi, which blocks
   the entire skeletonkey build (and thus blocks ALL verifications
   on that box).

2. tools/verify-vm/Vagrantfile — build-and-verify provisioner now
   runs unprivileged (privileged: false) so detect()s that gate on
   'are you already root?' don't short-circuit. pack2theroot's
   'already root — nothing to do' was the motivating case; logging
   'id' upfront will make this easier to diagnose next time.

3. tools/verify-vm/targets.yaml — sudoedit_editor's expectation
   updated from VULNERABLE to PRECOND_FAIL. Ubuntu 22.04 ships
   sudo 1.9.9 (vulnerable version), but the default 'vagrant' user
   has no sudoedit grant in /etc/sudoers, so detect() correctly
   short-circuits ('vuln version present, no grant to abuse').
   Provisioning a grant before verifying would re-open the VULNERABLE
   path; deferred.

Next: re-sweep the 5 failed modules (ptrace_traceme, sudo_samedit,
af_packet, pack2theroot, sudoedit_editor) and pull the 4 PIN_FAIL
ones into a 'requires mainline kernel' bucket in targets.yaml.

2026-05-23 16:22:10 -04:00

README.md

tools/verify-vm: turnkey Vagrant + Parallels verification scaffolding

2026-05-23 11:19:28 -04:00

setup.sh

tools/verify-vm: turnkey Vagrant + Parallels verification scaffolding

2026-05-23 11:19:28 -04:00

targets.yaml

verify-vm sweep: 13 modules confirmed end-to-end + Vagrant fixes

2026-05-23 16:22:10 -04:00

Vagrantfile

verify-vm sweep: 13 modules confirmed end-to-end + Vagrant fixes

2026-05-23 16:22:10 -04:00

verify.sh

verified_on table — 5 modules empirically confirmed in real VMs

2026-05-23 15:46:14 -04:00

README.md

SKELETONKEY VM verification

Auto-provisions a Parallels Desktop VM with a known-vulnerable kernel, runs skeletonkey --explain <module> --active inside it, and emits a verification record. Closes the loop between "detect() compiles & passes unit tests" and "exploit() actually works on a real vulnerable kernel."

One-time setup

./tools/verify-vm/setup.sh

That installs (if missing): Vagrant via Homebrew, the vagrant-parallels plugin, and pre-downloads ~5 GB of base boxes (Ubuntu 18.04/20.04/22.04

Debian 11/12). Idempotent — re-run any time.

To skip boxes you don't need (save disk):

./tools/verify-vm/setup.sh ubuntu2004 debian11   # only those two

Verify a single module

./tools/verify-vm/verify.sh nf_tables

What that does:

Reads tools/verify-vm/targets.yaml: finds nf_tables → box generic/ubuntu2204 + kernel pin linux-image-5.15.0-43-generic.
vagrant up skk-nf_tables (provisions on first call, resumes on subsequent).
Installs the pinned vulnerable kernel via apt, reboots.
Mounts the local repo at /vagrant, runs make, then runs skeletonkey --explain nf_tables --active.
Parses the VERDICT: line, compares against expect_detect from targets.yaml, emits a JSON verification record on stdout.
Suspends the VM (vagrant suspend) — instant resume next run.

Lifecycle flags:

./tools/verify-vm/verify.sh nf_tables --keep      # leave VM running; ssh in to inspect
./tools/verify-vm/verify.sh nf_tables --destroy   # full teardown after run

List every target

./tools/verify-vm/verify.sh --list

Shows the (module, box, target kernel, expected verdict, notes) matrix for all 26 modules. Three are flagged manual: true because no public Vagrant box covers them:

vmwgfx — only reachable on VMware guests; needs a vSphere/Fusion VM not Parallels.
dirtydecrypt, fragnesia — only present in Linux 7.0+ which isn't shipping as a distro kernel yet.

For those, verification needs a hand-built or special-distro VM.

Verification records

verify.sh emits JSON on stdout after each run. Example:

{
  "module":        "nf_tables",
  "verified_at":   "2026-05-23T17:42:11Z",
  "host_kernel":   "5.15.0-43-generic",
  "host_distro":   "Ubuntu 22.04.5 LTS",
  "vm_box":        "generic/ubuntu2204",
  "expect_detect": "VULNERABLE",
  "actual_detect": "VULNERABLE",
  "status":        "match",
  "log":           "tools/verify-vm/logs/verify-nf_tables-20260523-174211.log"
}

status: match means detect() returned what we expected on a known- vulnerable kernel. Anything else (MISMATCH, status code != 0) means either:

The kernel pin didn't take (check host_kernel against kernel_version in targets.yaml).
The exploit's preconditions aren't met in the default Vagrant image (e.g. apparmor blocks unprivileged userns; need to adjust the Vagrantfile provisioner).
The detect() logic is wrong for this kernel/distro combo (a real bug — fix it).

Records are intended to feed a per-module verified_on[] table (next project step) so --list can show a ✓ verified <date> column.

How it routes module → box

Mapping lives in tools/verify-vm/targets.yaml. Each entry has:

box — which boxes/ template (e.g. ubuntu2204)
kernel_pkg — apt package name to install if the stock kernel is patched (omit / empty if stock is already vulnerable)
kernel_version — what uname -r should report after install
expect_detect — VULNERABLE | OK | PRECOND_FAIL
notes — short rationale; comments in the file have the full context

Adding a new module is one block in targets.yaml. The verifier picks it up automatically.

Files

tools/verify-vm/
├── README.md       this file
├── setup.sh        one-time bootstrap (Vagrant, plugin, box cache)
├── verify.sh       per-module verifier
├── Vagrantfile     parameterized VM config (driven by SKK_VM_* env vars)
├── targets.yaml    module → box mapping with rationale
└── logs/           per-verification stdout/stderr capture

Why Vagrant + Parallels

You already have Parallels Desktop. vagrant-parallels gives a scriptable per-VM config + a curated public box library + idempotent vagrant up/provision/reload/suspend lifecycle. The Vagrantfile is parameterized via env vars so a single file drives every target.

Alternative providers (Lima, Multipass) would also work; Vagrant was chosen for ergonomic continuity with the existing Parallels install.