fix(memory): block extra path symlink traversal

samzong · steipete · commit c6748a8eebb2 · 2026-05-11T12:34:01.000+01:00
## Considered and deferred

- packages/memory-host-sdk/src/host/read-file.ts:77 [BOT-SCOPE]: Fully race-proof parent traversal would need a lower-level pinned/openat-style primitive; this diff fixes static symlink traversal and rejects symlink components before read.
diff --git a/packages/memory-host-sdk/src/host/fs-utils.ts b/packages/memory-host-sdk/src/host/fs-utils.ts
@@ -1,7 +1,8 @@
 import { configureFsSafePython } from "@openclaw/fs-safe/config";
 export { root } from "@openclaw/fs-safe/root";
-export { isPathInside } from "@openclaw/fs-safe/path";
+export { isPathInside, isPathInsideWithRealpath } from "@openclaw/fs-safe/path";
 export {
+  assertNoSymlinkParents,
   readRegularFile,
   statRegularFile,
   type RegularFileStatResult,
diff --git a/packages/memory-host-sdk/src/host/read-file.test.ts b/packages/memory-host-sdk/src/host/read-file.test.ts
@@ -0,0 +1,99 @@
+import fs from "node:fs/promises";
+import os from "node:os";
+import path from "node:path";
+import { describe, expect, it } from "vitest";
+import { readMemoryFile } from "./read-file.js";
+
+async function createDirectorySymlink(target: string, linkPath: string): Promise<boolean> {
+  try {
+    await fs.symlink(target, linkPath, "dir");
+    return true;
+  } catch (err) {
+    const code = (err as NodeJS.ErrnoException).code;
+    if (code === "EPERM" || code === "EACCES") {
+      return false;
+    }
+    throw err;
+  }
+}
+
+describe("readMemoryFile", () => {
+  it("returns empty text for missing files under extra path directories", async () => {
+    const tmpRoot = await fs.mkdtemp(path.join(os.tmpdir(), "memory-read-file-"));
+    try {
+      const workspaceDir = path.join(tmpRoot, "workspace");
+      const extraDir = path.join(tmpRoot, "extra");
+      const missingPath = path.join(extraDir, "missing.md");
+      await fs.mkdir(workspaceDir, { recursive: true });
+      await fs.mkdir(extraDir, { recursive: true });
+
+      const result = await readMemoryFile({
+        workspaceDir,
+        extraPaths: [extraDir],
+        relPath: missingPath,
+      });
+
+      expect(result).toEqual({
+        text: "",
+        path: path.relative(workspaceDir, missingPath).replace(/\\/g, "/"),
+      });
+    } finally {
+      await fs.rm(tmpRoot, { recursive: true, force: true });
+    }
+  });
+
+  it("rejects extra path reads through symlinked directory components", async () => {
+    const tmpRoot = await fs.mkdtemp(path.join(os.tmpdir(), "memory-read-file-"));
+    try {
+      const workspaceDir = path.join(tmpRoot, "workspace");
+      const extraDir = path.join(tmpRoot, "extra");
+      const outsideDir = path.join(tmpRoot, "outside");
+      await fs.mkdir(workspaceDir, { recursive: true });
+      await fs.mkdir(extraDir, { recursive: true });
+      await fs.mkdir(outsideDir, { recursive: true });
+      await fs.writeFile(path.join(extraDir, "inside.md"), "inside", "utf-8");
+      await fs.writeFile(path.join(outsideDir, "private.md"), "private", "utf-8");
+
+      const inside = await readMemoryFile({
+        workspaceDir,
+        extraPaths: [extraDir],
+        relPath: path.join(extraDir, "inside.md"),
+      });
+      expect(inside.text).toBe("inside");
+
+      const insideLinkPath = path.join(extraDir, "inside-link");
+      if (!(await createDirectorySymlink(extraDir, insideLinkPath))) {
+        return;
+      }
+      await expect(
+        readMemoryFile({
+          workspaceDir,
+          extraPaths: [extraDir],
+          relPath: path.join(insideLinkPath, "inside.md"),
+        }),
+      ).rejects.toThrow("path required");
+
+      const outsideLinkPath = path.join(extraDir, "link");
+      if (!(await createDirectorySymlink(outsideDir, outsideLinkPath))) {
+        return;
+      }
+
+      await expect(
+        readMemoryFile({
+          workspaceDir,
+          extraPaths: [extraDir],
+          relPath: path.join(outsideLinkPath, "private.md"),
+        }),
+      ).rejects.toThrow("path required");
+      await expect(
+        readMemoryFile({
+          workspaceDir,
+          extraPaths: [extraDir],
+          relPath: path.join(outsideLinkPath, "missing.md"),
+        }),
+      ).rejects.toThrow("path required");
+    } finally {
+      await fs.rm(tmpRoot, { recursive: true, force: true });
+    }
+  });
+});
diff --git a/packages/memory-host-sdk/src/host/read-file.ts b/packages/memory-host-sdk/src/host/read-file.ts
@@ -7,8 +7,10 @@ import {
   type OpenClawConfig,
 } from "./config-utils.js";
 import {
+  assertNoSymlinkParents,
   isFileMissingError,
   isPathInside,
+  isPathInsideWithRealpath,
   readRegularFile,
   root,
   statRegularFile,
@@ -20,6 +22,29 @@ import {
   type MemoryReadResult,
 } from "./read-file-shared.js";
 
+async function isAllowedAdditionalDirectoryPath(
+  additionalPath: string,
+  absPath: string,
+): Promise<boolean> {
+  if (!isPathInside(additionalPath, absPath)) {
+    return false;
+  }
+  try {
+    await assertNoSymlinkParents({ rootDir: additionalPath, targetPath: absPath });
+  } catch {
+    return false;
+  }
+  if (!isPathInsideWithRealpath(additionalPath, absPath)) {
+    try {
+      await fs.lstat(absPath);
+    } catch (err) {
+      return isFileMissingError(err);
+    }
+    return false;
+  }
+  return true;
+}
+
 export async function readMemoryFile(params: {
   workspaceDir: string;
   extraPaths?: string[];
@@ -49,7 +74,7 @@ export async function readMemoryFile(params: {
           continue;
         }
         if (stat.isDirectory()) {
-          if (isPathInside(additionalPath, absPath)) {
+          if (await isAllowedAdditionalDirectoryPath(additionalPath, absPath)) {
             const candidateStat = await fs.lstat(absPath).catch(() => null);
             if (candidateStat?.isSymbolicLink()) {
               continue;
