### ### Domain for all zygote spawned apps ### ### This file is the base policy for all zygote spawned apps. ### Other policy files, such as isolated_app.te, untrusted_app.te, etc ### extend from this policy. Only policies which should apply to ALL ### zygote spawned apps should be added here. ### type appdomain_tmpfs, file_type; ### ### Neverallow rules ### ### These are things that Android apps should NEVER be able to do ### # Superuser capabilities. # bluetooth requires net_admin and wake_alarm. network stack app requires net_admin. neverallow { appdomain -bluetooth -network_stack } self:capability_class_set *; # Block device access. neverallow appdomain dev_type:blk_file { read write }; # Access to any of the following character devices. neverallow appdomain { audio_device camera_device dm_device radio_device rpmsg_device video_device }:chr_file { read write }; # Note: Try expanding list of app domains in the future. neverallow { untrusted_app isolated_app shell } graphics_device:chr_file { read write }; neverallow { appdomain -nfc } nfc_device:chr_file { read write }; neverallow { appdomain -bluetooth } hci_attach_dev:chr_file { read write }; neverallow appdomain tee_device:chr_file { read write }; # Privileged netlink socket interfaces. neverallow { appdomain -network_stack } domain:{ netlink_tcpdiag_socket netlink_nflog_socket netlink_xfrm_socket netlink_audit_socket netlink_dnrt_socket } *; # These messages are broadcast messages from the kernel to userspace. # Do not allow the writing of netlink messages, which has been a source # of rooting vulns in the past. neverallow { appdomain -network_stack } domain:netlink_kobject_uevent_socket { write append }; # Sockets under /dev/socket that are not specifically typed. neverallow appdomain socket_device:sock_file write; # Unix domain sockets. neverallow appdomain adbd_socket:sock_file write; neverallow { appdomain -radio } rild_socket:sock_file write; # ptrace access to non-app domains. neverallow appdomain { domain -appdomain }:process ptrace; # The Android security model guarantees the confidentiality and integrity # of application data and execution state. Ptrace bypasses those # confidentiality guarantees. Disallow ptrace access from system components # to apps. Crash_dump is excluded, as it needs ptrace access to # produce stack traces. llkd is excluded, as it needs ptrace access to # inspect stack traces for live lock conditions. neverallow { domain -appdomain -crash_dump userdebug_or_eng(`-llkd') } appdomain:process ptrace; # Read or write access to /proc/pid entries for any non-app domain. # A different form of hidepid=2 like protections neverallow appdomain { domain -appdomain }:file no_w_file_perms; neverallow { appdomain -shell } { domain -appdomain }:file no_rw_file_perms; # signal access to non-app domains. # sigchld allowed for parent death notification. # signull allowed for kill(pid, 0) existence test. # All others prohibited. # -perfetto is to allow shell (which is an appdomain) to kill perfetto # (see private/shell.te). neverallow appdomain { domain -appdomain -perfetto }:process { sigkill sigstop signal }; # Write to rootfs. neverallow appdomain rootfs:dir_file_class_set { create write setattr relabelfrom relabelto append unlink link rename }; # Write to /system. neverallow appdomain system_file:dir_file_class_set { create write setattr relabelfrom relabelto append unlink link rename }; # Write to entrypoint executables. neverallow appdomain exec_type:file { create write setattr relabelfrom relabelto append unlink link rename }; # Write to system-owned parts of /data. # This is the default type for anything under /data not otherwise # specified in file_contexts. Define a different type for portions # that should be writable by apps. neverallow appdomain system_data_file:dir_file_class_set { create write setattr relabelfrom relabelto append unlink link rename }; # Write to various other parts of /data. neverallow appdomain drm_data_file:dir_file_class_set { create write setattr relabelfrom relabelto append unlink link rename }; neverallow { appdomain -platform_app } apk_data_file:dir_file_class_set { create write setattr relabelfrom relabelto append unlink link rename }; neverallow { appdomain -platform_app } apk_tmp_file:dir_file_class_set { create write setattr relabelfrom relabelto append unlink link rename }; neverallow { appdomain -platform_app } apk_private_data_file:dir_file_class_set { create write setattr relabelfrom relabelto append unlink link rename }; neverallow { appdomain -platform_app } apk_private_tmp_file:dir_file_class_set { create write setattr relabelfrom relabelto append unlink link rename }; neverallow { appdomain -shell } shell_data_file:dir_file_class_set { create setattr relabelfrom relabelto append unlink link rename }; neverallow { appdomain -bluetooth } bluetooth_data_file:dir_file_class_set { create write setattr relabelfrom relabelto append unlink link rename }; neverallow { domain -credstore -init } credstore_data_file:dir_file_class_set *; neverallow appdomain keystore_data_file:dir_file_class_set { create write setattr relabelfrom relabelto append unlink link rename }; neverallow appdomain systemkeys_data_file:dir_file_class_set { create write setattr relabelfrom relabelto append unlink link rename }; neverallow appdomain wifi_data_file:dir_file_class_set { create write setattr relabelfrom relabelto append unlink link rename }; neverallow appdomain dhcp_data_file:dir_file_class_set { create write setattr relabelfrom relabelto append unlink link rename }; # access tmp apk files neverallow { appdomain -untrusted_app_all -platform_app -priv_app } { apk_tmp_file apk_private_tmp_file }:dir_file_class_set *; neverallow untrusted_app_all { apk_tmp_file apk_private_tmp_file }:{ devfile_class_set dir fifo_file lnk_file sock_file } *; neverallow untrusted_app_all { apk_tmp_file apk_private_tmp_file }:file ~{ getattr read }; # Access to factory files. neverallow appdomain efs_file:dir_file_class_set write; neverallow { appdomain -shell } efs_file:dir_file_class_set read; # Write to various pseudo file systems. neverallow { appdomain -bluetooth -nfc } sysfs:dir_file_class_set write; neverallow appdomain proc:dir_file_class_set write; # Access to syslog(2) or /proc/kmsg. neverallow appdomain kernel:system { syslog_read syslog_mod syslog_console }; # SELinux is not an API for apps to use neverallow { appdomain -shell } *:security { compute_av check_context }; neverallow { appdomain -shell } *:netlink_selinux_socket *; # Ability to perform any filesystem operation other than statfs(2). # i.e. no mount(2), unmount(2), etc. neverallow appdomain fs_type:filesystem ~getattr; # prevent creation/manipulation of globally readable symlinks neverallow appdomain { apk_data_file cache_file cache_recovery_file dev_type rootfs system_file tmpfs }:lnk_file no_w_file_perms; # Applications should use the activity model for receiving events neverallow { appdomain -shell # bugreport } input_device:chr_file ~getattr; # Do not allow access to Bluetooth-related system properties except for a few allowed domains. # neverallow rules for access to Bluetooth-related data files are above. neverallow { appdomain -bluetooth -system_app } { bluetooth_audio_hal_prop bluetooth_a2dp_offload_prop bluetooth_prop exported_bluetooth_prop }:file create_file_perms; # allow system_app to access Nfc-related system properties. set_prop(system_app, nfc_prop) # allow system_app to access radio_config system properties. set_prop(system_app, radio_control_prop) # Apps cannot access proc_uid_time_in_state neverallow appdomain proc_uid_time_in_state:file *; # Apps cannot access proc_uid_concurrent_active_time neverallow appdomain proc_uid_concurrent_active_time:file *; # Apps cannot access proc_uid_concurrent_policy_time neverallow appdomain proc_uid_concurrent_policy_time:file *; # Apps cannot access proc_uid_cpupower neverallow appdomain proc_uid_cpupower:file *; # Apps may not read /proc/net/{tcp,tcp6,udp,udp6}. These files leak information across the # application boundary. VPN apps may use the ConnectivityManager.getConnectionOwnerUid() API to # perform UID lookups. neverallow { appdomain -shell } proc_net_tcp_udp:file *; # Apps cannot access bootstrap files. The bootstrap files are only for # extremely early processes (like init, etc.) which are started before # the runtime APEX is activated and Bionic libs are provided from there. # If app process accesses (or even load/execute) the bootstrap files, # it might cause problems such as ODR violation, etc. neverallow appdomain system_bootstrap_lib_file:file { open read write append execute execute_no_trans map }; neverallow appdomain system_bootstrap_lib_file:dir { open read getattr search }; # Allow to read ro.vendor.camera.extensions.enabled get_prop(appdomain, camera2_extensions_prop) # Allow to ro.camerax.extensions.enabled get_prop(appdomain, camerax_extensions_prop)