MINOR: [C++][CSV] avoid int32 overflow in block parser value counts#50074
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metsw24-max wants to merge 1 commit into
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MINOR: [C++][CSV] avoid int32 overflow in block parser value counts#50074metsw24-max wants to merge 1 commit into
metsw24-max wants to merge 1 commit into
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Rationale for this change
The CSV block parser sizes its per-chunk value array from
num_cols, the column count inferred from the first line of the input, times the rows-in-chunk count.PresizedValueDescWritercomputes2 + num_rows * num_cols, andParseSpecializedcomputesnum_cols_ * (num_rows_ - start) * 10, both inint32_t. A CSV whose first line carries a few million fields pushes these products pastINT32_MAX, which is signed-integer-overflow UB (UBSan flags both expressions).What changes are included in this PR?
Widen both multiplications to
int64_t, matching theirint64_tdestinations.Are these changes tested?
Existing CSV parser tests pass. The overflow was confirmed with a standalone UBSan build of the two expressions, clean after widening.
Are there any user-facing changes?
No.