Roland McGrath schrieb folgendes am Mon, Jan 15, 2001 at 07:47:04PM -0500: > Each process has a port that is its root directory, just as it has a port > that is its current working directory. The root directory port is > inherited by fork/exec just like the current directory port is. This is > how chroot works (the other piece of chroot is a filesystem RPC used to get > a directory port that doesn't let /.. get out of the chosen "root" > directory). As with chroot on Unix, a setuid program (called a secure exec > in Hurdish) reverts to the global root directory port. So, modulo setuid, > you can chroot your shell to a filesystem of your choice and the processes > that descend from it will see that filesystem as the root for their lookups. > > So, by setting a translator the implements the filesystem name space you > want to see on ~/myroot, you can do "chroot ~/myroot" to go into that world. On Unix root can break out of the chrooted environment by the following:
# mknod hda1 b 3 1; # assume hda1 is your root filesystem # mkdir mnt # mount -n hda1 mnt # chroot mnt # echo "I'm now in the original root directory!" Of course, you can still use system calls to achieve the same result. Is there such an escape possible too? -- Stefan Karrmann
