Fix GH-22666: pdo_odbc heap overflow on oversized output param#149
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Fix GH-22666: pdo_odbc heap overflow on oversized output param#149iliaal wants to merge 1 commit into
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odbc_stmt_param_hook() sizes an output-param buffer from the declared maxlen but then copies the runtime value into it using the value's own length, and at fetch-back hands ZVAL_STRINGL the driver-reported length. Both trust a length that can exceed the buffer: the input copy overflows the heap (controlled write), and on a truncated OUTPUT value the driver reports the full length via the shared indicator, so the readback over-reads. Record the bound capacity in a new outbuflen field and clamp the copy and the readback to it. LOB output is rejected at bind, so those copy sites stay unreachable. Fixes phpGH-22666
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Submitted upstream as php#22674. |
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ext/pdo_odbc sizes an output-param buffer from the declared maxlen but copies the runtime value in by its own length (heap write overflow) and reads it back by the driver-reported length, which on a truncated OUTPUT value exceeds the buffer (01004 over-read). Records the bound capacity and clamps both the input copy and the read-back to it. Over-long values are bounded to maxlen, which is all the driver round-trips anyway since the buffer is bound at maxlen before the value is known. Reproduces with the SQLite3 ODBC driver; the test skips without it.