a8f13667c2
The file permissions of the idmap2 binary are currently not set correctly when the system forks and execs the idmap binary during zygote. This chnages sets the uid and gid after forking to the same uid and gid of the parent process. Bug: 134897503 Test: device boots and generates idmap Change-Id: Ic7fac49e5982f3c47713603b905c3a6be117a05b
126 lines
2.9 KiB
C++
126 lines
2.9 KiB
C++
/*
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* Copyright (C) 2018 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#ifdef _WIN32
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// nothing to see here
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#else
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#include <memory>
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#include <string>
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#include <vector>
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#include <sys/types.h>
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#include <sys/wait.h>
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#include <unistd.h>
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#include "android-base/logging.h"
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#include "androidfw/PosixUtils.h"
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namespace {
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std::unique_ptr<std::string> ReadFile(int fd) {
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std::unique_ptr<std::string> str(new std::string());
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char buf[1024];
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ssize_t r;
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while ((r = read(fd, buf, sizeof(buf))) > 0) {
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str->append(buf, r);
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}
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if (r != 0) {
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return nullptr;
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}
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return str;
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}
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}
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namespace android {
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namespace util {
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std::unique_ptr<ProcResult> ExecuteBinary(const std::vector<std::string>& argv) {
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int stdout[2]; // stdout[0] read, stdout[1] write
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if (pipe(stdout) != 0) {
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PLOG(ERROR) << "pipe";
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return nullptr;
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}
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int stderr[2]; // stdout[0] read, stdout[1] write
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if (pipe(stderr) != 0) {
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PLOG(ERROR) << "pipe";
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close(stdout[0]);
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close(stdout[1]);
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return nullptr;
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}
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auto gid = getgid();
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auto uid = getuid();
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char const** argv0 = (char const**)malloc(sizeof(char*) * (argv.size() + 1));
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for (size_t i = 0; i < argv.size(); i++) {
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argv0[i] = argv[i].c_str();
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}
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argv0[argv.size()] = nullptr;
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switch (fork()) {
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case -1: // error
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free(argv0);
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PLOG(ERROR) << "fork";
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return nullptr;
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case 0: // child
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if (setgid(gid) != 0) {
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PLOG(ERROR) << "setgid";
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exit(1);
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}
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if (setuid(uid) != 0) {
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PLOG(ERROR) << "setuid";
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exit(1);
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}
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close(stdout[0]);
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if (dup2(stdout[1], STDOUT_FILENO) == -1) {
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abort();
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}
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close(stderr[0]);
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if (dup2(stderr[1], STDERR_FILENO) == -1) {
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abort();
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}
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execvp(argv0[0], const_cast<char* const*>(argv0));
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PLOG(ERROR) << "execv";
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abort();
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default: // parent
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free(argv0);
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close(stdout[1]);
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close(stderr[1]);
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int status;
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wait(&status);
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if (!WIFEXITED(status)) {
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return nullptr;
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}
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std::unique_ptr<ProcResult> result(new ProcResult());
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result->status = status;
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const auto out = ReadFile(stdout[0]);
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result->stdout = out ? *out : "";
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close(stdout[0]);
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const auto err = ReadFile(stderr[0]);
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result->stderr = err ? *err : "";
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close(stderr[0]);
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return result;
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}
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}
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} // namespace util
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} // namespace android
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#endif
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