### ### A domain for further sandboxing privileged apps. ### typeattribute priv_app coredomain; app_domain(priv_app) # Access the network. net_domain(priv_app) # Access bluetooth. bluetooth_domain(priv_app) # Allow the allocation and use of ptys # Used by: https://play.privileged.com/store/apps/details?id=jackpal.androidterm create_pty(priv_app) # Allow loading executable code from writable priv-app home # directories. This is a W^X violation, however, it needs # to be supported for now for the following reasons. # * /data/user_*/0/*/code_cache/* POSSIBLE uses (b/117841367) # 1) com.android.opengl.shaders_cache # 2) com.android.skia.shaders_cache # 3) com.android.renderscript.cache # * /data/user_de/0/com.google.android.gms/app_chimera # TODO: Tighten (b/112357170) allow priv_app privapp_data_file:file execute; # Chrome Crashpad uses the the dynamic linker to load native executables # from an APK (b/112050209, crbug.com/928422) allow priv_app system_linker_exec:file execute_no_trans; allow priv_app privapp_data_file:lnk_file create_file_perms; # Priv apps can find services that expose both @SystemAPI and normal APIs. allow priv_app app_api_service:service_manager find; allow priv_app system_api_service:service_manager find; allow priv_app audioserver_service:service_manager find; allow priv_app cameraserver_service:service_manager find; allow priv_app drmserver_service:service_manager find; allow priv_app mediadrmserver_service:service_manager find; allow priv_app mediaextractor_service:service_manager find; allow priv_app mediametrics_service:service_manager find; allow priv_app mediaserver_service:service_manager find; allow priv_app network_watchlist_service:service_manager find; allow priv_app nfc_service:service_manager find; allow priv_app oem_lock_service:service_manager find; allow priv_app persistent_data_block_service:service_manager find; allow priv_app radio_service:service_manager find; allow priv_app recovery_service:service_manager find; allow priv_app stats_service:service_manager find; # Allow privileged apps to interact with gpuservice binder_call(priv_app, gpuservice) allow priv_app gpu_service:service_manager find; # Write to /cache. allow priv_app { cache_file cache_recovery_file }:dir create_dir_perms; allow priv_app { cache_file cache_recovery_file }:file create_file_perms; # /cache is a symlink to /data/cache on some devices. Allow reading the link. allow priv_app cache_file:lnk_file r_file_perms; # Access to /data/media. allow priv_app media_rw_data_file:dir create_dir_perms; allow priv_app media_rw_data_file:file create_file_perms; # Used by Finsky / Android "Verify Apps" functionality when # running "adb install foo.apk". allow priv_app shell_data_file:file r_file_perms; allow priv_app shell_data_file:dir r_dir_perms; # Allow traceur to pass file descriptors through a content provider to betterbug allow priv_app trace_data_file:file { getattr read }; # Allow verifier to access staged apks. allow priv_app { apk_tmp_file apk_private_tmp_file }:dir r_dir_perms; allow priv_app { apk_tmp_file apk_private_tmp_file }:file r_file_perms; # For AppFuse. allow priv_app vold:fd use; allow priv_app fuse_device:chr_file { read write }; # /proc access allow priv_app { proc_vmstat }:file r_file_perms; allow priv_app sysfs_type:dir search; # Read access to /sys/class/net/wlan*/address r_dir_file(priv_app, sysfs_net) # Read access to /sys/block/zram*/mm_stat r_dir_file(priv_app, sysfs_zram) r_dir_file(priv_app, rootfs) # access the mac address allowxperm priv_app self:udp_socket ioctl SIOCGIFHWADDR; # Allow com.android.vending to communicate with statsd. binder_call(priv_app, statsd) # Allow Phone to read/write cached ringtones (opened by system). allow priv_app ringtone_file:file { getattr read write }; # Access to /data/preloads allow priv_app preloads_data_file:file r_file_perms; allow priv_app preloads_data_file:dir r_dir_perms; allow priv_app preloads_media_file:file r_file_perms; allow priv_app preloads_media_file:dir r_dir_perms; read_runtime_log_tags(priv_app) # 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(priv_app) # Allow priv_apps to request and collect incident reports. # (Also requires DUMP and PACKAGE_USAGE_STATS permissions) allow priv_app incident_service:service_manager find; binder_call(priv_app, incidentd) allow priv_app incidentd:fifo_file { read write }; # Allow profiling if the app opts in by being marked profileable/debuggable. can_profile_heap(priv_app) can_profile_perf(priv_app) # Allow priv_apps to check whether Dynamic System Update is enabled get_prop(priv_app, dynamic_system_prop) # suppress denials for non-API accesses. dontaudit priv_app exec_type:file getattr; dontaudit priv_app device:dir read; dontaudit priv_app fs_bpf:dir search; dontaudit priv_app net_dns_prop:file read; dontaudit priv_app proc:file read; dontaudit priv_app proc_interrupts:file read; dontaudit priv_app proc_modules:file read; dontaudit priv_app proc_net:file read; dontaudit priv_app proc_stat:file read; dontaudit priv_app proc_version:file read; dontaudit priv_app sysfs:dir read; dontaudit priv_app sysfs:file read; dontaudit priv_app sysfs_android_usb:file read; dontaudit priv_app sysfs_dm:file r_file_perms; dontaudit priv_app wifi_prop:file read; dontaudit priv_app { wifi_prop exported_wifi_prop }:file read; # allow privileged apps to use UDP sockets provided by the system server but not # modify them other than to connect allow priv_app system_server:udp_socket { connect getattr read recvfrom sendto write getopt setopt }; # allow apps like Phonesky to check the file signature of an apk installed on # the Incremental File System, and fill missing blocks in the apk allowxperm priv_app apk_data_file:file ioctl { INCFS_IOCTL_READ_SIGNATURE INCFS_IOCTL_FILL_BLOCKS }; # allow privileged data loader apps (e.g. com.android.vending) to read logs from Incremental File System allow priv_app incremental_control_file:file { read getattr ioctl }; # allow apps like Phonesky to request permission to fill blocks of an apk file # on the Incremental File System. allowxperm priv_app incremental_control_file:file ioctl INCFS_IOCTL_PERMIT_FILL; # Required for Phonesky to be able to read APEX files under /data/apex/active/. allow priv_app apex_data_file:dir search; allow priv_app staging_data_file:file r_file_perms; ### ### neverallow rules ### # Receive or send uevent messages. neverallow priv_app domain:netlink_kobject_uevent_socket *; # Receive or send generic netlink messages neverallow priv_app domain:netlink_socket *; # Too much leaky information in debugfs. It's a security # best practice to ensure these files aren't readable. neverallow priv_app debugfs:file read; # Do not allow privileged apps to register services. # Only trusted components of Android should be registering # services. neverallow priv_app service_manager_type:service_manager add; # Do not allow privileged apps to connect to the property service # or set properties. b/10243159 neverallow priv_app property_socket:sock_file write; neverallow priv_app init:unix_stream_socket connectto; neverallow priv_app property_type:property_service set; # Do not allow priv_app to be assigned mlstrustedsubject. # This would undermine the per-user isolation model being # enforced via levelFrom=user in seapp_contexts and the mls # constraints. As there is no direct way to specify a neverallow # on attribute assignment, this relies on the fact that fork # permission only makes sense within a domain (hence should # never be granted to any other domain within mlstrustedsubject) # and priv_app is allowed fork permission to itself. neverallow priv_app mlstrustedsubject:process fork; # Do not allow priv_app to hard link to any files. # In particular, if priv_app links to other app data # files, installd will not be able to guarantee the deletion # of the linked to file. Hard links also contribute to security # bugs, so we want to ensure priv_app never has this # capability. neverallow priv_app file_type:file link; # priv apps should not be able to open trace data files, they should depend # upon traceur to pass a file descriptor which they can then read neverallow priv_app trace_data_file:dir *; neverallow priv_app trace_data_file:file { no_w_file_perms open }; # Do not allow priv_app access to cgroups. neverallow priv_app cgroup:file *; # Do not allow loading executable code from non-privileged # application home directories. Code loading across a security boundary # is dangerous and allows a full compromise of a privileged process # by an unprivileged process. b/112357170 neverallow priv_app app_data_file:file no_x_file_perms; # Do not follow untrusted app provided symlinks neverallow priv_app app_data_file:lnk_file { open read getattr };