Fix off-by-one buffer overflow in integration test mergeFunction#243
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GlassOfWhiskey merged 1 commit intoJul 22, 2026
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`resultpath` was allocated as `strlen(destdir) + strlen("/result.dat")`
bytes, but the subsequent sprintf writes that many characters plus the
terminating NUL, overflowing the heap buffer by one byte.
This is harmless under low optimization, but with _FORTIFY_SOURCE active
(e.g. -O3 on recent GCC/glibc) the fortified sprintf detects the overflow
and aborts with "*** buffer overflow detected ***", crashing the
RunTestSplitMergeAndMapReduceFunction integration test.
Reserve one extra byte for the NUL terminator.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Codecov Report✅ All modified and coverable lines are covered by tests. Additional details and impacted files@@ Coverage Diff @@
## master #243 +/- ##
==========================================
+ Coverage 63.45% 63.46% +0.01%
==========================================
Files 78 79 +1
Lines 3273 3274 +1
Branches 2008 2008
==========================================
+ Hits 2077 2078 +1
+ Misses 938 399 -539
- Partials 258 797 +539 ☔ View full report in Codecov by Harness. 🚀 New features to boost your workflow:
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marcoSanti
dismissed
their stale review
June 28, 2026 19:45
Using LLMs might have licensing issues. Removing approval pending investigation of licensing issues
GlassOfWhiskey
changed the title
mergeFunction
GlassOfWhiskey
merged commit Jul 22, 2026
5a6097d
into
High-Performance-IO:master
83 of 84 checks passed
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The
resultpathvariable was allocated asstrlen(destdir) + strlen("/result.dat")bytes, but the subsequentsprintfwrites that many characters plus the terminatingNULL, overflowing the heap buffer by one byte.With
_FORTIFY_SOURCEactive (e.g.-O3on recent GCC/glibc) the fortifiedsprintfdetects the overflow and aborts with*** buffer overflow detected ***, crashing theRunTestSplitMergeAndMapReduceFunctionintegration test.Reserve one extra byte for the
NULLterminator.