Disk cache: Add a check to make sure that the index table mask is not bigger ...

net/disk_cache/backend_impl.cc

 // Copyright (c) 2006-2008 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 "net/disk_cache/backend_impl.h"
 
 #include "base/file_util.h"
 #include "base/histogram.h"
 #include "base/message_loop.h"
 #include "base/string_util.h"
@@ skipping 828 matching lines @@
 }
 
 void BackendImpl::PrepareForRestart() {
   data_->header.crash = 0;
   index_ = NULL;
   data_ = NULL;
   block_files_.CloseFiles();
   rankings_.Reset();
   init_ = false;
   restarted_ = true;
+
+  // TODO(rvargas): remove this line at the end of this experiment.
+  max_size_ = 0;
 }
 
 int BackendImpl::NewEntry(Addr address, EntryImpl** entry, bool* dirty) {
   scoped_refptr<EntryImpl> cache_entry(new EntryImpl(this, address));
   IncreaseNumRefs();
   *entry = NULL;
 
   if (!address.is_initialized() || address.is_separate_file() ||
       address.file_type() != BLOCK_256) {
     LOG(WARNING) << "Wrong entry address.";
@@ skipping 227 matching lines @@
     return false;
   }
 
   if (current_size < GetIndexSize(data_->header.table_len) ||
       data_->header.table_len & (kBaseTableLen - 1)) {
     LOG(ERROR) << "Corrupt Index file";
     return false;
   }
 
   AdjustMaxCacheSize(data_->header.table_len);
-  
+
   // We need to avoid integer overflows.
   DCHECK(max_size_ < kint32max - kint32max / 10);
   if (data_->header.num_bytes < 0 ||
       data_->header.num_bytes > max_size_ + max_size_ / 10) {
     LOG(ERROR) << "Invalid cache (current) size";
     return false;
   }
 
   if (data_->header.num_entries < 0) {
     LOG(ERROR) << "Invalid number of entries";
     return false;
   }
 
   if (!mask_)
     mask_ = data_->header.table_len - 1;
 
+  // TODO(rvargas): remove this. For some reason, we are receiving crashes with
+  // mask_ being bigger than the actual table length. (bug 7217).
+  if (mask_ > 0xffff) {
+    LOG(ERROR) << "Invalid cache mask";
+    ReportError(ERR_INVALID_MASK);
+    return false;
+  }
+
   return true;
 }
 
 int BackendImpl::CheckAllEntries() {
   int num_dirty = 0;
   int num_entries = 0;
   DCHECK(mask_ < kuint32max);
   for (int i = 0; i <= static_cast<int>(mask_); i++) {
     Addr address(data_->table[i]);
     if (!address.is_initialized())
@@ skipping 27 matching lines @@
 
   return num_dirty;
 }
 
 bool BackendImpl::CheckEntry(EntryImpl* cache_entry) {
   RankingsNode* rankings = cache_entry->rankings()->Data();
   return !rankings->pointer;
 }
 
 }  // namespace disk_cache