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.
leviathan
1571b88725