### ### Untrusted apps. ### ### This file defines the rules for untrusted apps. ### Apps are labeled based on mac_permissions.xml (maps signer and ### optionally package name to seinfo value) and seapp_contexts (maps UID ### and optionally seinfo value to domain for process and type for data ### directory). The untrusted_app domain is the default assignment in ### seapp_contexts for any app with UID between APP_AID (10000) ### and AID_ISOLATED_START (99000) if the app has no specific seinfo ### value as determined from mac_permissions.xml. In current AOSP, this ### domain is assigned to all non-system apps as well as to any system apps ### that are not signed by the platform key. To move ### a system app into a specific domain, add a signer entry for it to ### mac_permissions.xml and assign it one of the pre-existing seinfo values ### or define and use a new seinfo value in both mac_permissions.xml and ### seapp_contexts. ### ### untrusted_app includes all the appdomain rules, plus the ### additional following rules: ### type untrusted_app, domain; app_domain(untrusted_app) net_domain(untrusted_app) bluetooth_domain(untrusted_app) # Some apps ship with shared libraries and binaries that they write out # to their sandbox directory and then execute. allow untrusted_app app_data_file:file { rx_file_perms execmod }; allow untrusted_app tun_device:chr_file rw_file_perms; # ASEC allow untrusted_app asec_apk_file:dir { getattr }; allow untrusted_app asec_apk_file:file r_file_perms; # Execute libs in asec containers. allow untrusted_app asec_public_file:file { execute execmod }; # Allow the allocation and use of ptys # Used by: https://play.google.com/store/apps/details?id=jackpal.androidterm create_pty(untrusted_app) # Used by Finsky / Android "Verify Apps" functionality when # running "adb install foo.apk". # TODO: Long term, we don't want apps probing into shell data files. # Figure out a way to remove these rules. allow untrusted_app shell_data_file:file r_file_perms; allow untrusted_app shell_data_file:dir r_dir_perms; # # Rules migrated from old app domains coalesced into untrusted_app. # This includes what used to be media_app, shared_app, and release_app. # # Access /dev/mtp_usb. allow untrusted_app mtp_device:chr_file rw_file_perms; # Access to /data/media. allow untrusted_app media_rw_data_file:dir create_dir_perms; allow untrusted_app media_rw_data_file:file create_file_perms; # Write to /cache. allow untrusted_app cache_file:dir create_dir_perms; allow untrusted_app cache_file:file create_file_perms; ### ### neverallow rules ### # Too much leaky information in debugfs. It's a security # best practice to ensure these files aren't readable. neverallow untrusted_app debugfs:file read; # Do not allow untrusted apps to register services. # Only trusted components of Android should be registering # services. neverallow untrusted_app service_manager_type:service_manager add;