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2 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
 leviathan
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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.
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leviathan
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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.
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