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<base href="https://bugs.freedesktop.org/" />
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - Unsecure/unreliable shared memory"
href="https://bugs.freedesktop.org/show_bug.cgi?id=90512">90512</a>
</td>
</tr>
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<th>Summary</th>
<td>Unsecure/unreliable shared memory
</td>
</tr>
<tr>
<th>Product</th>
<td>cairo
</td>
</tr>
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<th>Version</th>
<td>unspecified
</td>
</tr>
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<th>Hardware</th>
<td>All
</td>
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<th>OS</th>
<td>All
</td>
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<th>Status</th>
<td>NEW
</td>
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<th>Severity</th>
<td>major
</td>
</tr>
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<th>Priority</th>
<td>medium
</td>
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<th>Component</th>
<td>general
</td>
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<th>Assignee</th>
<td>chris@chris-wilson.co.uk
</td>
</tr>
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<th>Reporter</th>
<td>wbrana@gmail.com
</td>
</tr>
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<th>QA Contact</th>
<td>cairo-bugs@cairographics.org
</td>
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<p>
<div>
<pre>Cairo is using shared memory using shmget with permissions 600 in following
files:
cairo-xlib-surface-shm.c
cairo-xcb-shm.c
cairo-xcb-connection.c
which
- is unsecure because other applications from same user can access that memory
using shmat and shmid from /proc/sysvipc/shm
- doesn't work if application is running as different non-root user from
Xserver
Cairo should use new functions with Xserver 1.15 and newer:
"In the 1.15 release of the X.org server[1] the MIT-SHM extension gains two
additional requests: 'X_ShmAttachFd' and 'X_ShmCreateSegment', to be able to
pass shared memory through file descriptors from client to server and from
server to client"</pre>
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</p>
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