mirror of
https://github.com/google/sandboxed-api.git
synced 2024-03-22 13:11:30 +08:00
ca6ec4337d
Recenly, Debian based distribution kernels started activating the Tomoyo Linux Security Module by default. Even if it is not used, this changes the behavior of `/dev/fd` (pointing to `/proc/self/fd` by default), which Sandbox2 needs during `execveat()`. As a result, Sandbox2 and Sandboxed API always fail without one of the following conditions - `/proc` mounted within the sandboxee - `/dev` mounted - `/dev/fd` symlinked to `/proc/self/fd` in the sandboxee's mount namespace Some code pointers to upstream Linux 5.12.2: - https://elixir.bootlin.com/linux/v5.12.2/source/fs/exec.c#L1775 - https://elixir.bootlin.com/linux/v5.12.2/source/security/tomoyo/tomoyo.c#L107 - https://elixir.bootlin.com/linux/v5.12.2/source/security/tomoyo/domain.c#L729 To find out whether your system has Tomoyo enabled, use this command, similar to what this change does in code: ``` $ cat /sys/kernel/security/lsm | grep tomoyo && echo "Tomoyo active" capability,yama,apparmor,tomoyo Tomoyo active ``` The config setting `CONFIG_DEFAULT_SECURITY` controls which LSMs are built into the kernel by default. PiperOrigin-RevId: 372919524 Change-Id: I2181819c04f15f57d96c44ea9977d0def4a1b623
93 lines
3.1 KiB
C++
93 lines
3.1 KiB
C++
// Copyright 2019 Google LLC
|
|
//
|
|
// 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 SANDBOXED_API_SANDBOX2_MOUNTTREE_H_
|
|
#define SANDBOXED_API_SANDBOX2_MOUNTTREE_H_
|
|
|
|
#include <string>
|
|
#include <vector>
|
|
|
|
#include "absl/base/attributes.h"
|
|
#include "absl/status/status.h"
|
|
#include "absl/status/statusor.h"
|
|
#include "absl/strings/string_view.h"
|
|
#include "sandboxed_api/sandbox2/mounttree.pb.h"
|
|
|
|
namespace sandbox2 {
|
|
|
|
class Mounts {
|
|
public:
|
|
Mounts() {
|
|
MountTree::Node root;
|
|
root.mutable_root_node()->set_is_ro(true);
|
|
*mount_tree_.mutable_node() = root;
|
|
}
|
|
|
|
explicit Mounts(MountTree mount_tree) : mount_tree_(std::move(mount_tree)) {}
|
|
|
|
Mounts(const Mounts&) = default;
|
|
Mounts(Mounts&&) = default;
|
|
Mounts& operator=(const Mounts&) = default;
|
|
Mounts& operator=(Mounts&&) = default;
|
|
|
|
absl::Status AddFile(absl::string_view path, bool is_ro = true);
|
|
|
|
absl::Status AddFileAt(absl::string_view outside, absl::string_view inside,
|
|
bool is_ro = true);
|
|
|
|
absl::Status AddDirectoryAt(absl::string_view outside,
|
|
absl::string_view inside, bool is_ro = true);
|
|
|
|
absl::Status AddMappingsForBinary(const std::string& path,
|
|
absl::string_view ld_library_path = {});
|
|
|
|
absl::Status AddTmpfs(absl::string_view inside, size_t sz);
|
|
|
|
void CreateMounts(const std::string& root_path) const;
|
|
|
|
MountTree GetMountTree() const { return mount_tree_; }
|
|
|
|
void SetRootWritable() {
|
|
mount_tree_.mutable_node()->mutable_root_node()->set_is_ro(false);
|
|
}
|
|
|
|
bool IsRootReadOnly() const {
|
|
return mount_tree_.has_node() && mount_tree_.node().has_root_node() &&
|
|
mount_tree_.node().root_node().is_ro();
|
|
}
|
|
|
|
// Lists the outside and inside entries of the input tree in the output
|
|
// parameters, in an ls-like manner. Each entry is traversed in the
|
|
// depth-first order. However, the entries on the same level of hierarchy are
|
|
// traversed in their natural order in the tree. The elements in the output
|
|
// containers match each other pairwise: outside_entries[i] is mounted as
|
|
// inside_entries[i]. The elements of inside_entries are prefixed with either
|
|
// 'R' (read-only) or 'W' (writable).
|
|
void RecursivelyListMounts(std::vector<std::string>* outside_entries,
|
|
std::vector<std::string>* inside_entries);
|
|
|
|
absl::StatusOr<std::string> ResolvePath(absl::string_view path) const;
|
|
|
|
private:
|
|
friend class MountTreeTest;
|
|
|
|
absl::Status Insert(absl::string_view path, const MountTree::Node& node);
|
|
|
|
MountTree mount_tree_;
|
|
};
|
|
|
|
} // namespace sandbox2
|
|
|
|
#endif // SANDBOXED_API_SANDBOX2_MOUNTTREE_H_
|