Privilege reduction

chroot mechanism (or jail)

Used to reduce the visibility of a file system.

• Each process descriptor has a root i-node number.

  • From which absolute pathname resolution takes place.

• chroot changes it to an arbitrary directory.

  • The process file system view gets reduced.

Used to protect the file system from potentially problematic applications.

• e.g. public servers and downloaded applications.

• But it is not bulletproof!