Fix Io\Poll memory-safety and error-handling issues#85
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Several issues in the new Io\Poll API, found by review and confirmed under valgrind: - Watcher kept a raw pointer to its Context's php_poll_ctx with no reference, so dropping the Context while holding a Watcher left remove()/modify() dereferencing freed memory (use-after-free). The Context now neutralizes its watchers (active=false, poll_ctx=NULL) before it is destroyed, so those calls throw InactiveWatcherException. - StreamPollHandle took a reference on the stream resource in the constructor but never released it, leaking the descriptor for the rest of the request. Store the zend_resource and release it in the handle cleanup; the php_stream may already be freed by then (e.g. the user closed it), so the cleanup must not dereference it. - Watcher and Context had no get_gc handler, so reference cycles through Watcher::$data were uncollectable. Add get_gc for both. - The epoll and poll backends returned -1 from wait() without recording the error, so the thrown exception carried a stale code. Set it from errno, which maps EINTR to the interrupted error. - The kqueue grouped-event path bounded the result buffer only with a ZEND_ASSERT, allowing an out-of-bounds write in release builds when more distinct descriptors were ready than the caller's maxEvents. Cap it at runtime, matching the raw-event path. - php_poll_create_by_name() dereferenced a NULL backend name; guard it.
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Promoted upstream: php#22316. |
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Fixes memory-safety and error-handling bugs in the new Io\Poll API, found by review and confirmed under valgrind on the epoll backend.
Tests cover the UAF, the fd leak, and the get_gc cycle on Linux.