891216e34b
Maliciously formed, or badly corrupted, filesystems can cause kernel panics. In general, such acts of foot-shooting can only be accomplished by root, but in a world with VM images that is moving towards automated mounts it is important to have some form of prevention. Reported by: Christopher Krah, Thomas Barabosch, and Jan-Niclas Hilgert of Fraunhofer FKIE. Incidentaly this should also fix a memory corruption issue reported by Dr Silvio Cesare of InfoSect. Huge thanks to all reseachers for making us aware of the issue. admbug: 872, 891 Reviewed by: fsu Obtained from: NetBSD (with minor changes) MFC after: 3 days