Security-Enhanced Linux secures the chrome_sandbox processes via flexible mandatory access control.
The chrome_sandbox processes execute with the chrome_sandbox_t SELinux type. You can check if you have these processes running by executing the ps command with the -Z qualifier.
For example:
ps -eZ | grep chrome_sandbox_t
The chrome_sandbox_t SELinux type can be entered via the chrome_sandbox_exec_t file type.
The default entrypoint paths for the chrome_sandbox_t domain are the following:
/opt/google/chrome[^/]*/chrome-sandbox, /usr/lib/chromium-browser/chrome-sandbox, /usr/lib/chrome-sandbox
You can see the context of a process using the -Z option to psP Policy governs the access confined processes have to files. SELinux chrome_sandbox policy is very flexible allowing users to setup their chrome_sandbox processes in as secure a method as possible.
The following process types are defined for chrome_sandbox:
chrome_sandbox_t, chrome_sandbox_nacl_t
Note: semanage permissive -a chrome_sandbox_t can be used to make the process type chrome_sandbox_t permissive. SELinux does not deny access to permissive process types, but the AVC (SELinux denials) messages are still generated.
If you want to allow all domains to execute in fips_mode, you must turn on the fips_mode boolean. Enabled by default.
setsebool -P fips_mode 1
If you want to allow confined applications to use nscd shared memory, you must turn on the nscd_use_shm boolean. Enabled by default.
setsebool -P nscd_use_shm 1
If you want to allow regular users direct dri device access, you must turn on the selinuxuser_direct_dri_enabled boolean. Enabled by default.
setsebool -P selinuxuser_direct_dri_enabled 1
If you want to allow unconfined users to transition to the chrome sandbox domains when running chrome-sandbox, you must turn on the unconfined_chrome_sandbox_transition boolean. Enabled by default.
setsebool -P unconfined_chrome_sandbox_transition 1
If you want to support ecryptfs home directories, you must turn on the use_ecryptfs_home_dirs boolean. Disabled by default.
setsebool -P use_ecryptfs_home_dirs 1
If you want to support fusefs home directories, you must turn on the use_fusefs_home_dirs boolean. Disabled by default.
setsebool -P use_fusefs_home_dirs 1
If you want to support NFS home directories, you must turn on the use_nfs_home_dirs boolean. Disabled by default.
setsebool -P use_nfs_home_dirs 1
If you want to support SAMBA home directories, you must turn on the use_samba_home_dirs boolean. Disabled by default.
setsebool -P use_samba_home_dirs 1
If you want to allows clients to write to the X server shared memory segments, you must turn on the xserver_clients_write_xshm boolean. Disabled by default.
setsebool -P xserver_clients_write_xshm 1
The SELinux process type chrome_sandbox_t can manage files labeled with the following file types. The paths listed are the default paths for these file types. Note the processes UID still need to have DAC permissions.
cgroup_t
/sys/fs/cgroup
chrome_sandbox_home_t
/home/[^/]+/.cache/chromium(/.*)?
/home/[^/]+/.config/chromium(/.*)?
/home/[^/]+/.cache/google-chrome(/.*)?
/home/[^/]+/.cache/google-chrome-unstable(/.*)?
chrome_sandbox_tmp_t
chrome_sandbox_tmpfs_t
home_cert_t
/root/.pki(/.*)?
/root/.cert(/.*)?
/home/[^/]+/.pki(/.*)?
/home/[^/]+/.cert(/.*)?
/home/[^/]+/.local/share/networkmanagement/certificates(/.*)?
/home/[^/]+/.kde/share/apps/networkmanagement/certificates(/.*)?
mozilla_home_t
/home/[^/]+/.lyx(/.*)?
/home/[^/]+/.java(/.*)?
/home/[^/]+/.adobe(/.*)?
/home/[^/]+/.gnash(/.*)?
/home/[^/]+/.webex(/.*)?
/home/[^/]+/.IBMERS(/.*)?
/home/[^/]+/.galeon(/.*)?
/home/[^/]+/.spicec(/.*)?
/home/[^/]+/POkemon.*(/.*)?
/home/[^/]+/.icedtea(/.*)?
/home/[^/]+/.mozilla(/.*)?
/home/[^/]+/.phoenix(/.*)?
/home/[^/]+/.netscape(/.*)?
/home/[^/]+/.ICAClient(/.*)?
/home/[^/]+/.quakelive(/.*)?
/home/[^/]+/.macromedia(/.*)?
/home/[^/]+/.thunderbird(/.*)?
/home/[^/]+/.gcjwebplugin(/.*)?
/home/[^/]+/.grl-podcasts(/.*)?
/home/[^/]+/.cache/mozilla(/.*)?
/home/[^/]+/.icedteaplugin(/.*)?
/home/[^/]+/zimbrauserdata(/.*)?
/home/[^/]+/.juniper_networks(/.*)?
/home/[^/]+/.cache/icedtea-web(/.*)?
/home/[^/]+/abc
/home/[^/]+/mozilla.pdf
/home/[^/]+/.gnashpluginrc
user_fonts_cache_t
/root/.fontconfig(/.*)?
/root/.fonts/auto(/.*)?
/root/.fonts.cache-.*
/home/[^/]+/.fontconfig(/.*)?
/home/[^/]+/.fonts/auto(/.*)?
/home/[^/]+/.fonts.cache-.*
user_tmp_t
/dev/shm/mono.*
/var/run/user(/.*)?
/tmp/.ICE-unix(/.*)?
/tmp/.X11-unix(/.*)?
/dev/shm/pulse-shm.*
/tmp/.X0-lock
/tmp/hsperfdata_root
/var/tmp/hsperfdata_root
/home/[^/]+/tmp
/home/[^/]+/.tmp
/tmp/gconfd-[^/]+
xserver_tmpfs_t
You can see the context of a file using the -Z option to lsP Policy governs the access confined processes have to these files. SELinux chrome_sandbox policy is very flexible allowing users to setup their chrome_sandbox processes in as secure a method as possible.
STANDARD FILE CONTEXT
SELinux defines the file context types for the chrome_sandbox, if you wanted to store files with these types in a diffent paths, you need to execute the semanage command to sepecify alternate labeling and then use restorecon to put the labels on disk.
semanage fcontext -a -t chrome_sandbox_home_t '/srv/mychrome_sandbox_content(/.*)?'
restorecon -R -v /srv/mychrome_sandbox_content
Note: SELinux often uses regular expressions to specify labels that match multiple files.
The following file types are defined for chrome_sandbox:
chrome_sandbox_exec_t
- Set files with the chrome_sandbox_exec_t type, if you want to transition an executable to the chrome_sandbox_t domain.
chrome_sandbox_home_t
- Set files with the chrome_sandbox_home_t type, if you want to store chrome sandbox files in the users home directory.
chrome_sandbox_nacl_exec_t
- Set files with the chrome_sandbox_nacl_exec_t type, if you want to transition an executable to the chrome_sandbox_nacl_t domain.
chrome_sandbox_tmp_t
- Set files with the chrome_sandbox_tmp_t type, if you want to store chrome sandbox temporary files in the /tmp directories.
chrome_sandbox_tmpfs_t
- Set files with the chrome_sandbox_tmpfs_t type, if you want to store chrome sandbox files on a tmpfs file system.
Note: File context can be temporarily modified with the chcon command. If you want to permanently change the file context you need to use the semanage fcontext command. This will modify the SELinux labeling database. You will need to use restorecon to apply the labels.
semanage permissive can also be used to manipulate whether or not a process type is permissive.
semanage module can also be used to enable/disable/install/remove policy modules.
semanage boolean can also be used to manipulate the booleans
system-config-selinux is a GUI tool available to customize SELinux policy settings.