fix(trajectory): preserve safe path checks for window writes

src/trajectory/runtime.test.ts

@@ -228,6 +228,30 @@ describe("trajectory runtime", () => {
     expect(raw).toContain("new-recorder");
   });
 
+  it.runIf(process.platform !== "win32")(
+    "refuses runtime capture through symlinked parent directories",
+    async () => {
+      const tmpDir = makeTempDir();
+      const targetDir = path.join(tmpDir, "target");
+      const linkDir = path.join(tmpDir, "link");
+      fs.mkdirSync(targetDir);
+      fs.symlinkSync(targetDir, linkDir);
+      const recorder = createTrajectoryRuntimeRecorder({
+        sessionId: "session-1",
+        sessionFile: path.join(linkDir, "session.jsonl"),
+        maxRuntimeFileBytes: 2_400,
+      });
+
+      const runtimeRecorder = expectTrajectoryRuntimeRecorder(recorder);
+      runtimeRecorder.recordEvent("prompt.submitted", {
+        prompt: "hello",
+      });
+      await runtimeRecorder.flush();
+
+      expect(fs.existsSync(path.join(targetDir, "session.trajectory.jsonl"))).toBe(false);
+    },
+  );
+
   it("describes queued writer state for cleanup timeout logs", () => {
     const recorder = createTrajectoryRuntimeRecorder({
       sessionId: "session-1",

src/trajectory/runtime.ts

@@ -6,7 +6,7 @@ import type {
   QueuedFileWriterDiagnostics,
 } from "../agents/queued-file-writer.js";
 import type { OpenClawConfig } from "../config/types.openclaw.js";
-import { writeSiblingTempFile } from "../infra/fs-safe-advanced.js";
+import { assertNoSymlinkParents, writeSiblingTempFile } from "../infra/fs-safe-advanced.js";
 import { readRegularFileSync } from "../infra/fs-safe.js";
 import { redactSecrets } from "../logging/redact.js";
 import { parseBooleanValue } from "../utils/boolean.js";
@@ -283,10 +283,18 @@ async function replaceTrajectoryWindow(params: {
   appendedLines: string[];
 }): Promise<void> {
   const dir = path.dirname(params.filePath);
+  await fs.promises.mkdir(dir, { recursive: true, mode: 0o700 });
+  await assertNoSymlinkParents({
+    rootDir: path.parse(path.resolve(dir)).root,
+    targetPath: path.resolve(dir),
+    allowMissing: false,
+    allowRootChildSymlink: true,
+    requireDirectories: true,
+    messagePrefix: "Refusing to write trajectory under",
+  });
   const lines = readTrajectoryWindowLines(params.filePath, params.maxFileBytes);
   lines.push(...params.appendedLines);
   trimJsonlWindow(lines, params.maxFileBytes);
-  await fs.promises.mkdir(dir, { recursive: true, mode: 0o700 });
   await writeSiblingTempFile({
     dir,
     chmodDir: false,