In PD-disaggregated serving, a GPUDirect RDMA race often returns HTTP 200 OK while silently mixing one user's KV cache into another's response. Applying vstack uncovered 3 classes of RDMA and cache lifecycle bugs in production engines, resulting in 6 proposed upstream fixes.

With TLAPS and Z3, we also proved why local timeouts fail under one-sided RDMA: without hardware stop or revocation evidence, any local-only timeout policy must either risk memory corruption if it frees a page early, or hold the exposed page indefinitely.