RoaringBitmap / RoaringBitmap/roaring

(code might give the impression of possible) integer overflows in binary search

Open
#71 8 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

documentation
Dominant language
Go
Stars
2.9k
Forks
262
Avg merge
2h 34m
Merged PRs (30d)
8

Description

Both the C and the java binary search implementations are subject to a classic integer overflow bug in binary search; e.g. at
https://github.com/RoaringBitmap/CRoaring/blob/master/include/roaring/containers/run.h#L91
instead of
int32_t middleIndex = (low + high) >> 1;
prefer:
int32_t middleIndex = low + ((high-low) >> 1);

Contributor guide

No contributing guide indexed for this repository

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start with include/roaring/containers/run.h at the linked binary-search code, then locate the corresponding Java implementation. Check both midpoint calculations for the reported integer-overflow risk and verify that the implementations use the safer calculation consistently.

Written by the indexing model from the issue text.

Assessment

Tech stack
c, java
Domain
search
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
45/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.