fix(security): harden archive extraction (#16203)

* fix(browser): confine upload paths for file chooser

* fix(browser): sanitize suggested download filenames

* chore(lint): avoid control regex in download sanitizer

* test(browser): cover absolute escape paths

* docs(browser): update upload example path

* refactor(browser): centralize upload path confinement

* fix(infra): harden tmp dir selection

* fix(security): harden archive extraction

* fix(infra): harden tar extraction filter

src/browser/paths.ts

@@ -0,0 +1,49 @@
+import path from "node:path";
+import { resolvePreferredOpenClawTmpDir } from "../infra/tmp-openclaw-dir.js";
+
+export const DEFAULT_BROWSER_TMP_DIR = resolvePreferredOpenClawTmpDir();
+export const DEFAULT_TRACE_DIR = DEFAULT_BROWSER_TMP_DIR;
+export const DEFAULT_DOWNLOAD_DIR = path.join(DEFAULT_BROWSER_TMP_DIR, "downloads");
+export const DEFAULT_UPLOAD_DIR = path.join(DEFAULT_BROWSER_TMP_DIR, "uploads");
+
+export function resolvePathWithinRoot(params: {
+  rootDir: string;
+  requestedPath: string;
+  scopeLabel: string;
+  defaultFileName?: string;
+}): { ok: true; path: string } | { ok: false; error: string } {
+  const root = path.resolve(params.rootDir);
+  const raw = params.requestedPath.trim();
+  if (!raw) {
+    if (!params.defaultFileName) {
+      return { ok: false, error: "path is required" };
+    }
+    return { ok: true, path: path.join(root, params.defaultFileName) };
+  }
+  const resolved = path.resolve(root, raw);
+  const rel = path.relative(root, resolved);
+  if (!rel || rel.startsWith("..") || path.isAbsolute(rel)) {
+    return { ok: false, error: `Invalid path: must stay within ${params.scopeLabel}` };
+  }
+  return { ok: true, path: resolved };
+}
+
+export function resolvePathsWithinRoot(params: {
+  rootDir: string;
+  requestedPaths: string[];
+  scopeLabel: string;
+}): { ok: true; paths: string[] } | { ok: false; error: string } {
+  const resolvedPaths: string[] = [];
+  for (const raw of params.requestedPaths) {
+    const pathResult = resolvePathWithinRoot({
+      rootDir: params.rootDir,
+      requestedPath: raw,
+      scopeLabel: params.scopeLabel,
+    });
+    if (!pathResult.ok) {
+      return { ok: false, error: pathResult.error };
+    }
+    resolvedPaths.push(pathResult.path);
+  }
+  return { ok: true, paths: resolvedPaths };
+}