<html>
<body>
<div style="font-family: Verdana, Arial, Helvetica, Sans-Serif;">
<table bgcolor="#f9f3c9" width="100%" cellpadding="8" style="border: 1px #c9c399 solid;">
<tr>
<td>
This is an automatically generated e-mail. To reply, visit:
<a href="https://reviewboard.asterisk.org/r/1994/">https://reviewboard.asterisk.org/r/1994/</a>
</td>
</tr>
</table>
<br />
<div>
<table width="100%" border="0" bgcolor="white" style="border: 1px solid #C0C0C0; border-collapse: collapse; margin: 2px padding: 2px;">
<thead>
<tr>
<th colspan="4" bgcolor="#F0F0F0" style="border-bottom: 1px solid #C0C0C0; font-size: 9pt; padding: 4px 8px; text-align: left;">
<a href="https://reviewboard.asterisk.org/r/1994/diff/1/?file=28969#file28969line1768" style="color: black; font-weight: bold; text-decoration: underline;">branches/1.8/apps/app_voicemail.c</a>
<span style="font-weight: normal;">
(Diff revision 1)
</span>
</th>
</tr>
</thead>
<tbody style="background-color: #e4d9cb; padding: 4px 8px; text-align: center;">
<tr>
<td colspan="4"><pre style="font-size: 8pt; line-height: 140%; margin: 0; ">static void free_user(struct ast_vm_user *vmu)</pre></td>
</tr>
</tbody>
<tbody>
<tr>
<th bgcolor="#b1ebb0" style="border-right: 1px solid #C0C0C0;" align="right"><font size="2"></font></th>
<td bgcolor="#c5ffc4" width="50%"><pre style="font-size: 8pt; line-height: 140%; margin: 0; "></pre></td>
<th bgcolor="#b1ebb0" style="border-left: 1px solid #C0C0C0; border-right: 1px solid #C0C0C0;" align="right"><font size="2">1768</font></th>
<td bgcolor="#c5ffc4" width="50%"><pre style="font-size: 8pt; line-height: 140%; margin: 0; "> <span class="p">}</span></pre></td>
</tr>
<tr>
<th bgcolor="#b1ebb0" style="border-right: 1px solid #C0C0C0;" align="right"><font size="2"></font></th>
<td bgcolor="#c5ffc4" width="50%"><pre style="font-size: 8pt; line-height: 140%; margin: 0; "></pre></td>
<th bgcolor="#b1ebb0" style="border-left: 1px solid #C0C0C0; border-right: 1px solid #C0C0C0;" align="right"><font size="2">1769</font></th>
<td bgcolor="#c5ffc4" width="50%"><pre style="font-size: 8pt; line-height: 140%; margin: 0; "> <span class="n">vms</span><span class="o">-></span><span class="n">dh_arraysize</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span></pre></td>
</tr>
</tbody>
</table>
<pre style="margin-left: 2em; white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">You should probably put this inside the if block above. It doesn't hurt to have it here, but it makes more sense in the if block.</pre>
</div>
<br />
<div>
<table width="100%" border="0" bgcolor="white" style="border: 1px solid #C0C0C0; border-collapse: collapse; margin: 2px padding: 2px;">
<thead>
<tr>
<th colspan="4" bgcolor="#F0F0F0" style="border-bottom: 1px solid #C0C0C0; font-size: 9pt; padding: 4px 8px; text-align: left;">
<a href="https://reviewboard.asterisk.org/r/1994/diff/1/?file=28969#file28969line8048" style="color: black; font-weight: bold; text-decoration: underline;">branches/1.8/apps/app_voicemail.c</a>
<span style="font-weight: normal;">
(Diff revision 1)
</span>
</th>
</tr>
</thead>
<tbody style="background-color: #e4d9cb; padding: 4px 8px; text-align: center;">
<tr>
<td colspan="4"><pre style="font-size: 8pt; line-height: 140%; margin: 0; ">static int close_mailbox(struct vm_state *vms, struct ast_vm_user *vmu)</pre></td>
</tr>
</tbody>
<tbody>
<tr>
<th bgcolor="#f0f0f0" style="border-right: 1px solid #C0C0C0;" align="right"><font size="2">8037</font></th>
<td bgcolor="#ffffff" width="50%"><pre style="font-size: 8pt; line-height: 140%; margin: 0; "><span class="nl">done:</span></pre></td>
<th bgcolor="#f0f0f0" style="border-left: 1px solid #C0C0C0; border-right: 1px solid #C0C0C0;" align="right"><font size="2">8038</font></th>
<td bgcolor="#ffffff" width="50%"><pre style="font-size: 8pt; line-height: 140%; margin: 0; "><span class="nl">done:</span></pre></td>
</tr>
</tbody>
<tbody>
<tr>
<th bgcolor="#e9eaa8" style="border-right: 1px solid #C0C0C0;" align="right"><font size="2">8038</font></th>
<td bgcolor="#fdfebc" width="50%"><pre style="font-size: 8pt; line-height: 140%; margin: 0; "> <span class="k">if</span> <span class="p">(</span><span class="n">vms</span><span class="o">-></span><span class="n">deleted</span> <span class="o">&&</span> <span class="n">last_msg_idx</span><span class="p">)</span> <span class="p">{</span></pre></td>
<th bgcolor="#e9eaa8" style="border-left: 1px solid #C0C0C0; border-right: 1px solid #C0C0C0;" align="right"><font size="2">8039</font></th>
<td bgcolor="#fdfebc" width="50%"><pre style="font-size: 8pt; line-height: 140%; margin: 0; "> <span class="k">if</span> <span class="p">(</span><span class="n">vms</span><span class="o">-></span><span class="n">dh_arraysize</span><span class="p">)</span> <span class="p">{</span></pre></td>
</tr>
</tbody>
<tbody>
<tr>
<th bgcolor="#f0f0f0" style="border-right: 1px solid #C0C0C0;" align="right"><font size="2">8039</font></th>
<td bgcolor="#ffffff" width="50%"><pre style="font-size: 8pt; line-height: 140%; margin: 0; "> <span class="n">ast_free</span><span class="p">(</span><span class="n">vms</span><span class="o">-></span><span class="n">deleted</span><span class="p">);</span></pre></td>
<th bgcolor="#f0f0f0" style="border-left: 1px solid #C0C0C0; border-right: 1px solid #C0C0C0;" align="right"><font size="2">8040</font></th>
<td bgcolor="#ffffff" width="50%"><pre style="font-size: 8pt; line-height: 140%; margin: 0; "> <span class="n">ast_free</span><span class="p">(</span><span class="n">vms</span><span class="o">-></span><span class="n">deleted</span><span class="p">);</span></pre></td>
</tr>
</tbody>
<tbody>
<tr>
<th bgcolor="#e9eaa8" style="border-right: 1px solid #C0C0C0;" align="right"><font size="2">8040</font></th>
<td bgcolor="#fdfebc" width="50%"><pre style="font-size: 8pt; line-height: 140%; margin: 0; "> <span class="p">}</span></pre></td>
<th bgcolor="#e9eaa8" style="border-left: 1px solid #C0C0C0; border-right: 1px solid #C0C0C0;" align="right"><font size="2">8041</font></th>
<td bgcolor="#fdfebc" width="50%"><pre style="font-size: 8pt; line-height: 140%; margin: 0; "> <span class="n">vms</span><span class="o">-></span><span class="n">deleted</span> <span class="o">=</span> <span class="nb">NULL</span><span class="p">;</span></pre></td>
</tr>
</tbody>
<tbody>
<tr>
<th bgcolor="#ebb1ba" style="border-right: 1px solid #C0C0C0;" align="right"><font size="2">8041</font></th>
<td bgcolor="#ffc5ce" width="50%"><pre style="font-size: 8pt; line-height: 140%; margin: 0; "> <span class="k">if</span> <span class="p">(</span><span class="n">vms</span><span class="o">-></span><span class="n">heard</span> <span class="o">&&</span> <span class="n">last_msg_idx</span><span class="p">)</span> <span class="p">{</span></pre></td>
<th bgcolor="#ebb1ba" style="border-left: 1px solid #C0C0C0; border-right: 1px solid #C0C0C0;" align="right"><font size="2"></font></th>
<td bgcolor="#ffc5ce" width="50%"><pre style="font-size: 8pt; line-height: 140%; margin: 0; "></pre></td>
</tr>
</tbody>
<tbody>
<tr>
<th bgcolor="#f0f0f0" style="border-right: 1px solid #C0C0C0;" align="right"><font size="2">8042</font></th>
<td bgcolor="#ffffff" width="50%"><pre style="font-size: 8pt; line-height: 140%; margin: 0; "> <span class="n">ast_free</span><span class="p">(</span><span class="n">vms</span><span class="o">-></span><span class="n">heard</span><span class="p">);</span></pre></td>
<th bgcolor="#f0f0f0" style="border-left: 1px solid #C0C0C0; border-right: 1px solid #C0C0C0;" align="right"><font size="2">8042</font></th>
<td bgcolor="#ffffff" width="50%"><pre style="font-size: 8pt; line-height: 140%; margin: 0; "> <span class="n">ast_free</span><span class="p">(</span><span class="n">vms</span><span class="o">-></span><span class="n">heard</span><span class="p">);</span></pre></td>
</tr>
</tbody>
<tbody>
<tr>
<th bgcolor="#b1ebb0" style="border-right: 1px solid #C0C0C0;" align="right"><font size="2"></font></th>
<td bgcolor="#c5ffc4" width="50%"><pre style="font-size: 8pt; line-height: 140%; margin: 0; "></pre></td>
<th bgcolor="#b1ebb0" style="border-left: 1px solid #C0C0C0; border-right: 1px solid #C0C0C0;" align="right"><font size="2">8043</font></th>
<td bgcolor="#c5ffc4" width="50%"><pre style="font-size: 8pt; line-height: 140%; margin: 0; "> <span class="n">vms</span><span class="o">-></span><span class="n">heard</span> <span class="o">=</span> <span class="nb">NULL</span><span class="p">;</span></pre></td>
</tr>
<tr>
<th bgcolor="#b1ebb0" style="border-right: 1px solid #C0C0C0;" align="right"><font size="2"></font></th>
<td bgcolor="#c5ffc4" width="50%"><pre style="font-size: 8pt; line-height: 140%; margin: 0; "></pre></td>
<th bgcolor="#b1ebb0" style="border-left: 1px solid #C0C0C0; border-right: 1px solid #C0C0C0;" align="right"><font size="2">8044</font></th>
<td bgcolor="#c5ffc4" width="50%"><pre style="font-size: 8pt; line-height: 140%; margin: 0; "> <span class="n">vms</span><span class="o">-></span><span class="n">dh_arraysize</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span></pre></td>
</tr>
</tbody>
<tbody>
<tr>
<th bgcolor="#f0f0f0" style="border-right: 1px solid #C0C0C0;" align="right"><font size="2">8043</font></th>
<td bgcolor="#ffffff" width="50%"><pre style="font-size: 8pt; line-height: 140%; margin: 0; "> <span class="p">}</span></pre></td>
<th bgcolor="#f0f0f0" style="border-left: 1px solid #C0C0C0; border-right: 1px solid #C0C0C0;" align="right"><font size="2">8045</font></th>
<td bgcolor="#ffffff" width="50%"><pre style="font-size: 8pt; line-height: 140%; margin: 0; "> <span class="p">}</span></pre></td>
</tr>
</tbody>
</table>
<pre style="margin-left: 2em; white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">This is an area where I think you might run into an issue, but only if IMAP storage is in use.
With ODBC and file storage, vm_state variables are always local variables, and so synchronization across threads is not an issue to consider.
With IMAP, on the other hand, the vm_state that you are operating on may be local to the stack, thread-local, or it could be a pointing to a persistent vm_state in a global list. That being said, here in close_mailbox(), this modification of vms->dh_arraysize (as well as its access earlier in the function) is not protected by a lock. The result is that you could end up with badness due to competing threads mucking around with the data. The modifications/accesses of vms->dh_arraysize in open_mailbox() and vm_allocate_dh() are lock-protected.</pre>
</div>
<br />
<p>- Mark</p>
<br />
<p>On June 20th, 2012, 8:18 a.m., opticron wrote:</p>
<table bgcolor="#fefadf" width="100%" cellspacing="0" cellpadding="8" style="background-image: url('https://reviewboard.asterisk.org/media/rb/images/review_request_box_top_bg.png'); background-position: left top; background-repeat: repeat-x; border: 1px black solid;">
<tr>
<td>
<div>Review request for Asterisk Developers.</div>
<div>By opticron.</div>
<p style="color: grey;"><i>Updated June 20, 2012, 8:18 a.m.</i></p>
<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Description </h1>
<table width="100%" bgcolor="#ffffff" cellspacing="0" cellpadding="10" style="border: 1px solid #b8b5a0">
<tr>
<td>
<pre style="margin: 0; padding: 0; white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">This patch reworks the handling of array allocation and freeing to ensure that freed memory is not used.</pre>
</td>
</tr>
</table>
<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Testing </h1>
<table width="100%" bgcolor="#ffffff" cellspacing="0" cellpadding="10" style="border: 1px solid #b8b5a0">
<tr>
<td>
<pre style="margin: 0; padding: 0; white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">Poked through voicemail manually. Testing has been performed on issue ASTERISK-19923 and seems to have corrected the segfault in that case.</pre>
</td>
</tr>
</table>
<div style="margin-top: 1.5em;">
<b style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Bugs: </b>
<a href="https://issues.asterisk.org/jira/browse/AST-894">AST-894</a>
</div>
<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Diffs</b> </h1>
<ul style="margin-left: 3em; padding-left: 0;">
<li>branches/1.8/apps/app_voicemail.c <span style="color: grey">(368806)</span></li>
</ul>
<p><a href="https://reviewboard.asterisk.org/r/1994/diff/" style="margin-left: 3em;">View Diff</a></p>
</td>
</tr>
</table>
</div>
</body>
</html>