Fix heap over-read seeding the long-column buffer in pdo_odbc#95
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In the long-column fetch path, when the ODBC driver reports the total column length rather than SQL_NO_TOTAL, the result string was seeded by copying orig_fetched_len + 1 bytes out of C->data, which holds at most LONG_COLUMN_BUFFER_SIZE bytes from the first SQLGetData. For a column larger than that buffer this reads past C->data. Seed only the bytes actually present in the buffer, matching the SQL_NO_TOTAL branch; the remainder is still fetched by the loop.
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Promoted upstream to php#22349 (base PHP-8.5). Closing this fork PR; keeping the branch since the upstream PR's head points at it. |
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In the long-column fetch path, when the ODBC driver reports the total column length rather than SQL_NO_TOTAL, the result string was seeded by copying orig_fetched_len + 1 bytes out of C->data, which holds at most LONG_COLUMN_BUFFER_SIZE bytes from the first SQLGetData. For a column larger than that buffer this reads past C->data. Seed only the bytes actually present, matching the SQL_NO_TOTAL branch; the remainder is still fetched by the loop.