120 lines
4.2 KiB
Markdown
120 lines
4.2 KiB
Markdown
# Architecture
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## Module model
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Each CVE (or tightly-related family of CVEs sharing a primitive) is
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a **module** under `modules/`. A module is a self-contained
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exploit + detection + metadata bundle that exports a standard
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interface to the top-level dispatcher.
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### Module layout
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```
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modules/<module_name>/
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├── MODULE.md # Human-readable writeup of the bug
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├── NOTICE.md # Credits to original researcher
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├── kernel-range.json # Machine-readable affected kernels
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├── module.c # Implements iamroot_module interface
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├── module.h
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├── detect/
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│ ├── auditd.rules # blue team detection
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│ ├── sigma.yml
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│ └── yara.yara
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├── src/ # exploit internals
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└── tests/ # per-module tests (run in CI matrix)
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```
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### `iamroot_module` interface (planned, Phase 1)
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```c
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struct iamroot_module {
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const char *name; /* "copy_fail" */
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const char *cve; /* "CVE-2026-31431" */
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const char *summary; /* one-line description */
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/* Return 1 if host appears vulnerable, 0 if patched/immune,
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* -1 if probe couldn't run. May call entrybleed_leak_kbase()
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* etc. from core/ if a leak primitive is needed. */
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int (*detect)(struct iamroot_host *host);
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/* Run the exploit. Caller has already passed the
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* authorization gate. Returns 0 on root acquired,
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* nonzero on failure. */
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int (*exploit)(struct iamroot_host *host, struct iamroot_opts *opts);
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/* Apply a runtime mitigation for this CVE (sysctl, module
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* blacklist, etc.). Returns 0 on success. NULL if no
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* mitigation is offered. */
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int (*mitigate)(struct iamroot_host *host);
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/* Undo --exploit-backdoor or --mitigate side effects. */
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int (*cleanup)(struct iamroot_host *host);
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/* Affected kernel version range, distros covered, etc. */
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const struct iamroot_kernel_range *ranges;
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size_t n_ranges;
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};
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```
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Modules register themselves at link time via a constructor-attribute
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table. The top-level `iamroot` binary iterates the registry on each
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invocation.
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## Shared `core/`
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Code that more than one module needs lives in `core/`:
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- `core/common.c` — fingerprinting (kernel version, distro, LSM,
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hardening flags), logging, error handling
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- `core/apparmor_bypass.c` — Ubuntu's
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`apparmor_restrict_unprivileged_userns=1` defeat via
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`change_onexec("crun")` re-exec
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- `core/exploit_su.c` — once we have page-cache-write or
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/etc/passwd-overwrite, this is the shared "drop to root shell"
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helper
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- `core/fcrypt.c` — file-encryption helpers used by multiple modules
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- `core/entrybleed.c` (planned, Phase 3) — kbase leak primitive that
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any module needing KASLR-defeat can call
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## Top-level dispatcher
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`iamroot.c` (planned, Phase 1) is the CLI entry point. Responsibilities:
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1. Parse args (`--scan`, `--exploit <name>`, `--mitigate`,
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`--detect-rules`, `--cleanup`, etc.)
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2. Fingerprint the host
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3. For `--scan`: iterate module registry, call each module's
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`detect()`, emit table of results
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4. For `--exploit <name>`: locate module, gate behind `--i-know`,
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call its `exploit()`
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5. For `--detect-rules`: walk module registry, concatenate detection
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files in the requested format
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## CI matrix
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`.github/workflows/ci.yml` (planned, Phase 4) runs each module's
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test against a matrix of distro × kernel VMs. Each test asserts:
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- on a vulnerable VM: `detect()` returns 1, `exploit()` returns 0
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and produces uid=0
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- on a patched VM: `detect()` returns 0, `exploit()` either refuses
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or fails gracefully
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Failures on a previously-working matrix entry open an issue
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automatically (likely cause: distro shipped a backport that broke
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the module).
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## Adding a new CVE
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1. `git checkout -b add-cve-XXXX-NNNN`
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2. `cp -r modules/_stubs/_template modules/<module_name>`
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3. Fill in `MODULE.md`, `NOTICE.md`, `kernel-range.json`
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4. Implement `module.c` exposing the `iamroot_module` interface
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5. Ship at least one detection rule under `detect/`
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6. Add tests under `tests/`
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7. PR. CI runs the matrix. If it lands root on at least one
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vulnerable matched VM AND fails cleanly on a patched VM, it
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merges.
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See `docs/module-template.md` (planned) for the per-module checklist.
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