From da79ea0baa1abdfcbf0547c56727f3b141e8465f Mon Sep 17 00:00:00 2001
From: Jiabin Yin <54463072+Nolkee@users.noreply.github.com>
Date: Thu, 5 Nov 2026 18:33:36 +0800
Subject: [PATCH] fix(il2cpp): reject module image references outside retained
 inventory (#8956)

---
 .../analysisView/il2cppMetadataView.test.ts   | 28 ++++++++
 src/domain/il2cpp/il2cppMetadata.ts           |  8 +++
 tests/acceptance/il2cppMetadataCli.test.ts    | 67 +++++++++++++++++++
 3 files changed, 103 insertions(+)

diff --git a/src/domain/analysisView/il2cppMetadataView.test.ts b/src/domain/analysisView/il2cppMetadataView.test.ts
index 23e27840fc..8b5a0c59d7 100644
--- a/src/domain/analysisView/il2cppMetadataView.test.ts
+++ b/src/domain/analysisView/il2cppMetadataView.test.ts
@@ -482,6 +482,34 @@ const linkedReport = (): Il2cppMetadata => ({
   parameter_types: [{ type: 0, name: "int" }],
 });
 
+it.each([-1, 1, 99])(
+  "rejects imported code-generation module image reference %i",
+  (image) => {
+    const value = linkedReport();
+    value.binary!.code_gen_modules[0]!.image = image;
+    const parsed = il2cppMetadataParentSchema.safeParse(value);
+    expect(parsed.success).toBe(false);
+    if (!parsed.success)
+      expect(parsed.error.issues).toEqual(
+        expect.arrayContaining([
+          expect.objectContaining({
+            path: ["binary", "code_gen_modules", 0, "image"],
+          }),
+        ]),
+      );
+    for (const selection of [{}, { image_indices: [image] }]) {
+      const view = projectIl2cppMetadataView(parent(value, false), {
+        kind: "il2cpp-metadata",
+        collection: "code_gen_modules",
+        ...selection,
+        offset: 0,
+        limit: 64,
+      });
+      expect(view.ok).toBe(false);
+    }
+  },
+);
+
 it("selects every folded method by numeric address with stable indices and both source identities", () => {
   const source = parent(freezeJsonSnapshot(linkedReport()), true);
   const view = projectIl2cppMetadataView(source, {
diff --git a/src/domain/il2cpp/il2cppMetadata.ts b/src/domain/il2cpp/il2cppMetadata.ts
index 2599df5f9a..e8e88df6a0 100644
--- a/src/domain/il2cpp/il2cppMetadata.ts
+++ b/src/domain/il2cpp/il2cppMetadata.ts
@@ -444,6 +444,14 @@ const validateMetadataFacts = (
               "Type reference is outside the linked type table or names an unavailable type.",
           });
       });
+  report.binary?.code_gen_modules.forEach((row, index) => {
+    if (row.image >= report.images.length)
+      context.addIssue({
+        code: "custom",
+        path: ["binary", "code_gen_modules", index, "image"],
+        message: "Code-generation module image is outside the retained images.",
+      });
+  });
   report.method_addresses?.forEach((row, index) => {
     if (codeRowContradicts(row, report.binary?.image_base))
       context.addIssue({
diff --git a/tests/acceptance/il2cppMetadataCli.test.ts b/tests/acceptance/il2cppMetadataCli.test.ts
index 0327902d1f..89c0530704 100644
--- a/tests/acceptance/il2cppMetadataCli.test.ts
+++ b/tests/acceptance/il2cppMetadataCli.test.ts
@@ -56,6 +56,73 @@ const parseMetadataSummary = (value: unknown) =>
     parseEvidence(value).normalized_result,
   );
 
+cliTest(
+  "rejects out-of-range module image references through CLI and MCP",
+  async ({ cli }) => {
+    const root = await createTestTempDirectory("rea-il2cpp-module-image-");
+    const path = join(root, "global-metadata.dat");
+    const binaryPath = join(root, "GameAssembly.dylib");
+    await writeFile(
+      path,
+      createLinkedIl2cppMetadataFixture({ version: 39 }).bytes,
+    );
+    await writeFile(binaryPath, createIl2cppBinaryFixture());
+    const produced = await runFileCli(cli, {
+      arguments: [
+        "inspect-il2cpp-metadata",
+        path,
+        "--binary",
+        binaryPath,
+        "--detail",
+        "complete",
+        "--json",
+      ],
+    });
+    expect(produced.exitCode, produced.stderr).toBe(0);
+    const original = parseCliMetadata(produced.json);
+    expect(original.binary!.code_gen_modules.length).toBeGreaterThan(0);
+    const { call } = await connectLocalToolsMcp();
+    for (const image of [
+      0,
+      original.images.length - 1,
+      -1,
+      original.images.length,
+      99,
+    ]) {
+      const report = structuredClone(original);
+      report.binary!.code_gen_modules[0]!.image = image;
+      const evidence = createEvidence(
+        { path, format: "file", sha256: report.artifact.sha256 },
+        { id: "il2cpp-metadata", name: "IL2CPP", version: "1" },
+        {
+          operation: "inspect_il2cpp_metadata",
+          parameters: { path },
+          result: report,
+        },
+      );
+      const request = {
+        source: { kind: "inline", evidence },
+        view: { kind: "il2cpp-metadata", collection: "code_gen_modules" },
+      };
+      const query = join(root, `image-${image}.json`);
+      await writeFile(query, JSON.stringify(request));
+      const result = await runFileCli(cli, {
+        arguments: ["inspect-analysis-view", query, "--json"],
+      });
+      const mcp = await call("inspect_analysis_view", request);
+      if (image >= 0 && image < original.images.length) {
+        expect(result.exitCode, result.stderr).toBe(0);
+        expect(mcp.isError, JSON.stringify(mcp)).not.toBe(true);
+      } else {
+        expect(result.exitCode, `image ${image}`).toBe(1);
+        expect(result.json).toMatchObject({ code: "invalid_request" });
+        expect(parseMcpToolError(mcp).error.code).toBe("invalid_request");
+      }
+    }
+  },
+  30000,
+);
+
 cliTest(
   "rejects impossible imported metadata owners through CLI and MCP",
   async ({ cli }) => {