| typeattribute app_zygote coredomain; |
| |
| ###### |
| ###### Policy below is different from regular zygote-spawned apps |
| ###### |
| |
| # Allow access to temporary files, which is normally permitted through |
| # a domain macro. |
| tmpfs_domain(app_zygote); |
| |
| # Set the UID/GID of the process. |
| # This will be further limited to a range of isolated UIDs with seccomp. |
| allow app_zygote self:global_capability_class_set { setgid setuid }; |
| # Drop capabilities from bounding set. |
| allow app_zygote self:global_capability_class_set setpcap; |
| # Switch SELinux context to isolated app domain. |
| allow app_zygote self:process setcurrent; |
| allow app_zygote isolated_app:process dyntransition; |
| |
| # For JIT |
| allow app_zygote self:process execmem; |
| |
| # Allow app_zygote to stat the files that it opens. It must |
| # be able to inspect them so that it can reopen them on fork |
| # if necessary: b/30963384. |
| allow app_zygote debugfs_trace_marker:file getattr; |
| |
| # get system_server process group |
| allow app_zygote system_server:process getpgid; |
| |
| # Interaction between the app_zygote and its children. |
| allow app_zygote isolated_app:process setpgid; |
| |
| # TODO (b/63631799) fix this access |
| dontaudit app_zygote mnt_expand_file:dir getattr; |
| |
| # Get seapp_contexts |
| allow app_zygote seapp_contexts_file:file r_file_perms; |
| # Check validity of SELinux context before use. |
| selinux_check_context(app_zygote) |
| # Check SELinux permissions. |
| selinux_check_access(app_zygote) |
| |
| # Read and inspect temporary files managed by zygote. |
| allow app_zygote zygote_tmpfs:file { read getattr }; |
| |
| ###### |
| ###### Policy below is shared with regular zygote-spawned apps |
| ###### |
| |
| # Child of zygote. |
| allow app_zygote zygote:fd use; |
| allow app_zygote zygote:process sigchld; |
| |
| # For ART (read /data/dalvik-cache). |
| r_dir_file(app_zygote, dalvikcache_data_file); |
| allow app_zygote dalvikcache_data_file:file execute; |
| |
| # For ART (allow userfaultfd and related ioctls) |
| userfaultfd_use(app_zygote) |
| |
| # Read /data/misc/apexdata/ to (get to com.android.art/dalvik-cache). |
| allow app_zygote apex_module_data_file:dir search; |
| # For ART APEX (read /data/misc/apexdata/com.android.art/dalvik-cache). |
| r_dir_file(app_zygote, apex_art_data_file) |
| |
| # Allow reading/executing installed binaries to enable preloading |
| # application data |
| allow app_zygote apk_data_file:dir r_dir_perms; |
| allow app_zygote apk_data_file:file { r_file_perms execute }; |
| |
| # /oem accesses. |
| allow app_zygote oemfs:dir search; |
| |
| # Allow app_zygote access to /vendor/overlay |
| r_dir_file(app_zygote, vendor_overlay_file) |
| |
| allow app_zygote system_data_file:lnk_file r_file_perms; |
| allow app_zygote system_data_file:file { getattr read map }; |
| |
| # Send unsolicited message to system_server |
| unix_socket_send(app_zygote, system_unsolzygote, system_server) |
| |
| # Allow the app_zygote to access the runtime feature flag properties. |
| get_prop(app_zygote, device_config_runtime_native_prop) |
| get_prop(app_zygote, device_config_runtime_native_boot_prop) |
| |
| # Allow app_zygote to access odsign verification status |
| get_prop(app_zygote, odsign_prop) |
| |
| ##### |
| ##### Neverallow |
| ##### |
| |
| # Only permit transition to isolated_app. |
| neverallow app_zygote { domain -isolated_app }:process dyntransition; |
| |
| # Only setcon() transitions, no exec() based transitions, except for crash_dump. |
| neverallow app_zygote { domain -crash_dump }:process transition; |
| |
| # Must not exec() a program without changing domains. |
| # Having said that, exec() above is not allowed. |
| neverallow app_zygote *:file execute_no_trans; |
| |
| # The only way to enter this domain is for the zygote to fork a new |
| # app_zygote child. |
| neverallow { domain -zygote } app_zygote:process dyntransition; |
| |
| # Disallow write access to properties. |
| neverallow app_zygote property_socket:sock_file write; |
| neverallow app_zygote property_type:property_service set; |
| |
| # Should not have any access to data files. |
| neverallow app_zygote app_data_file_type:file { rwx_file_perms }; |
| |
| neverallow app_zygote { |
| service_manager_type |
| -activity_service |
| -webviewupdate_service |
| }:service_manager find; |
| |
| # Isolated apps should not be able to access the driver directly. |
| neverallow app_zygote gpu_device:chr_file { rwx_file_perms }; |
| |
| # Do not allow app_zygote access to /cache. |
| neverallow app_zygote cache_file:dir ~{ r_dir_perms }; |
| neverallow app_zygote cache_file:file ~{ read getattr }; |
| |
| # Do not allow most socket access. This is socket_class_set, excluding unix_dgram_socket, |
| # unix_stream_socket, and netlink_selinux_socket. |
| neverallow app_zygote domain:{ |
| socket tcp_socket udp_socket rawip_socket netlink_socket packet_socket key_socket |
| appletalk_socket netlink_route_socket netlink_tcpdiag_socket |
| netlink_nflog_socket netlink_xfrm_socket netlink_audit_socket |
| netlink_dnrt_socket netlink_kobject_uevent_socket tun_socket netlink_iscsi_socket |
| netlink_fib_lookup_socket netlink_connector_socket netlink_netfilter_socket |
| netlink_generic_socket netlink_scsitransport_socket netlink_rdma_socket netlink_crypto_socket |
| sctp_socket icmp_socket ax25_socket ipx_socket netrom_socket atmpvc_socket |
| x25_socket rose_socket decnet_socket atmsvc_socket rds_socket irda_socket |
| pppox_socket llc_socket can_socket tipc_socket bluetooth_socket iucv_socket |
| rxrpc_socket isdn_socket phonet_socket ieee802154_socket caif_socket |
| alg_socket nfc_socket vsock_socket kcm_socket qipcrtr_socket smc_socket |
| } *; |
| |
| # Only allow app_zygote to talk to the logd socket, and |
| # su/heapprofd/traced_perf on eng/userdebug. This is because |
| # cap_setuid/cap_setgid allow to forge uid/gid in SCM_CREDENTIALS. |
| # Think twice before changing. |
| neverallow app_zygote { |
| domain |
| -app_zygote |
| -logd |
| -system_server |
| userdebug_or_eng(`-su') |
| userdebug_or_eng(`-heapprofd') |
| userdebug_or_eng(`-traced_perf') |
| }:unix_dgram_socket *; |
| |
| neverallow app_zygote { |
| domain |
| -app_zygote |
| -prng_seeder |
| userdebug_or_eng(`-su') |
| userdebug_or_eng(`-heapprofd') |
| userdebug_or_eng(`-traced_perf') |
| }:unix_stream_socket *; |
| |
| # Never allow ptrace |
| neverallow app_zygote *:process ptrace; |
| |
| # Do not allow access to Bluetooth-related system properties. |
| # neverallow rules for Bluetooth-related data files are listed above. |
| neverallow app_zygote { |
| bluetooth_a2dp_offload_prop |
| bluetooth_audio_hal_prop |
| bluetooth_prop |
| exported_bluetooth_prop |
| }:file create_file_perms; |