Disallow was_within_same_page = true for a cross-process navigation.

content/browser/frame_host/navigator_impl.cc

 // Copyright 2013 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 "content/browser/frame_host/navigator_impl.h"
 
 #include <utility>
 
 #include "base/metrics/histogram.h"
 #include "base/time/time.h"
@@ skipping 420 matching lines @@
 }
 
 void NavigatorImpl::DidNavigate(
     RenderFrameHostImpl* render_frame_host,
     const FrameHostMsg_DidCommitProvisionalLoad_Params& params) {
   FrameTree* frame_tree = render_frame_host->frame_tree_node()->frame_tree();
   bool oopifs_possible = SiteIsolationPolicy::AreCrossProcessFramesPossible();
 
   bool is_navigation_within_page = controller_->IsURLInPageNavigation(
       params.url, params.was_within_same_page, render_frame_host);
+
+  // If a frame claims it navigated within page, it must be the current frame,
+  // not a pending one.
+  if (is_navigation_within_page &&
+      render_frame_host !=
+          render_frame_host->frame_tree_node()
+              ->render_manager()
+              ->current_frame_host()) {
+    bad_message::ReceivedBadMessage(render_frame_host->GetProcess(),
+                                    bad_message::NC_IN_PAGE_NAVIGATION);
+    is_navigation_within_page = false;
+  }
+
   if (ui::PageTransitionIsMainFrame(params.transition)) {
     if (delegate_) {
       // When overscroll navigation gesture is enabled, a screenshot of the page
       // in its current state is taken so that it can be used during the
       // nav-gesture. It is necessary to take the screenshot here, before
       // calling RenderFrameHostManager::DidNavigateMainFrame, because that can
       // change WebContents::GetRenderViewHost to return the new host, instead
       // of the one that may have just been swapped out.
       if (delegate_->CanOverscrollContent()) {
         // Don't take screenshots if we are staying on the same page. We want
@@ skipping 587 matching lines @@
       entry->set_should_replace_entry(pending_entry->should_replace_entry());
       entry->SetRedirectChain(pending_entry->GetRedirectChain());
     }
     controller_->SetPendingEntry(std::move(entry));
     if (delegate_)
       delegate_->NotifyChangedNavigationState(content::INVALIDATE_TYPE_URL);
   }
 }
 
 }  // namespace content