Files
cloud-hypervisor/fuzz/fuzz_targets/qcow.rs
Henry Hrvoje Tonkovac f720e619c1 misc: use prelude size_of
size_of is part of std::prelude as of Rust 1.80 (with size_of_val,
align_of, align_of_val), and the workspace MSRV is 1.89, so qualifying
it (mem::size_of, std::mem::size_of, core::mem::size_of) is unnecessary.

Convert every qualified size_of call-site to the bare prelude form and
drop the now-redundant `use std::mem::size_of;` imports, keeping
`use std::mem;` where it still serves non-prelude items (transmute,
swap, replace, take, zeroed, MaybeUninit, offset_of). size_of is the
only one of the four currently used in the tree.

Pure refactor, no behavioural change. Follow-up to the
clippy::absolute_paths cleanup (#7670), as discussed in #8444.

Signed-off-by: Henry Hrvoje Tonkovac <htonkovac@gmail.com>
Assisted-by: Claude:Opus-4.8
2026-06-25 16:54:35 +00:00

84 lines
2.9 KiB
Rust

// Copyright 2018 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE-BSD-3-Clause file.
//
// SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
#![no_main]
use std::ffi;
use std::fs::File;
use std::io::{self, Cursor, Read, Seek, SeekFrom, Write};
use std::os::unix::io::{FromRawFd, RawFd};
use std::sync::Arc;
use block::async_io::GuestMemoryTarget;
use block::disk_file::AsyncDiskFile;
use block::formats::qcow::QcowDisk;
use libfuzzer_sys::{fuzz_target, Corpus};
use vm_memory::{Bytes, GuestAddress, GuestMemoryMmap};
// Take the first 64 bits of data as an address and the next 64 bits as data to
// store there. The rest of the data is used as a qcow image.
fuzz_target!(|bytes: &[u8]| -> Corpus {
if bytes.len() < 16 {
// Need an address and data, each are 8 bytes.
return Corpus::Reject;
}
let mut disk_image = Cursor::new(bytes);
let addr = read_u64(&mut disk_image);
let value = read_u64(&mut disk_image);
let shm = memfd_create(&ffi::CString::new("fuzz").unwrap(), 0).unwrap();
let mut disk_file: File = unsafe { File::from_raw_fd(shm) };
disk_file.write_all(&bytes[16..]).unwrap();
disk_file.seek(SeekFrom::Start(0)).unwrap();
let Ok(disk) = QcowDisk::new(disk_file, false, false, true, false) else {
return Corpus::Keep;
};
let Ok(mut async_io) = disk.create_async_io(1) else {
return Corpus::Keep;
};
let len = size_of::<u64>();
let Ok(mem) = GuestMemoryMmap::<()>::from_ranges(&[(GuestAddress(0), len)]) else {
return Corpus::Keep;
};
let mem = Arc::new(mem);
let _ = mem.write_slice(&value.to_le_bytes(), GuestAddress(0));
let range = [(GuestAddress(0), len as u32)];
let off = addr as libc::off_t;
if let Ok(target) = GuestMemoryTarget::new(Arc::clone(&mem), &range) {
let _ = async_io.write_from_memory(off, target, 0);
while async_io.next_completed_request().is_some() {}
}
if let Ok(target) = GuestMemoryTarget::new(Arc::clone(&mem), &range) {
let _ = async_io.read_to_memory(off, target, 1);
while async_io.next_completed_request().is_some() {}
}
let _ = async_io.write_zeroes(addr, len as u64, 2);
while async_io.next_completed_request().is_some() {}
let _ = async_io.punch_hole(addr, len as u64, 3);
while async_io.next_completed_request().is_some() {}
let _ = async_io.fsync(Some(4));
while async_io.next_completed_request().is_some() {}
Corpus::Keep
});
fn read_u64<T: Read>(readable: &mut T) -> u64 {
let mut buf = [0u8; size_of::<u64>()];
readable.read_exact(&mut buf[..]).unwrap();
u64::from_le_bytes(buf)
}
fn memfd_create(name: &ffi::CStr, flags: u32) -> Result<RawFd, io::Error> {
let res = unsafe { libc::syscall(libc::SYS_memfd_create, name.as_ptr(), flags) };
if res < 0 {
Err(io::Error::last_os_error())
} else {
Ok(res as RawFd)
}
}