Building Custom Profiles

Several Firejail command line configuration options can be passed to the program using profile files. User-defined profiles are stored in ~/.config/firejail directory. Assuming app_name is the name of command you use to start the application, the steps for building a custom profile are as follows:

1. Create a .config/firejail directory in your home directory:

$ cd ~
$ mkdir -p .config/firejail
$ cd .config/firejail

2. Copy in this directory the default security profile used by Firejail to run unrecognized applications:

cp /etc/firejail/default.profile app_name.profile

The new profile file – app_name.profile – needs to have the same name as the application, with only a .profile extension added. For example, if you intend to run mplayer, your file name will be mplayer.profile.

3. Edit and modify the new profile file, comment out lines, blacklist directories, whitelist files, etc. Use “man 5 firejail-profile” for a description and the correct syntax of all commands.

4. Start your application:

$ firejail app_name

As you start the application, you’ll see Firejail picking up the new security profile file (Reading profile /home/username/.config/firejail/app_name.profile.):

$ firejail app_name
Reading profile /home/username/.config/firejail/app_name.profile
Reading profile /etc/firejail/disable-common.inc
Reading profile /etc/firejail/disable-programs.inc
Reading profile /etc/firejail/disable-passwdmgr.inc

30 thoughts on “Building Custom Profiles”

Harri January 27, 2016 at 6:29 pm

I’m trying to make a custom profile like this:
include /etc/firejail/generic.profile
whitelist ${HOME}/somefile
read-only ${HOME}/somefile

For some reason using a white-list seems to discard access to home directory (only “somefile” shown). Does using any white-listed file for example home directory whitelisted by default?
For some reason “somefile” is also read-write instead of read-only. Is this a bug perhaps? Also some files blacklisted in generic.profile seem to be accessible and readable. (I’m using version firejail_0.9.36_1_amd64.deb on Mint 17.2)

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1. netblue30 Post authorJanuary 28, 2016 at 1:23 pm
  > For some reason using a white-list seems to discard access to home directory (only “somefile” shown).
  
  Yes, this is true. Whitelisting allows only the files and directories you specify in the list, everything else is removed.
  
  > For some reason “somefile” is also read-write instead of read-only.
  
  It seems to work:
  $ cd ~ $ touch t $ firejail --whitelist=~/t --read-only=~/t Reading profile /etc/firejail/generic.profile Reading profile /etc/firejail/disable-mgmt.inc Reading profile /etc/firejail/disable-secret.inc Reading profile /etc/firejail/disable-common.inc ** Note: you can use --noprofile to disable generic.profile ** Parent pid 1563, child pid 1564 Child process initialized $ echo "asdfasdfadsf" > t bash: t: Read-only file system $
  Also blacklisting seems to work, give me an example. Thanks!
  
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Ronald McDonald February 18, 2016 at 8:37 pm

Hi,

I want to use firejail with soulseek, which is a music sharing program (the linux client is nicotine).

While protecting my system using firejail, I also have to make 1000s (literally thousands) or directories available read only. These thousands of directories all descend from one of five base directories, and ultimately from one single directory. above that.

The problem is that – as far as can see – firejail does not give recursive permissions to sub-directories. I will have to (make a script to) write thousands of
:
whitelist some/dir/name/dir1/
read-only some/dir/name/dir1/
whitelist some/dir/name/dir2/
read-only some/dir/name/dir2/
:
:
pairings.

Is there any way, like linking under my (firejail faked) home directory, to have firejail make thousands of directories available read only?

thanks for any help and thanks for a great application.

R

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1. netblue30 Post authorFebruary 19, 2016 at 8:20 pm
  
  You only need to whitelist the top directory. The top directory needs to be in your user home directory. If the top directory is a symbolic link, the real directory also needs to be in user home.
  
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Doud February 21, 2016 at 7:34 pm

If I enter $firejail firefox then Firejail opens the distribution version, 44, of Firefox.
I use a different version 38esr, of Firefox as my default. How do I get Firejail to open my default version?

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Richard June 21, 2016 at 9:18 am

Is there anywhere custom profiles can be checked? I think I have my ktorrent profile configured correctly but it would be nice to be certain

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1. netblue30 Post authorJune 22, 2016 at 2:51 pm
  
  Yes, in a terminal run a simple sandbox with your profile:
  
  $ firejail –profile=path_to_your_profile_file
  
  It will complain if it finds a problem with the profile file.
  
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fox12 July 20, 2016 at 6:46 am

how do i know which files and directories to whitelist? im trying to generate a custom profile for liferea rss reader.

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1. netblue30 Post authorJuly 22, 2016 at 2:48 am
  
  I’ll try to bring in support for it in the next version. You need to find the directories where liferea is keeping its internal data in your home directory. They seem to be ~/.config/liferea and ~/.local/share/liferea/
  
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Alex Turbov August 24, 2016 at 3:09 pm

Is there a way to make some directory RO, but one child of it as RW w/o root privileges?
I’m trying to sandbox my unit tests and disabling any write the sources tree, but have a build tree (which is a child) enabled… i.e. smth like:

–[unit-tests.profile]—
read-only /work/my-sources
read-write /work/my-sources/build/debug
——

unit tests are executed as a separate `builder` user (and it is not supposed to be the `root` user!)

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1. netblue30 Post authorAugust 25, 2016 at 3:36 pm
  Yes, this is supported in upcoming version 0.9.42:
  $ man firejail [...] --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. Example: $ mkdir ~/test $ touch ~/test/a $ firejail --read-only=~/test --read-write=~/test/a [...]
  There is a 0.9.42~rc1 version on the download page, or you can grab the latest on mainline from github.
  
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Roger October 16, 2016 at 2:26 pm

Can –whitelist and –noexec be combined?
I want whitelisted folders to block execution of scripts.
A jailed app should be able to read/write only from a whitelisted folder and no other folders but not be able to execute.

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1. netblue30 Post authorOctober 17, 2016 at 11:04 pm
  
  Yes, it should work:
  
  $ firejail –whitelist=~/mydir –noexec=~/mydir program-name
  
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Roger October 16, 2016 at 2:31 pm

Does the whitelist option on the command line override the default.profile or do I need the –no-profile option also?

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1. netblue30 Post authorOctober 17, 2016 at 11:05 pm
  
  No, it does not overwrite it. It is equivalent with adding a whitelist entry in the profile.
  
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Roger October 18, 2016 at 2:57 am

Thanks for the answers. I tried to keep them short and simple.
I have an app from here that is for recording audio (dictation mostly):
https://launchpad.net/~audio-recorder/+archive/ubuntu/ppa

I am trying to block internet access and confine to a folder.
Seems like something common someone would want to do to an new app that handles sensitive information.

If I run with just firejail it is fine:
$ firejail audio-recorder –show-window=0
Reading profile /home/dad/.config/firejail/audio-recorder.profile
Reading profile /etc/firejail/disable-common.inc
Reading profile /etc/firejail/disable-programs.inc
Reading profile /etc/firejail/disable-passwdmgr.inc
Parent pid 29206, child pid 29211
Child process initialized

Parent is shutting down, bye…
(the gui launches)

If I add the whitelist option I get this:
$ firejail –whitelist=~/Audio audio-recorder –show-window=0
Reading profile /home/dad/.config/firejail/audio-recorder.profile
Reading profile /etc/firejail/disable-common.inc
Reading profile /etc/firejail/disable-programs.inc
Reading profile /etc/firejail/disable-passwdmgr.inc
Parent pid 29313, child pid 29314
Child process initialized
libdc1394 error: Failed to initialize libdc1394
(gst-plugin-scanner:5): GLib-GObject-WARNING **: cannot register existing type ‘ClutterGstVideoSink’
(gst-plugin-scanner:5): GLib-GObject-CRITICAL **: g_type_add_interface_static: assertion ‘G_TYPE_IS_INSTANTIATABLE (instance_type)’ failed
(gst-plugin-scanner:5): GLib-GObject-CRITICAL **: g_type_add_interface_static: assertion ‘G_TYPE_IS_INSTANTIATABLE (instance_type)’ failed
(gst-plugin-scanner:5): GLib-CRITICAL **: g_once_init_leave: assertion ‘result != 0’ failed
(gst-plugin-scanner:5): GLib-GObject-CRITICAL **: g_object_new: assertion ‘G_TYPE_IS_OBJECT (object_type)’ failed
ERROR: Caught a segmentation fault while loading plugin file:
/usr/lib/x86_64-linux-gnu/gstreamer-1.0/libgstclutter-3.0.so
Please either:
– remove it and restart.
– run with –gst-disable-segtrap –gst-disable-registry-fork and debug.
(audio-recorder:2): GStreamer-CRITICAL **: Trying to stop a GstDeviceProvider v4l2deviceprovider0 which is already stopped
(audio-recorder:2): GStreamer-CRITICAL **: Trying to stop a GstDeviceProvider pulsedeviceprovider0 which is already stopped
Parent is shutting down, bye…

(the gui launches and is missing quite a few options)

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1. netblue30 Post authorOctober 19, 2016 at 12:24 pm
  
  Use –net=none on command line or “net none” in your profile file. It will block any network access.
  
  libdc1394 error – in your profile file use “protocol unix,inet,inet6,netlink”. You need “netlink” protocol, the program probably tries to access a video camera.
  
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Roger October 20, 2016 at 6:03 am

I have been experimenting with –net=none.
It seems to block all networking.
As an experiment I disabled my Internet access and ran VLC using firejail. No issues.
I turned the internet back on and ran:
>firejail –net=none vlc
Got all kinds of errors.

Can I block the Internet only or do I have to block all networking?
With all of the damn spying going on nowadays apps will “phone home” like E.T.
This must absolutely come to a stop.
I am hopeful firejail can help me get this done.
I am also concerned that apps may be accessig my home folder files.
firejail handles this quite well and for that I am very grateful.

I really cannot turn off my internet every single time an app runs.
Windows XP had an app firewall.
I have been looking into various app firewalls for linux such as Leopard Flower Firewall and Douane
I am still hopeful that firejail is the one stop solution I have been looking for.

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1. netblue30 Post authorOctober 22, 2016 at 7:04 pm
  
  > firejail –net=none vlc – Got all kinds of errors.
  
  –net command also disables Unix sockets, some of the program functionality will be lost. – for example DBus functionality. Some applications don’t like it and will not manage to start.
  
  Another way to disable internet access is to use –private command. For your VLC example, you open /etc/firejail/vlc.profile file in a text editor and replace the line “protocol unix,inet,inet6” with “protocol unix”.
  
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uli November 25, 2016 at 11:19 pm

There was no default tor profile so I wrote this file ~/.config/firejail/torbrowser-launcher.profile
# Firejail profile for Tor Browser Bundle
include /etc/firejail/disable-passwdmgr.inc
include /etc/firejail/disable-programs.inc
include /etc/firejail/disable-common.inc
include /etc/firejail/disable-devel.inc
caps.drop all
nonewprivs
nogroups
shell none
seccomp
protocol unix,inet,inet6,netlink
netfilter
tracelog
noroot
private
private-tmp
When I try to start up with the command firejail torbrowser-launcher the newest tor browser is loaded down and installed, then I get the following error message:
Running /home/uli/.local/share/torbrowser/tbb/x86_64/tor-browser_en-US/start-tor-browser.desktop
Unhandled Error
Traceback (most recent call last):
File “/usr/lib64/python2.7/site-packages/twisted/web/_newclient.py”, line 916, in dispatcher
return func(*args, **kwargs)
File “/usr/lib64/python2.7/site-packages/twisted/web/_newclient.py”, line 1472, in _finishResponse_WAITING
self._giveUp(Failure(reason))
File “/usr/lib64/python2.7/site-packages/twisted/web/_newclient.py”, line 1525, in _giveUp
self._disconnectParser(reason)
File “/usr/lib64/python2.7/site-packages/twisted/web/_newclient.py”, line 1513, in _disconnectParser
parser.connectionLost(reason)
— —
File “/usr/lib64/python2.7/site-packages/twisted/web/_newclient.py”, line 537, in connectionLost
self.response._bodyDataFinished()
File “/usr/lib64/python2.7/site-packages/twisted/web/_newclient.py”, line 916, in dispatcher
return func(*args, **kwargs)
File “/usr/lib64/python2.7/site-packages/twisted/web/_newclient.py”, line 1161, in _bodyDataFinished_CONNECTED
self._bodyProtocol.connectionLost(reason)
File “/usr/lib/python2.7/site-packages/torbrowser_launcher/launcher.py”, line 329, in connectionLost
self.all_done(reason)
File “/usr/lib/python2.7/site-packages/torbrowser_launcher/launcher.py”, line 346, in response_finished
self.run_task()
File “/usr/lib/python2.7/site-packages/torbrowser_launcher/launcher.py”, line 282, in run_task
self.verify()
File “/usr/lib/python2.7/site-packages/torbrowser_launcher/launcher.py”, line 491, in verify
self.run_task()
File “/usr/lib/python2.7/site-packages/torbrowser_launcher/launcher.py”, line 286, in run_task
self.extract()
File “/usr/lib/python2.7/site-packages/torbrowser_launcher/launcher.py”, line 531, in extract
self.run_task()
File “/usr/lib/python2.7/site-packages/torbrowser_launcher/launcher.py”, line 290, in run_task
self.run()
File “/usr/lib/python2.7/site-packages/torbrowser_launcher/launcher.py”, line 583, in run
subprocess.call([self.common.paths[‘tbb’][‘start’]], cwd=self.common.paths[‘tbb’][‘dir_tbb’])
File “/usr/lib64/python2.7/subprocess.py”, line 523, in call
return Popen(*popenargs, **kwargs).wait()
File “/usr/lib64/python2.7/subprocess.py”, line 711, in __init__
errread, errwrite)
File “/usr/lib64/python2.7/subprocess.py”, line 1343, in _execute_child
raise child_exception
exceptions.OSError: [Errno 13] Permission denied
Any idea what went wrong?

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1. netblue30 Post authorNovember 27, 2016 at 12:54 am
  
  My guess will be “private” command in your profile. This cleans up you home directory, and it will remove /home/uli/.local/share/torbrowser/tbb/x86_64/tor-browser_en-US/start-tor-browser.desktop from the sandbox.
  
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adsfasdfasdfasdf December 1, 2016 at 5:51 am

How to configure to use the custom profiles by default. For the default profiles I can just use firecfg. How about the custom ones?

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1. netblue30 Post authorDecember 3, 2016 at 12:55 pm
  
  You place them in ~/.config/firejail directory.
  
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2. netblue30 Post authorDecember 3, 2016 at 1:05 pm
  
  If you have a profile file, you put it in /home/username/.config/firejail directory. Then, you can create symbolic links by hand in /usr/local/bin directory (ln -s /usr/local/bin/program-name /usr/bin/firejail)
  
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  1. adsfasdfasdfasdf December 10, 2016 at 5:51 am
    
    thanks for the reply, much appreciated
    
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Mr.Fox March 20, 2017 at 11:37 pm

Is there a way i can start my local applications in firejail as different users 🙂 its like make the application started in firejail think its running on different user. While still it should have access to my local content.

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1. netblue30 Post authorMarch 22, 2017 at 4:32 pm
  
  You would need to have sudo access to switch the user:
  
  $ sudo -u username firejail …
  
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2. netblue30 Post authorMarch 22, 2017 at 4:35 pm
  
  Sorry, I’ve missed the local content:
  
  $ sudo -u username firejail –allusers …
  
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Chong April 25, 2017 at 8:50 pm

when using firejail –private firefox
i have noticed that after closing the session and starting a new session that my history is saved off? I was expecting that using the private option would have started a clean session the second time around.

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1. netblue30 Post authorApril 26, 2017 at 2:09 pm
  
  You are probably running into this problem: https://firejail.wordpress.com/support/frequently-asked-questions/#firefox
  
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