private/sdk_sandbox.te

###
### SDK Sandbox process.
###
### This file defines the security policy for the sdk sandbox processes.

type sdk_sandbox, domain;

typeattribute sdk_sandbox coredomain;

net_domain(sdk_sandbox)
app_domain(sdk_sandbox)

# Write app-specific trace data to the Perfetto traced damon. This requires
# connecting to its producer socket and obtaining a (per-process) tmpfs fd.
perfetto_producer(sdk_sandbox)

# Allow profiling if the app opts in by being marked profileable/debuggable.
can_profile_heap(sdk_sandbox)
can_profile_perf(sdk_sandbox)

# allow sdk sandbox to use UDP sockets provided by the system server but not
# modify them other than to connect
allow sdk_sandbox system_server:udp_socket {
        connect getattr read recvfrom sendto write getopt setopt };

# allow sandbox to search in sdk system server directory
# additionally, for webview to work, getattr has been permitted
allow sdk_sandbox sdk_sandbox_system_data_file:dir { getattr search };
# allow sandbox to create files and dirs in sdk data directory
allow sdk_sandbox sdk_sandbox_data_file:dir create_dir_perms;
allow sdk_sandbox sdk_sandbox_data_file:file create_file_perms;

###
### neverallow rules
###

neverallow sdk_sandbox { app_data_file privapp_data_file sdk_sandbox_data_file }:file { execute execute_no_trans };

# Receive or send uevent messages.
neverallow sdk_sandbox domain:netlink_kobject_uevent_socket *;

# Receive or send generic netlink messages
neverallow sdk_sandbox domain:netlink_socket *;

# Too much leaky information in debugfs. It's a security
# best practice to ensure these files aren't readable.
neverallow sdk_sandbox debugfs:file read;

# execute gpu_device
neverallow sdk_sandbox gpu_device:chr_file execute;

# access files in /sys with the default sysfs label
neverallow sdk_sandbox sysfs:file *;

# Avoid reads from generically labeled /proc files
# Create a more specific label if needed
neverallow sdk_sandbox proc:file { no_rw_file_perms no_x_file_perms };

# Directly access external storage
neverallow sdk_sandbox { sdcard_type media_rw_data_file }:file {open create};
neverallow sdk_sandbox { sdcard_type media_rw_data_file }:dir search;

# Avoid reads to proc_net, it contains too much device wide information about
# ongoing connections.
neverallow sdk_sandbox proc_net:file no_rw_file_perms;

# SDK sandbox processes have their own storage not related to app_data_file or privapp_data_file
neverallow sdk_sandbox { app_data_file privapp_data_file }:dir no_rw_file_perms;
neverallow sdk_sandbox { app_data_file privapp_data_file }:file no_rw_file_perms;

# SDK sandbox processes don't  have any access to external storage
neverallow sdk_sandbox { media_rw_data_file }:dir no_rw_file_perms;
neverallow sdk_sandbox { media_rw_data_file }:file no_rw_file_perms;

neverallow { sdk_sandbox } tmpfs:dir no_rw_file_perms;

neverallow sdk_sandbox hal_drm_service:service_manager find;

# Only certain system components should have access to sdk_sandbox_system_data_file
# sdk_sandbox only needs search. Restricted in follow up neverallow rule.
neverallow {
    domain
    -init
    -installd
    -system_server
    -vold_prepare_subdirs
} sdk_sandbox_system_data_file:dir { relabelfrom };

neverallow {
    domain
    -init
    -installd
    -sdk_sandbox
    -system_server
    -vold_prepare_subdirs
    -zygote
} sdk_sandbox_system_data_file:dir { create_dir_perms relabelto };

# sdk_sandbox only needs to traverse through the sdk_sandbox_system_data_file
neverallow sdk_sandbox sdk_sandbox_system_data_file:dir ~{ getattr search };

# Only dirs should be created at sdk_sandbox_system_data_file level
neverallow { domain -init } sdk_sandbox_system_data_file:file *;