pageant: Out-of-bounds read / oversized allocation in `pageant` MemoryMap::read via a malicious Pageant agent (Windows)

Summary MemoryMap::read in the pageant crate part of the russh workspace, used by russh's SSH-agent client on Windows via AgentClient::connectpageant copies a peer-controlled number of bytes out of an 8192-byte shared-memory view with no bounds check — unlike the sibling MemoryMap::write, which...