CVE-2014-1453

El servidor NFS (nfsserver) en FreeBSD 8.3 hasta 10.0 no adquiere bloqueos en el orden debido cuando convierte un manejador de archivo de directorio hacia un vnode, lo que permite a usuarios remotos autenticados causar una denegación de servicios (bloqueo) a través de vectores que involucran un hilo que utiliza el orden correcto de bloqueo.

The Network File System (NFS) allows a host to export some or all of its file systems so that other hosts can access them over the network and mount them as if they were on local disks. FreeBSD includes both server and client implementations of NFS. The kernel holds a lock over the source directory vnode while trying to convert the target directory file handle to a vnode, which needs to be returned with the lock held, too. This order may be in violation of normal lock order, which in conjunction with other threads that grab locks in the right order, constitutes a deadlock condition because no thread can proceed. An attacker on a trusted client could cause the NFS server become deadlocked, resulting in a denial of service.