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        <tr>
          <th>Bug ID</th>
          <td><a class="bz_bug_link 
          bz_status_NEW "
   title="NEW - Memory leak for a protected element having pending events in ImageLoader"
   href="https://bugs.webkit.org/show_bug.cgi?id=146538">146538</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>Memory leak for a protected element having pending events in ImageLoader
          </td>
        </tr>

        <tr>
          <th>Classification</th>
          <td>Unclassified
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>WebKit
          </td>
        </tr>

        <tr>
          <th>Version</th>
          <td>528+ (Nightly build)
          </td>
        </tr>

        <tr>
          <th>Hardware</th>
          <td>Unspecified
          </td>
        </tr>

        <tr>
          <th>OS</th>
          <td>Unspecified
          </td>
        </tr>

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

        <tr>
          <th>Severity</th>
          <td>Normal
          </td>
        </tr>

        <tr>
          <th>Priority</th>
          <td>P2
          </td>
        </tr>

        <tr>
          <th>Component</th>
          <td>WebCore Misc.
          </td>
        </tr>

        <tr>
          <th>Assignee</th>
          <td>webkit-unassigned&#64;lists.webkit.org
          </td>
        </tr>

        <tr>
          <th>Reporter</th>
          <td>kyounga.ra&#64;gmail.com
          </td>
        </tr></table>
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        <div>
        <pre>We found a memory leak possibility in ImageLoader.
See the code below
====
ImageLoader::~ImageLoader()
{
..
    if (m_elementIsProtected)
        element().deref();
}
void ImageLoader::updatedHasPendingEvent()
{
    bool wasProtected = m_elementIsProtected;
    m_elementIsProtected = m_hasPendingLoadEvent || m_hasPendingErrorEvent;
    if (wasProtected == m_elementIsProtected)
        return;

    if (m_elementIsProtected) {
        if (m_derefElementTimer.isActive())
            m_derefElementTimer.stop();
        else
            element().ref();
    } else {
        ASSERT(!m_derefElementTimer.isActive());
        m_derefElementTimer.startOneShot(0);
    }
}
void ImageLoader::timerFired()
{
    element().deref();
}
====

Let's supposed that an protected element is to be &quot;unprotected&quot;.
The &quot;m_elementIsProtected&quot; flag is false immediately, but deref() is called later using Timer.
If ImageLoader is destroyed before the timer is fired, the element's refCount never be zero.
I didn't create a test case but there is logically 100% memory leak in this case.</pre>
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