| # webview_zygote is an auxiliary zygote process that is used to spawn |
| # isolated_app processes for rendering untrusted web content. |
| |
| # The webview_zygote needs to be able to transition domains. |
| typeattribute webview_zygote mlstrustedsubject; |
| |
| # When init launches the WebView zygote's executable, transition the |
| # resulting process into webview_zygote domain. |
| init_daemon_domain(webview_zygote) |
| |
| # Access to system files for SELinux contexts. |
| allow webview_zygote rootfs:file r_file_perms; |
| |
| # Allow reading/executing installed binaries to enable preloading the |
| # installed WebView implementation. |
| allow webview_zygote apk_data_file:dir r_dir_perms; |
| allow webview_zygote apk_data_file:file { r_file_perms execute }; |
| |
| # Access to the WebView relro file. |
| allow webview_zygote shared_relro_file:dir search; |
| allow webview_zygote shared_relro_file:file r_file_perms; |
| |
| # Set the UID/GID of the process. |
| allow webview_zygote self:capability { setgid setuid }; |
| # Drop capabilities from bounding set. |
| allow webview_zygote self:capability setpcap; |
| # Switch SELinux context to app domains. |
| allow webview_zygote self:process setcurrent; |
| allow webview_zygote isolated_app:process dyntransition; |
| |
| # For art. |
| allow webview_zygote dalvikcache_data_file:dir r_dir_perms; |
| allow webview_zygote dalvikcache_data_file:lnk_file r_file_perms; |
| allow webview_zygote dalvikcache_data_file:file { r_file_perms execute }; |
| |
| # Allow webview_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 webview_zygote debugfs_trace_marker:file getattr; |
| |
| # Allow webview_zygote to manage the pgroup of its children. |
| allow webview_zygote system_server:process getpgid; |
| |
| # Interaction between the webview_zygote and its children. |
| allow webview_zygote isolated_app:process setpgid; |
| |
| # Check validity of SELinux context before use. |
| selinux_check_context(webview_zygote) |
| # Check SELinux permissions. |
| selinux_check_access(webview_zygote) |
| |
| ##### |
| ##### Neverallow |
| ##### |
| |
| # Only permit transition to isolated_app. |
| neverallow webview_zygote { domain -isolated_app }:process dyntransition; |
| |
| # Only setcon() transitions, no exec() based transitions, except for crash_dump. |
| neverallow webview_zygote { domain -crash_dump }:process transition; |
| |
| # Must not exec() a program without changing domains. |
| # Having said that, exec() above is not allowed. |
| neverallow webview_zygote *:file execute_no_trans; |
| |
| # The only way to enter this domain is for init to exec() us. |
| neverallow { domain -init } webview_zygote:process transition; |
| neverallow * webview_zygote:process dyntransition; |
| |
| # Disallow write access to properties. |
| neverallow webview_zygote property_socket:sock_file write; |
| neverallow webview_zygote property_type:property_service set; |
| |
| # Should not have any access to app data files. |
| neverallow webview_zygote { |
| app_data_file |
| system_app_data_file |
| bluetooth_data_file |
| nfc_data_file |
| radio_data_file |
| shell_data_file |
| }:file { rwx_file_perms }; |
| |
| neverallow webview_zygote { |
| service_manager_type |
| -activity_service |
| -webviewupdate_service |
| }:service_manager find; |
| |
| # Isolated apps shouldn't be able to access the driver directly. |
| neverallow webview_zygote gpu_device:chr_file { rwx_file_perms }; |
| |
| # Do not allow webview_zygote access to /cache. |
| neverallow webview_zygote cache_file:dir ~{ r_dir_perms }; |
| neverallow webview_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 webview_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 |
| } *; |
| |
| # Do not allow access to Bluetooth-related system properties. |
| # neverallow rules for Bluetooth-related data files are listed above. |
| neverallow webview_zygote bluetooth_prop:file create_file_perms; |