From b35f827c97ceb24e33fb2514ff62c8636bc46f59 Mon Sep 17 00:00:00 2001 From: Tom Cherry Date: Mon, 22 Oct 2018 14:50:52 -0700 Subject: [PATCH] init: if vendor_init can read a property, let it be a trigger too There is a list of 'stable_properties' that vendor_init can use as property triggers for Treble property compliance. This list came about since init parses init scripts before all partitions are mounted and therefore before all property context files are available, such that init cannot use the normal SELinux mechanisms for determining if a given property is vendor_init readable. Currently though, we require all partitions that would contain property context files to be mounted during first stage mount, so we can use the normal SELinux mechanisms here, so this change deprecates the stable_properties list and moves init to use SELinux to determine if a property can be a trigger. Bug: 71814576 Test: vendor_init fails to use non-readable properties as a trigger Test: vendor_init successfully uses readable properties as a trigger Change-Id: I6a914e8c212a3418cbf4a8a07215056aad2e0162 --- init/action_parser.cpp | 16 ++++------ init/host_init_stubs.cpp | 3 ++ init/host_init_stubs.h | 1 + init/property_service.cpp | 16 ++++++++++ init/property_service.h | 2 ++ init/stable_properties.h | 67 --------------------------------------- 6 files changed, 28 insertions(+), 77 deletions(-) delete mode 100644 init/stable_properties.h diff --git a/init/action_parser.cpp b/init/action_parser.cpp index 148116200..2d497b386 100644 --- a/init/action_parser.cpp +++ b/init/action_parser.cpp @@ -19,7 +19,11 @@ #include #include -#include "stable_properties.h" +#if defined(__ANDROID__) +#include "property_service.h" +#else +#include "host_init_stubs.h" +#endif using android::base::GetBoolProperty; using android::base::StartsWith; @@ -36,15 +40,7 @@ bool IsActionableProperty(Subcontext* subcontext, const std::string& prop_name) return true; } - if (kExportedActionableProperties.count(prop_name) == 1) { - return true; - } - for (const auto& prefix : kPartnerPrefixes) { - if (android::base::StartsWith(prop_name, prefix)) { - return true; - } - } - return false; + return CanReadProperty(subcontext->context(), prop_name); } Result ParsePropertyTrigger(const std::string& trigger, Subcontext* subcontext, diff --git a/init/host_init_stubs.cpp b/init/host_init_stubs.cpp index 8866bdcd6..b85e54a69 100644 --- a/init/host_init_stubs.cpp +++ b/init/host_init_stubs.cpp @@ -30,6 +30,9 @@ namespace init { std::string default_console = "/dev/console"; // property_service.h +bool CanReadProperty(const std::string& source_context, const std::string& name) { + return true; +} uint32_t SetProperty(const std::string& key, const std::string& value) { android::base::SetProperty(key, value); return 0; diff --git a/init/host_init_stubs.h b/init/host_init_stubs.h index 0af11f667..63ceead67 100644 --- a/init/host_init_stubs.h +++ b/init/host_init_stubs.h @@ -39,6 +39,7 @@ namespace init { extern std::string default_console; // property_service.h +bool CanReadProperty(const std::string& source_context, const std::string& name); extern uint32_t (*property_set)(const std::string& name, const std::string& value); uint32_t HandlePropertySet(const std::string& name, const std::string& value, const std::string& source_context, const ucred& cr, std::string* error); diff --git a/init/property_service.cpp b/init/property_service.cpp index 6aed0a393..53288697d 100644 --- a/init/property_service.cpp +++ b/init/property_service.cpp @@ -111,6 +111,22 @@ void property_init() { LOG(FATAL) << "Failed to load serialized property info file"; } } + +bool CanReadProperty(const std::string& source_context, const std::string& name) { + const char* target_context = nullptr; + property_info_area->GetPropertyInfo(name.c_str(), &target_context, nullptr); + + PropertyAuditData audit_data; + + audit_data.name = name.c_str(); + + ucred cr = {.pid = 0, .uid = 0, .gid = 0}; + audit_data.cr = &cr; + + return selinux_check_access(source_context.c_str(), target_context, "file", "read", + &audit_data) == 0; +} + static bool CheckMacPerms(const std::string& name, const char* target_context, const char* source_context, const ucred& cr) { if (!target_context || !source_context) { diff --git a/init/property_service.h b/init/property_service.h index cacd987f7..9022f5a8a 100644 --- a/init/property_service.h +++ b/init/property_service.h @@ -26,6 +26,8 @@ namespace android { namespace init { +bool CanReadProperty(const std::string& source_context, const std::string& name); + extern uint32_t (*property_set)(const std::string& name, const std::string& value); uint32_t HandlePropertySet(const std::string& name, const std::string& value, diff --git a/init/stable_properties.h b/init/stable_properties.h deleted file mode 100644 index baef833f7..000000000 --- a/init/stable_properties.h +++ /dev/null @@ -1,67 +0,0 @@ -/* - * Copyright (C) 2018 The Android Open Source Project - * - * Licensed under the Apache License, Version 2.0 (the "License"); - * you may not use this file except in compliance with the License. - * You may obtain a copy of the License at - * - * http://www.apache.org/licenses/LICENSE-2.0 - * - * Unless required by applicable law or agreed to in writing, software - * distributed under the License is distributed on an "AS IS" BASIS, - * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - * See the License for the specific language governing permissions and - * limitations under the License. - */ - -#ifndef _INIT_STABLE_PROPERTIES_H -#define _INIT_STABLE_PROPERTIES_H - -#include -#include - -namespace android { -namespace init { - -static constexpr const char* kPartnerPrefixes[] = { - "init.svc.vendor.", "ro.vendor.", "persist.vendor.", "vendor.", "init.svc.odm.", "ro.odm.", - "persist.odm.", "odm.", "ro.boot.", -}; - -static const std::set kExportedActionableProperties = { - "dev.bootcomplete", - "init.svc.console", - "init.svc.dumpstatez", - "init.svc.mediadrm", - "init.svc.surfaceflinger", - "init.svc.zygote", - "persist.bluetooth.btsnoopenable", - "persist.sys.crash_rcu", - "persist.sys.usb.usbradio.config", - "persist.sys.zram_enabled", - "ro.board.platform", - "ro.bootmode", - "ro.build.type", - "ro.crypto.state", - "ro.crypto.type", - "ro.debuggable", - "sys.boot_completed", - "sys.boot_from_charger_mode", - "sys.retaildemo.enabled", - "sys.shutdown.requested", - "sys.usb.config", - "sys.usb.configfs", - "sys.usb.ffs.mtp.ready", - "sys.usb.ffs.ready", - "sys.user.0.ce_available", - "sys.vdso", - "vold.decrypt", - "vold.post_fs_data_done", - "vts.native_server.on", - "wlan.driver.status", -}; - -} // namespace init -} // namespace android - -#endif