Section (1) chroot
chroot — run command or interactive shell with special root directory
Run COMMAND with root directory set to NEWROOT.
specify supplementary groups as g1,g2,..,gN
specify user and group (ID or name) to use
do not change working directory to _zsingle_quotesz_/_zsingle_quotesz_
display this help and exit
output version information and exit
If no command is given, run _zsingle_quotesz_$SHELL
−i_zsingle_quotesz_ (default: _zsingle_quotesz_/bin/sh
GNU coreutils online help: <https://www.gnu.org/software/coreutils/>
Report any translation bugs to <https://translationproject.org/team/>
Full documentation <https://www.gnu.org/software/coreutils/chroot>
or available locally via: info _zsingle_quotesz_(coreutils) chroot invocation_zsingle_quotesz_
Copyright © 2019 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.
Section (2) chroot
chroot — change root directory
||const char *path
chroot() changes the root
directory of the calling process to that specified in
path. This directory
will be used for pathnames beginning with
/. The root directory is inherited by all
children of the calling process.
Only a privileged process (Linux: one with the
CAP_SYS_CHROOT capability in
its user namespace) may call
This call changes an ingredient in the pathname resolution
process and does nothing else. In particular, it is not
intended to be used for any kind of security purpose, neither
to fully sandbox a process nor to restrict filesystem system
calls. In the past,
has been used by daemons to restrict themselves prior to
passing paths supplied by untrusted users to system calls
such as open(2). However, if a
folder is moved out of the chroot directory, an attacker can
exploit that to get out of the chroot directory as well. The
easiest way to do that is to chdir(2) to the to-be-moved
directory, wait for it to be moved out, then open a path like
A slightly trickier variation also works under some circumstances if chdir(2) is not permitted. If a daemon allows a chroot directory to be specified, that usually means that if you want to prevent remote users from accessing files outside the chroot directory, you must ensure that folders are never moved out of it.
This call does not change the current working directory,
so that after the call _zsingle_quotesz_
be outside the tree rooted at _zsingle_quotesz_
/_zsingle_quotesz_. In particular, the superuser can escape
from a chroot jail by doing:
mkdir foo; chroot foo; cd ..
This call does not close open file descriptors, and such file descriptors may allow access to files outside the chroot tree.
On success, zero is returned. On error, −1 is
errno is set
Depending on the filesystem, other errors can be returned. The more general errors are listed below:
Search permission is denied on a component of the path prefix. (See also path_resolution(7).)
pathpoints outside your accessible address space.
An I/O error occurred.
Too many symbolic links were encountered in resolving
pathis too long.
The file does not exist.
Insufficient kernel memory was available.
A component of
pathis not a directory.
The caller has insufficient privilege.
The magic symbolic link,
/proc/[pid]/root, can be used to discover a
process_zsingle_quotesz_s root directory; see proc(5) for details.
FreeBSD has a stronger
jail() system call.
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Copyright (c) 1992 Drew Eckhardt (drewcs.colorado.edu), March 28, 1992
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Modified by Michael Haardt <michaelmoria.de>
Modified 1993-07-21 by Rik Faith <faithcs.unc.edu>
Modified 1994-08-21 by Michael Chastain <mecshell.portal.com>
Modified 1996-06-13 by aeb
Modified 1996-11-06 by Eric S. Raymond <esrthyrsus.com>
Modified 1997-08-21 by Joseph S. Myers <jsm28cam.ac.uk>
Modified 2004-06-23 by Michael Kerrisk <mtk.manpagesgmail.com>