mirror of
https://github.com/cloud-hypervisor/cloud-hypervisor.git
synced 2024-08-25 01:11:16 +00:00
50 lines
1.7 KiB
Rust
50 lines
1.7 KiB
Rust
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// Copyright 2018 The Chromium OS Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE-BSD-3-Clause file.
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#![no_main]
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use libfuzzer_sys::fuzz_target;
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use qcow::{QcowFile, RawFile};
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use std::ffi;
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use std::fs::File;
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use std::io::{self, Cursor, Read, Seek, SeekFrom, Write};
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use std::mem::size_of;
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use std::os::unix::io::{FromRawFd, RawFd};
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// Take the first 64 bits of data as an address and the next 64 bits as data to
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// store there. The rest of the data is used as a qcow image.
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fuzz_target!(|bytes| {
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if bytes.len() < 16 {
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// Need an address and data, each are 8 bytes.
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return;
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}
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let mut disk_image = Cursor::new(bytes);
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let addr = read_u64(&mut disk_image);
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let value = read_u64(&mut disk_image);
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let shm = memfd_create(&ffi::CString::new("fuzz").unwrap(), 0).unwrap();
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let mut disk_file: File = unsafe { File::from_raw_fd(shm) };
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disk_file.write_all(&bytes[16..]).unwrap();
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disk_file.seek(SeekFrom::Start(0)).unwrap();
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if let Ok(mut qcow) = QcowFile::from(RawFile::new(disk_file, false)) {
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if qcow.seek(SeekFrom::Start(addr)).is_ok() {
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let _ = qcow.write_all(&value.to_le_bytes());
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}
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}
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});
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fn read_u64<T: Read>(readable: &mut T) -> u64 {
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let mut buf = [0u8; size_of::<u64>()];
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readable.read_exact(&mut buf[..]).unwrap();
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u64::from_le_bytes(buf)
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}
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fn memfd_create(name: &ffi::CStr, flags: u32) -> Result<RawFd, io::Error> {
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let res = unsafe { libc::syscall(libc::SYS_memfd_create, name.as_ptr(), flags) };
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if res < 0 {
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Err(io::Error::last_os_error())
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} else {
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Ok(res as RawFd)
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}
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}
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