Out-of-bounds read and panic in ReadDir in github.com/cloudsoda/go-smb2 and github.com/hirochachacha/go-smb2

Summary

ReadDir and ReadDirPlus parse the QUERY_DIRECTORY SMB response by advancing through entries using the server-supplied NextEntryOffset field. The pre-fix code does not bound next against the remaining buffer before re-slicing, and the entry decoder IsInvalid check performs length arithmetic in int after narrowing from uint16.

A guest or anonymous directory listing against an attacker-controlled or man-in-the-middle SMB server crashes the Go client process with a runtime panic when the response contains an entry whose NextEntryOffset is larger than the remaining buffer, or whose declared FileNameLength produces a length that does not match the actual buffer size.