<html>
<head>
<base href="https://bugs.freedesktop.org/" />
</head>
<body><table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Priority</th>
<td>medium
</td>
</tr>
<tr>
<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - Buffer overrun when enumerating files"
href="https://bugs.freedesktop.org/show_bug.cgi?id=69887">69887</a>
</td>
</tr>
<tr>
<th>Assignee</th>
<td>systemd-bugs@lists.freedesktop.org
</td>
</tr>
<tr>
<th>Summary</th>
<td>Buffer overrun when enumerating files
</td>
</tr>
<tr>
<th>QA Contact</th>
<td>systemd-bugs@lists.freedesktop.org
</td>
</tr>
<tr>
<th>Severity</th>
<td>major
</td>
</tr>
<tr>
<th>Classification</th>
<td>Unclassified
</td>
</tr>
<tr>
<th>OS</th>
<td>All
</td>
</tr>
<tr>
<th>Reporter</th>
<td>hpj@copyleft.no
</td>
</tr>
<tr>
<th>Hardware</th>
<td>Other
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Version</th>
<td>unspecified
</td>
</tr>
<tr>
<th>Component</th>
<td>general
</td>
</tr>
<tr>
<th>Product</th>
<td>systemd
</td>
</tr></table>
<p>
<div>
<pre>Created <span class=""><a href="attachment.cgi?id=86736" name="attach_86736" title="Patch that fixes the bug">attachment 86736</a> <a href="attachment.cgi?id=86736&action=edit" title="Patch that fixes the bug">[details]</a></span>
Patch that fixes the bug
There is a buffer overrun in src/shared/util.c:get_files_in_directory() when
the number of files in the directory to be enumerated exceeds 15.
It does not account for the sentinel NULL when resizing the buffer, and the
NULL is re-added after each new item, causing an overrun whenever the buffer is
about to be realloc()ed.
This can cause e.g. gnome-shell to crash and display a blank screen in gdm when
the user has more than 15 files in /run/systemd/sessions/. I've seen user
reports of this, and verified it experimentally with valgrind.
I'm attaching a patch that fixes the issue by ensuring there's enough space for
the sentinel.</pre>
</div>
</p>
<hr>
<span>You are receiving this mail because:</span>
<ul>
<li>You are the QA Contact for the bug.</li>
<li>You are the assignee for the bug.</li>
</ul>
</body>
</html>