fix(desktop): deny shell cwd outside bot computer home

Remove hostRoots from this-mac desktop sandbox so shell execution stays
inside the bot computer workspace, matching container path rules.

Add resolveDesktopExecuteCwd to map virtual /home/rakazo paths onto the
local home and reject host-absolute cwd requests via containment checks.

Co-authored-by: cynarAI <cynarAI@users.noreply.github.com>

packages/adapters/src/desktop-sandbox-paths.test.ts

@@ -1,8 +1,44 @@
+import { mkdtempSync, rmSync } from "node:fs";
+import { tmpdir } from "node:os";
 import path from "node:path";
-import { describe, expect, it } from "vitest";
-import { isAllowedDesktopPath, normalizeDesktopWorkspacePath } from "./desktop-sandbox-paths.js";
+import { afterAll, describe, expect, it } from "vitest";
+import {
+  isAllowedDesktopPath,
+  normalizeDesktopWorkspacePath,
+  resolveDesktopExecuteCwd,
+} from "./desktop-sandbox-paths.js";
 
 describe("desktop sandbox path rules", () => {
+  const home = mkdtempSync(path.join(tmpdir(), "rakazo-desktop-home-"));
+
+  afterAll(() => {
+    rmSync(home, { recursive: true, force: true });
+  });
+
+  it("resolves shell cwd inside the computer home", () => {
+    expect(resolveDesktopExecuteCwd(undefined, home)).toBe(home);
+    expect(resolveDesktopExecuteCwd(".", home)).toBe(home);
+    expect(resolveDesktopExecuteCwd("/home/rakazo", home)).toBe(home);
+    expect(resolveDesktopExecuteCwd("notes/result.txt", home)).toBe(
+      path.join(home, "notes/result.txt"),
+    );
+    expect(resolveDesktopExecuteCwd("/home/rakazo/notes/result.txt", home)).toBe(
+      path.join(home, "notes/result.txt"),
+    );
+  });
+
+  it("denies host-absolute shell cwd outside the computer home", () => {
+    const outside = path.join(tmpdir(), "outside");
+    const cwd = resolveDesktopExecuteCwd(outside, home);
+    expect(isAllowedDesktopPath(cwd, [home])).toBe(false);
+    expect(isAllowedDesktopPath(resolveDesktopExecuteCwd("/etc", home), [home])).toBe(false);
+  });
+
+  it("rejects traversal in shell cwd requests", () => {
+    expect(() => resolveDesktopExecuteCwd("../outside", home)).toThrow(/escapes/i);
+    expect(() => resolveDesktopExecuteCwd("/home/rakazo/../outside", home)).toThrow(/escapes/i);
+  });
+
   it("compares Windows roots case-insensitively without accepting siblings or other drives", () => {
     const roots = ["C:\\Users\\Owner\\Rakazo\\bot"];
 

packages/adapters/src/desktop-sandbox-paths.ts

@@ -10,6 +10,30 @@ export function normalizeDesktopWorkspacePath(value: string, platform = process.
   return normalizeWorkspacePath(value);
 }
 
+/** Map shell cwd requests onto the desktop computer home, matching container rules. */
+export function resolveDesktopExecuteCwd(requestCwd: string | undefined, home: string): string {
+  if (
+    !requestCwd ||
+    requestCwd === "." ||
+    requestCwd === "/" ||
+    requestCwd === "/home/rakazo" ||
+    requestCwd === "/home/user"
+  ) {
+    return home;
+  }
+  if (requestCwd.startsWith("/home/rakazo/")) {
+    return path.join(
+      home,
+      normalizeDesktopWorkspacePath(requestCwd.slice("/home/rakazo/".length)),
+    );
+  }
+  if (path.isAbsolute(requestCwd)) {
+    // Host-absolute paths must not be rebased into the workspace; containment rejects them.
+    return path.resolve(requestCwd);
+  }
+  return path.join(home, normalizeDesktopWorkspacePath(requestCwd));
+}
+
 export function isAllowedDesktopPath(
   target: string,
   roots: string[],

packages/adapters/src/desktop-sandbox.ts

@@ -35,7 +35,11 @@ import {
   normalizeWorkspacePath,
   placeholderObservation,
 } from "./computer-support.js";
-import { isAllowedDesktopPath, normalizeDesktopWorkspacePath } from "./desktop-sandbox-paths.js";
+import {
+  isAllowedDesktopPath,
+  normalizeDesktopWorkspacePath,
+  resolveDesktopExecuteCwd,
+} from "./desktop-sandbox-paths.js";
 import {
   createExclusiveChildViaDirectoryFdWin32,
   mkdirChildViaDirectoryFdWin32,
@@ -61,7 +65,7 @@ interface DesktopBox {
 export class DesktopSandboxProvider implements SandboxProvider {
   readonly boxes = new Map<string, DesktopBox>();
 
-  constructor(private readonly opts: { root?: string; hostRoots?: string[] } = {}) {}
+  constructor(private readonly opts: { root?: string } = {}) {}
 
   describe() {
     return {
@@ -128,8 +132,8 @@ export class DesktopSandboxProvider implements SandboxProvider {
       yield { type: "exit", code: 1 };
       return;
     }
-    const cwd = resolveExecuteCwd(request.cwd, box.home);
-    if (!isAllowedDesktopPath(cwd, this.allowedRoots(box.home))) {
+    const cwd = resolveDesktopExecuteCwd(request.cwd, box.home);
+    if (!isAllowedDesktopPath(cwd, [box.home])) {
       yield { type: "stderr", data: "path is outside this computer's home" };
       yield { type: "exit", code: 1 };
       return;
@@ -302,9 +306,6 @@ export class DesktopSandboxProvider implements SandboxProvider {
     return box;
   }
 
-  private allowedRoots(home: string) {
-    return [home, ...(this.opts.hostRoots ?? [])];
-  }
 }
 
 async function localWorkspaceTarget(home: string, relative: string, mustExist: boolean) {
@@ -683,11 +684,6 @@ async function* walkDesktopWorkspace(home: string, directory: string): AsyncIter
   }
 }
 
-function resolveExecuteCwd(requestCwd: string | undefined, home: string) {
-  if (!requestCwd || requestCwd === "/home/rakazo" || requestCwd === "/home/user") return home;
-  return path.resolve(home, requestCwd);
-}
-
 function runCommand(
   argv: string[],
   cwd: string,

packages/adapters/src/host-aware-sandbox.test.ts

@@ -70,23 +70,26 @@ describe("host-aware sandbox", () => {
     expect(sandbox.pageBrowser).toBeUndefined();
   });
 
-  it("lets this-mac cwd run under a host root", async () => {
-    const desktop = new DesktopSandboxProvider({ hostRoots: [hostRoot] });
+  it("refuses shell cwd outside the bot computer home", async () => {
+    const desktop = new DesktopSandboxProvider();
     const computer = await desktop.provision({ botId: "host", homePath: "/tmp/host-home" }, ctx);
-    let code = 1;
+    let stderr = "";
+    let code = 0;
     for await (const event of desktop.execute(
       computer,
-      { argv: ["echo", "ok"], cwd: hostRoot },
+      { argv: ["echo", "nope"], cwd: hostRoot },
       ctx,
     )) {
+      if (event.type === "stderr") stderr += event.data;
       if (event.type === "exit") code = event.code;
     }
-    expect(code).toBe(0);
+    expect(code).toBe(1);
+    expect(stderr).toMatch(/outside this computer's home/i);
     await desktop.destroy(computer, ctx);
   });
 
-  it("still refuses paths outside home and host roots", async () => {
-    const desktop = new DesktopSandboxProvider({ hostRoots: [hostRoot] });
+  it("still refuses paths outside the bot computer home", async () => {
+    const desktop = new DesktopSandboxProvider();
     const computer = await desktop.provision({ botId: "deny", homePath: "/tmp/deny" }, ctx);
     let stderr = "";
     let code = 0;
@@ -103,6 +106,21 @@ describe("host-aware sandbox", () => {
     await desktop.destroy(computer, ctx);
   });
 
+  it("keeps shell cwd inside the bot computer home", async () => {
+    const desktop = new DesktopSandboxProvider();
+    const computer = await desktop.provision({ botId: "inside", homePath: "/tmp/inside" }, ctx);
+    let code = 1;
+    for await (const event of desktop.execute(
+      computer,
+      { argv: ["echo", "ok"], cwd: "projects/site" },
+      ctx,
+    )) {
+      if (event.type === "exit") code = event.code;
+    }
+    expect(code).toBe(0);
+    await desktop.destroy(computer, ctx);
+  });
+
   it("provisions on the host provider when enabled", async () => {
     const isolated = new FakeSandboxProvider();
     const host = new DesktopSandboxProvider();

packages/adapters/src/host-aware-sandbox.ts

@@ -1,4 +1,3 @@
-import { homedir } from "node:os";
 import type {
   AdapterContext,
   CommandRequest,
@@ -25,19 +24,13 @@ export function createRunSandbox(
   opts: SandboxProviderOptions & { prisma?: PrismaClient },
 ): SandboxProvider {
   if (kind === "desktop") {
-    return new DesktopSandboxProvider({
-      root: opts.dataDir,
-      hostRoots: [homedir()],
-    });
+    return new DesktopSandboxProvider({ root: opts.dataDir });
   }
   const primary = createSandboxProvider(kind, opts);
   if (kind !== "docker" || !opts.prisma) return primary;
   return new HostAwareSandbox(
     primary,
-    new DesktopSandboxProvider({
-      root: opts.dataDir,
-      hostRoots: [homedir()],
-    }),
+    new DesktopSandboxProvider({ root: opts.dataDir }),
     async () => {
       const settings = await opts.prisma!.deploymentSettings.findUnique({
         where: { id: "default" },