profile(5) 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"

other.profile file name can be prefixed with ${HOME}. This will force Firejail to look for the file in user home directory.

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

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"

ignore command
Ignore command.

Example: "ignore seccomp"

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

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.
mkdir directory
Create a directory in user home 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 also need to be created using mkdir. Example from firefox profile:


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

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-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-tmp
Mount an empty temporary filesystem on top of /tmp directory.
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
Build a new user home in a temporary filesystem, and mount-bind file_or_directory. The modifications to file_or_directory are persistent, everything else is discarded when the sandbox is closed.
writable-etc
Mount /etc directory read-write.
writable-var
Mount /var directory read-write.

Security filters

The following security filters are currently implemented:

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. The default list is as follows: mount, umount2, ptrace, kexec_load, kexec_file_load, open_by_handle_at, init_module, finit_module, delete_module, iopl, ioperm, swapon, swapoff, syslog, process_vm_readv, process_vm_writev, sysfs,_sysctl, adjtimex, clock_adjtime, lookup_dcookie, perf_event_open, fanotify_init, kcmp, add_key, request_key, keyctl, uselib, acct, modify_ldt, pivot_root, io_setup, io_destroy, io_getevents, io_submit, io_cancel, remap_file_pages, mbind, get_mempolicy, set_mempolicy, migrate_pages, move_pages, vmsplice, perf_event_open, chroot, tuxcall, reboot, mfsservctl and get_kernel_syms.
seccomp syscall,syscall,syscall
Enable seccomp filter and blacklist the system calls in the list on top of default seccomp filter.
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.
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 results 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.

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-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 1,2,3
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.

User Environment

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"

nogroups
Disable supplementary user groups
shell none
Run the program directly, without a shell.
ipc-namespace
Enable IPC namespace.
nosound
Disable sound system.

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.

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.

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.

RELOCATING PROFILES

For various reasons some users might want to keep the profile files in a different directory. Using --profile-path command line option, Firejail can be instructed to look for profiles into this directory.

This is an example of relocating the profile files into a new directory, /home/netblue/myprofiles. Start by creating the new directory and copy all the profile files in:


$ mkdir ~/myprofiles && cd ~/myprofiles && cp /etc/firejail/* .


Using sed utility, modify the absolute paths for include commands:


$ sed -i "s/\/etc\/firejail/\/home\/netblue\/myprofiles/g" *.profile
$ sed -i "s/\/etc\/firejail/\/home\/netblue\/myprofiles/g" *.inc


Start Firejail using the new path:


$ firejail --profile-path=~/myprofiles

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: http://firejail.wordpress.com