UNIVERSITY OF MASSACHUSETTS, AMHERST • Department of Computer Science
Gene Novark & Emery Berger University of Massachusetts, Amherst
DIEHARDER: SECURING THE HEAP
[originally presented at CCS 2011]
UNIVERSITY OF MASSACHUSETTS, AMHERST • Department of Computer Science
DieHard: ProbabilisFc Memory Safety for C/C++ Programs [PLDI 2005]
Direct inspira4on for Windows 7’s Fault-‐Tolerant Heap (2009)
UNIVERSITY OF MASSACHUSETTS, AMHERST • Department of Computer Science
DieHard: ProbabilisFc Memory Safety for C/C++ Programs [PLDI 2005]
Direct inspira4on for Windows 7’s Fault-‐Tolerant Heap (2009)
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sensitive data / metadata
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All data / metadata sensitive
sensitive data / metadata
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guard / unmapped page
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guard / unmapped page
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Address-‐space layout randomization
object free space
heap metadata
object free space prev. object
object size
heap metadata (GNU libc, others)
object free space
heap metadata
x
object free space
heap metadata
x
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≈ 4-5 bits of entropy
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Maximal entropy: log N bits (e.g., ≈ 25-30)
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44.2 sec
44.2 sec 41.6 sec
UNIVERSITY OF MASSACHUSETTS, AMHERST • Department of Computer Science
Gene Novark & Emery Berger University of Massachusetts, Amherst
DIEHARDER: SECURING THE HEAP
