doc: net_proc: reference past defect regarding invalid GETDATA types

src/net_processing.cpp

@@ -2426,6 +2426,9 @@ void PeerManagerImpl::ProcessGetData(CNode& pfrom, Peer& peer, const std::atomic
         }
         // else: If the first item on the queue is an unknown type, we erase it
         // and continue processing the queue on the next call.
+        // NOTE: previously we wouldn't do so and the peer sending us a malformed GETDATA could
+        // result in never making progress and this thread using 100% allocated CPU. See
+        // https://bitcoincore.org/en/2024/07/03/disclose-getdata-cpu.
     }
 
     peer.m_getdata_requests.erase(peer.m_getdata_requests.begin(), it);