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<style>p { margin: 0; }A new class of bugs: How compiler optimizations harm our systems through undefined behavior</style>
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<div><span class="event-speaker"> <a moz-do-not-send="true"
href="http://pdos.csail.mit.edu/%7Exi/"
target="_blank">Xi Wang</a>, </span><span
class="event-speaker-from"><a moz-do-not-send="true"
href="http://web.mit.edu/" target="_blank">Massachusetts
Institute of Technology</a></span><br>
<span></span>Wednesday, February 26, 4:30pm<br>
Computer Science 105<br>
<br>
Software bugs introduce security vulnerabilities into our
computer systems. To understand and mitigate an
increasing number of bugs, practitioners categorize them
into classes, such as buffer overflow or SQL injection,
and handle each class separately. <br>
<br>
<p>This talk introduces a new class of bugs called
unstable code: code that is unexpectedly discarded by
compiler optimizations due to undefined behavior in the
program. I will discuss its prevalence and security
impact in systems, and present a systematic approach for
reasoning about unstable code, as well as a static
checker called Stack that implements this approach to
precisely identify unstable code in real systems.
Applying Stack to widely used software has uncovered
160 new bugs that have been confirmed and fixed by
developers. It has also been adopted by several
companies to scan their codebases.</p>
<p><br>
</p>
Xi Wang is a PhD candidate in Computer Science at MIT,
advised by M. Frans Kaashoek and Nickolai Zeldovich. His
research interests are in building secure and reliable
systems. He was awarded a Best Paper Award at SOSP 2013,
a Best Student Paper Award at EuroSys 2008, and an MIT
Jacobs Presidential Fellowship in 2008.<br>
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