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80 lines
2.2 KiB
80 lines
2.2 KiB
/*
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* Copyright (C) 2021 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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#if !defined _GNU_SOURCE
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#define _GNU_SOURCE
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#endif
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#include <err.h>
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#include <fcntl.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <sys/mman.h>
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#include <sys/uio.h>
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#include <sys/wait.h>
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#include <unistd.h>
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#include "../includes/common.h"
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#define SYSCHK(x) \
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({ \
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typeof(x) __res = (x); \
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if (__res == (typeof(x)) - 1) err(1, "SYSCHK(" #x ")"); \
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__res; \
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})
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static char *data;
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static int child_fn(void) {
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int pipe_fds[2];
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SYSCHK(pipe(pipe_fds));
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struct iovec iov = {.iov_base = data, .iov_len = 0x1000};
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SYSCHK(vmsplice(pipe_fds[1], &iov, 1, 0));
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SYSCHK(munmap(data, 0x1000));
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sleep(2);
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char buf[0x1000];
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SYSCHK(read(pipe_fds[0], buf, 0x1000));
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printf("read string from child: %s\n", buf);
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// check if buf has been altered by parent process
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if (strcmp("BORING DATA", buf) == 0) {
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return EXIT_SUCCESS;
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}
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if (strcmp("THIS IS SECRET", buf) == 0) {
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return EXIT_VULNERABLE;
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}
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return EXIT_FAILURE;
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}
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int main(void) {
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if (posix_memalign((void **)&data, 0x1000, 0x1000)) errx(1, "posix_memalign()");
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strcpy(data, "BORING DATA");
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pid_t child = SYSCHK(fork());
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if (child == 0) {
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exit(child_fn());
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}
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sleep(1);
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strcpy(data, "THIS IS SECRET");
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int status;
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SYSCHK(waitpid(child, &status, 0));
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printf("child WEXITSTATUS(status) => %d\n", WEXITSTATUS(status));
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return WEXITSTATUS(status);
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}
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