profile — Security profile file syntax for Firejail
Usage
firejail --profile=filename.profile
firejail --profile=profile_name
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:
$ 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
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
- ?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 conditional supported is HAS_APPIMAGE.
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
-
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 ehh0" - 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.
- keep-var-tmp
/var/tmp directory is untouched.
- 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-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-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 disc, dri, null, full, zero, tty, pts, ptmx, random, snd, urandom, video, log and shm devices are available.
- keep-dev-shm
/dev/shm directory is untouched (even with private-dev).
- 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, /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.
- 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 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.
- 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.
- nodbus
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.
- nosound
Disable sound system.
- noautopulse
Disable automatic ~/.config/pulse init, for complex setups such as remote pulse servers or non-standard socket paths.
- notv
Disable DVB (Digital Video Broadcasting) TV devices.
- nou2f
Disable U2F 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|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 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.
- 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.
- 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.
- 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
See Also
firejail(1), firemon(1), firecfg(1), firejail-login(5) firejail-users(5)
Referenced By
firecfg(1), firejail(1), firejail-login(5), firejail-users(5), firemon(1).