Affected: Maven: io.netty:netty-codec-http

The `SpdyHttpDecoder` handler in Netty's SPDY-to-HTTP codec allocates a pooled `ByteBuf` when processing a client-initiated `SYN_STREAM` frame with `FLAG_FIN=0`, storing the partially-constructed `FullHttpRequest` in an internal map (`messageMap`) to accumulate subsequent `DATA` frames. When the remote peer sends an `RST_STREAM` for that stream, or when the accumulated content exceeds `maxContentLength`, the decoder removes the entry from the map but **never releases the pooled ByteBuf**, permanently leaking the allocated memory.