xref: /aosp_15_r20/external/crosvm/fuzz/fuzz_targets/qcow_fuzzer.rs (revision bb4ee6a4ae7042d18b07a98463b9c8b875e44b39)
1 // Copyright 2019 The ChromiumOS Authors
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #![cfg(not(test))]
6 #![no_main]
7 
8 use std::io::Cursor;
9 use std::io::Read;
10 use std::io::Seek;
11 use std::io::SeekFrom;
12 use std::io::Write;
13 use std::mem::size_of;
14 
15 use base::FileReadWriteAtVolatile;
16 use base::VolatileSlice;
17 use crosvm_fuzz::fuzz_target;
18 use disk::QcowFile;
19 
20 // Take the first 64 bits of data as an address and the next 64 bits as data to
21 // store there. The rest of the data is used as a qcow image.
22 fuzz_target!(|bytes| {
23     if bytes.len() < 16 {
24         // Need an address and data, each are 8 bytes.
25         return;
26     }
27     let mut disk_image = Cursor::new(bytes);
28     let addr = read_u64(&mut disk_image);
29     let value = read_u64(&mut disk_image);
30     let mut disk_file = tempfile::tempfile().unwrap();
31     disk_file.write_all(&bytes[16..]).unwrap();
32     disk_file.seek(SeekFrom::Start(0)).unwrap();
33     if let Ok(qcow) = QcowFile::from(
34         disk_file,
35         disk::DiskFileParams {
36             path: "/foo".into(),
37             is_read_only: false,
38             is_sparse_file: false,
39             is_overlapped: false,
40             is_direct: false,
41             lock: true,
42             depth: 0,
43         },
44     ) {
45         let mut mem = value.to_le_bytes().to_owned();
46         let vslice = VolatileSlice::new(&mut mem);
47         let _ = qcow.write_all_at_volatile(vslice, addr);
48     }
49 });
50 
read_u64<T: Read>(readable: &mut T) -> u6451 fn read_u64<T: Read>(readable: &mut T) -> u64 {
52     let mut buf = [0u8; size_of::<u64>()];
53     readable.read_exact(&mut buf[..]).unwrap();
54     u64::from_le_bytes(buf)
55 }
56