c121735f42
Allow isolated apps to read/write/append/lock already open sdcard
file descriptors passed to it by normal app processes. isolated_apps are
used by processes like Google drive when handling untrusted content.
Addresses the following denial:
audit(0.0:1508): avc: denied { read } for
path="/storage/emulated/0/Download/02-corejava.pdf" dev="fuse" ino=310
scontext=u:r:isolated_app:s0:c512,c768 tcontext=u:object_r:fuse:s0
tclass=file permissive=0
This partially reverts the tightening added in
ce4b5eeaee.
Add a TODO to consider removing isolated_apps ability to write or append
to files on the sdcard. This limits the damage that can occur should the
isolated_app process be compromised.
Bug: 32896414
Test: Policy compiles. Rule add only, so no possibility of breakage.
Change-Id: Ia128569608fc9c872c90e6c380106b7c81eb7b6f
111 lines
4.6 KiB
Text
111 lines
4.6 KiB
Text
###
|
|
### Services with isolatedProcess=true in their manifest.
|
|
###
|
|
### This file defines the rules for isolated apps. An "isolated
|
|
### app" is an APP with UID between AID_ISOLATED_START (99000)
|
|
### and AID_ISOLATED_END (99999).
|
|
###
|
|
### isolated_app includes all the appdomain rules, plus the
|
|
### additional following rules:
|
|
###
|
|
|
|
type isolated_app, domain;
|
|
app_domain(isolated_app)
|
|
|
|
# Access already open app data files received over Binder or local socket IPC.
|
|
allow isolated_app app_data_file:file { append read write getattr lock };
|
|
|
|
allow isolated_app activity_service:service_manager find;
|
|
allow isolated_app display_service:service_manager find;
|
|
allow isolated_app webviewupdate_service:service_manager find;
|
|
|
|
# Google Breakpad (crash reporter for Chrome) relies on ptrace
|
|
# functionality. Without the ability to ptrace, the crash reporter
|
|
# tool is broken.
|
|
# b/20150694
|
|
# https://code.google.com/p/chromium/issues/detail?id=475270
|
|
allow isolated_app self:process ptrace;
|
|
|
|
# b/32896414: Allow accessing sdcard file descriptors passed to isolated_apps
|
|
# by other processes. Open should never be allowed, and is blocked by
|
|
# neverallow rules below.
|
|
# TODO: consider removing write/append. We want to limit isolated_apps
|
|
# ability to mutate files of any type.
|
|
allow isolated_app sdcard_type:file { read write append getattr lock };
|
|
auditallow isolated_app sdcard_type:file { write append };
|
|
|
|
# For webviews, isolated_app processes can be forked from the webview_zygote
|
|
# in addition to the zygote. Allow access to resources inherited from the
|
|
# webview_zygote process. These rules are specialized copies of the ones in app.te.
|
|
# Inherit FDs from the webview_zygote.
|
|
allow isolated_app webview_zygote:fd use;
|
|
# Read system properties managed by webview_zygote.
|
|
allow isolated_app webview_zygote_tmpfs:file read;
|
|
# Notify webview_zygote of child death.
|
|
allow isolated_app webview_zygote:process sigchld;
|
|
# Inherit logd write socket.
|
|
allow isolated_app webview_zygote:unix_dgram_socket write;
|
|
|
|
#####
|
|
##### Neverallow
|
|
#####
|
|
|
|
# Do not allow isolated_app to directly open tun_device
|
|
neverallow isolated_app tun_device:chr_file open;
|
|
|
|
# Do not allow isolated_app to set system properties.
|
|
neverallow isolated_app property_socket:sock_file write;
|
|
neverallow isolated_app property_type:property_service set;
|
|
|
|
# Isolated apps should not directly open app data files themselves.
|
|
neverallow isolated_app app_data_file:file open;
|
|
|
|
# Only allow appending to /data/anr/traces.txt (b/27853304, b/18340553)
|
|
# TODO: are there situations where isolated_apps write to this file?
|
|
# TODO: should we tighten these restrictions further?
|
|
neverallow isolated_app anr_data_file:file ~{ open append };
|
|
neverallow isolated_app anr_data_file:dir ~search;
|
|
|
|
# b/17487348
|
|
# Isolated apps can only access three services,
|
|
# activity_service, display_service and webviewupdate_service.
|
|
neverallow isolated_app {
|
|
service_manager_type
|
|
-activity_service
|
|
-display_service
|
|
-webviewupdate_service
|
|
}:service_manager find;
|
|
|
|
# Isolated apps shouldn't be able to access the driver directly.
|
|
neverallow isolated_app gpu_device:chr_file { rw_file_perms execute };
|
|
|
|
# Do not allow isolated_app access to /cache
|
|
neverallow isolated_app cache_file:dir ~{ r_dir_perms };
|
|
neverallow isolated_app cache_file:file ~{ read getattr };
|
|
|
|
# Restrict socket ioctls. Either 1. disallow privileged ioctls, 2. disallow the
|
|
# ioctl permission, or 3. disallow the socket class.
|
|
neverallowxperm isolated_app domain:{ rawip_socket tcp_socket udp_socket } ioctl priv_sock_ioctls;
|
|
neverallow isolated_app *:{ netlink_route_socket netlink_selinux_socket } ioctl;
|
|
neverallow isolated_app *:{
|
|
socket netlink_socket packet_socket key_socket appletalk_socket
|
|
netlink_firewall_socket netlink_tcpdiag_socket netlink_nflog_socket
|
|
netlink_xfrm_socket netlink_audit_socket netlink_ip6fw_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
|
|
} *;
|
|
|
|
# Do not allow isolated_app to access external storage, except for files passed
|
|
# via file descriptors (b/32896414).
|
|
neverallow isolated_app { storage_file mnt_user_file sdcard_type }:dir ~getattr;
|
|
neverallow isolated_app { storage_file mnt_user_file }:file_class_set *;
|
|
neverallow isolated_app sdcard_type:{ devfile_class_set lnk_file sock_file fifo_file } *;
|
|
neverallow isolated_app sdcard_type:file ~{ read write append getattr lock };
|
|
|
|
# Do not allow USB access
|
|
neverallow isolated_app { usb_device usbaccessory_device }:chr_file *;
|
|
|
|
# Restrict the webview_zygote control socket.
|
|
neverallow isolated_app webview_zygote_socket:sock_file write;
|