Fix potential use-after-free in error handling. #895
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- Store PQresultStatus() result in a local variable before calling cdbdisp_clearCdbPgResults() - Prevent accessing PQresultStatus() after clearing CDB results - Improve consistency in error handling across different functions - Avoid redundant function calls by caching result of PQresultStatus() Enhances safety and readability in segment result processing
reshke
approved these changes
Jan 26, 2025
avamingli
approved these changes
Jan 27, 2025
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Fixes #ISSUE_Number
What does this PR do?
Motivation:
The original code called PQresultStatus() after invoking cdbdisp_clearCdbPgResults(),
which can lead to undefined behavior or potential segmentation faults.
Accessing a pg_result pointer after clearing the CDB results may reference
already freed memory.
Changes:
This change ensures that all result status checks and error reporting occur
before releasing the memory associated with the query results.
Enhances safety and readability in segment result processing
Type of Change
Breaking Changes
Test Plan
make installcheckmake -C src/test installcheck-cbdb-parallelImpact
Performance:
User-facing changes:
Dependencies:
Checklist
Additional Context
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