Fix GH-22844: StreamPollHandle use-after-free after fclose()#22848
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iliaal wants to merge 1 commit into
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Fix GH-22844: StreamPollHandle use-after-free after fclose()#22848iliaal wants to merge 1 commit into
iliaal wants to merge 1 commit into
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StreamPollHandle cached the raw php_stream* but referenced only the resource container, not the stream, so fclose() freed the stream while the handle kept a dangling pointer that isValid(), getStream() and get_fd dereferenced. Re-derive the stream from the held resource each time. A watcher likewise re-derived its registration fd from that stream in remove(), so removing a watcher after its stream closed leaked the Poll-backend entry and could be re-hit through a reused fd in wait(); cache the fd at add() and use it for removal. Fixes phpGH-22844
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StreamPollHandlestored the rawphp_stream *but referenced only the resource container, sofclose()freed the stream (viapefree()) and clearedres->ptr/res->typewhile the handle kept a dangling pointer. isValid(), getStream() and the internal get_fd (reached viaContext::add()) then dereferenced freed memory. The accessors now re-derive the stream from the held resource and report a closed resource as absent: getStream() returns null, isValid() returns false.A watcher re-derived its registration fd from that same stream in
remove(), so a watcher removed after its stream closed couldn't recover the fd and left the Poll backend holding the freed watcher, which a reused fd would then write through inwait(). It now caches the fd fromadd()and removes by that. Reproduced under ASAN; getStream()'s stub return becomesresource|null.Fixes #22844