Check the response URL origin in BufferedDataSource to avoid mixing cross-origin responses.

media/blink/buffered_data_source.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 "media/blink/buffered_data_source.h"
 
 #include "base/bind.h"
 #include "base/callback_helpers.h"
 #include "base/location.h"
 #include "base/single_thread_task_runner.h"
@@ skipping 338 matching lines @@
 
   bool init_cb_is_null = false;
   {
     base::AutoLock auto_lock(lock_);
     init_cb_is_null = init_cb_.is_null();
   }
   if (init_cb_is_null) {
     loader_->Stop();
     return;
   }
+  response_original_url_ = loader_->response_original_url();
 
   // All responses must be successful. Resources that are assumed to be fully
   // buffered must have a known content length.
   bool success = status == BufferedResourceLoader::kOk &&
                  (!assume_fully_buffered() ||
                   loader_->instance_size() != kPositionNotSpecified);
 
   if (success) {
     total_bytes_ = loader_->instance_size();
     streaming_ =
@@ skipping 27 matching lines @@
                                    loader_->range_supported());
   }
 
   base::ResetAndReturn(&init_cb_).Run(success);
 }
 
 void BufferedDataSource::PartialReadStartCallback(
     BufferedResourceLoader::Status status) {
   DCHECK(render_task_runner_->BelongsToCurrentThread());
   DCHECK(loader_.get());
-
-  if (status == BufferedResourceLoader::kOk) {
+  if (status == BufferedResourceLoader::kOk &&
+      CheckPartialResponseURL(loader_->response_original_url())) {
     // Once the request has started successfully, we can proceed with
     // reading from it.
     ReadInternal();
     return;
   }
 
   // Stop the resource loader since we have received an error.
   loader_->Stop();
 
   // TODO(scherkus): we shouldn't have to lock to signal host(), see
   // http://crbug.com/113712 for details.
   base::AutoLock auto_lock(lock_);
   if (stop_signal_received_)
     return;
   ReadOperation::Run(read_op_.Pass(), kReadError);
 }
 
+bool BufferedDataSource::CheckPartialResponseURL(
+    const GURL& partial_response_original_url) const {
+  // We check the redirected URL of partial responses in case malicious
+  // attackers scan the bytes of other origin resources by mixing their
+  // generated bytes and the target response. See http://crbug.com/489060#c32
+  // for details.
+  // If the origin of the new response is different from the first response we
+  // deny the redirected response.
+  return response_original_url_.GetOrigin() ==
+         partial_response_original_url.GetOrigin();
+}
+
 void BufferedDataSource::ReadCallback(
     BufferedResourceLoader::Status status,
     int bytes_read) {
   DCHECK(render_task_runner_->BelongsToCurrentThread());
 
   // TODO(scherkus): we shouldn't have to lock to signal host(), see
   // http://crbug.com/113712 for details.
   base::AutoLock auto_lock(lock_);
   if (stop_signal_received_)
     return;
@@ skipping 116 matching lines @@
   }
 
   // If media is currently playing or the page indicated preload=auto or the
   // the server does not support the byte range request or we do not want to go
   // too far ahead of the read head, use threshold strategy to enable/disable
   // deferring when the buffer is full/depleted.
   loader_->UpdateDeferStrategy(BufferedResourceLoader::kCapacityDefer);
 }
 
 }  // namespace media