fix(sandbox): validate remote hardlink counts

src/agents/sandbox/remote-fs-bridge.test.ts

@@ -232,6 +232,56 @@ describe("remote sandbox fs bridge", () => {
       });
     });
   });
+
+  it("does not reject malformed non-decimal hardlink counts", async () => {
+    await withTempDir("openclaw-remote-fs-bridge-hardlink-", async (stateDir) => {
+      const workspaceDir = path.join(stateDir, "workspace");
+      await fs.mkdir(workspaceDir, { recursive: true });
+      const runtime: RemoteShellSandboxHandle = {
+        remoteWorkspaceDir: workspaceDir,
+        remoteAgentWorkspaceDir: workspaceDir,
+        runRemoteShellScript: async (command) => {
+          if (command.script.includes('if [ -e "$1" ] || [ -L "$1" ]')) {
+            return { stdout: Buffer.from("1\n"), stderr: Buffer.alloc(0), code: 0 };
+          }
+          if (command.script.includes('readlink -f -- "$cursor"')) {
+            return {
+              stdout: Buffer.from(`${workspaceDir}/note.txt\n`),
+              stderr: Buffer.alloc(0),
+              code: 0,
+            };
+          }
+          if (command.script.includes('stat -c "%F|%h"')) {
+            return {
+              stdout: Buffer.from("regular file|0x2\n"),
+              stderr: Buffer.alloc(0),
+              code: 0,
+            };
+          }
+          if (command.script.includes('stat -c "%F|%s|%y"')) {
+            return {
+              stdout: Buffer.from("regular file|12|2026-05-29 12:00:00.000000000 +0000\n"),
+              stderr: Buffer.alloc(0),
+              code: 0,
+            };
+          }
+          throw new Error(`unexpected remote script: ${command.script}`);
+        },
+      };
+      const bridge = createRemoteShellSandboxFsBridge({
+        sandbox: createSandbox({
+          workspaceDir,
+          agentWorkspaceDir: workspaceDir,
+        }),
+        runtime,
+      });
+
+      await expect(bridge.stat({ filePath: "note.txt" })).resolves.toMatchObject({
+        type: "file",
+        size: 12,
+      });
+    });
+  });
 });
 
 async function withTempDir<T>(prefix: string, run: (stateDir: string) => Promise<T>): Promise<T> {

src/agents/sandbox/remote-fs-bridge.ts

@@ -1,4 +1,5 @@
 import path from "node:path";
+import { parseStrictNonNegativeInteger } from "../../infra/parse-finite-number.js";
 import { isPathInside } from "../../infra/path-guards.js";
 import type {
   SandboxBackendCommandParams,
@@ -24,6 +25,14 @@ type ResolvedRemotePath = SandboxResolvedPath & {
   source: RemoteMountSource;
 };
 
+function hasMultipleHardlinks(raw: string): boolean {
+  const linkCount = parseStrictNonNegativeInteger(raw);
+  if (linkCount !== undefined) {
+    return linkCount > 1;
+  }
+  return /^\d+$/.test(raw);
+}
+
 type MountInfo = {
   localRoot: string;
   containerRoot: string;
@@ -513,7 +522,7 @@ class RemoteShellSandboxFsBridge implements SandboxFsBridge {
       return;
     }
     const [kind = "", linksRaw = "1"] = output.split("|");
-    if (kind === "regular file" && Number(linksRaw) > 1) {
+    if (kind === "regular file" && hasMultipleHardlinks(linksRaw)) {
       throw new Error(
         `Hardlinked path is not allowed under sandbox mount root: ${params.containerPath}`,
       );