From faebeacaa0705f37be6c8e19ef55be3eda7d7eeb Mon Sep 17 00:00:00 2001
From: Luis Hector Chavez <lhchavez@google.com>
Date: Mon, 25 Jun 2018 11:09:52 -0700
Subject: [PATCH] Reduce the number of processes that can start adbd
This change makes it such that only init can start adbd directly. It
also introduces new rules for ctl.{start,stop,restart} properties such
that only usbd and recovery (and su, since it's permissive) can directly
ask init to start adbd.
Bug: 64720460
Test: adbd still runs
Test: /data/nativetest64/adbd_test/adbd_test
Test: python system/core/adb/test_adb.py
Test: "USB debugging" in System Settings still start/stop adbd
Test: Recovery menu still make the device show as "recovery" in adb
devices
Test: "Apply update from ADB" in recovery menu still works
Change-Id: Iafcda8aa44e85129afcc958036b472d856fa1192
---
private/compat/26.0/26.0.cil | 2 +-
private/compat/27.0/27.0.cil | 2 +-
private/property_contexts | 5 +++++
public/adbd.te | 4 ++++
public/property.te | 2 ++
public/recovery.te | 2 +-
public/usbd.te | 2 ++
7 files changed, 16 insertions(+), 3 deletions(-)
diff --git a/private/compat/26.0/26.0.cil b/private/compat/26.0/26.0.cil
index 4699ecf43..f53a194dd 100644
--- a/private/compat/26.0/26.0.cil
+++ b/private/compat/26.0/26.0.cil
@@ -121,7 +121,7 @@
(typeattributeset ctl_bootanim_prop_26_0 (ctl_bootanim_prop))
(typeattributeset ctl_bugreport_prop_26_0 (ctl_bugreport_prop))
(typeattributeset ctl_console_prop_26_0 (ctl_console_prop))
-(typeattributeset ctl_default_prop_26_0 (ctl_default_prop ctl_restart_prop ctl_start_prop ctl_stop_prop))
+(typeattributeset ctl_default_prop_26_0 (ctl_default_prop ctl_restart_prop ctl_start_prop ctl_stop_prop ctl_adbd_prop))
(typeattributeset ctl_dumpstate_prop_26_0 (ctl_dumpstate_prop))
(typeattributeset ctl_fuse_prop_26_0 (ctl_fuse_prop))
(typeattributeset ctl_mdnsd_prop_26_0 (ctl_mdnsd_prop))
diff --git a/private/compat/27.0/27.0.cil b/private/compat/27.0/27.0.cil
index e5d50e472..8eedf56a6 100644
--- a/private/compat/27.0/27.0.cil
+++ b/private/compat/27.0/27.0.cil
@@ -826,7 +826,7 @@
(typeattributeset ctl_bootanim_prop_27_0 (ctl_bootanim_prop))
(typeattributeset ctl_bugreport_prop_27_0 (ctl_bugreport_prop))
(typeattributeset ctl_console_prop_27_0 (ctl_console_prop))
-(typeattributeset ctl_default_prop_27_0 (ctl_default_prop ctl_restart_prop ctl_start_prop ctl_stop_prop))
+(typeattributeset ctl_default_prop_27_0 (ctl_default_prop ctl_restart_prop ctl_start_prop ctl_stop_prop ctl_adbd_prop))
(typeattributeset ctl_dumpstate_prop_27_0 (ctl_dumpstate_prop))
(typeattributeset ctl_fuse_prop_27_0 (ctl_fuse_prop))
(typeattributeset ctl_mdnsd_prop_27_0 (ctl_mdnsd_prop))
diff --git a/private/property_contexts b/private/property_contexts
index 6ebad3591..37d442754 100644
--- a/private/property_contexts
+++ b/private/property_contexts
@@ -115,6 +115,11 @@ ctl.interface_start$ u:object_r:ctl_interface_start_prop:s0
ctl.interface_stop$ u:object_r:ctl_interface_stop_prop:s0
ctl.interface_restart$ u:object_r:ctl_interface_restart_prop:s0
+ # Restrict access to starting/stopping adbd
+ctl.start$adbd u:object_r:ctl_adbd_prop:s0
+ctl.stop$adbd u:object_r:ctl_adbd_prop:s0
+ctl.restart$adbd u:object_r:ctl_adbd_prop:s0
+
# NFC properties
nfc. u:object_r:nfc_prop:s0
diff --git a/public/adbd.te b/public/adbd.te
index 95854c01e..82373fd1d 100644
--- a/public/adbd.te
+++ b/public/adbd.te
@@ -2,3 +2,7 @@
# it lives in the rootfs and has no unique file type.
type adbd, domain;
type adbd_exec, exec_type, file_type;
+
+# Only init is allowed to enter the adbd domain via exec()
+neverallow { domain -init } adbd:process transition;
+neverallow * adbd:process dyntransition;
diff --git a/public/property.te b/public/property.te
index 508eed594..b92f18a7e 100644
--- a/public/property.te
+++ b/public/property.te
@@ -5,6 +5,7 @@ type bluetooth_prop, property_type;
type bootloader_boot_reason_prop, property_type;
type config_prop, property_type, core_property_type;
type cppreopt_prop, property_type, core_property_type;
+type ctl_adbd_prop, property_type;
type ctl_bootanim_prop, property_type;
type ctl_bugreport_prop, property_type;
type ctl_console_prop, property_type;
@@ -327,6 +328,7 @@ compatible_property_only(`
-boottime_prop
-config_prop
-cppreopt_prop
+ -ctl_adbd_prop
-ctl_bootanim_prop
-ctl_bugreport_prop
-ctl_console_prop
diff --git a/public/recovery.te b/public/recovery.te
index 48fffe645..dcec9705e 100644
--- a/public/recovery.te
+++ b/public/recovery.te
@@ -109,7 +109,7 @@ recovery_only(`
set_prop(recovery, powerctl_prop)
# Start/stop adbd via ctl.start adbd
- set_prop(recovery, ctl_default_prop)
+ set_prop(recovery, ctl_adbd_prop)
# Read serial number of the device from system properties
get_prop(recovery, serialno_prop)
diff --git a/public/usbd.te b/public/usbd.te
index 98786e062..6dd133413 100644
--- a/public/usbd.te
+++ b/public/usbd.te
@@ -1,3 +1,5 @@
type usbd, domain;
type usbd_exec, exec_type, file_type;
+# Start/stop adbd via ctl.start adbd
+set_prop(usbd, ctl_adbd_prop)
--
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