platform_system_vold/VoldNativeServiceValidation.h
Yurii Zubrytskyi 090ae07bc2 [vold] Check incremental paths before mounting
Vold was trusting system_server too much and allowed for pretty
much any path in mount()/bindMount() calls for incremental.
This CL adds validation to make sure it's only accessing own
directories. This includes enforcing no symlinks in the paths

Ignore-AOSP-First: security fix
Bug: 198657657
Test: manual
Change-Id: I6035447f94ef44c4ae3294c3ae47de2d7210683a
2021-11-02 11:20:39 -07:00

42 lines
1.4 KiB
C++

/*
* Copyright (C) 2020 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.
*/
#pragma once
#include <binder/Status.h>
#include <string>
#include <stdint.h>
#include <sys/types.h>
namespace android::vold {
binder::Status Ok();
binder::Status Exception(uint32_t code, const std::string& msg);
binder::Status CheckPermission(const char* permission);
binder::Status CheckUidOrRoot(uid_t expectedUid);
binder::Status CheckArgumentId(const std::string& id);
binder::Status CheckArgumentPath(const std::string& path);
binder::Status CheckArgumentHex(const std::string& hex);
// Incremental service is only allowed to touch its own directory, and the installed apps dir.
// This function ensures the caller isn't doing anything tricky.
enum class IncrementalPathKind { MountSource, MountTarget, Bind, Any };
binder::Status CheckIncrementalPath(IncrementalPathKind kind, const std::string& path);
} // namespace android::vold