### ### 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. ### # Allow apps to connect to the keystore unix_socket_connect(appdomain, keystore, keystore) # Receive and use open file descriptors inherited from zygote. allow appdomain zygote:fd use; # Read system properties managed by zygote. allow appdomain zygote_tmpfs:file read; # Notify zygote of death; allow appdomain zygote:process sigchld; # Communicate with system_server. allow appdomain system:fifo_file rw_file_perms; allow appdomain system:unix_stream_socket { read write setopt }; binder_call(appdomain, system) # Communicate with surfaceflinger. allow appdomain surfaceflinger:unix_stream_socket { read write setopt }; binder_call(appdomain, surfaceflinger) # App sandbox file accesses. allow appdomain app_data_file:dir create_dir_perms; allow appdomain app_data_file:notdevfile_class_set create_file_perms; # Read/write data files created by the platform apps if they # were passed to the app via binder or local IPC. Do not allow open. allow appdomain platform_app_data_file:file { getattr read write }; # lib subdirectory of /data/data dir is system-owned. allow appdomain system_data_file:dir r_dir_perms; allow appdomain system_data_file:file { execute open }; # Execute the shell or other system executables. allow appdomain shell_exec:file rx_file_perms; allow appdomain system_file:file rx_file_perms; # Read/write wallpaper file (opened by system). allow appdomain wallpaper_file:file { read write }; # Write to /data/anr/traces.txt. allow appdomain anr_data_file:dir search; allow appdomain anr_data_file:file { open append }; # Write to /proc/net/xt_qtaguid/ctrl file. allow appdomain qtaguid_proc:file rw_file_perms; # Everybody can read the xt_qtaguid resource tracking misc dev. # So allow all apps to read from /dev/xt_qtaguid. allow appdomain qtaguid_device:chr_file r_file_perms; # Use the Binder. binder_use(appdomain) # Perform binder IPC to binder services. binder_call(appdomain, binderservicedomain) # Perform binder IPC to other apps. binder_call(appdomain, appdomain) # Appdomain interaction with isolated apps r_dir_file(appdomain, isolated_app) binder_call(appdomain, isolated_app) # Already connected, unnamed sockets being passed over some other IPC # hence no sock_file or connectto permission. This appears to be how # Chrome works, may need to be updated as more apps using isolated services # are examined. allow appdomain isolated_app:unix_stream_socket { read write }; # Backup ability for every app. BMS opens and passes the fd # to any app that has backup ability. Hence, no open permissions here. allow appdomain backup_data_file:file { read write }; allow appdomain cache_backup_file:file { read write }; # Backup ability using 'adb backup' allow appdomain system_data_file:lnk_file getattr; # Allow all applications to read downloaded files allow appdomain download_file:file r_file_perms; file_type_auto_trans(appdomain, download_file, download_file) # Allow applications to communicate with netd via /dev/socket/dnsproxyd # to do DNS resolution unix_socket_connect(appdomain, dnsproxyd, netd) # Allow applications to communicate with drmserver over binder binder_call(appdomain, drmserver) # Allow applications to communicate with mediaserver over binder binder_call(appdomain, mediaserver) # Allow applications to make outbound tcp connections to any port allow appdomain port_type:tcp_socket name_connect; # Allow apps to see changes to the routing table. allow appdomain self:netlink_route_socket { read bind create nlmsg_read ioctl getattr setattr getopt setopt shutdown }; # Allow apps to use rawip sockets. This is needed for apps which execute # /system/bin/ping, for example. allow appdomain self:rawip_socket create_socket_perms; ### ### Neverallow rules ### ### These are things that Android apps should NEVER be able to do ### # Superuser capabilities. # Only exception is sys_nice for binder, might not be necessary. neverallow { appdomain -unconfineddomain } self:capability ~sys_nice; neverallow { appdomain -unconfineddomain } self:capability2 *; # Block device access. neverallow { appdomain -unconfineddomain } dev_type:blk_file { read write }; # Kernel memory access. neverallow { appdomain -unconfineddomain } kmem_device:chr_file { read write }; # Setting SELinux enforcing status or booleans. # Conditionally allowed to system_app for SEAndroidManager. neverallow { appdomain -unconfineddomain } kernel:security { setenforce setbool }; # Load security policy. neverallow appdomain kernel:security load_policy; # Privileged netlink socket interfaces. neverallow { appdomain -unconfineddomain } self:{ netlink_socket netlink_firewall_socket netlink_tcpdiag_socket netlink_nflog_socket netlink_xfrm_socket netlink_selinux_socket netlink_audit_socket netlink_ip6fw_socket netlink_dnrt_socket netlink_kobject_uevent_socket } *; # ptrace access to non-app domains. neverallow { appdomain -unconfineddomain } { domain -appdomain }:process ptrace; # Transition to a non-app domain. neverallow { appdomain -unconfineddomain } ~appdomain:process { transition dyntransition }; # Write to /system. neverallow { appdomain -unconfineddomain } system_file:dir_file_class_set write; # 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. # Exception for system_app for Settings. neverallow { appdomain -unconfineddomain -system_app } system_data_file:dir_file_class_set write;