0dd738d810
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
51 lines
2.3 KiB
Text
51 lines
2.3 KiB
Text
###
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### Untrusted_app_25
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###
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### This file defines the rules for untrusted apps running with
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### targetSdkVersion <= 25.
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###
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### Apps are labeled based on mac_permissions.xml (maps signer and
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### optionally package name to seinfo value) and seapp_contexts (maps UID
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### and optionally seinfo value to domain for process and type for data
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### directory). The untrusted_app domain is the default assignment in
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### seapp_contexts for any app with UID between APP_AID (10000)
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### and AID_ISOLATED_START (99000) if the app has no specific seinfo
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### value as determined from mac_permissions.xml. In current AOSP, this
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### domain is assigned to all non-system apps as well as to any system apps
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### that are not signed by the platform key. To move
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### a system app into a specific domain, add a signer entry for it to
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### mac_permissions.xml and assign it one of the pre-existing seinfo values
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### or define and use a new seinfo value in both mac_permissions.xml and
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### seapp_contexts.
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###
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typeattribute untrusted_app_25 coredomain;
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app_domain(untrusted_app_25)
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untrusted_app_domain(untrusted_app_25)
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net_domain(untrusted_app_25)
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bluetooth_domain(untrusted_app_25)
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# b/34115651 - net.dns* properties read
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# This will go away in a future Android release
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get_prop(untrusted_app_25, net_dns_prop)
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# b/35917228 - /proc/misc access
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# This will go away in a future Android release
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allow untrusted_app_25 proc_misc:file r_file_perms;
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# Access to /proc/tty/drivers, to allow apps to determine if they
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# are running in an emulated environment.
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# b/33214085 b/33814662 b/33791054 b/33211769
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# https://github.com/strazzere/anti-emulator/blob/master/AntiEmulator/src/diff/strazzere/anti/emulator/FindEmulator.java
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# This will go away in a future Android release
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allow untrusted_app_25 proc_tty_drivers:file r_file_perms;
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# Text relocation support for API < 23
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# https://android.googlesource.com/platform/bionic/+/master/android-changes-for-ndk-developers.md#text-relocations-enforced-for-api-level-23
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allow untrusted_app_25 { apk_data_file app_data_file asec_public_file }:file execmod;
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# The ability to call exec() on files in the apps home directories
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# for targetApi<=25. This is also allowed for targetAPIs 26, 27,
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# and 28 in untrusted_app_27.te.
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allow untrusted_app_25 app_data_file:file execute_no_trans;
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