cve 2025 40039

This tag covers CVE-2025-40039, a Linux kernel vulnerability in the ksmbd subsystem. The flaw is a race condition in the kernel SMB server's RPC handle list that could lead to inconsistent state, data corruption, or use-after-free when RPC handles are accessed concurrently. The fix corrects rw_semaphore usage and adds proper read/write locking around XArray operations. While the vulnerability is in Linux, it is relevant to Windows users who run Linux virtual machines or SMB servers on Windows via WSL or Hyper-V, as it affects cross-platform file sharing. The tag includes discussion of the vulnerability details, the patch, and implications for systems using ksmbd.