Fix GH-22668: odbc heap over-read on oversized column value#22670
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Fix GH-22668: odbc heap over-read on oversized column value#22670iliaal wants to merge 1 commit into
iliaal wants to merge 1 commit into
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| --SKIPIF-- | ||
| <?php | ||
| $file = tempnam(sys_get_temp_dir(), "gh22668"); | ||
| $conn = @odbc_connect("Driver=SQLite3;Database=$file", null, null); |
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Again, see if we can use SQL Server, if possible to reproduce it if not, :memory: and we'll have to figure out adding it to CI
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Checked ext/odbc against the 2022 container directly, same as #22672: it doesn't reproduce. SQL Server reports a field length >= the value (VARCHAR(50) -> 50), or 0/INT_MAX for LOB types which take the long-column path, never a short display size against an over-long value. Switched the test to :memory:. If you'd rather it run than skip, I'll add the SQLite ODBC driver to CI, which covers #22672 as well.
ext/odbc bound a displaysize+1 buffer per column but built the result string from the driver-reported vallen. A conforming driver truncates an over-long value into the buffer yet reports the full length, so the fetch over-read past the allocation and returned adjacent heap bytes to userland. Store the bound capacity in odbc_result_value and clamp the string length to it at the three bound-buffer fetch sites (odbc_fetch_array/object, odbc_fetch_into, odbc_result); the SQLGetData long-column paths stay bounded by longreadlen. Fixes phpGH-22668
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ext/odbc builds the result string from the driver-reported vallen, which on truncation exceeds the bound displaysize+1 buffer (SQL_SUCCESS_WITH_INFO), over-reading heap into the returned value. Clamps the length to the bound capacity at the three fetch sites. Reproduces with the SQLite3 ODBC driver; the test skips without it.
Fixes #22668