1typeattribute app_zygote coredomain; 2 3###### 4###### Policy below is different from regular zygote-spawned apps 5###### 6 7# Allow access to temporary files, which is normally permitted through 8# a domain macro. 9tmpfs_domain(app_zygote); 10 11# Set the UID/GID of the process. 12# This will be further limited to a range of isolated UIDs with seccomp. 13allow app_zygote self:global_capability_class_set { setgid setuid }; 14# Drop capabilities from bounding set. 15allow app_zygote self:global_capability_class_set setpcap; 16# Switch SELinux context to isolated app domain. 17allow app_zygote self:process setcurrent; 18allow app_zygote isolated_app:process dyntransition; 19 20# For JIT 21allow app_zygote self:process execmem; 22 23# Allow exec mapping from tmpfs (memfds) for binary translation 24allow app_zygote app_zygote_tmpfs:file execute; 25 26# Allow app_zygote to stat the files that it opens. It must 27# be able to inspect them so that it can reopen them on fork 28# if necessary: b/30963384. 29allow app_zygote debugfs_trace_marker:file getattr; 30 31# get system_server process group 32allow app_zygote system_server:process getpgid; 33 34# Interaction between the app_zygote and its children. 35allow app_zygote isolated_app:process setpgid; 36 37# TODO (b/63631799) fix this access 38dontaudit app_zygote mnt_expand_file:dir getattr; 39 40# Get seapp_contexts 41allow app_zygote seapp_contexts_file:file r_file_perms; 42# Check validity of SELinux context before use. 43selinux_check_context(app_zygote) 44# Check SELinux permissions. 45selinux_check_access(app_zygote) 46 47# Read and inspect temporary files managed by zygote. 48allow app_zygote zygote_tmpfs:file { read getattr }; 49 50###### 51###### Policy below is shared with regular zygote-spawned apps 52###### 53 54# Child of zygote. 55allow app_zygote zygote:fd use; 56allow app_zygote zygote:process sigchld; 57 58# For ART (read /data/dalvik-cache). 59r_dir_file(app_zygote, dalvikcache_data_file); 60allow app_zygote dalvikcache_data_file:file execute; 61 62# For ART (allow userfaultfd and related ioctls) 63userfaultfd_use(app_zygote) 64 65# Read /data/misc/apexdata/ to (get to com.android.art/dalvik-cache). 66allow app_zygote apex_module_data_file:dir search; 67# For ART APEX (read /data/misc/apexdata/com.android.art/dalvik-cache). 68r_dir_file(app_zygote, apex_art_data_file) 69 70# Allow reading/executing installed binaries to enable preloading 71# application data 72allow app_zygote apk_data_file:dir r_dir_perms; 73allow app_zygote apk_data_file:file { r_file_perms execute }; 74 75# /oem accesses. 76allow app_zygote oemfs:dir search; 77 78# Allow app_zygote access to /vendor/overlay 79r_dir_file(app_zygote, vendor_overlay_file) 80# Allow app_zygote to read vendor_overlay_file from vendor apex as well 81allow app_zygote vendor_apex_metadata_file:dir { getattr search }; 82 83allow app_zygote system_data_file:lnk_file r_file_perms; 84allow app_zygote system_data_file:file { getattr read map }; 85 86# Send unsolicited message to system_server 87unix_socket_send(app_zygote, system_unsolzygote, system_server) 88 89# Allow the app_zygote to access the runtime feature flag properties. 90get_prop(app_zygote, device_config_runtime_native_prop) 91get_prop(app_zygote, device_config_runtime_native_boot_prop) 92 93# Allow app_zygote to access odsign verification status 94get_prop(app_zygote, odsign_prop) 95 96# /data/resource-cache 97allow app_zygote resourcecache_data_file:file r_file_perms; 98allow app_zygote resourcecache_data_file:dir r_dir_perms; 99 100##### 101##### Neverallow 102##### 103 104# Only permit transition to isolated_app. 105neverallow app_zygote { domain -isolated_app }:process dyntransition; 106 107# Only setcon() transitions, no exec() based transitions, except for crash_dump. 108neverallow app_zygote { domain -crash_dump }:process transition; 109 110# Must not exec() a program without changing domains. 111# Having said that, exec() above is not allowed. 112neverallow app_zygote *:file execute_no_trans; 113 114# The only way to enter this domain is for the zygote to fork a new 115# app_zygote child. 116neverallow { domain -zygote } app_zygote:process dyntransition; 117 118# Disallow write access to properties. 119neverallow app_zygote property_socket:sock_file write; 120neverallow app_zygote property_type:property_service set; 121 122# Should not have any access to data files. 123neverallow app_zygote app_data_file_type:file { rwx_file_perms }; 124 125neverallow app_zygote { 126 service_manager_type 127 -activity_service 128 -webviewupdate_service 129}:service_manager find; 130 131# Isolated apps should not be able to access the driver directly. 132neverallow app_zygote gpu_device:chr_file { rwx_file_perms }; 133 134# Do not allow app_zygote access to /cache. 135neverallow app_zygote cache_file:dir ~{ r_dir_perms }; 136neverallow app_zygote cache_file:file ~{ read getattr }; 137 138# Do not allow most socket access. This is socket_class_set, excluding unix_dgram_socket, 139# unix_stream_socket, and netlink_selinux_socket. 140neverallow app_zygote domain:{ 141 socket tcp_socket udp_socket rawip_socket netlink_socket packet_socket key_socket 142 appletalk_socket netlink_route_socket netlink_tcpdiag_socket 143 netlink_nflog_socket netlink_xfrm_socket netlink_audit_socket 144 netlink_dnrt_socket netlink_kobject_uevent_socket tun_socket netlink_iscsi_socket 145 netlink_fib_lookup_socket netlink_connector_socket netlink_netfilter_socket 146 netlink_generic_socket netlink_scsitransport_socket netlink_rdma_socket netlink_crypto_socket 147 sctp_socket icmp_socket ax25_socket ipx_socket netrom_socket atmpvc_socket 148 x25_socket rose_socket decnet_socket atmsvc_socket rds_socket irda_socket 149 pppox_socket llc_socket can_socket tipc_socket bluetooth_socket iucv_socket 150 rxrpc_socket isdn_socket phonet_socket ieee802154_socket caif_socket 151 alg_socket nfc_socket vsock_socket kcm_socket qipcrtr_socket smc_socket 152} *; 153 154# Only allow app_zygote to talk to the logd socket, and su on eng/userdebug. 155# This is because cap_setuid/cap_setgid allow to forge uid/gid in 156# SCM_CREDENTIALS. Think twice before changing. 157neverallow app_zygote { 158 domain 159 -app_zygote 160 -logd 161 -system_server 162 userdebug_or_eng(`-su') 163}:unix_dgram_socket *; 164 165neverallow app_zygote { 166 domain 167 -app_zygote 168 -prng_seeder 169 userdebug_or_eng(`-su') 170}:unix_stream_socket *; 171 172# Never allow ptrace 173neverallow app_zygote *:process ptrace; 174 175# Do not allow access to Bluetooth-related system properties. 176# neverallow rules for Bluetooth-related data files are listed above. 177neverallow app_zygote { 178 bluetooth_a2dp_offload_prop 179 bluetooth_audio_hal_prop 180 bluetooth_prop 181 exported_bluetooth_prop 182}:file create_file_perms; 183