-
Nick Kralevich authored
untrusted_app: Remove the ability to run execve() on files within an application's home directory. Executing code from a writable /home directory is a W^X violation (https://en.wikipedia.org/wiki/W%5EX). Additionally, loading code from application home directories violates a security requirement that all executable code mapped into memory must come from signed sources, or be derived from signed sources. Note: this change does *not* remove the ability to load executable code through other mechanisms, such as mmap(PROT_EXEC) of a file descriptor from the app's home directory. In particular, functionality like dlopen() on files in an app's home directory continues to work even after this change. untrusted_app_25 and untrusted_app_27: For backwards compatibility, continue to allow these domains to execve() files from the application's home directory. seapp_contexts: Bump the minimum API level required to enter the untrusted_app domain. This will run API level 27-28 processes in the API level 27 sandbox. API level 28 will continue to run with levelFrom=all, and API level 27 will continue to run with levelFrom=user. Bug: 112357170 Test: Device boots and no obvious problems. Test: See CTS test at https://android-review.googlesource.com/c/platform/cts/+/804228 Change-Id: Ief9ae3a227d16ab5792f43bacbb577c1e70185a0
0dd738d8
untrusted_app_27.te 1.35 KiB
###
### Untrusted_27.
###
### This file defines the rules for untrusted apps running with
### 25 < targetSdkVersion <= 28.
###
### This file defines the rules for untrusted apps.
### Apps are labeled based on mac_permissions.xml (maps signer and
### optionally package name to seinfo value) and seapp_contexts (maps UID
### and optionally seinfo value to domain for process and type for data
### directory). The untrusted_app_27 domain is the default assignment in
### seapp_contexts for any app with UID between APP_AID (10000)
### and AID_ISOLATED_START (99000) if the app has no specific seinfo
### value as determined from mac_permissions.xml. In current AOSP, this
### domain is assigned to all non-system apps as well as to any system apps
### that are not signed by the platform key. To move
### a system app into a specific domain, add a signer entry for it to
### mac_permissions.xml and assign it one of the pre-existing seinfo values
### or define and use a new seinfo value in both mac_permissions.xml and
### seapp_contexts.
###
typeattribute untrusted_app_27 coredomain;
app_domain(untrusted_app_27)
untrusted_app_domain(untrusted_app_27)
net_domain(untrusted_app_27)
bluetooth_domain(untrusted_app_27)
# The ability to call exec() on files in the apps home directories
# for targetApi 26, 27, and 28.
allow untrusted_app_27 app_data_file:file execute_no_trans;