CrossSiteResourceHandler: cancel request if the RFH is gone

content/browser/loader/cross_site_resource_handler_browsertest.cc

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/callback.h"
+#include "base/command_line.h"
+#include "base/memory/weak_ptr.h"
+#include "base/single_thread_task_runner.h"
+#include "base/thread_task_runner_handle.h"
+#include "content/browser/frame_host/render_frame_host_impl.h"
+#include "content/browser/loader/resource_dispatcher_host_impl.h"
+#include "content/browser/web_contents/web_contents_impl.h"
+#include "content/common/frame_messages.h"
+#include "content/public/browser/resource_dispatcher_host.h"
+#include "content/public/browser/resource_dispatcher_host_delegate.h"
+#include "content/public/browser/resource_throttle.h"
+#include "content/public/browser/web_contents.h"
+#include "content/public/test/browser_test_utils.h"
+#include "content/public/test/content_browser_test.h"
+#include "content/public/test/content_browser_test_utils.h"
+#include "content/public/test/test_utils.h"
+#include "content/shell/browser/shell.h"
+#include "content/shell/browser/shell_resource_dispatcher_host_delegate.h"
+#include "ipc/ipc_security_test_util.h"
+#include "net/dns/mock_host_resolver.h"
+#include "net/test/embedded_test_server/embedded_test_server.h"
+#include "net/url_request/url_request.h"
+
+namespace content {
+
+namespace {
+
+// A ResourceDispatchHostDelegate that uses ResourceThrottles to pause a
+// targeted request temporarily, to run a chunk of test code.
+class TestResourceDispatcherHostDelegate
+    : public ShellResourceDispatcherHostDelegate {
+ public:
+  using RequestDeferredHook = base::Callback<void(const base::Closure& resume)>;
+  TestResourceDispatcherHostDelegate() : throttle_created_(false) {}
+
+  void RequestBeginning(net::URLRequest* request,
+                        ResourceContext* resource_context,
+                        AppCacheService* appcache_service,
+                        ResourceType resource_type,
+                        ScopedVector<ResourceThrottle>* throttles) override {
+    CHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+    ShellResourceDispatcherHostDelegate::RequestBeginning(
+        request, resource_context, appcache_service, resource_type, throttles);
+    // Expect only a single request for the tracked url.

[nasko, 2015/10/05 18:01:54]

nit: Empty line between code and new comment line.

[ncarter (slow), 2015/10/05 18:31:37]

Done.

+    ASSERT_FALSE(throttle_created_);

[nasko, 2015/10/05 18:01:54]

I don't see how throttle_created_ can actually become true. It is initialized to
false in the constructor and set to false in SetTrackedURLOnIOThread.

[ncarter (slow), 2015/10/05 18:31:37]

Good catch; I think I lose my copy+paste privileges for a week. Fixed.

+    // If this is a request for the tracked URL, add a throttle to track it.
+    if (request->url() == tracked_url_) {
+      throttles->push_back(
+          new DeferStartForTestCallback(request, this, run_on_start_));
+    }
+  }
+
+  // Starts tracking a URL.  The request for previously tracked URL, if any,
+  // must have been made and deleted before calling this function.
+  void SetTrackedURL(const GURL& tracked_url,
+                     const RequestDeferredHook& run_on_start) {
+    CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+    // Should not currently be tracking any URL.
+    ASSERT_FALSE(run_loop_);
+
+    // Create a RunLoop that will be stopped once the request for the tracked
+    // URL has been destroyed, to allow tracking the URL while also waiting for
+    // other events.
+    run_loop_.reset(new base::RunLoop());
+
+    BrowserThread::PostTask(
+        BrowserThread::IO, FROM_HERE,
+        base::Bind(&TestResourceDispatcherHostDelegate::SetTrackedURLOnIOThread,
+                   base::Unretained(this), tracked_url, run_on_start,
+                   run_loop_->QuitClosure()));
+  }
+
+  // Waits until the tracked URL has been requested, and the request for it has
+  // been destroyed.
+  bool WaitForTrackedURLAndGetCompleted() {
+    CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+    run_loop_->Run();
+    run_loop_.reset();
+    return tracked_request_completed_;
+  }
+
+ private:
+  // A ResourceThrottle which defers the request at WillStartRequest time until
+  // a test-supplied callback completes. Notifies |tracker| when the request is
+  // destroyed.
+  class DeferStartForTestCallback : public ResourceThrottle {

[nasko, 2015/10/05 18:01:54]

Shouldn't this class bear some mention of Throttle on its name?

[ncarter (slow), 2015/10/05 18:31:37]

Done.

+   public:
+    DeferStartForTestCallback(net::URLRequest* request,
+                              TestResourceDispatcherHostDelegate* tracker,
+                              const RequestDeferredHook& run_on_start)
+        : request_(request),
+          tracker_(tracker),
+          run_on_start_(run_on_start),
+          weak_factory_(this) {}

[nasko, 2015/10/05 18:01:54]

It seems that this constructor should be setting throttle_created_ to true.

[ncarter (slow), 2015/10/05 18:31:37]

Done.

+
+    void WillStartRequest(bool* defer) override {
+      *defer = true;
+      base::Closure resume_request_on_io_thread = base::Bind(
+          base::IgnoreResult(&BrowserThread::PostTask), BrowserThread::IO,
+          FROM_HERE, base::Bind(&DeferStartForTestCallback::Resume,
+                                weak_factory_.GetWeakPtr()));
+      BrowserThread::PostTask(
+          BrowserThread::UI, FROM_HERE,
+          base::Bind(run_on_start_, resume_request_on_io_thread));
+    }
+
+    ~DeferStartForTestCallback() override {
+      // If the request is deleted without being cancelled, its status will
+      // indicate it succeeded, so have to check if the request is still pending
+      // as well.
+      tracker_->OnTrackedRequestDestroyed(!request_->is_pending() &&
+                                          request_->status().is_success());
+    }
+
+    // ResourceThrottle implementation:
+    const char* GetNameForLogging() const override {
+      return "DeferStartForTestCallback";
+    }
+
+   private:
+    void Resume() { controller()->Resume(); }
+    net::URLRequest* request_;
+    TestResourceDispatcherHostDelegate* tracker_;
+    RequestDeferredHook run_on_start_;
+    base::WeakPtrFactory<DeferStartForTestCallback> weak_factory_;
+
+    DISALLOW_COPY_AND_ASSIGN(DeferStartForTestCallback);
+  };
+
+  void SetTrackedURLOnIOThread(const GURL& tracked_url,
+                               const RequestDeferredHook& run_on_start,
+                               const base::Closure& run_loop_quit_closure) {
+    CHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+    throttle_created_ = false;
+    tracked_url_ = tracked_url;
+    run_on_start_ = run_on_start;
+    run_loop_quit_closure_ = run_loop_quit_closure;
+  }
+
+  void OnTrackedRequestDestroyed(bool completed) {
+    CHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+    tracked_request_completed_ = completed;
+    tracked_url_ = GURL();
+    run_on_start_ = RequestDeferredHook();
+
+    BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
+                            run_loop_quit_closure_);
+  }
+
+  // These live on the IO thread.
+  GURL tracked_url_;
+  bool throttle_created_;
+  base::Closure run_loop_quit_closure_;
+  RequestDeferredHook run_on_start_;
+
+  // This lives on the UI thread.
+  scoped_ptr<base::RunLoop> run_loop_;
+
+  // Set on the IO thread while |run_loop_| is non-NULL, read on the UI thread
+  // after deleting run_loop_.
+  bool tracked_request_completed_;
+
+  DISALLOW_COPY_AND_ASSIGN(TestResourceDispatcherHostDelegate);
+};
+
+class CrossSiteResourceHandlerTest : public ContentBrowserTest {
+ public:
+  CrossSiteResourceHandlerTest() : old_delegate_(NULL) {}
+
+  // ContentBrowserTest implementation:
+  void SetUpOnMainThread() override {
+    BrowserThread::PostTask(
+        BrowserThread::IO, FROM_HERE,
+        base::Bind(
+            &CrossSiteResourceHandlerTest::InjectResourceDispatcherHostDelegate,
+            base::Unretained(this)));
+    host_resolver()->AddRule("*", "127.0.0.1");
+    ASSERT_TRUE(embedded_test_server()->InitializeAndWaitUntilReady());
+    content::SetupCrossSiteRedirector(embedded_test_server());
+  }
+
+  void TearDownOnMainThread() override {
+    BrowserThread::PostTask(
+        BrowserThread::IO, FROM_HERE,
+        base::Bind(&CrossSiteResourceHandlerTest::
+                       RestoreResourceDispatcherHostDelegate,
+                   base::Unretained(this)));
+  }
+
+ protected:
+  void SetUpCommandLine(base::CommandLine* command_line) override {
+    IsolateAllSitesForTesting(command_line);
+  }
+
+  void InjectResourceDispatcherHostDelegate() {
+    DCHECK_CURRENTLY_ON(BrowserThread::IO);
+    old_delegate_ = ResourceDispatcherHostImpl::Get()->delegate();
+    ResourceDispatcherHostImpl::Get()->SetDelegate(&tracking_delegate_);
+  }
+
+  void RestoreResourceDispatcherHostDelegate() {
+    DCHECK_CURRENTLY_ON(BrowserThread::IO);
+    ResourceDispatcherHostImpl::Get()->SetDelegate(old_delegate_);
+    old_delegate_ = NULL;

[nasko, 2015/10/05 18:01:54]

nullptr

[ncarter (slow), 2015/10/05 18:31:37]

Done, everywhere.

+  }
+
+  TestResourceDispatcherHostDelegate& tracking_delegate() {
+    return tracking_delegate_;
+  }
+
+ private:
+  TestResourceDispatcherHostDelegate tracking_delegate_;
+  ResourceDispatcherHostDelegate* old_delegate_;
+};
+
+void SimulateMaliciousFrameDetachOnUIThread(int render_process_id,
+                                            int frame_routing_id,
+                                            const base::Closure& done_cb) {
+  RenderFrameHostImpl* rfh =
+      RenderFrameHostImpl::FromID(render_process_id, frame_routing_id);
+  CHECK(rfh);
+
+  // Inject a frame detach message. An attacker-controlled renderer could do
+  // this without also cancelling the pending navigation (as blink would, if you
+  // removed the iframe from the document via js).
+  rfh->OnMessageReceived(FrameHostMsg_Detach(frame_routing_id));
+  done_cb.Run();
+}
+
+}  // namespace
+
+IN_PROC_BROWSER_TEST_F(CrossSiteResourceHandlerTest,
+                       NoDeliveryToDetachedFrame) {
+  GURL attacker_page = embedded_test_server()->GetURL(
+      "evil.com", "/cross_site_iframe_factory.html?evil(evil)");
+  NavigateToURL(shell(), attacker_page);
+
+  FrameTreeNode* root = static_cast<WebContentsImpl*>(shell()->web_contents())
+                            ->GetFrameTree()
+                            ->root();
+
+  RenderFrameHost* child_frame = root->child_at(0)->current_frame_host();
+
+  // Attacker initiates a navigation to a cross-site document. Under --site-per-
+  // process, these bytes must not be sent to the attacker process.
+  GURL target_resource =
+      embedded_test_server()->GetURL("a.com", "/title1.html");
+
+  // We add a testing hook to simulate the attacker-controlled process sending
+  // FrameHostMsg_Detach before the http response arrives. At the time this test
+  // was written, the resource request had a lifetime separate from the RFH,
+  tracking_delegate().SetTrackedURL(
+      target_resource, base::Bind(&SimulateMaliciousFrameDetachOnUIThread,
+                                  child_frame->GetProcess()->GetID(),
+                                  child_frame->GetRoutingID()));
+  ExecuteScript(
+      shell()->web_contents()->GetMainFrame(),
+      base::StringPrintf("document.getElementById('child-0').src='%s'",
+                         target_resource.spec().c_str()));
+
+  // Wait for the scenario to play out. If this returns false, it means the
+  // request did not succeed, which is good in this case.
+  EXPECT_FALSE(tracking_delegate().WaitForTrackedURLAndGetCompleted())
+      << "Request should have been cancelled before reaching the renderer.";
+}
+
+}  // namespace content