Exterminator: Automatically Correcting Memory Errors with High Probability

Novark, Berger, Zorn

fault detection memory allocation bugs security buffer overflow dangling pointer

@article{novark:cacm-2008,
  title={{Exterminator}: Automatically Correcting Memory Errors
         with High Probability},
  author={Gene Novark and Emery D. Berger and Benjamin G. Zorn},
  journal={Communications of the {ACM}},
  volume={51},
  number={12},
  month={December},
  year={2008}

Overviews Exterminator, a memory allocator that detects and corrects buffer overflows and dangling pointers at runtime

• Generate multiple heaps for a program, randomizing both the canary value filling the heap and the memory allocation locations
  • Iterative mode: Run the program multiple times to generate those images
  • Replicated mode: Maintain multiple randomized heaps at once
  • Cumulative mode: Combine heap summaries captured from many users
• Analyze those images to determine probable under-allocations, determining a value to pad the size by, as well as erroneous frees, determining a deferral period for the deallocation

Of note:

• Correcting for memory problems by having multiple copies of the heap running at once and voting between them on each read (much like RAID), to determine the correct value