Fix HashTable UAF when rebound from a parameter __toString() - #23252
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iliaal wants to merge 1 commit into
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Fix HashTable UAF when rebound from a parameter __toString()#23252iliaal wants to merge 1 commit into
iliaal wants to merge 1 commit into
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dispatch_param_event iterates bound_params with ZEND_HASH_FOREACH while sqlite's EXEC_PRE hook can run __toString; execute() then destroys the table and bindValue() replaces buckets. Steal one _reserved bit as in_param_event (no layout size change; the header is installed) and throw Error from bindParam, bindValue, bindColumn, execute, and closeCursor while the hook is running. fetch is left unguarded: nested FOREACH is read-only and FETCH_POST writes column zvals, not the HashTable. 8.5/master already have a uint16_t bitfield with in_fetch; the forward merge needs in_param_event:1 and reserved:11.
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dispatch_param_event walks bound_params with ZEND_HASH_FOREACH while sqlite's EXEC_PRE hook can run __toString. From there execute() frees the table and bindValue() replaces buckets. This steals one _reserved bit as in_param_event (no layout size change; the header is installed) and throws Error from bind/execute/closeCursor while the hook is running. 8.5/master already have a refactored uint16_t bitfield with in_fetch; the forward merge needs in_param_event:1 and reserved:11.