<html>
    <head>
      <base href="https://llvm.org/bugs/" />
    </head>
    <body><table border="1" cellspacing="0" cellpadding="8">
        <tr>
          <th>Bug ID</th>
          <td><a class="bz_bug_link 
          bz_status_NEW "
   title="NEW --- - possible overflow issue in std::allocator::allocate"
   href="https://llvm.org/bugs/show_bug.cgi?id=26812">26812</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>possible overflow issue in std::allocator::allocate
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>libc++
          </td>
        </tr>

        <tr>
          <th>Version</th>
          <td>3.8
          </td>
        </tr>

        <tr>
          <th>Hardware</th>
          <td>PC
          </td>
        </tr>

        <tr>
          <th>OS</th>
          <td>All
          </td>
        </tr>

        <tr>
          <th>Status</th>
          <td>NEW
          </td>
        </tr>

        <tr>
          <th>Severity</th>
          <td>normal
          </td>
        </tr>

        <tr>
          <th>Priority</th>
          <td>P
          </td>
        </tr>

        <tr>
          <th>Component</th>
          <td>All Bugs
          </td>
        </tr>

        <tr>
          <th>Assignee</th>
          <td>unassignedclangbugs@nondot.org
          </td>
        </tr>

        <tr>
          <th>Reporter</th>
          <td>ionelpopescu97@yahoo.com
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>llvm-bugs@lists.llvm.org, mclow.lists@gmail.com
          </td>
        </tr>

        <tr>
          <th>Classification</th>
          <td>Unclassified
          </td>
        </tr></table>
      <p>
        <div>
        <pre>std::allocator::allocate is currently implemented like this:

_LIBCPP_INLINE_VISIBILITY pointer allocate(size_type __n,
allocator<void>::const_pointer = 0)
{return static_cast<pointer>(_VSTD::__allocate(__n * sizeof(_Tp)));}

If __n > allocator::max_size() this will cause an overflow ant the result will
not be throwing a std::bad_alloc, but instead it will allocate a size
determined by overflow.

It should be better implemented like this:
_LIBCPP_INLINE_VISIBILITY pointer allocate(size_type __n,
allocator<void>::const_pointer = 0)
{
    if (__n > max_size()) {
#ifndef _LIBCPP_NO_EXCEPTIONS
        throw std::bad_alloc();
#endif
    }
    return static_cast<pointer>(_VSTD::__allocate(__n * sizeof(_Tp)));
}</pre>
        </div>
      </p>
      <hr>
      <span>You are receiving this mail because:</span>
      
      <ul>
          <li>You are on the CC list for the bug.</li>
      </ul>
    </body>
</html>