Disallow navigations to blob URLs with non-canonical origins.

content/browser/child_process_security_policy_impl.cc

 // Copyright (c) 2012 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/child_process_security_policy_impl.h"
 
 #include <algorithm>
 #include <utility>
 
 #include "base/command_line.h"
@@ skipping 561 matching lines @@
     // Every child process can request <about:blank>.
     if (base::LowerCaseEqualsASCII(url.spec(), url::kAboutBlankURL))
       return true;
     // URLs like <about:version>, <about:crash>, <view-source:...> shouldn't be
     // requestable by any child process.  Also, this case covers
     // <javascript:...>, which should be handled internally by the process and
     // not kicked up to the browser.
     return false;
   }
 
+  // https://crbug.com/646278 Valid blob URLs should contain canonically
+  // serialized origins.
+  if (url.SchemeIsBlob() &&
+      !base::StartsWith(url.GetContent(), url::Origin(url).Serialize() + "/",
+                        base::CompareCase::INSENSITIVE_ASCII)) {
+    return false;
+  }
+
   // If the process can commit the URL, it can request it.
   if (CanCommitURL(child_id, url))
     return true;
 
   // Also allow URLs destined for ShellExecute and not the browser itself.
   return !GetContentClient()->browser()->IsHandledURL(url) &&
          !net::URLRequest::IsHandledURL(url);
 }
 
 bool ChildProcessSecurityPolicyImpl::CanCommitURL(int child_id,
                                                   const GURL& url) {
   if (!url.is_valid())
     return false;  // Can't commit invalid URLs.
 
   // Of all the pseudo schemes, only about:blank is allowed to commit.
   if (IsPseudoScheme(url.scheme()))
     return base::LowerCaseEqualsASCII(url.spec(), url::kAboutBlankURL);
 

[ncarter (slow), 2016/09/16 21:21:03]

Probably need this here too.

[Charlie Reis, 2016/09/16 21:45:02]

Agreed.

   // TODO(creis): Tighten this for Site Isolation, so that a URL from a site
   // that is isolated can only be committed in a process dedicated to that site.
   // CanRequestURL should still allow all web-safe schemes. See
   // https://crbug.com/515309.
   if (IsWebSafeScheme(url.scheme()))
     return true;  // The scheme has been white-listed for every child process.
 
   {
     base::AutoLock lock(lock_);
 
@@ skipping 241 matching lines @@
   base::AutoLock lock(lock_);
 
   SecurityStateMap::iterator state = security_state_.find(child_id);
   if (state == security_state_.end())
     return false;
 
   return state->second->can_send_midi_sysex();
 }
 
 }  // namespace content