FIREJAIL(1) firejail man page FIREJAIL(1) NAME Firejail - Linux namespaces sandbox program SYNOPSIS Start a sandbox: firejail [OPTIONS] [program and arguments] File transfer from an existing sandbox firejail {--ls | --get | --put} dir_or_filename Network traffic shaping for an existing sandbox: firejail --bandwidth={name|pid} bandwidth-command Monitoring: firejail {--list | --netstats | --top | --tree} Miscellaneous: firejail {-? | --debug-caps | --debug-errnos | --debug-syscalls | --debug-protocols | --help | --version} DESCRIPTION Firejail is a SUID sandbox program that reduces the risk of security breaches by restricting the running environment of untrusted applica‐ tions using Linux namespaces, seccomp-bpf and Linux capabilities. It allows a process and all its descendants to have their own private view of the globally shared kernel resources, such as the network stack, process table, mount table. Firejail can work in a SELinux or AppArmor environment, and it is integrated with Linux Control Groups. Written in C with virtually no dependencies, the software runs on any Linux computer with a 3.x kernel version or newer. It can sandbox any type of processes: servers, graphical applications, and even user login sessions. Firejail allows the user to manage application security using security profiles. Each profile defines a set of permissions for a specific application or group of applications. The software includes security profiles for a number of more common Linux programs, such as Mozilla Firefox, Chromium, VLC, Transmission etc. USAGE Without any options, the sandbox consists of a filesystem build in a new mount namespace, and new PID and UTS namespaces. IPC, network and user namespaces can be added using the command line options. The default Firejail filesystem is based on the host filesystem with the main system directories mounted read-only. These directories are /etc, /var, /usr, /bin, /sbin, /lib, /lib32, /libx32 and /lib64. Only /home and /tmp are writable. As it starts up, Firejail tries to find a security profile based on the name of the application. If an appropriate profile is not found, Fire‐ jail will use a default profile. The default profile is quite restric‐ tive. In case the application doesn't work, use --noprofile option to disable it. For more information, please see SECURITY PROFILES section below. If a program argument is not specified, Firejail starts /bin/bash shell. Examples: $ firejail [OPTIONS] # starting a /bin/bash shell $ firejail [OPTIONS] firefox # starting Mozilla Firefox # sudo firejail [OPTIONS] /etc/init.d/nginx start OPTIONS -- Signal the end of options and disables further option process‐ ing. --allow-debuggers Allow tools such as strace and gdb inside the sandbox by whitelisting system calls ptrace and process_vm_readv. This option is only available when running on Linux kernels 4.8 or newer - a kernel bug in ptrace system call allows a full bypass of the seccomp filter. Example: $ firejail --allow-debuggers --profile=/etc/firejail/fire‐ fox.profile strace -f firefox --allusers All directories under /home are visible inside the sandbox. By default, only current user home directory is visible. Example: $ firejail --allusers --apparmor Enable AppArmor confinement. For more information, please see APPARMOR section below. --appimage Sandbox an AppImage (https://appimage.org/) application. Example: $ firejail --appimage krita-3.0-x86_64.appimage $ firejail --appimage --private krita-3.0-x86_64.appimage $ firejail --appimage --net=none --x11 krita-3.0-x86_64.appimage --audit Audit the sandbox, see AUDIT section for more details. --audit=test-program Audit the sandbox, see AUDIT section for more details. --bandwidth=name|pid Set bandwidth limits for the sandbox identified by name or PID, see TRAFFIC SHAPING section for more details. --bind=filename1,filename2 Mount-bind filename1 on top of filename2. This option is only available when running as root. Example: # firejail --bind=/config/etc/passwd,/etc/passwd --blacklist=dirname_or_filename Blacklist directory or file. File globbing is supported, see FILE GLOBBING section for more details. Example: $ firejail --blacklist=/sbin --blacklist=/usr/sbin $ firejail --blacklist=~/.mozilla $ firejail "--blacklist=/home/username/My Virtual Machines" $ firejail --blacklist=/home/username/My\ Virtual\ Machines --build The command builds a whitelisted profile. The profile is printed on the screen. If /usr/bin/strace is installed on the system, it also builds a whitelisted seccomp profile. The program is run in a very relaxed sandbox, with only --caps.drop=all and --nonew‐ privs. Programs that raise user privileges are not supported in order to allow strace to run. Chromium and Chromium-based browsers will not work. Example: $ firejail --build=profile-file vlc ~/Videos/test.mp4 --build=profile-file The command builds a whitelisted profile, and saves it in pro‐ file-file. If /usr/bin/strace is installed on the system, it also builds a whitelisted seccomp profile. The program is run in a very relaxed sandbox, with only --caps.drop=all and --nonew‐ privs. Programs that raise user privileges are not supported in order to allow strace to run. Chromium and Chromium-based browsers will not work. Example: $ firejail --build=vlc.profile vlc ~/Videos/test.mp4 -c Execute command and exit. --caps Linux capabilities is a kernel feature designed to split up the root privilege into a set of distinct privileges. These privi‐ leges can be enabled or disabled independently, thus restricting what a process running as root can do in the system. By default root programs run with all capabilities enabled. --caps option disables the following capabilities: CAP_SYS_MOD‐ ULE, CAP_SYS_RAWIO, CAP_SYS_BOOT, CAP_SYS_NICE, CAP_SYS_TTY_CON‐ FIG, CAP_SYSLOG, CAP_MKNOD, CAP_SYS_ADMIN. The filter is applied to all processes started in the sandbox. Example: $ sudo firejail --caps /etc/init.d/nginx start --caps.drop=all Drop all capabilities for the processes running in the sandbox. This option is recommended for running GUI programs or any other program that doesn't require root privileges. It is a must-have option for sandboxing untrusted programs installed from unoffi‐ cial sources - such as games, Java programs, etc. Example: $ firejail --caps.drop=all warzone2100 --caps.drop=capability,capability,capability Define a custom blacklist Linux capabilities filter. Example: $ firejail --caps.drop=net_broadcast,net_admin,net_raw --caps.keep=capability,capability,capability Define a custom whitelist Linux capabilities filter. Example: $ sudo firejail --caps.keep=chown,net_bind_service,setgid,\ setuid /etc/init.d/nginx start --caps.print=name|pid Print the caps filter for the sandbox identified by name or by PID. Example: $ firejail --name=mygame --caps.drop=all warzone2100 & $ firejail --caps.print=mygame Example: $ firejail --list 3272:netblue:firejail --private firefox $ firejail --caps.print=3272 --cgroup=tasks-file Place the sandbox in the specified control group. tasks-file is the full path of cgroup tasks file. Example: # firejail --cgroup=/sys/fs/cgroup/g1/tasks --chroot=dirname Chroot the sandbox into a root filesystem. Unlike the regular filesystem container, the system directories are mounted read- write. If the sandbox is started as a regular user, default sec‐ comp and capabilities filters are enabled. This option is not available on Grsecurity systems. Example: $ firejail --chroot=/media/ubuntu warzone2100 --cpu=cpu-number,cpu-number,cpu-number Set CPU affinity. Example: $ firejail --cpu=0,1 handbrake --cpu.print=name|pid Print the CPU cores in use by the sandbox identified by name or by PID. Example: $ firejail --name=mygame --caps.drop=all warzone2100 & $ firejail --cpu.print=mygame Example: $ firejail --list 3272:netblue:firejail --private firefox $ firejail --cpu.print=3272 --csh Use /bin/csh as default user shell. Example: $ firejail --csh --debug Print debug messages. Example: $ firejail --debug firefox --debug-blacklists Debug blacklisting. Example: $ firejail --debug-blacklists firefox --debug-caps Print all recognized capabilities in the current Firejail soft‐ ware build and exit. Example: $ firejail --debug-caps --debug-check-filename Debug filename checking. Example: $ firejail --debug-check-filename firefox --debug-errnos Print all recognized error numbers in the current Firejail soft‐ ware build and exit. Example: $ firejail --debug-errnos --debug-private-lib Debug messages for --private-lib option. --debug-protocols Print all recognized protocols in the current Firejail software build and exit. Example: $ firejail --debug-protocols --debug-syscalls Print all recognized system calls in the current Firejail soft‐ ware build and exit. Example: $ firejail --debug-syscalls --debug-whitelists Debug whitelisting. Example: $ firejail --debug-whitelists firefox --defaultgw=address Use this address as default gateway in the new network names‐ pace. Example: $ firejail --net=eth0 --defaultgw=10.10.20.1 firefox --disable-mnt Disable /mnt, /media, /run/mount and /run/media access. Example: $ firejail --disable-mnt firefox --dns=address Set a DNS server for the sandbox. Up to three DNS servers can be defined. Use this option if you don't trust the DNS setup on your network. Example: $ firejail --dns=8.8.8.8 --dns=8.8.4.4 firefox Note: this feature is not supported on systemd-resolved setups. --dns.print=name|pid Print DNS configuration for a sandbox identified by name or by PID. Example: $ firejail --name=mygame --caps.drop=all warzone2100 & $ firejail --dns.print=mygame Example: $ firejail --list 3272:netblue:firejail --private firefox $ firejail --dns.print=3272 --env=name=value Set environment variable in the new sandbox. Example: $ firejail --env=LD_LIBRARY_PATH=/opt/test/lib --force By default, if Firejail is started in an existing sandbox, it will run the program in a bash shell. This option disables this behavior, and attempts to start Firejail in the existing sand‐ box. There could be lots of reasons for it to fail, for example if the existing sandbox disables admin capabilities, SUID bina‐ ries, or if it runs seccomp. --fs.print=name|print Print the filesystem log for the sandbox identified by name or by PID. Example: $ firejail --name=mygame --caps.drop=all warzone2100 & $ firejail --fs.print=mygame Example: $ firejail --list 3272:netblue:firejail --private firefox $ firejail --fs.print=3272 --get=name|pid filename Get a file from sandbox container, see FILE TRANSFER section for more details. --git-install Download, compile and install mainline git version of Firejail from the official repository on GitHub. The software is installed in /usr/local/bin, and takes precedence over the (old) version installed in /usr/bin. If for any reason the new version doesn't work, the user can uninstall it using --git-uninstall command and revert to the old version. Prerequisites: git and compile support are required for this command to work. On Debian/Ubuntu systems this support is installed using "sudo apt-get install build-essential git". Example: $ firejail --git-install --git-uninstall Remove the Firejail version previously installed in /usr/local/bin using --git-install command. Example: $ firejail --git-uninstall -?, --help Print options end exit. --hostname=name Set sandbox hostname. Example: $ firejail --hostname=officepc firefox --hosts-file=file Use file as /etc/hosts. Example: $ firejail --hosts-file=~/myhosts firefox --ignore=command Ignore command in profile file. Example: $ firejail --ignore=shell --ignore=seccomp firefox --interface=interface Move interface in a new network namespace. Up to four --inter‐ face options can be specified. Note: wlan devices are not sup‐ ported for this option. Example: $ firejail --interface=eth1 --interface=eth0.vlan100 --ip=address Assign IP addresses to the last network interface defined by a --net option. A default gateway is assigned by default. Example: $ firejail --net=eth0 --ip=10.10.20.56 firefox --ip=none No IP address and no default gateway are configured for the last interface defined by a --net option. Use this option in case you intend to start an external DHCP client in the sandbox. Example: $ firejail --net=eth0 --ip=none If the corresponding interface doesn't have an IP address con‐ figured, this option is enabled by default. --ip6=address Assign IPv6 addresses to the last network interface defined by a --net option. Example: $ firejail --net=eth0 --ip6=2001:0db8:0:f101::1/64 firefox Note: you don't need this option if you obtain your ip6 address from router via SLAAC (your ip6 address and default route will be configured by kernel automatically). --iprange=address,address Assign an IP address in the provided range to the last network interface defined by a --net option. A default gateway is assigned by default. Example: $ firejail --net=eth0 --iprange=192.168.1.100,192.168.1.150 --ipc-namespace Enable a new IPC namespace if the sandbox was started as a reg‐ ular user. IPC namespace is enabled by default for sandboxes started as root. Example: $ firejail --ipc-namespace firefox --join=name|pid Join the sandbox identified by name or by PID. By default a /bin/bash shell is started after joining the sandbox. If a pro‐ gram is specified, the program is run in the sandbox. If --join command is issued as a regular user, all security filters are configured for the new process the same they are configured in the sandbox. If --join command is issued as root, the security filters, cgroups and cpus configurations are not applied to the process joining the sandbox. Example: $ firejail --name=mygame --caps.drop=all warzone2100 & $ firejail --join=mygame Example: $ firejail --list 3272:netblue:firejail --private firefox $ firejail --join=3272 --join-filesystem=name|pid Join the mount namespace of the sandbox identified by name or PID. By default a /bin/bash shell is started after joining the sandbox. If a program is specified, the program is run in the sandbox. This command is available only to root user. Security filters, cgroups and cpus configurations are not applied to the process joining the sandbox. --join-network=name|PID Join the network namespace of the sandbox identified by name. By default a /bin/bash shell is started after joining the sandbox. If a program is specified, the program is run in the sandbox. This command is available only to root user. Security filters, cgroups and cpus configurations are not applied to the process joining the sandbox. Example: # start firefox $ firejail --net=eth0 --name=browser firefox & # change netfilter configuration $ sudo firejail --join-network=browser bash -c "cat /etc/fire‐ jail/nolocal.net | /sbin/iptables-restore" # verify netfilter configuration $ sudo firejail --join-network=browser /sbin/iptables -vL # verify IP addresses $ sudo firejail --join-network=browser ip addr Switching to pid 1932, the first child process inside the sand‐ box 1: lo: mtu 65536 qdisc noqueue state UNKNOWN group default link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0-1931: mtu 1500 qdisc noqueue state UNKNOWN group default link/ether 76:58:14:42:78:e4 brd ff:ff:ff:ff:ff:ff inet 192.168.1.158/24 brd 192.168.1.255 scope global eth0-1931 valid_lft forever preferred_lft forever inet6 fe80::7458:14ff:fe42:78e4/64 scope link valid_lft forever preferred_lft forever --join-or-start=name Join the sandbox identified by name or start a new one. Same as "firejail --join=name" if sandbox with specified name exists, otherwise same as "firejail --name=name ..." Note that in contrary to other join options there is respective profile option. --ls=name|pid dir_or_filename List files in sandbox container, see FILE TRANSFER section for more details. --list List all sandboxes, see MONITORING section for more details. Example: $ firejail --list 7015:netblue:firejail firefox 7056:netblue:firejail --net=eth0 transmission-gtk 7064:netblue:firejail --noroot xterm $ --mac=address Assign MAC addresses to the last network interface defined by a --net option. Example: $ firejail --net=eth0 --mac=00:11:22:33:44:55 firefox --machine-id Spoof id number in /etc/machine-id file - a new random id is generated inside the sandbox. Example: $ firejail --machine-id --memory-deny-write-execute Install a seccomp filter to block attempts to create memory map‐ pings that are both writable and executable, to change mappings to be executable, or to create executable shared memory. The filter examines the arguments of mmap, mmap2, mprotect, pkey_mprotect and shmat system calls and kills the process if necessary. Note: shmat is not implemented as a system call on some plat‐ forms including i386, and it cannot be handled by seccomp-bpf. --mtu=number Assign a MTU value to the last network interface defined by a --net option. Example: $ firejail --net=eth0 --mtu=1492 --name=name Set sandbox name. Several options, such as --join and --shut‐ down, can use this name to identify a sandbox. Example: $ firejail --name=mybrowser firefox --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 automati‐ cally 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. Example: $ sudo brctl addbr br0 $ sudo ifconfig br0 10.10.20.1/24 $ sudo brctl addbr br1 $ sudo ifconfig br1 10.10.30.1/24 $ firejail --net=br0 --net=br1 --net=ethernet_interface Enable a new network namespace and connect it to this ethernet interface using the standard Linux macvlan driver. Unless speci‐ fied 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 sup‐ ported for this option. Example: $ firejail --net=eth0 --ip=192.168.1.80 --dns=8.8.8.8 firefox --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. Example: $ firejail --net=none vlc Note: --net=none can crash the application on some platforms. In these cases, it can be replaced with --protocol=unix. --netns=name Run the program in a named, persistent network namespace. These can be created and configured using "ip netns". --netfilter Enable a default firewall if a new network namespace is created inside the sandbox. This option has no effect for sandboxes using the system network namespace. The default firewall is optimized for regular desktop applica‐ tions. No incoming connections are accepted: *filter :INPUT DROP [0:0] :FORWARD DROP [0:0] :OUTPUT ACCEPT [0:0] -A INPUT -i lo -j ACCEPT -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT # allow ping -A INPUT -p icmp --icmp-type destination-unreachable -j ACCEPT -A INPUT -p icmp --icmp-type time-exceeded -j ACCEPT -A INPUT -p icmp --icmp-type echo-request -j ACCEPT # drop STUN (WebRTC) requests -A OUTPUT -p udp --dport 3478 -j DROP -A OUTPUT -p udp --dport 3479 -j DROP -A OUTPUT -p tcp --dport 3478 -j DROP -A OUTPUT -p tcp --dport 3479 -j DROP COMMIT Example: $ firejail --net=eth0 --netfilter firefox --netfilter=filename Enable the firewall specified by filename if a new network namespace is created inside the sandbox. This option has no effect for sandboxes using the system network namespace. Please use the regular iptables-save/iptables-restore format for the filter file. The following examples are available in /etc/firejail directory: webserver.net is a webserver firewall that allows access only to TCP ports 80 and 443. Example: $ firejail --netfilter=/etc/firejail/webserver.net --net=eth0 \ /etc/init.d/apache2 start nolocal.net is a desktop client firewall that disable access to local network. Example: $ firejail --netfilter=/etc/firejail/nolocal.net \ --net=eth0 firefox --netfilter=filename,arg1,arg2,arg3 ... This is the template version of the previous command. $ARG1, $ARG2, $ARG3 ... in the firewall script are replaced with arg1, arg2, arg3 ... passed on the command line. Up to 16 arguments are supported. Example: $ firejail --net=eth0 --ip=192.168.1.105 \ --netfilter=/etc/firejail/tcpserver.net,5001 server-program --netfilter.print=name|pid Print the firewall installed in the sandbox specified by name or PID. Example: $ firejail --name=browser --net=eth0 --netfilter firefox & $ firejail --netfilter.print=browser --netfilter6=filename Enable the IPv6 firewall specified by filename if a new network namespace is created inside the sandbox. This option has no effect for sandboxes using the system network namespace. Please use the regular iptables-save/iptables-restore format for the filter file. --netfilter6.print=name|pid Print the IPv6 firewall installed in the sandbox specified by name or PID. Example: $ firejail --name=browser --net=eth0 --netfilter firefox & $ firejail --netfilter6.print=browser --netstats Monitor network namespace statistics, see MONITORING section for more details. Example: $ firejail --netstats PID User RX(KB/s) TX(KB/s) Command 1294 netblue 53.355 1.473 firejail --net=eth0 firefox 7383 netblue 9.045 0.112 firejail --net=eth0 transmission --nice=value Set nice value for all processes running inside the sandbox. Only root may specify a negative value. Example: $ firejail --nice=2 firefox --no3d Disable 3D hardware acceleration. Example: $ firejail --no3d firefox --noblacklist=dirname_or_filename Disable blacklist for this directory or file. Example: $ firejail $ nc dict.org 2628 bash: /bin/nc: Permission denied $ exit $ firejail --noblacklist=/bin/nc $ nc dict.org 2628 220 pan.alephnull.com dictd 1.12.1/rf on Linux 3.14-1-amd64 --nodvd Disable DVD and audio CD devices. Example: $ firejail --nodvd --noexec=dirname_or_filename Remount directory or file noexec, nodev and nosuid. File glob‐ bing is supported, see FILE GLOBBING section for more details. Example: $ firejail --noexec=/tmp /etc and /var are noexec by default if the sandbox was started as a regular user. If there are more than one mount operation on the path of the file or directory, noexec should be applied to the last one. Always check if the change took effect inside the sandbox. --nogroups Disable supplementary groups. Without this option, supplementary groups are enabled for the user starting the sandbox. For root user supplementary groups are always disabled. Note: By default all regular user groups are removed with the exception of the current user. This can be changed using --allusers command option. Example: $ id uid=1000(netblue) gid=1000(netblue) groups=1000(net‐ blue),24(cdrom),25(floppy),27(sudo),29(audio) $ firejail --nogroups Parent pid 8704, child pid 8705 Child process initialized $ id uid=1000(netblue) gid=1000(netblue) groups=1000(netblue) $ --noprofile Do not use a security profile. 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 [...] --noroot Install a user namespace with a single user - the current user. root user does not exist in the new namespace. This option requires a Linux kernel version 3.8 or newer. The option is not supported for --chroot and --overlay configurations, or for sandboxes started as root. Example: $ firejail --noroot Parent pid 8553, child pid 8554 Child process initialized $ ping google.com ping: icmp open socket: Operation not permitted $ --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 capabil‐ ities) does not result in an increase of privilege. This option is enabled by default if seccomp filter is activated. --nosound Disable sound system. Example: $ firejail --nosound firefox --notv Disable DVB (Digital Video Broadcasting) TV devices. Example: $ firejail --notv vlc --novideo Disable video devices. --nowhitelist=dirname_or_filename Disable whitelist for this directory or file. --output=logfile stdout logging and log rotation. Copy stdout to logfile, and keep the size of the file under 500KB using log rotation. Five files with prefixes .1 to .5 are used in rotation. Example: $ firejail --output=sandboxlog /bin/bash [...] $ ls -l sandboxlog* -rw-r--r-- 1 netblue netblue 333890 Jun 2 07:48 sandboxlog -rw-r--r-- 1 netblue netblue 511488 Jun 2 07:48 sandboxlog.1 -rw-r--r-- 1 netblue netblue 511488 Jun 2 07:48 sandboxlog.2 -rw-r--r-- 1 netblue netblue 511488 Jun 2 07:48 sandboxlog.3 -rw-r--r-- 1 netblue netblue 511488 Jun 2 07:48 sandboxlog.4 -rw-r--r-- 1 netblue netblue 511488 Jun 2 07:48 sandboxlog.5 --output-stderr=logfile Similar to --output, but stderr is also stored. --overlay Mount a filesystem overlay on top of the current filesystem. Unlike the regular filesystem container, the system directories are mounted read-write. All filesystem modifications go into the overlay. The overlay is stored in $HOME/.firejail/ direc‐ tory. OverlayFS support is required in Linux kernel for this option to work. OverlayFS was officially introduced in Linux kernel ver‐ sion 3.18. This option is not available on Grsecurity systems. Example: $ firejail --overlay firefox --overlay-named=name Mount a filesystem overlay on top of the current filesystem. Unlike the regular filesystem container, the system directories are mounted read-write. All filesystem modifications go into the overlay. The overlay is stored in $HOME/.firejail/ direc‐ tory. The created overlay can be reused between multiple ses‐ sions. OverlayFS support is required in Linux kernel for this option to work. OverlayFS was officially introduced in Linux kernel ver‐ sion 3.18. This option is not available on Grsecurity systems. Example: $ firejail --overlay-named=jail1 firefox --overlay-tmpfs Mount a filesystem overlay on top of the current filesystem. All filesystem modifications are discarded when the sandbox is closed. OverlayFS support is required in Linux kernel for this option to work. OverlayFS was officially introduced in Linux kernel ver‐ sion 3.18. This option is not available on Grsecurity systems. Example: $ firejail --overlay-tmpfs firefox --overlay-clean Clean all overlays stored in $HOME/.firejail directory. Example: $ firejail --overlay-clean --private Mount new /root and /home/user directories in temporary filesys‐ tems. All modifications are discarded when the sandbox is closed. Example: $ firejail --private firefox --private=directory Use directory as user home. Example: $ firejail --private=/home/netblue/firefox-home firefox --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 modifica‐ tions are discarded when the sandbox is closed. Example: $ firejail --private-home=.mozilla firefox --private-bin=file,file Build a new /bin in a temporary filesystem, and copy the pro‐ grams in the list. If no listed file is found, /bin directory will be empty. The same directory is also bind-mounted over /sbin, /usr/bin, /usr/sbin and /usr/local/bin. All modifica‐ tions are discarded when the sandbox is closed. File globbing is supported, see FILE GLOBBING section for more details. Example: $ firejail --private-bin=bash,sed,ls,cat Parent pid 20841, child pid 20842 Child process initialized $ ls /bin bash cat ls sed --private-lib=file,directory This feature is currently under heavy development. Only amd64 platforms are supported at this moment. The idea is to build a new /lib in a temporary filesystem, with only the library files necessary to run the application. It could be as simple as: $ firejail --private-lib galculator but it gets complicated really fast: $ firejail --private-lib=x86_64-linux-gnu/xed,x86_64-linux- gnu/gdk-pixbuf-2.0,libenchant.so.1,librsvg-2.so.2 xed The feature is integrated with --private-bin: $ firejail --private-lib --private-bin=bash,ls,ps $ ls /lib ld-linux-x86-64.so.2 libgpg-error.so.0 libprocps.so.6 libsys‐ temd.so.0 libc.so.6 liblz4.so.1 libpthread.so.0 libtinfo.so.5 libdl.so.2 liblzma.so.5 librt.so.1 x86_64-linux-gnu libgcrypt.so.20 libpcre.so.3 libselinux.so.1 $ ps PID TTY TIME CMD 1 pts/0 00:00:00 firejail 45 pts/0 00:00:00 bash 48 pts/0 00:00:00 ps $ --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. Example: $ firejail --private-dev Parent pid 9887, child pid 9888 Child process initialized $ ls /dev cdrom cdrw dri dvd dvdrw full log null ptmx pts random shm snd sr0 tty urandom zero $ --private-etc=file,directory Build a new /etc in a temporary filesystem, and copy the files and directories in the list. If no listed file is found, /etc directory will be empty. All modifications are discarded when the sandbox is closed. Example: $ firejail --private-etc=group,hostname,localtime, \ nsswitch.conf,passwd,resolv.conf --private-opt=file,directory Build a new /opt in a temporary filesystem, and copy the files and directories in the list. If no listed file is found, /opt directory will be empty. All modifications are discarded when the sandbox is closed. Example: $ firejail --private-opt=firefox /opt/firefox/firefox --private-srv=file,directory Build a new /srv in a temporary filesystem, and copy the files and directories in the list. If no listed file is found, /srv directory will be empty. All modifications are discarded when the sandbox is closed. Example: # firejail --private-srv=www /etc/init.d/apache2 start --private-tmp Mount an empty temporary filesystem on top of /tmp directory whitelisting X11 and PulseAudio sockets. Example: $ firejail --private-tmp $ ls -al /tmp drwxrwxrwt 4 nobody nogroup 80 Apr 30 11:46 . drwxr-xr-x 30 nobody nogroup 4096 Apr 26 22:18 .. drwx------ 2 nobody nogroup 4096 Apr 30 10:52 pulse-PKd‐ htXMmr18n drwxrwxrwt 2 nobody nogroup 4096 Apr 30 10:52 .X11-unix --profile=filename Load a custom security profile from filename. For filename use an absolute path or a path relative to the current path. For more information, see SECURITY PROFILES section below. Example: $ firejail --profile=myprofile --profile.print=name|pid Print the name of the profile file for the sandbox identified by name or or PID. Example: $ firejail --profile.print=browser /etc/firejail/firefox.profile --protocol=protocol,protocol,protocol 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. This option is not supported for i386 architecture. Example: $ firejail --protocol=unix,inet,inet6 firefox --protocol.print=name|pid Print the protocol filter for the sandbox identified by name or PID. Example: $ firejail --name=mybrowser firefox & $ firejail --protocol.print=mybrowser unix,inet,inet6,netlink Example: $ firejail --list 3272:netblue:firejail --private firefox $ firejail --protocol.print=3272 unix,inet,inet6,netlink --put=name|pid src-filename dest-filename Put a file in sandbox container, see FILE TRANSFER section for more details. --quiet Turn off Firejail's output. --read-only=dirname_or_filename Set directory or file read-only. File globbing is supported, see FILE GLOBBING section for more details. Example: $ firejail --read-only=~/.mozilla firefox A short note about mixing --whitelist and --read-only options. Whitelisted directories should be made read-only independently. Making a parent directory read-only, will not make the whitelist read-only. Example: $ firejail --whitelist=~/work --read-only=~ --read-only=~/work --read-write=dirname_or_filename Set directory or file read-write. Only files or directories belonging to the current user are allowed for this operation. File globbing is supported, see FILE GLOBBING section for more details. Example: $ mkdir ~/test $ touch ~/test/a $ firejail --read-only=~/test --read-write=~/test/a --rlimit-as=number Set the maximum size of the process's virtual memory (address space) in bytes. --rlimit-cpu=number Set the maximum limit, in seconds, for the amount of CPU time each sandboxed process can consume. When the limit is reached, the processes are killed. The CPU limit is a limit on CPU seconds rather than elapsed time. CPU seconds is basically how many seconds the CPU has been in use and does not necessarily directly relate to the elapsed time. Linux kernel keeps track of CPU seconds for each process independently. --rlimit-fsize=number Set the maximum file size that can be created by a process. --rlimit-nofile=number Set the maximum number of files that can be opened by a process. --rlimit-nproc=number Set the maximum number of processes that can be created for the real user ID of the calling process. --rlimit-sigpending=number Set the maximum number of pending signals for a process. --rmenv=name Remove environment variable in the new sandbox. Example: $ firejail --rmenv=DBUS_SESSION_BUS_ADDRESS --scan ARP-scan all the networks from inside a network namespace. This makes it possible to detect macvlan kernel device drivers run‐ ning on the current host. Example: $ firejail --net=eth0 --scan --seccomp Enable seccomp filter and blacklist the syscalls in the default list (@default). The default list is as follows: mount, umount2, ptrace, kexec_load, kexec_file_load, name_to_handle_at, open_by_handle_at, create_module, init_module, finit_module, delete_module, iopl, ioperm, ioprio_set, swapon, swapoff, sys‐ log, process_vm_readv, process_vm_writev, sysfs,_sysctl, adj‐ timex, clock_adjtime, lookup_dcookie, perf_event_open, fan‐ otify_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, set_mempolicy, migrate_pages, move_pages, vmsplice, chroot, tuxcall, reboot, mfsservctl, get_kernel_syms, bpf, clock_settime, personality, process_vm_writev, query_module, settimeofday, stime, umount, userfaultfd, ustat, vm86, vm86old, afs_syscall, bdflush, break, ftime, getpmsg, gtty, lock, mpx, pciconfig_iobase, pcicon‐ fig_read, pciconfig_write, prof, profil, putpmsg, rtas, s390_runtime_instr, s390_mmio_read, s390_mmio_write, security, setdomainname, sethostname, sgetmask, ssetmask, stty, sub‐ page_prot, switch_endian, ulimit, vhangup and vserver. To help creating useful seccomp filters more easily, the follow‐ ing system call groups are defined: @clock, @cpu-emulation, @debug, @default, @default-nodebuggers, @default-keep, @module, @obsolete, @privileged, @raw-io, @reboot, @resources and @swap. In addtion, a system call can be specified by its number instead of name with prefix $, so for example $165 would be equal to mount on i386. System architecture is strictly imposed only if flag --sec‐ comp.block-secondary is used. The filter is applied at run time only if the correct architecture was detected. For the case of I386 and AMD64 both 32-bit and 64-bit filters are installed. Firejail will print seccomp violations to the audit log if the kernel was compiled with audit support (CONFIG_AUDIT flag). Example: $ firejail --seccomp --seccomp=syscall,@group Enable seccomp filter, blacklist the default list (@default) and the syscalls or syscall groups specified by the command. Example: $ firejail --seccomp=utime,utimensat,utimes firefox $ firejail --seccomp=@clock,mkdir,unlinkat transmission-gtk Instead of dropping the syscall, a specific error number can be returned using syscall:errorno syntax. Example: $ firejail --seccomp=unlinkat:ENOENT,utimensat,utimes Parent pid 10662, child pid 10663 Child process initialized $ touch testfile $ rm testfile rm: cannot remove `testfile': Operation not permitted If the blocked system calls would also block Firejail from oper‐ ating, they are handled by adding a preloaded library which per‐ forms seccomp system calls later. Example: $ firejail --noprofile --shell=none --seccomp=execve bash Parent pid 32751, child pid 32752 Post-exec seccomp protector enabled list in: execve, check list: @default-keep prelist: (null), postlist: execve Child process initialized in 46.44 ms $ ls Bad system call --seccomp.block_secondary Enable seccomp filter and filter system call architectures so that only the native architecture is allowed. For example, on amd64, i386 and x32 system calls are blocked as well as changing the execution domain with personality(2) system call. --seccomp.drop=syscall,@group Enable seccomp filter, and blacklist the syscalls or the syscall groups specified by the command. Example: $ firejail --seccomp.drop=utime,utimensat,utimes,@clock Instead of dropping the syscall, a specific error number can be returned using syscall:errorno syntax. Example: $ firejail --seccomp.drop=unlinkat:ENOENT,utimensat,utimes Parent pid 10662, child pid 10663 Child process initialized $ touch testfile $ rm testfile rm: cannot remove `testfile': Operation not permitted --seccomp.keep=syscall,syscall,syscall Enable seccomp filter, and whitelist the syscalls specified by the command. The system calls needed by Firejail (group @default-keep: prctl, execve) are handled with the preload library. Example: $ firejail --shell=none --seccomp.keep=poll,select,[...] trans‐ mission-gtk --seccomp.print=name|PID Print the seccomp filter for the sandbox identified by name or PID. Example: $ firejail --name=browser firefox & $ firejail --seccomp.print=browser SECCOMP Filter: VALIDATE_ARCHITECTURE EXAMINE_SYSCALL BLACKLIST 165 mount BLACKLIST 166 umount2 BLACKLIST 101 ptrace BLACKLIST 246 kexec_load BLACKLIST 304 open_by_handle_at BLACKLIST 175 init_module BLACKLIST 176 delete_module BLACKLIST 172 iopl BLACKLIST 173 ioperm BLACKLIST 167 swapon BLACKLIST 168 swapoff BLACKLIST 103 syslog BLACKLIST 310 process_vm_readv BLACKLIST 311 process_vm_writev BLACKLIST 133 mknod BLACKLIST 139 sysfs BLACKLIST 156 _sysctl BLACKLIST 159 adjtimex BLACKLIST 305 clock_adjtime BLACKLIST 212 lookup_dcookie BLACKLIST 298 perf_event_open BLACKLIST 300 fanotify_init RETURN_ALLOW $ --shell=none Run the program directly, without a user shell. Example: $ firejail --shell=none script.sh --shell=program Set default user shell. Use this shell to run the application using -c shell option. For example "firejail --shell=/bin/dash firefox" will start Mozilla Firefox as "/bin/dash -c firefox". By default Bash shell (/bin/bash) is used. Options such as --zsh and --csh can also set the default shell. Example: $firejail --shell=/bin/dash script.sh --shutdown=name|PID Shutdown the sandbox identified by name or PID. Example: $ firejail --name=mygame --caps.drop=all warzone2100 & $ firejail --shutdown=mygame Example: $ firejail --list 3272:netblue:firejail --private firefox $ firejail --shutdown=3272 --timeout=hh:mm:ss Kill the sandbox automatically after the time has elapsed. The time is specified in hours/minutes/seconds format. $ firejail --timeout=01:30:00 firefox --tmpfs=dirname Mount a tmpfs filesystem on directory dirname. This option is available only when running the sandbox as root. File globbing is supported, see FILE GLOBBING section for more details. Example: # firejail --tmpfs=/var --top Monitor the most CPU-intensive sandboxes, see MONITORING section for more details. Example: $ firejail --top --trace Trace open, access and connect system calls. Example: $ firejail --trace wget -q www.debian.org Reading profile /etc/firejail/wget.profile 3:wget:fopen64 /etc/wgetrc:0x5c8e8ce6c0 3:wget:fopen /etc/hosts:0x5c8e8cfb70 3:wget:socket AF_INET SOCK_DGRAM IPPROTO_IP:3 3:wget:connect 3 8.8.8.8 port 53:0 3:wget:socket AF_INET SOCK_STREAM IPPROTO_IP:3 3:wget:connect 3 130.89.148.14 port 80:0 3:wget:fopen64 index.html:0x5c8e8d1a60 parent is shutting down, bye... --tracelog This option enables auditing blacklisted files and directories. A message is sent to syslog in case the file or the directory is accessed. Example: $ firejail --tracelog firefox Sample messages: $ sudo tail -f /var/log/syslog [...] Dec 3 11:43:25 debian firejail[70]: blacklist violation - sand‐ box 26370, exe firefox, syscall open64, path /etc/shadow Dec 3 11:46:17 debian firejail[70]: blacklist violation - sand‐ box 26370, exe firefox, syscall opendir, path /boot [...] --tree Print a tree of all sandboxed processes, see MONITORING section for more details. Example: $ firejail --tree 11903:netblue:firejail iceweasel 11904:netblue:iceweasel 11957:netblue:/usr/lib/iceweasel/plugin-container 11969:netblue:firejail --net=eth0 transmission-gtk 11970:netblue:transmission-gtk --version Print program version and exit. Example: $ firejail --version firejail version 0.9.27 --veth-name=name Use this name for the interface connected to the bridge for --net=bridge_interface commands, instead of the default one. Example: $ firejail --net=br0 --veth-name=if0 --whitelist=dirname_or_filename 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. Example: $ firejail --noprofile --whitelist=~/.mozilla $ firejail --whitelist=/tmp/.X11-unix --whitelist=/dev/null $ firejail "--whitelist=/home/username/My Virtual Machines" --writable-etc Mount /etc directory read-write. Example: $ sudo firejail --writable-etc --writable-run-user Disable the default blacklisting of /run/user/$UID/systemd and /run/user/$UID/gnupg. Example: $ sudo firejail --writable-run-user --writable-var Mount /var directory read-write. Example: $ sudo firejail --writable-var --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. Example: $ sudo firejail --writable-var-log --x11 Sandbox the application using Xpra, Xephyr, Xvfb or Xorg secu‐ rity extension. The sandbox will prevents screenshot and key‐ logger applications started inside the sandbox from accessing clients running outside the sandbox. Firejail will try first Xpra, and if Xpra is not installed on the system, it will try to find Xephyr. If all fails, Firejail will not attempt to use Xvfb or X11 security extension. Xpra, Xephyr and Xvfb modes require a network namespace to be instantiated in order to disable X11 abstract Unix socket. If this is not possible, the user can disable the abstract socket by adding "-nolisten local" on Xorg command line at system level. Example: $ firejail --x11 --net=eth0 firefox --x11=none Blacklist /tmp/.X11-unix directory, ${HOME}/.Xauthority and the 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 Start Xephyr and attach the sandbox to this server. Xephyr is a display server implementing the X11 display server protocol. A network namespace needs to be instantiated in order to deny access to X11 abstract Unix domain socket. Xephyr runs in a window just like any other X11 application. The default window size is 800x600. This can be modified in /etc/firejail/firejail.config file. The recommended way to use this feature is to run a window man‐ ager inside the sandbox. A security profile for OpenBox is pro‐ vided. Xephyr is developed by Xorg project. On Debian platforms it is installed with the command sudo apt-get install xserver-xephyr. This feature is not available when running as root. Example: $ firejail --x11=xephyr --net=eth0 openbox --x11=xorg Sandbox the application using the untrusted mode implemented by X11 security extension. The extension is available in Xorg package and it is installed by default on most Linux distribu‐ tions. It provides support for a simple trusted/untrusted con‐ nection model. Untrusted clients are restricted in certain ways to prevent them from reading window contents of other clients, stealing input events, etc. The untrusted mode has several limitations. A lot of regular programs assume they are a trusted X11 clients and will crash or lock up when run in untrusted mode. Chromium browser and xterm are two examples. Firefox and transmission-gtk seem to be working fine. A network namespace is not required for this option. Example: $ firejail --x11=xorg firefox --x11=xpra Start Xpra (https://xpra.org) and attach the sandbox to this server. Xpra is a persistent remote display server and client for forwarding X11 applications and desktop screens. A network namespace needs to be instantiated in order to deny access to X11 abstract Unix domain socket. On Debian platforms Xpra is installed with the command sudo apt- get install xpra. This feature is not available when running as root. Example: $ firejail --x11=xpra --net=eth0 firefox --x11=xvfb Start Xvfb X11 server and attach the sandbox to this server. Xvfb, short for X virtual framebuffer, performs all graphical operations in memory without showing any screen output. Xvfb is mainly used for remote access and software testing on headless servers. On Debian platforms Xvfb is installed with the command sudo apt- get install xvfb. This feature is not available when running as root. Example: remote VNC access On the server we start a sandbox using Xvfb and openbox window manager. The default size of Xvfb screen is 800x600 - it can be changed in /etc/firejail/firejail.config (xvfb-screen). Some sort of networking (--net) is required in order to isolate the abstract sockets used by other X servers. $ firejail --net=none --x11=xvfb openbox *** Attaching to Xvfb display 792 *** Reading profile /etc/firejail/openbox.profile Reading profile /etc/firejail/disable-common.inc Reading profile /etc/firejail/disable-common.local Parent pid 5400, child pid 5401 On the server we also start a VNC server and attach it to the display handled by our Xvfb server (792). $ x11vnc -display :792 On the client machine we start a VNC viewer and use it to con‐ nect to our server: $ vncviewer --xephyr-screen=WIDTHxHEIGHT Set screen size for --x11=xephyr. The setting will overwrite the default set in /etc/firejail/firejail.config for the current sandbox. Run xrandr to get a list of supported resolutions on your computer. Example: $ firejail --net=eth0 --x11=xephyr --xephyr-screen=640x480 fire‐ fox --zsh Use /usr/bin/zsh as default user shell. Example: $ firejail --zsh DESKTOP INTEGRATION A symbolic link to /usr/bin/firejail under the name of a program, will start the program in Firejail sandbox. The symbolic link should be placed in the first $PATH position. On most systems, a good place is /usr/local/bin directory. Example: Make a firefox symlink to /usr/bin/firejail: $ ln -s /usr/bin/firejail /usr/local/bin/firefox Verify $PATH $ which -a firefox /usr/local/bin/firefox /usr/bin/firefox Starting firefox in this moment, automatically invokes “firejail firefox”. This works for clicking on desktop environment icons, menus etc. Use "firejail --tree" to verify the program is sandboxed. $ firejail --tree 1189:netblue:firejail firefox 1190:netblue:firejail firefox 1220:netblue:/bin/sh -c "/usr/lib/firefox/firefox" 1221:netblue:/usr/lib/firefox/firefox We provide a tool that automates all this integration, please see man 1 firecfg for more details. FILE GLOBBING Globbing is the operation that expands a wildcard pattern into the list of pathnames matching the pattern. Matching is defined by: - '?' matches any character - '*' matches any string - '[' denotes a range of characters The gobing feature is implemented using glibc glob command. For more information on the wildcard syntax see man 7 glob. The following command line options are supported: --blacklist, --pri‐ vate-bin, --noexec, --read-only, --read-write, and --tmpfs. Examples: $ firejail --private-bin=sh,bash,python* $ firejail --blacklist=~/dir[1234] $ firejail --read-only=~/dir[1-4] APPARMOR AppArmor support is disabled by default at compile time. Use --enable- apparmor configuration option to enable it: $ ./configure --prefix=/usr --enable-apparmor During software install, a generic AppArmor profile file, firejail- default, is placed in /etc/apparmor.d directory. The profile needs to be loaded into the kernel by running the following command as root: # aa-enforce firejail-default The installed profile tries to replicate some advanced security fea‐ tures inspired by kernel-based Grsecurity: - Prevent information leakage in /proc and /sys directories. The resulting filesystem is barely enough for running commands such as "top" and "ps aux". - Allow running programs only from well-known system paths, such as /bin, /sbin, /usr/bin etc. Running programs and scripts from user home or other directories writable by the user is not allowed. - Allow access to files only in the following standard directo‐ ries: /bin, /dev, /etc, /home, /lib*, /media, /mnt, /opt, /proc, /root, /run, /sbin, /srv, /sys, /tmp, /usr, and /var - Disable D-Bus. D-Bus has long been a huge security hole, and most programs don't use it anyway. You should have no problems running Chromium or Firefox. This feature is available only on Ubuntu kernels. To enable AppArmor confinement on top of your current Firejail security features, pass --apparmor flag to Firejail command line. You can also include apparmor command in a Firejail profile file. Example: $ firejail --apparmor firefox FILE TRANSFER These features allow the user to inspect the filesystem container of an existing sandbox and transfer files from the container to the host filesystem. --get=name|pid filename Retrieve the container file and store it on the host in the cur‐ rent working directory. The container is specified by name or PID. --ls=name|pid dir_or_filename List container files. The container is specified by name or PID. --put=name|pid src-filename dest-filename Put src-filename in sandbox container. The container is speci‐ fied by name or PID. Examples: $ firejail --name=mybrowser --private firefox $ firejail --ls=mybrowser ~/Downloads drwxr-xr-x netblue netblue 4096 . drwxr-xr-x netblue netblue 4096 .. -rw-r--r-- netblue netblue 7847 x11-x305.png -rw-r--r-- netblue netblue 6800 x11-x642.png -rw-r--r-- netblue netblue 34139 xpra-clipboard.png $ firejail --get=mybrowser ~/Downloads/xpra-clipboard.png $ firejail --put=mybrowser xpra-clipboard.png ~/Downloads/xpra- clipboard.png TRAFFIC SHAPING Network bandwidth is an expensive resource shared among all sandboxes running on a system. Traffic shaping allows the user to increase net‐ work performance by controlling the amount of data that flows into and out of the sandboxes. Firejail implements a simple rate-limiting shaper based on Linux com‐ mand tc. The shaper works at sandbox level, and can be used only for sandboxes configured with new network namespaces. Set rate-limits: $ firejail --bandwidth=name|pid set network download upload Clear rate-limits: $ firejail --bandwidth=name|pid clear network Status: $ firejail --bandwidth=name|pid status where: name - sandbox name pid - sandbox pid network - network interface as used by --net option download - download speed in KB/s (kilobyte per second) upload - upload speed in KB/s (kilobyte per second) Example: $ firejail --name=mybrowser --net=eth0 firefox & $ firejail --bandwidth=mybrowser set eth0 80 20 $ firejail --bandwidth=mybrowser status $ firejail --bandwidth=mybrowser clear eth0 AUDIT Audit feature allows the user to point out gaps in security profiles. The implementation replaces the program to be sandboxed with a test program. By default, we use faudit program distributed with Firejail. A custom test program can also be supplied by the user. Examples: Running the default audit program: $ firejail --audit transmission-gtk Running a custom audit program: $ firejail --audit=~/sandbox-test transmission-gtk In the examples above, the sandbox configures transmission-gtk profile and starts the test program. The real program, transmission-gtk, will not be started. Limitations: audit feature is not implemented for --x11 commands. MONITORING Option --list prints a list of all sandboxes. The format for each process entry is as follows: PID:USER:Command Option --tree prints the tree of processes running in the sandbox. The format for each process entry is as follows: PID:USER:Command Option --top is similar to the UNIX top command, however it applies only to sandboxes. Option --netstats prints network statistics for active sandboxes installing new network namespaces. Listed below are the available fields (columns) in alphabetical order for --top and --netstat options: Command Command used to start the sandbox. CPU% CPU usage, the sandbox share of the elapsed CPU time since the last screen update PID Unique process ID for the task controlling the sandbox. Prcs Number of processes running in sandbox, including the control‐ ling process. RES Resident Memory Size (KiB), sandbox non-swapped physical memory. It is a sum of the RES values for all processes running in the sandbox. RX(KB/s) Network receive speed. SHR Shared Memory Size (KiB), it reflects memory shared with other processes. It is a sum of the SHR values for all processes run‐ ning in the sandbox, including the controlling process. TX(KB/s) Network transmit speed. Uptime Sandbox running time in hours:minutes:seconds format. User The owner of the sandbox. SECURITY PROFILES 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. Exam‐ ple: $ firejail icecat Command name #icecat# Found icecat profile in /home/netblue/.config/firejail directory Reading profile /home/netblue/.config/firejail/icecat.profile [...] 3. Use default.profile file if the sandbox is started by a regular user, or server.profile file if the sandbox is started by root. Fire‐ jail 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 [...] See man 5 firejail-profile for profile file syntax information. RESTRICTED SHELL To configure a restricted shell, replace /bin/bash with /usr/bin/fire‐ jail in /etc/passwd file for each user that needs to be restricted. Alternatively, you can specify /usr/bin/firejail in adduser command: adduser --shell /usr/bin/firejail username Additional arguments passed to firejail executable upon login are declared in /etc/firejail/login.users file. EXAMPLES firejail Sandbox a regular /bin/bash session. firejail firefox Start Mozilla Firefox. firejail --debug firefox Debug Firefox sandbox. firejail --private firefox Start Firefox with a new, empty home directory. firejail --net=none vlc Start VLC in an unconnected network namespace. firejail --net=eth0 firefox Start Firefox in a new network namespace. An IP address is assigned automatically. firejail --net=br0 --ip=10.10.20.5 --net=br1 --net=br2 Start a /bin/bash session in a new network namespace and connect it to br0, br1, and br2 host bridge devices. IP addresses are assigned automatically for the interfaces connected to br1 and b2 firejail --list List all sandboxed processes. LICENSE This program 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 firemon(1), firecfg(1), firejail-profile(5), firejail-login(5) 0.9.52 Dec 2017 FIREJAIL(1)
Advertisements
I’m having some difficulty in getting mpd to background properly inside firejail. Using “mpd; sleep inf;” worked before, but it’s now responding with “mpd; sleep inf;: command not found”. What is the “official” way to get this working again? Thanks!
LikeLike
It should work without “sleep inf”. Try “firejail mpd”.
LikeLike
Nope, it just dies with “parent is shutting down, bye…”.
LikeLike
I’ll try to fix it, you can track it here: https://github.com/netblue30/firejail/issues/320
LikeLike
nosound option is breaking profiles.
I tried it in icedove, piding, firefox, and it breaks all of them. if i try to use a profile that has that option it just gives an error in that line. If I do it like “firejail –nosound firefox” however it works flawlessly. I am using 0.9.38
Any idea?
LikeLike
nosound profile command is not available in 0.9.38. It will come in the next version.
LikeLike
Also when I use the nosound option in one application, all the system gets sound deactivated 😦 is it normal??
LikeLike
Yes, it disables ALSA and PulseAudio.
LikeLike
I expected it to just prevent that specific application from using sound. It is very “anti-feature” this way, since to prevent one application from being exploited and used to spy, we lose sound in all the other apps. Any workaround?
LikeLike
It disables the sound only for applications inside the sandbox. Unless you are running into this PulseAudio bug: https://firejail.wordpress.com/support/known-problems/
LikeLike
When I installed this for use with Chrome it created a profile somewhere for Chrome so it starts with a loaded Chrome cache and some features enabled on Chrome extensions. So I clear the cache and change the extension settings every time I use it firejail google-chrome is how I start it. I’ve even removed it and reinstalled it but the profile is always the same. This is the latest version also. How do I go about deleting this? It’s acting like its in private mode which I thought was deprecated, Help!
LikeLike
google-chrome configuration is persistent, and is stored in ~/.config/google-chrome directory. So, if you add a bookmark, next time you start chrome, your bookmark should be there. You can delete the configuration before starting chrome (rm -fr ~/.config/google-chrome). Your Download directory is also persistent.
If you really want to start every time with a default chrome config, you should run “firejail –private google-chrome”.
LikeLiked by 1 person
[quote]
This works for clicking on desktop environment icons, menus etc. Use
“firejail –tree” to verify the program is sandboxed.
[/quote]
Sadly it’s not working for most applications in Gnome3 in Debian Stretch. Probably because in the *.desktop files there is the full path written.
Do you know a workaround or you suggest to file a bugreport?
LikeLike
I would suggest a bug report on https://github.com/netblue30/firejail
LikeLike
Actually I found “firecfg –fix” in the meantime which is solving this issue. 🙂
Works fine now.
LikeLike
Thanks!
LikeLike
Hi. Many thanks for FireJail – it’s an amazing achievement.
Is there a way for FireJail to sandbox internet-facing programs, whose user-data & config files are NOT stored as conventional in /home, but instead are in separate partition /DATA [albeit symlinked back to /home] ? So far all my tests with combinations of –blacklist & –noblacklist in their launchers [for eg, Thunderbird & Firefox] have failed [& –whitelist can’t be used at all if i understand correctly, given their active directories are not in /home], in that either the programs can’t launch at all [because can’t access their config & data], or they launch but ALL other directories & files in /DATA are exposed to internet. Please?
LikeLike
Sorry, there is no support in this moment for user directories located outside /home.
LikeLike
That’s the unfortunate conclusion i’d come to, but given i am still not very skilled with FJ, i felt it best to ask you. Thank you.
LikeLike
No problem.
LikeLike
Pingback: Sandbox your applications with Firejail – Own your bits
Trying to use –private-home with Google Chrome default profile. I am trying to preserve the add-ons and plug-ins from my default Chrome profile. I’ve tried many iterations, including [firejail –private-home=~/.google-chrome/Default google-chrome-stable]
But Chrome just fails to load when I double-click on it in Firetools.
I have tried using many directory path options, but to no avail. Someone please help.
LikeLike
Use –private only if you need a browser reseted to factory defaults, without any plugins and addons.
By default Firejail will allow you to use all Chrome addons and plugins. The only directories exposed in your home are Downloads and Chrome configuration files.
I would say just start it as “firejail chrome” and you should be ok. We do this for all browsers.
LikeLike
netblue,
Thx for the info. Much appreciated. As I have been looking into optimizing the security features of Firejail and found out that –seccomp, –overlay and –overlay-tmpfs do not work with Chrome, I have managed to come up with the following (not sure if I’ve missed anything):
firejail –caps.drop=all –noroot –allow-private-blacklist –blacklist=/Home/ –read-only=~ google-chrome-stable
Chrome loads no problem and at least I’ve added some additional security features to further tighten the security of the sandbox.
I’m currently running Fedora v26 and as it relates to all the command-line parameters that add additional measures of security, It has taken a while to figure out what works with Chrome and what doesn’t.
That being said, and as others have mentioned previously, thank you for all your hard work (and anyone else who worked on Firejail/Firetools).
Cheers.
LikeLike
Oops. I apologize for not mentioning this in my response above. My main purpose for implementing Firejail / Firetools is solely to improve upon the overall security of internet browsing sessions. I’m not testing software or writing code. This is just to help prevent virus / malware injection. Thanks again!
LikeLike
Question: why don’t you use the default profile for Chrome distributed by firejail?
You’ll find it in /etc/firejail/google-*.,profile. We have profiles for all Chrome variants, including Chromium. All of them are basically the same, with very small differences. Some of features such as seccomp won’t work for Chrome browser because Chrom starts a second sandbox inside firejail sandbox.
LikeLike
Indeed sir.
I found the /etc/firejail/google*.profile files and performed the steps (as you outlined in the profiles section here on the site) to save a new google-chrome-stable profile in my [/home/.config/firejail] directory and add the nonewprivs and noroot parameters. I also rem’ed out the caps.keep sys_chroot, sys_admin line and added caps.drop all. Now all I have to do is ‘firejail google-chrome-stable.’ I (again) apologize as I don’t really know if the chroot and admin capabilities are needed in Chrome for pure internet browsing. I conducted some on-line research on those capabilities, but couldn’t come up with anything definitive. As you can see, my working knowledge of Linux is not yet up to snuff.
NetBlue, again my sincere thanks for an awesome program.
LikeLike
Pingback: Sandbox your applications with Firejail – Linux Now
Pingback: Using Firejail to sandbox applications in Linux – Excerpts of the Regginator
Hi
You’ve made a great tool here, and I’m grateful.
However, I am finding it hard to use. Partly that’s because I am learning about computer science as I go. I’m a noob.
But partly I am having trouble with the documentation. I find it dense, counter-intuititve and overwhelming. I’m not talking about the content (well, sometimes). Its the structure.
Case in point: I want to read up how to transfer a file out of sandbox into my host system’s Documents folder. This page has three places at least where “FILE TRANSFER” is located, and I have two options to find them: scrolling, a long way, or; crtl+F in my browser.
Why don’t those entries link to each other? Or any, between other parts of the page or site.
FILE TRANSFERS (your caps) is part of a large series of section titles, to which there is no link between them nor a table of contents.
There isn’t even an anchor so I can bookmark the spot once I’ve found it. [Add in extra time looking fruitlessly for browser extensions that might help].
Please remember that if you aren’t a commandline guru, you’ve committed to Linux years ago but you’re still figuring out what the hell namespaces are, you don’t have the tacit knowledge that might help you sail through this space. Its called tacit knowledge – enormously valuable, years in the making and possession of it is easily forgotten even by those who have it. I don’t have it.
You’re basically asking me to trawl through a page of gobbledygook (technical term) for something I don’t really understand, and even forget how to spell between ctrl+Fs.
Basic structure would give me so much more working memory to the substantive task (i.e. file transfer) rather than document navigation.
What kills me is that I remember having figured this out six months ago, but I’ve got to do it all over again… I’ve already lost a couple of hours that I don’t have.
This is a great tool. Can you make it more accessible? I am sure its not just me, but I’m pretty vocal (most else just slink away quietly and frustrated).
(To put money where my mouth is, I would have time in about 6 weeks to help. I’d have to learn a few things, but I’d be willing).
Constructively,
B.
LikeLike
You are right, there is more work to do on the documentation side. And yes, it is way to technical in this moment.
LikeLike
Furthermore, I just flat out can’t get the transfer to work.
First, I do this:
11:31:25 b:~ $ firemon –list
3799:b:/usr/bin/firejail /usr/bin/keepass2 /xxxxxxxxxxxxxxx
3821:b:/usr/bin/firejail /usr/bin/firefox
4632:b:/usr/bin/firejail /usr/bin/VirtualBox
13497:b:/usr/bin/firejail /usr/bin/google-chrome-stable
20129:b:firejail –private firefox –private-window –no-remote –no-first-run
22100:b:/usr/bin/firejail /usr/bin/pluma /home/b/xxxxxxxxxxxxxx
(edit – multiple x added by me)
I haven’t named my private firefox session (second from bottom) – I haven’t a clue as to how, and I got lost looking for instructions last time. I start the thing from a desktop launcher for banking, government websites, etc.
But, the instructions say PID can be used, so
11:33:36 b:~ $ sudo firejail –ls=20129 ~/Downloads
drwx—— b b 60 .
drwx—— b b 220 ..
-rw-rw-r– b b 13058 Target Document
So, I want ‘Target Document’.
11:34:07 b:~ $ firejail –get=20129 ~/Downloads/’Target Document’
Warning: cannot open source file /home/b/Downloads/Target Document, file not copied
“WTF…?” I mutter to myself. I recheck instructions. Nope…
The all-powerful sudo?
15:32:36 b:~ $ sudo firejail –get=20129 ~/Downloads/’Target Document’
Warning: cannot open source file /home/b/Downloads/Centrelink Statement, file not copied
Nope. It took me quite a while before I realised the permissions were probably at the heart of it. However, I can’t figure out how to get into that sandbox to modify permissions, and anyway – why should I, as a user on the host (and as sudo, no less), have to modify rights to copy a file I downloaded? I don’t understand the constraints, but seems weird. (If an attacker is issuing commands from the host terminal, the game is over already, surely?)
I tried a couple of other tacks
15:43:07 b:~ $ firejail –chmod=20129 777 ~/Downloads
Error: invalid –chmod=20129 command line option
15:44:49 b:~ $ $ firejail –whitelist=~/.mozilla –whitelist=~/Download firefox
$: command not found
and even tried the whole command listed in the –ls output as the `name`, but it didn’t work. Read the whole Firefox entry and couldn’t see the solution. Don’t know where to look, and note that a search engine brings up others with transfer problems, but I can’t devine enough to apply fixes to my situation.
I am absolutely stumped. Please help.
LikeLike