fix(iter_filter): add bound check for iter filter context

[inabao]

cp #1588 to 0.16
link #1579 #1580

[gemini-code-assist]

Summary of Changes

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This pull request addresses several issues related to the IteratorFilterContext and graph search algorithms. It introduces robust error handling for empty graphs, prevents potential out-of-bounds memory access within the iterator filter, and refines the search logic in HNSW and basic searcher implementations for improved correctness and efficiency.

Highlights

• Empty Graph Handling: Introduced a check in HGraph::KnnSearch to handle cases where the graph has zero elements, returning an empty dataset immediately to prevent errors during IteratorFilterContext initialization.
• Iterator Filter Bound Checks: Implemented boundary checks within IteratorFilterContext::SetPoint and IteratorFilterContext::CheckPoint to prevent out-of-bounds access when inner_id exceeds max_size_.
• Search Logic Refinement: Adjusted the order of operations in HierarchicalNSW::searchBaseLayerST and BasicSearcher::search_impl to ensure visited_array or vl is marked before calling iter_ctx->CheckPoint, streamlining the search logic.

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Changelog

• src/algorithm/hgraph.cpp
  • Added a check for cur_count == 0 to return an empty dataset early in KnnSearch.
• src/algorithm/hnswlib/hnswalg.cpp
  • Reordered visited_array marking to occur before iter_ctx->CheckPoint call in searchBaseLayerST.
• src/impl/basic_searcher.cpp
  • Reordered vl marking to occur before iter_ctx->CheckPoint call in search_impl.
• src/index/iterator_filter.cpp
  • Added inner_id >= max_size_ bound check in SetPoint.
  • Added inner_id < max_size_ bound check in CheckPoint.

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[gemini-code-assist]

Code Review

This pull request aims to fix a bounds check issue in the iterator filter context. The changes in src/index/iterator_filter.cpp correctly add bounds checks to SetPoint and CheckPoint, preventing potential out-of-bounds memory access. The addition of an empty graph check in src/algorithm/hgraph.cpp also improves robustness.

However, the modifications in src/algorithm/hnswlib/hnswalg.cpp and src/impl/basic_searcher.cpp appear to be problematic. They remove a necessary de-duplication check for candidates, which could lead to incorrect search results and performance issues. Furthermore, the changes do not fully resolve the underlying out-of-bounds access vulnerability. I have provided suggestions to correctly fix the potential crash while maintaining the de-duplication logic.

[codecov]

Codecov Report

❌ Patch coverage is 70.00000% with 3 lines in your changes missing coverage. Please review.

❌ Your patch status has failed because the patch coverage (70.00%) is below the target coverage (80.00%). You can increase the patch coverage or adjust the target coverage.

@@            Coverage Diff             @@
##             0.16    #1608      +/-   ##
==========================================
+ Coverage   92.21%   92.30%   +0.08%     
==========================================
  Files         295      295              
  Lines       15677    15688      +11     
==========================================
+ Hits        14457    14481      +24     
+ Misses       1220     1207      -13     

Flag	Coverage Δ
cpp	92.30% <70.00%> (+0.08%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Components	Coverage Δ
common	92.62% <ø> (ø)
datacell	92.73% <ø> (+0.83%)	⬆️
index	91.22% <78.57%> (-0.28%)	⬇️
simd	100.00% <ø> (ø)

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[wxyucs]

lgtm

[LHT129]

LGTM