dirtydecrypt + fragnesia: pin CVE fix commits, version-based detect()

Both modules' detect() was precondition-only because we didn't know the
mainline fix commits at port time. Debian's security tracker now
provides them — pinning here turns detect() into a proper version-
based verdict (still with --active for empirical override).

dirtydecrypt (CVE-2026-31635):
- Fix commit a2567217ade970ecc458144b6be469bc015b23e5 in mainline 7.0
  ('rxrpc: fix oversized RESPONSE authenticator length check').
- Debian tracker confirms older stable branches (5.10 / 6.1 / 6.12) as
  <not-affected, vulnerable code not present>: the rxgk RESPONSE-
  handling code was added in 7.0.
- kernel_range table: { {7, 0, 0} }
- detect() pre-checks 'kernel < 7.0 -> SKELETONKEY_OK (predates)' then
  consults the table. With --active, the /tmp sentinel probe overrides
  empirically (catches pre-fix 7.0-rc kernels the version check
  reports as patched).

fragnesia (CVE-2026-46300):
- Fix in mainline 7.0.9 per Debian tracker ('linux unstable: 7.0.9-1
  fixed'). Older Debian-stable branches (bullseye 5.10 / bookworm 6.1
  / trixie 6.12) are still marked vulnerable as of 2026-05-22 - no
  backports yet.
- kernel_range table: { {7, 0, 9} }
- detect() keeps the userns + carrier preconditions, then consults
  the table: 7.0.9+ -> OK; older branches without an explicit backport
  entry -> VULNERABLE (version-only). --active confirms empirically.
- Table is intentionally minimal so distros that DO backport in the
  future flow into 'patched' once their branch lands an entry; until
  then, the conservative VULNERABLE verdict on unfixed branches is
  correct.

Other changes:
- module struct .kernel_range strings updated from 'fix commit not
  yet pinned' to the actual pinned-version prose.
- module_safety_rank bumped 86 -> 87 for both modules (version-pinned
  detect is now real; still below the verified copy_fail family at
  88 so --auto prefers verified modules when both apply).
- Both modules now #include core/kernel_range.h inside their
  #ifdef __linux__ block.
- MODULE.md verification-status sections rewritten: detect() is now
  version-pinned; only the exploit body remains unverified.
- CVES.md note + inventory rows updated: dropped the 'precondition-
  only' language for the pair; all three ported modules now have
  pinned fix references.
- README  tier description + module list aligned to the new state.

Both detect()s smoke-tested in docker gcc:latest on kernel 6.12.76-
linuxkit: dirtydecrypt correctly reports OK ('predates the rxgk code
added in 7.0'); fragnesia + pack2theroot correctly report
PRECOND_FAIL (no userns / no D-Bus in container). Local macOS + Linux
builds both clean.
This commit is contained in:
2026-05-22 23:06:15 -04:00
parent cdb8f5e8f9
commit a26f471ecf
7 changed files with 175 additions and 80 deletions
+15 -13
View File
@@ -68,18 +68,20 @@ The exploit mechanism itself is reproduced faithfully.
This module is a **faithful port** of
<https://github.com/v12-security/pocs/tree/main/fragnesia>, compiled
into the SKELETONKEY module interface. It has **not** been validated
end-to-end against a known-vulnerable kernel inside the SKELETONKEY CI
matrix.
into the SKELETONKEY module interface. The **exploit body** has not
been validated end-to-end against a known-vulnerable kernel inside the
SKELETONKEY CI matrix.
`detect()` deliberately does **not** return a kernel-version-based
patched/vulnerable verdict: the CVE-2026-46300 fix commit is not yet
pinned here. Instead:
**`detect()` is now version-pinned**: the Fragnesia fix ships in
mainline Linux **7.0.9** (Debian tracker source-of-truth, `linux
unstable: 7.0.9-1 fixed`). The `kernel_range` table marks the 7.0.x
branch patched at `7.0.9`; older Debian-stable branches (5.10 / 6.1 /
6.12) are currently still vulnerable per the tracker. With `--active`,
the detector runs the full ESP-in-TCP primitive against a `/tmp` file
and reports empirically — catches stable-branch backports the version
table doesn't know about, and CONFIG_INET_ESPINTCP=n kernels where the
primitive is structurally unreachable.
- preconditions missing → `PRECOND_FAIL`
- preconditions present, no `--active``TEST_ERROR` so `--auto` does
not fire it blind
- `--active` → empirical VULNERABLE / OK via the `/tmp` sentinel probe
**Before promoting to 🟢:** pin the fix commit + branch-backport
thresholds, add a `kernel_range`, and validate on a vulnerable VM.
**Before promoting to 🟢:** validate the exploit end-to-end on a
≤ 7.0.8 kernel. Extend the `kernel_range` table with backport
thresholds for 5.10 / 6.1 / 6.12 as distros publish them.