NAME¶

profile - Security profile file syntax, and information about building new application profiles.

SYNOPSIS¶

Using a specific profile:

Building a profile manually:

Aliases and redirections:

Running the profile builder:

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. 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:

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:

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:

Templates¶

In /usr/share/doc/firejail there are two templates to write new profiles.

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

Example:

# disable networking
net none # this command creates an empty network namespace

?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 this way are HAS_APPIMAGE, HAS_NET, HAS_NODBUS, HAS_NOSOUND, HAS_PRIVATE and HAS_X11. The conditionals ALLOW_TRAY, BROWSER_DISABLE_U2F and BROWSER_ALLOW_DRM can be enabled or disabled globally in Firejail's configuration file.

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

Note: When using one or more conditionals and --profile, it is recommended that the relevant option(s) (such as --appimage) be specified before --profile, so that their respective conditional(s) (such as ?HAS_APPIMAGE) inside of the profile evaluate to true.

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.

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.

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"
Example: "ignore net eth0"

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/directory that is inaccessible (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, see the firejail FILE GLOBBING section for more details. 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.

keep-config-pulse

Disable automatic ~/.config/pulse init, for complex setups such as remote pulse servers or non-standard socket paths.

keep-dev-shm

/dev/shm directory is untouched (even with private-dev).

keep-var-tmp

/var/tmp directory is untouched.

mkdir directory

Create a directory in user home, under /tmp, or under /run/user/<UID> 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

For files in /run/user/<PID> use ${RUNUSER} macro:

mkdir ${RUNUSER}/firejail-testing

mkfile file

Similar to mkdir, this command creates an empty file in user home, or /tmp, or under /run/user/<UID> 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.

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 and --private=directory cannot be used together.

Bug: Even with this enabled, some commands (such as mkdir, mkfile and private-cache) will still operate on the original home directory. Workaround: Disable the incompatible commands, such as by using "ignore mkdir" and "ignore mkfile". For details, see #903

private-bin file,file

Build a new /bin in a temporary filesystem, and copy the programs in the list. The files in the list must be expressed as relative to the /bin, /sbin, /usr/bin, /usr/sbin, or /usr/local/bin directories. The same directory is also bind-mounted over /sbin, /usr/bin and /usr/sbin. Multiple private-bin commands are allowed and they accumulate.

private-cache

Mount an empty temporary filesystem on top of the .cache directory in user home. All modifications are discarded when the sandbox is closed.

private-cwd

Set working directory inside jail to the home directory, and failing that, the root directory.

private-cwd directory

Set working directory inside the jail. Full directory path is required. Symbolic links are not allowed.

private-dev

Create a new /dev directory. Only disc, dri, dvb, hidraw, null, full, zero, tty, pts, ptmx, random, snd, urandom, video, log, shm and usb devices are available. Use the options no3d, nodvd, nosound, notv, nou2f and novideo for additional restrictions.

private-etc file,directory

Build a new /etc in a temporary filesystem, and copy the files and directories in the list. The files and directories in the list must be expressed as relative to the /etc directory, and must not contain the / character (e.g., /etc/foo must be expressed as foo, but /etc/foo/bar -- expressed as foo/bar -- is disallowed). All modifications are discarded when the sandbox is closed. Multiple private-etc commands are allowed and they accumulate.

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. The files and directories in the list must be expressed as relative to the current user's home directory. 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. The files and directories in the list must be expressed as relative to the /lib directory. This feature is still under development, see man 1 firejail for some examples.

private-opt file,directory

Build a new /opt in a temporary filesystem, and copy the files and directories in the list. The files and directories in the list must be expressed as relative to the /opt directory, and must not contain the / character (e.g., /opt/foo must be expressed as foo, but /opt/foo/bar -- expressed as foo/bar -- is disallowed). 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. The files and directories in the list must be expressed as relative to the /srv directory, and must not contain the / character (e.g., /srv/foo must be expressed as foo, but /srv/foo/bar -- expressed as foo/bar -- is disallowed). 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. Directories outside user home or not owned by the user are not allowed. Sandboxes running as root are exempt from these restrictions.

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 can be all directories in / (except /proc and /sys), /sys/module, /run/user/$UID, $HOME and all directories in /usr.

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.

whitelist-ro file_or_directory

Equivalent to "whitelist file_or_directory" followed by "read-only file_or_directory"

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:

allow-debuggers

Allow tools such as strace and gdb inside the sandbox by whitelisting system calls ptrace and process_vm_readv.

apparmor

Enable AppArmor confinement with the "firejail-default" AppArmor profile.

apparmor profile_name

Enable AppArmor confinement with a custom AppArmor profile. Note that the profile in question must already be loaded into the kernel.

caps

Enable default Linux capabilities filter. See capabilities(7) for details.

caps.drop capability,capability,capability

Blacklist given Linux capabilities.

caps.drop all

Blacklist all Linux capabilities.

caps.keep capability,capability,capability

Whitelist given Linux capabilities.

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.

noprinters

Disable printers.

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.

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, packet, and bluetooth. Multiple protocol commands are allowed and they accumulate.

restrict-namespaces

Install a seccomp filter that blocks attempts to create new cgroup, ipc, net, mount, pid, time, user or uts namespaces.

restrict-namespaces cgroup,ipc,net,mnt,pid,time,user,uts

Install a seccomp filter that blocks attempts to create any of the specified namespaces.

seccomp

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

seccomp.32

Enable seccomp filter and blacklist the syscalls in the default list for 32 bit system calls on a 64 bit architecture system.

seccomp syscall,syscall,syscall

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

seccomp.32 syscall,syscall,syscall

Enable seccomp filter and blacklist the system calls in the list on top of default seccomp filter for 32 bit system calls on a 64 bit architecture system.

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.32.drop syscall,syscall,syscall

Enable seccomp filter and blacklist the system calls in the list for 32 bit system calls on a 64 bit architecture system.

seccomp.keep syscall,syscall,syscall

Enable seccomp filter and whitelist the system calls in the list.

seccomp.32.keep syscall,syscall,syscall

Enable seccomp filter and whitelist the system calls in the list for 32 bit system calls on a 64 bit architecture system.

seccomp-error-action kill | log | ERRNO

Return a different error instead of EPERM to the process, kill it when an attempt is made to call a blocked system call, or allow but log the attempt.

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

DBus filtering¶

Access to the session and system DBus UNIX sockets can be allowed, filtered or disabled. To disable the abstract sockets (and force applications to use the filtered UNIX socket) you would need to request a new network namespace using --net command. Another option is to remove unix from the --protocol set.

Filtering requires installing the xdg-dbus-proxy utility. Filter rules can be specified for well-known DBus names, but they are also propagated to the owning unique name, too. The permissions are "sticky" and are kept even if the corresponding well-known name is released (however, applications rarely release well-known names in practice). Names may have a .* suffix to match all names underneath them, including themselves (e.g. "foo.bar.*" matches "foo.bar", "foo.bar.baz" and "foo.bar.baz.quux", but not "foobar"). For more information, see xdg-dbus-proxy(1).

Examples:

dbus-system filter

Enable filtered access to the system DBus. Filters can be specified with the dbus-system.talk and dbus-system.own commands.

dbus-system none

Disable access to the system DBus. Once access is disabled, it cannot be relaxed to filtering.

dbus-system.own org.gnome.ghex.*

Allow the application to own the name org.gnome.ghex and all names underneath in on the system DBus.

dbus-system.talk org.freedesktop.Notifications

Allow the application to talk to the name org.freedesktop.Notifications on the system DBus.

dbus-system.see org.freedesktop.Notifications

Allow the application to see but not talk to the name org.freedesktop.Notifications on the system DBus.

dbus-system.call org.freedesktop.Notifications=org.freedesktop.Notifications.*@/org/freedesktop/Notifications

Allow the application to call methods of the interface org.freedesktop.Notifications of the object exposed at the path /org/freedesktop/Notifications by the client owning the bus name org.freedesktop.Notifications on the system DBus.

dbus-system.broadcast org.freedesktop.Notifications=org.freedesktop.Notifications.*@/org/freedesktop/Notifications

Allow the application to receive broadcast signals from the interface org.freedesktop.Notifications of the object exposed at the path /org/freedesktop/Notifications by the client owning the bus name org.freedesktop.Notifications on the system DBus.

dbus-user filter

Enable filtered access to the session DBus. Filters can be specified with the dbus-user.talk and dbus-user.own commands.

dbus-user none

Disable access to the session DBus. Once access is disabled, it cannot be relaxed to filtering.

dbus-user.own org.gnome.ghex.*

Allow the application to own the name org.gnome.ghex and all names underneath in on the session DBus.

dbus-user.talk org.freedesktop.Notifications

Allow the application to talk to the name org.freedesktop.Notifications on the session DBus.

dbus-user.see org.freedesktop.Notifications

Allow the application to see but not talk to the name org.freedesktop.Notifications on the session DBus.

dbus-user.call org.freedesktop.Notifications=org.freedesktop.Notifications.*@/org/freedesktop/Notifications

Allow the application to call methods of the interface org.freedesktop.Notifications of the object exposed at the path /org/freedesktop/Notifications by the client owning the bus name org.freedesktop.Notifications on the session DBus.

dbus-user.broadcast org.freedesktop.Notifications=org.freedesktop.Notifications.*@/org/freedesktop/Notifications

Allow the application to receive broadcast signals from the the interface org.freedesktop.Notifications of the object exposed at the path /org/freedesktop/Notifications by the client owning the bus name org.freedesktop.Notifications on the session DBus.

nodbus (deprecated)

Disable D-Bus access (both system and session buses). Equivalent to dbus-system none and dbus-user none.

Individual filters can be overridden via the --ignore command. Supposing a profile has
[...]
dbus-user filter
dbus-user.own org.mozilla.firefox.*
dbus-user.talk org.freedesktop.Notifications
dbus-system none
[...]

and the user wants to disable notifications, this can be achieved by putting the below in a local override file:
[...]
ignore dbus-user.talk org.freedesktop.Notifications
[...]

Resource limits, CPU affinity¶

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.

Examples:

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.

rlimit-as 123456789012

Set the maximum size of the process's virtual memory to 123456789012 bytes.

rlimit-cpu 123

Set the 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.

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.

env name=value

Set environment variable. Examples:

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

ipc-namespace

Enable IPC namespace.

keep-fd

Inherit open file descriptors to sandbox.

name sandboxname

Set sandbox name. Example:

name browser

no3d

Disable 3D hardware acceleration.

noautopulse (deprecated)

See keep-config-pulse.

nodvd

Disable DVD and audio CD devices.

nogroups

Disable supplementary user groups

noinput

Disable input devices.

nosound

Disable sound system.

notv

Disable DVB (Digital Video Broadcasting) TV devices.

nou2f

Disable U2F devices.

novideo

Disable video capture devices.

machine-id

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

shell none

Run the program directly, without a shell.

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

ip dhcp

Acquire an IP address and default gateway for the last interface defined by a net command, as well as set the DNS servers according to the DHCP response. This command requires the ISC dhclient DHCP client to be installed and will start it automatically inside the sandbox.

Example:
net br0
ip dhcp

This command should not be used in conjunction with the dns command if the DHCP server is set to configure DNS servers for the clients, because the manually specified DNS servers will be overwritten.

The DHCP client will NOT release the DHCP lease when the sandbox terminates. If your DHCP server requires leases to be explicitly released, consider running a DHCP client and releasing the lease manually in conjunction with the net none command.

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

ip6 dhcp

Acquire an IPv6 address and default gateway for the last interface defined by a net command, as well as set the DNS servers according to the DHCP response. This command requires the ISC dhclient DHCP client to be installed and will start it automatically inside the sandbox.

Example:
net br0
ip6 dhcp

This command should not be used in conjunction with the dns command if the DHCP server is set to configure DNS servers for the clients, because the manually specified DNS servers will be overwritten.

The DHCP client will NOT release the DHCP lease when the sandbox terminates. If your DHCP server requires leases to be explicitly released, consider running a DHCP client and releasing the lease manually.

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.

mtu number

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

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|wireless_interface

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.

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.

net tap_interface

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.

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.

netlock

Generate a custom network filter and enable it.

netmask address

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.

netns namespace

Run the program in a named, persistent network namespace. These can be created and configured using "ip netns".

veth-name name

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

Other¶

deterministic-exit-code

Always exit firejail with the first child's exit status. The default behavior is to use the exit status of the final child to exit, which can be nondeterministic.

deterministic-shutdown

Always shut down the sandbox after the first child has terminated. The default behavior is to keep the sandbox alive as long as it contains running processes.

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/appname.profile

Global Firejail configuration consisting mainly of profiles for each application supported by default.

$HOME/.config/firejail/appname.profile

User application profiles, will take precedence over the global profiles.

/usr/share/doc/firejail/profile.template

Template for building new profiles.

/usr/share/doc/firejail/redirect_alias-profile.template

Template for aliasing/redirecting profiles.

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

SEE ALSO¶

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

https://github.com/netblue30/firejail/wiki/Creating-Profiles