core/host helper:
- Adds bool skeletonkey_host_kernel_at_least(h, M, m, p) — the
canonical 'kernel >= X.Y.Z' check. Replaces the manual
'v->major < X || (v->major == X && v->minor < Y)' pattern that
many modules use for their 'predates the bug' pre-check. Returns
false when h is NULL or h->kernel.major == 0 (degenerate cases),
true otherwise iff the host kernel sorts at or above the supplied
version.
- dirtydecrypt migrated as the demo: the 'kernel < 7.0 → predates'
pre-check now reads 'if (!host_kernel_at_least(ctx->host, 7, 0, 0))'.
Other modules still using the manual pattern continue to work
unchanged; migrating them is incremental polish.
tests/test_detect.c expansion (8 → 17 cases):
New fingerprints:
- h_kernel_4_4 — ancient (Linux 4.4 LTS); used for 'predates the
bug' on dirty_pipe.
- h_kernel_6_12 — recent (Linux 6.12 LTS); above every backport
threshold in the corpus — modules report OK via
the 'patched by mainline inheritance' branch of
kernel_range_is_patched.
- h_kernel_5_14_no_userns — vulnerable-era kernel (5.14.0, past
every relevant predates check while below every
backport entry) with unprivileged_userns_allowed
deliberately false; lets the userns gate fire
after the version check confirms vulnerable.
New tests (9):
- dirty_pipe + kernel 4.4 → OK (predates 5.8 introduction)
- dirty_pipe + kernel 6.12 → OK (above every backport)
- dirty_cow + kernel 6.12 → OK (above 4.9 fix)
- ptrace_traceme + kernel 6.12 → OK (above 5.1.17 fix)
- cgroup_release_agent + kernel 6.12 → OK (above 5.17 fix)
- nf_tables + vuln kernel + userns=false → PRECOND_FAIL
- fuse_legacy + vuln kernel + userns=false → PRECOND_FAIL
- cls_route4 + vuln kernel + userns=false → PRECOND_FAIL
- overlayfs_setuid + vuln kernel + userns=false → PRECOND_FAIL
Process note: initial 8th and 9th userns tests failed because the
chosen test kernel (5.10.0) tripped each module's predates check
(nf_tables bug introduced 5.14; overlayfs_setuid 5.11). Switched to
5.14.0, which is past every predates threshold AND below every
backport entry in this batch — the version verdict is now genuinely
'vulnerable' and the userns gate fires next. The bug-finding tests
caught a real-but-narrow modeling gap in the original picks.
Verification:
- Linux (docker gcc:latest, non-root user): 17/17 pass.
- macOS (local): builds clean, suite reports 'skipped — Linux-only'
as designed.
Adds tests/test_detect.c — a standalone harness that constructs
synthetic struct skeletonkey_host fingerprints (vulnerable / patched /
specific-gate-closed) and asserts each migrated module's detect()
returns the expected verdict. First real test coverage for the corpus;
catches regressions in the host-fingerprint-consuming logic.
Initial coverage — 8 deterministic cases across the 4 modules that
already consume ctx->host:
- dirtydecrypt: 3 cases verifying 'kernel < 7.0 -> predates the bug'
short-circuit on synthetic 6.12 / 6.14 / 6.8 hosts.
- fragnesia: unprivileged_userns_allowed=false -> PRECOND_FAIL.
- pack2theroot: is_debian_family=false -> PRECOND_FAIL.
- pack2theroot: has_dbus_system=false -> PRECOND_FAIL.
- overlayfs: distro=debian / distro=fedora -> 'not Ubuntu' -> OK.
Coverage grows automatically as more modules migrate to ctx->host
(task #12 below adds them). Each new module that consults the host
fingerprint can have its precondition gates tested with a one-line
EXPECT_DETECT call against a pre-built fingerprint.
Wiring:
- Makefile: new MODULE_OBJS var consolidates the module .o list so
both the main binary and the test binary can share it without
duplication. New TEST_BIN := skeletonkey-test target. 'make test'
builds and runs the suite.
- .github/workflows/build.yml: install libglib2.0-dev + pkg-config so
pack2theroot builds with GLib in CI (was previously stub-compiling).
New 'tests — detect() unit suite' step runs 'make test' as a
non-root user so modules' 'already root' gates don't short-circuit
before the synthetic host checks fire.
- Test harness compiles cross-platform but assertions are #ifdef
__linux__ guarded (on non-Linux all module detect() bodies stub-out
to PRECOND_FAIL, making assertions tautological); macOS dev build
reports 'skipped'.
Module change:
- pack2theroot p2tr_detect now consults ctx->host->is_root (with a
geteuid() fallback when ctx->host is null) instead of calling
geteuid() directly. Production behaviour is identical
(host->is_root is populated from geteuid() at startup); tests can
now construct non-root fingerprints regardless of the test
process's actual euid. Exposed a real consistency issue worth
fixing.
Verified in docker as non-root: 8/8 pass on Linux. macOS reports
'skipped' as designed.
leviathan