DOKK / manpages / debian 10 / firejail / firejail-profile.5.en
FIREJAIL-PROFILE(5) firejail profiles man page FIREJAIL-PROFILE(5)

profile - Security profile file syntax for Firejail


firejail --profile=profile_name

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. If a profile name is given, it is searched for first in the ~/.config/firejail directory and if not found then in /etc/firejail directory. Profile names do not include the .profile suffix. Example:

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

$ firejail --profile=icecat icecat-wrapper.sh
Reading profile /etc/firejail/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 commands:

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

Example: "blacklist ~/My Virtual Machines"

# this is a comment

?CONDITIONAL: profile line
Conditionally add profile line.

Example: "?HAS_APPIMAGE: whitelist ${HOME}/special/appimage/dir"

This example will load the whitelist profile line only if the --appimage option has been specified on the command line.

Currently the only conditionals supported are HAS_APPIMAGE, HAS_NODBUS and BROWSER_DISABLE_U2F.

The profile line may be any profile line that you would normally use in a profile except for "quiet" and "include" lines.

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.

The file name may also be just the name without the leading directory components. In this case, first the user config directory (${HOME}/.config/firejail) is searched for the file name and if not found then the system configuration directory is search for the file name. Note: Unlike the --profile option which takes a profile name without the '.profile' suffix, include must be given the full file name.

Example: "include firefox.profile" will load "${HOME}/.config/firejail/firefox.profile" file and if it does not exist "${CFG}/firefox.profile" will be loaded.

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.

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

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

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

Example: "nowhitelist ~/.config"

Ignore command.

Example: "ignore seccomp"
Example: "ignore net ehh0"

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

Example: "quiet"

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 directory or file. Examples:

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

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*

Mount-bind directory1 on top of directory2. This option is only available when running as root.
Mount-bind file1 on top of file2. This option is only available when running as root.
Disable /mnt, /media, /run/mount and /run/media access.
/var/tmp directory is untouched.
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

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.
Remount the file or the directory noexec, nodev and nosuid.
Mount a filesystem overlay on top of the current filesystem. The overlay is stored in $HOME/.firejail/<PID> directory.
Mount a filesystem overlay on top of the current filesystem. The overlay is stored in $HOME/.firejail/name directory.
Mount a filesystem overlay on top of the current filesystem. All filesystem modifications are discarded when the sandbox is closed.
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.
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.
Mount an empty temporary filesystem on top of the .cache directory in user home. All modifications are discarded when the sandbox is closed.
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.
Create a new /dev directory. Only disc, dri, null, full, zero, tty, pts, ptmx, random, snd, urandom, video, log and shm devices are available.
/dev/shm directory is untouched (even with private-dev).
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.
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.
Build a new /opt in a temporary filesystem, and copy the files and directories in the list. All modifications are discarded when the sandbox is closed.
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.
Mount an empty temporary filesystem on top of /tmp directory whitelisting /tmp/.X11-unix.
Make directory or file read-only.
Make directory or file read-write.
Mount an empty tmpfs filesystem on top of directory. This option is available only when running the sandbox as root.
Blacklist violations logged to syslog.
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, /etc, /media, /mnt, /opt, /srv, /sys/module, /usr/share, /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.

Mount /etc directory read-write.
Disable the default blacklisting of run/user/$UID/systemd and /run/user/$UID/gnupg.
Mount /var directory read-write.
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.

The following security filters are currently implemented:

Enable AppArmor confinement.
Enable default Linux capabilities filter.
Blacklist all Linux capabilities.
Blacklist given Linux capabilities.
Whitelist given Linux capabilities.
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.
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.
Enable seccomp filter and filter system call architectures so that only the native architecture is allowed.
Enable seccomp filter and blacklist the system calls in the list.
Enable seccomp filter and whitelist the system calls in the list.
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.
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.
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.
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.
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

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:

Set the maximum size of the process's virtual memory to 123456789012 bytes.
Set the maximum CPU time in seconds.
Set the maximum file size that can be created by a process to 1024 bytes.
Set the maximum number of processes that can be created for the real user ID of the calling process to 1000.
Set the maximum number of files that can be opened by a process to 500.
Set the maximum number of processes that can be created for the real user ID of the calling process to 200.
Use only CPU cores 0, 1 and 2.
Set a nice value of -5 to all processes running inside the sandbox.
The sandbox is placed in g1 control group.
Kill the sandbox automatically after the time has elapsed. The time is specified in hours/minutes/seconds format.

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

Set sandbox name. Example:

name browser

Set environment variable. Examples:

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

Disable DVD and audio CD devices.
Disable supplementary user groups
Run the program directly, without a shell.
Enable IPC namespace.
Disable D-Bus access. Only the regular UNIX socket is handled by this command. To disable the abstract socket, you would need to request a new network namespace using the net command. Another option is to remove unix from protocol set.
Disable sound system.
Disable automatic ~/.config/pulse init, for complex setups such as remote pulse servers or non-standard socket paths.
Disable DVB (Digital Video Broadcasting) TV devices.
Disable U2F devices.
Disable video devices.
Disable 3D hardware acceleration.

Networking features available in profile files.

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

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

Set a hostname for the sandbox.

Use file as /etc/hosts.

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

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

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

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

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

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

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

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

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.

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.

Enable a new network namespace and connect it to this ethernet interface using the standard Linux macvlan or ipvlan 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.

Enable a new network namespace and connect it to this ethernet tap interface using the standard Linux macvlan driver. If the tap interface is not configured, the sandbox will not try to configure the interface inside the sandbox. Please use ip, netmask and defaultgw to specify the configuration.

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.

Use this option when you want to assign an IP address in a new namespace and the parent interface specified by --net is not configured. An IP address and a default gateway address also have to be added.

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

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".

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

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

firejail(1), firemon(1), firecfg(1), firejail-login(5) firejail-users(5)

Jun 2022 0.9.58.2