CyberRota Analysis
AI-GeneratedThe vulnerability affects the Linux kernel's NFSv4/pnfs implementation, where the data server cache is improperly keyed, allowing multiple device IDs with different versions to share the same cache entry. This can lead to a NULL dereference due to mismatched sequence-slot handling when a client connects to a version it does not support. Organizations using Linux systems with NFSv4/pnfs should prioritize addressing this issue to prevent potential service disruptions and ensure compatibility across different NFS versions.
Original NVD Description
In the Linux kernel, the following vulnerability has been resolved: NFSv4/pnfs: key the data server cache on the NFS version nfs4_pnfs_ds_add() keys the per-net data server cache on the multipath address set alone, and struct nfs4_pnfs_ds records no version. That suffices for the files layout driver, which always connects with version 4, but flexfiles takes its version tuple from GETDEVICEINFO per device, and one address can legitimately serve both NFSv3 and NFSv4. Two deviceids on one address with different ds_versions[0].version therefore share a single nfs4_pnfs_ds, and whichever mirror connects first pins ds_clp to its own version. The other one is handed that client anyway, so it selects rpc_call_ops for a version the connection does not speak, and the mismatched sequence-slot handling dereferences NULL. Add the version to the cache key so the two cannot alias, giving each version its own nfs4_pnfs_ds and connection while both mirrors stay usable. Only the major version is compared, since that is what selects rpc_call_ops and rpc_ops; v4.0 and v4.1 keep sharing a client. The files layout driver passes the 4 it already hardcodes at connect time.