Ubuntu Manpage: profile - Security profile file syntax for Firejail

NAME

       profile - Security profile file syntax for Firejail

USAGE

       firejail --profile=filename.profile

DESCRIPTION

Several command line options can be passed to the program using profile files. Firejail chooses the
profile file as follows:

1. If a profile file is provided by the user with --profile option, the profile file is loaded. Example:

$ firejail --profile=/home/netblue/icecat.profile icecat
Reading profile /home/netblue/icecat.profile
[...]

2. If a profile file with the same name as the application is present in ~/.config/firejail directory or
in /etc/firejail, the profile is loaded. ~/.config/firejail takes precedence over /etc/firejail. Example:

$ firejail icecat
Command name #icecat#
Found icecat profile in /home/netblue/.config/firejail directory
Reading profile /home/netblue/.config/firejail/icecat.profile
[...]

3. Use a default.profile file if the sandbox is started by a regular user, or a server.profile file if
the sandbox is started by root. Firejail looks for these files in ~/.config/firejail directory, followed
by /etc/firejail directory. To disable default profile loading, use --noprofile command option. Example:

$ firejail
Reading profile /etc/firejail/default.profile
Parent pid 8553, child pid 8554
Child process initialized
[...]

$ firejail --noprofile
Parent pid 8553, child pid 8554
Child process initialized
[...]

Scripting

Scripting commands:

File and directory names
File and directory names containing spaces are supported. The space character ' ' should not be
escaped.

Example: "blacklist ~/My Virtual Machines"

# this is a comment

include other.profile
Include other.profile file.

Example: "include /etc/firejail/disable-common.inc"

The file name can be prefixed with a macro such as ${HOME} or ${CFG}. ${HOME} is expanded as user
home directory, and ${CFG} is expanded as Firejail system configuration directory - in most cases
/etc/firejail or /usr/local/etc/firejail.

Example: "include ${HOME}/myprofiles/profile1" will load "~/myprofiles/profile1" file.

Example: "include ${CFG}/firefox.profile" will load "/etc/firejail/firefox.profile" file.

System configuration files in ${CFG} are overwritten during software installation. Persistent
configuration at system level is handled in ".local" files. For every profile file in ${CFG}
directory, the user can create a corresponding .local file storing modifications to the persistent
configuration. Persistent .local files are included at the start of regular profile files.

noblacklist file_name
If the file name matches file_name, the file will not be blacklisted in any blacklist commands
that follow.

Example: "noblacklist ${HOME}/.mozilla"

nowhitelist file_name
If the file name matches file_name, the file will not be whitelisted in any whitelist commands
that follow.

Example: "nowhitelist ~/.config"

ignore Ignore command.

Example: "ignore seccomp"

quiet Disable Firejail's output. This should be the first uncommented command in the profile file.

Example: "quiet"

Filesystem

These profile entries define a chroot filesystem built on top of the existing host filesystem. Each line
describes a file element that is removed from the filesystem (blacklist), a read-only file or directory
(read-only), a tmpfs mounted on top of an existing directory (tmpfs), or mount-bind a directory or file
on top of another directory or file (bind). Use private to set private mode. File globbing is
supported, and PATH and HOME directories are searched. Examples:

blacklist file_or_directory
Blacklist directory or file. Examples:

blacklist /usr/bin
blacklist /usr/bin/gcc*
blacklist ${PATH}/ifconfig
blacklist ${HOME}/.ssh

blacklist-nolog file_or_directory
When --tracelog flag is set, blacklisting generates syslog messages if the sandbox tries to access
the file or directory. blacklist-nolog command disables syslog messages for this particular file
or directory. Examples:

blacklist-nolog /usr/bin
blacklist-nolog /usr/bin/gcc*

bind directory1,directory2
Mount-bind directory1 on top of directory2. This option is only available when running as root.

bind file1,file2
Mount-bind file1 on top of file2. This option is only available when running as root.

disable-mnt
Disable /mnt, /media, /run/mount and /run/media access.

mkdir directory
Create a directory in user home or under /tmp before the sandbox is started. The directory is
created if it doesn't already exist.

Use this command for whitelisted directories you need to preserve when the sandbox is closed.
Without it, the application will create the directory, and the directory will be deleted when the
sandbox is closed. Subdirectories are recursively created. Example from firefox profile:

mkdir ~/.mozilla
whitelist ~/.mozilla
mkdir ~/.cache/mozilla/firefox
whitelist ~/.cache/mozilla/firefox

mkfile file
Similar to mkdir, this command creates a file in user home or under /tmp before the sandbox is
started. The file is created if it doesn't already exist.

noexec file_or_directory
Remount the file or the directory noexec, nodev and nosuid.

overlay
Mount a filesystem overlay on top of the current filesystem. The overlay is stored in
$HOME/.firejail/<PID> directory.

overlay-named name
Mount a filesystem overlay on top of the current filesystem. The overlay is stored in
$HOME/.firejail/name directory.

overlay-tmpfs
Mount a filesystem overlay on top of the current filesystem. All filesystem modifications
are discarded when the sandbox is closed.

private
Mount new /root and /home/user directories in temporary filesystems. All modifications are
discarded when the sandbox is closed.

private directory
Use directory as user home.

private-home file,directory
Build a new user home in a temporary filesystem, and copy the files and directories in the list in
the new home. All modifications are discarded when the sandbox is closed.

private-bin file,file
Build a new /bin in a temporary filesystem, and copy the programs in the list. The same directory
is also bind-mounted over /sbin, /usr/bin and /usr/sbin.

private-dev
Create a new /dev directory. Only dri, null, full, zero, tty, pts, ptmx, random, urandom, log and
shm devices are available.

private-etc file,directory
Build a new /etc in a temporary filesystem, and copy the files and directories in the list. All
modifications are discarded when the sandbox is closed.

private-lib file,directory
Build a new /lib directory and bring in the libraries required by the application to run. This
feature is still under development, see man 1 firejail for some examples.

private-opt file,directory
Build a new /optin a temporary filesystem, and copy the files and directories in the list. All
modifications are discarded when the sandbox is closed.

private-srv file,directory
Build a new /srv in a temporary filesystem, and copy the files and directories in the list. All
modifications are discarded when the sandbox is closed.

private-tmp
Mount an empty temporary filesystem on top of /tmp directory whitelisting /tmp/.X11-unix.

read-only file_or_directory
Make directory or file read-only.

read-write file_or_directory
Make directory or file read-write.

tmpfs directory
Mount an empty tmpfs filesystem on top of directory. This option is available only when running
the sandbox as root.

tracelog
Blacklist violations logged to syslog.

whitelist file_or_directory
Whitelist directory or file. A temporary file system is mounted on the top directory, and the
whitelisted files are mount-binded inside. Modifications to whitelisted files are persistent,
everything else is discarded when the sandbox is closed. The top directory could be user home,
/dev, /media, /mnt, /opt, /srv, /var, and /tmp.

Symbolic link handling: with the exception of user home, both the link and the real file should be
in the same top directory. For user home, both the link and the real file should be owned by the
user.

writable-etc
Mount /etc directory read-write.

writable-run-user
Disable the default blacklisting of run/user/$UID/systemd and /run/user/$UID/gnupg.

writable-var
Mount /var directory read-write.

writable-var-log
Use the real /var/log directory, not a clone. By default, a tmpfs is mounted on top of /var/log
directory, and a skeleton filesystem is created based on the original /var/log.

Security filters

The following security filters are currently implemented:

apparmor
Enable AppArmor confinement.

caps Enable default Linux capabilities filter.

caps.drop all
Blacklist all Linux capabilities.

caps.drop capability,capability,capability
Blacklist given Linux capabilities.

caps.keep capability,capability,capability
Whitelist given Linux capabilities.

protocol protocol1,protocol2,protocol3
Enable protocol filter. The filter is based on seccomp and checks the first argument to socket
system call. Recognized values: unix, inet, inet6, netlink and packet.

seccomp
Enable seccomp filter and blacklist the syscalls in the default list. See man 1 firejail for more
details.

seccomp syscall,syscall,syscall
Enable seccomp filter and blacklist the system calls in the list on top of default seccomp filter.

seccomp.block-secondary
Enable seccomp filter and filter system call architectures so that only the native architecture is
allowed.

seccomp.drop syscall,syscall,syscall
Enable seccomp filter and blacklist the system calls in the list.

seccomp.keep syscall,syscall,syscall
Enable seccomp filter and whitelist the system calls in the list.

memory-deny-write-execute
Install a seccomp filter to block attempts to create memory mappings that are both writable and
executable, to change mappings to be executable or to create executable shared memory.

nonewprivs
Sets the NO_NEW_PRIVS prctl. This ensures that child processes cannot acquire new privileges
using execve(2); in particular, this means that calling a suid binary (or one with file
capabilities) does not result in an increase of privilege.

noroot Use this command to enable an user namespace. The namespace has only one user, the current user.
There is no root account (uid 0) defined in the namespace.

x11 Enable X11 sandboxing.

x11 none
Blacklist /tmp/.X11-unix directory, ${HOME}/.Xauthority and file specified in ${XAUTHORITY}
environment variable. Remove DISPLAY and XAUTHORITY environment variables. Stop with error
message if X11 abstract socket will be accessible in jail.

x11 xephyr
Enable X11 sandboxing with Xephyr server.

x11 xorg
Enable X11 sandboxing with X11 security extension.

x11 xpra
Enable X11 sandboxing with Xpra server.

x11 xvfb
Enable X11 sandboxing with Xvfb server.

xephyr-screen WIDTHxHEIGHT
Set screen size for x11 xephyr. This command should be included in the profile file before x11
xephyr command.

Example:

xephyr-screen 640x480
x11 xephyr

Resource limits, CPU affinity, Control Groups

These profile entries define the limits on system resources (rlimits) for the processes inside the
sandbox. The limits can be modified inside the sandbox using the regular ulimit command. cpu command
configures the CPU cores available, and cgroup command place the sandbox in an existing control group.

Examples:

rlimit-as 123456789012
Set he maximum size of the process's virtual memory to 123456789012 bytes.

rlimit-cpu 123
Set he maximum CPU time in seconds.

rlimit-fsize 1024
Set the maximum file size that can be created by a process to 1024 bytes.

rlimit-nproc 1000
Set the maximum number of processes that can be created for the real user ID of the calling
process to 1000.

rlimit-nofile 500
Set the maximum number of files that can be opened by a process to 500.

rlimit-sigpending 200
Set the maximum number of processes that can be created for the real user ID of the calling
process to 200.

cpu 0,1,2
Use only CPU cores 0, 1 and 2.

nice -5
Set a nice value of -5 to all processes running inside the sandbox.

cgroup /sys/fs/cgroup/g1/tasks
The sandbox is placed in g1 control group.

timeout hh:mm:ss
Kill the sandbox automatically after the time has elapsed. The time is specified in
hours/minutes/seconds format.

User Environment

       allusers
              All  user  home  directories  are  visible  inside the sandbox. By default, only current user home
              directory is visible.

       name sandboxname
              Set sandbox name. Example:

              name browser

       env name=value
              Set environment variable. Examples:

              env LD_LIBRARY_PATH=/opt/test/lib
              env CFLAGS="-W -Wall -Werror"

       nodvd  Disable DVD and audio CD devices.

       nogroups
              Disable supplementary user groups

       shell none
              Run the program directly, without a shell.

       ipc-namespace
              Enable IPC namespace.

       nosound
              Disable sound system.

       notv   Disable DVB (Digital Video Broadcasting) TV devices.

       novideo
              Disable video devices.

       no3d   Disable 3D hardware acceleration.

Networking

       Networking features available in profile files.

       defaultgw address
              Use this address as default gateway in the new network namespace.

       dns address
              Set a DNS server for the sandbox. Up to three DNS servers can be defined.

       hostname name
              Set a hostname for the sandbox.

       hosts-file file
              Use file as /etc/hosts.

       ip address
              Assign IP addresses to the last network interface defined by a net command. A default  gateway  is
              assigned by default.

              Example:
              net eth0
              ip 10.10.20.56

       ip none
              No  IP  address  and  no  default  gateway  are configured for the last interface defined by a net
              command. Use this option in case you intend to start an external DHCP client in the sandbox.

              Example:
              net eth0
              ip none

       ip6 address
              Assign IPv6 addresses to the last network interface defined by a net command.

              Example:
              net eth0
              ip6 2001:0db8:0:f101::1/64

       iprange address,address
              Assign  an  IP address in the provided range to the last network  interface  defined  by   a   net
              command.  A  default  gateway  is assigned by default.

              Example:

              net eth0
              iprange 192.168.1.150,192.168.1.160

       mac address
              Assign MAC addresses to the last network interface defined by a net command.

       machine-id
              Spoof id number in /etc/machine-id file - a new random id is generated inside the sandbox.

       mtu number
              Assign a MTU value to the last network interface defined by a net command.

       netfilter
              If a new network namespace is created, enabled default network filter.

       netfilter filename
              If a new network namespace is created, enabled the network filter in filename.

       net bridge_interface
              Enable  a  new  network  namespace and connect it to this bridge interface.  Unless specified with
              option --ip and --defaultgw, an IP address and a default gateway will be assigned automatically to
              the sandbox. The IP address is verified using ARP before assignment.  The  address  configured  as
              default  gateway  is the bridge device IP address. Up to four --net bridge devices can be defined.
              Mixing bridge and macvlan devices is allowed.

       net ethernet_interface
              Enable a new network namespace and connect it to this ethernet interface using the standard  Linux
              macvlan  driver.  Unless  specified  with option --ip and --defaultgw, an IP address and a default
              gateway will be assigned automatically to the sandbox. The IP address is verified using ARP before
              assignment. The address configured as default gateway is the default gateway of the  host.  Up  to
              four  --net  devices  can  be  defined.  Mixing bridge and macvlan devices is allowed.  Note: wlan
              devices are not supported for this option.

       net none
              Enable a new, unconnected network namespace. The only interface available in the new namespace  is
              a  new  loopback  interface  (lo).   Use this option to deny network access to programs that don't
              really need network access.

       veth-name name
              Use this name for the interface connected  to  the  bridge  for  --net=bridge_interface  commands,
              instead of the default one.

Other

       join-or-start sandboxname
              Join  the  sandbox  identified  by name or start a new one.  Same as "firejail --join=sandboxname"
              command if sandbox with specified name exists, otherwise same as "name sandboxname".

FILES

       /etc/firejail/filename.profile, $HOME/.config/firejail/filename.profile

LICENSE

       Firejail is free software; you can redistribute it and/or modify it under the terms of  the  GNU  General
       Public License as published by the Free Software Foundation; either version 2 of the License, or (at your
       option) any later version.

       Homepage: https://firejail.wordpress.com