platform_system_sepolicy/private/domain.te
Jeff Vander Stoep ab82125fc8 Improve tests protecting private app data
In particular, add assertions limiting which processes may
directly open files owned by apps. Reduce this to just apps, init,
and installd. App data is protected by a combination of selinux
permissions and Unix permissions, so limiting the open permission to
just apps (which are not allowed to have CAP_DAC_OVERRIDE or
CAP_DAC_READ_SEARCH) ensures that only installd and init have
complete access an app's private directory.

In addition to apps/init/installd, other processes currently granted
open are mediaserver, uncrypt, and vold. Uncrypt's access appears to
be deprecated (b/80299612). Uncrypt now uses /data/ota_package
instead. b/80418809 and b/80300620 track removal for vold and
mediaserver.

Test: build/boot aosp_taimen-userdebug. Verify no "granted" audit
messages in the logs.
Bug: 80190017
Bug: 80300620
Bug: 80418809
Fixes: 80299612
Change-Id: I153bc7b62294b36ccd596254a5976dd887fed046
2018-05-29 13:47:49 -07:00

178 lines
3.6 KiB
Text

# Transition to crash_dump when /system/bin/crash_dump* is executed.
# This occurs when the process crashes.
domain_auto_trans(domain, crash_dump_exec, crash_dump);
allow domain crash_dump:process sigchld;
# Limit ability to ptrace or read sensitive /proc/pid files of processes
# with other UIDs to these whitelisted domains.
neverallow {
domain
-vold
-dumpstate
userdebug_or_eng(`-incidentd')
-storaged
-system_server
userdebug_or_eng(`-perfprofd')
} self:global_capability_class_set sys_ptrace;
# Limit ability to generate hardware unique device ID attestations to priv_apps
neverallow { domain -priv_app } *:keystore_key gen_unique_id;
neverallow {
domain
-init
-vendor_init
userdebug_or_eng(`-domain')
} debugfs_tracing_debug:file no_rw_file_perms;
# Core domains are not permitted to use kernel interfaces which are not
# explicitly labeled.
# TODO(b/65643247): Apply these neverallow rules to all coredomain.
full_treble_only(`
# /proc
neverallow {
coredomain
-vold
} proc:file no_rw_file_perms;
# /sys
neverallow {
coredomain
-init
-ueventd
-vold
} sysfs:file no_rw_file_perms;
# /dev
neverallow {
coredomain
-fsck
-init
-ueventd
} device:{ blk_file file } no_rw_file_perms;
# debugfs
neverallow {
coredomain
-dumpstate
-init
-system_server
} debugfs:file no_rw_file_perms;
# tracefs
neverallow {
coredomain
-atrace
-dumpstate
-init
userdebug_or_eng(`-perfprofd')
-traced_probes
-shell
-traceur_app
} debugfs_tracing:file no_rw_file_perms;
# inotifyfs
neverallow {
coredomain
-init
} inotify:file no_rw_file_perms;
# pstorefs
neverallow {
coredomain
-bootstat
-charger
-dumpstate
-healthd
userdebug_or_eng(`-incidentd')
-init
-logd
-logpersist
-recovery_persist
-recovery_refresh
-shell
-system_server
} pstorefs:file no_rw_file_perms;
# configfs
neverallow {
coredomain
-init
-system_server
} configfs:file no_rw_file_perms;
# functionfs
neverallow {
coredomain
-adbd
-init
-mediaprovider
-system_server
} functionfs:file no_rw_file_perms;
# usbfs and binfmt_miscfs
neverallow {
coredomain
-init
}{ usbfs binfmt_miscfs }:file no_rw_file_perms;
')
# System_server owns dropbox data, and init creates/restorecons the directory
# Disallow direct access by other processes.
neverallow { domain -init -system_server } dropbox_data_file:dir *;
neverallow { domain -init -system_server } dropbox_data_file:file ~{ getattr read };
###
# Services should respect app sandboxes
neverallow {
domain
-appdomain
-installd # creation of sandbox
} app_data_file:dir_file_class_set { create unlink };
# Only the following processes should be directly accessing private app
# directories.
neverallow {
domain
-adbd
-appdomain
-dexoptanalyzer
-init
-installd
-mediaserver # b/80300620
userdebug_or_eng(`-perfprofd')
-profman
-runas
-system_server
-vold
} app_data_file:dir *;
# Only apps should be modifying app data. init and installd are exempted for
# restorecon and package install/uninstall.
neverallow {
domain
-appdomain
-init
-installd
} app_data_file:dir ~r_dir_perms;
neverallow {
domain
-appdomain
-installd
-mediaserver # b/80300620
userdebug_or_eng(`-perfprofd')
-vold # b/80418809
} app_data_file:file_class_set open;
neverallow {
domain
-appdomain
-installd # creation of sandbox
} app_data_file:dir_file_class_set { create unlink };
neverallow {
domain
-init
-installd
} app_data_file:dir_file_class_set { relabelfrom relabelto };