| ### |
| ### 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 }; |