Check that we've got a complete header before accessing its fields.

base/pickle.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 "base/pickle.h"
 
 #include <stdlib.h>
 
 #include <algorithm>  // for max()
 #include <limits>
@@ skipping 388 matching lines @@
   return true;
 }
 
 // static
 const char* Pickle::FindNext(size_t header_size,
                              const char* start,
                              const char* end) {
   DCHECK(header_size == AlignInt(header_size, sizeof(uint32)));
   DCHECK(header_size <= static_cast<size_t>(kPayloadUnit));
 
+  if (static_cast<size_t>(end - start) < sizeof(Header))
+    return NULL;
+
   const Header* hdr = reinterpret_cast<const Header*>(start);
   const char* payload_base = start + header_size;
   const char* payload_end = payload_base + hdr->payload_size;
   if (payload_end < payload_base)
     return NULL;
 
   return (payload_end > end) ? NULL : payload_end;
 }