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194b59f44b
This function is for really for the transport layer to trigger a device reset. Instead name it appropriately for the fuzzing specific use case. Signed-off-by: Rob Bradford <robert.bradford@intel.com>
100 lines
3.2 KiB
Rust
100 lines
3.2 KiB
Rust
// Copyright © 2022 Intel Corporation
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//
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// SPDX-License-Identifier: Apache-2.0
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#![no_main]
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use libfuzzer_sys::fuzz_target;
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use seccompiler::SeccompAction;
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use std::os::unix::io::{AsRawFd, FromRawFd};
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use std::sync::Arc;
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use virtio_devices::{VirtioDevice, VirtioInterrupt, VirtioInterruptType};
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use virtio_queue::{Queue, QueueT};
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use vm_memory::{bitmap::AtomicBitmap, Bytes, GuestAddress, GuestMemoryAtomic};
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use vmm_sys_util::eventfd::{EventFd, EFD_NONBLOCK};
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type GuestMemoryMmap = vm_memory::GuestMemoryMmap<AtomicBitmap>;
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const QUEUE_DATA_SIZE: usize = 4;
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const MEM_SIZE: usize = 256 * 1024 * 1024;
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// Max entries in the queue.
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const QUEUE_SIZE: u16 = 256;
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// Guest physical address for descriptor table.
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const DESC_TABLE_ADDR: u64 = 0;
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const DESC_TABLE_SIZE: u64 = 16_u64 * QUEUE_SIZE as u64;
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// Guest physical address for available ring
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const AVAIL_RING_ADDR: u64 = DESC_TABLE_ADDR + DESC_TABLE_SIZE;
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const AVAIL_RING_SIZE: u64 = 6_u64 + 2 * QUEUE_SIZE as u64;
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// Guest physical address for used ring (requires to 4-bytes aligned)
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const USED_RING_ADDR: u64 = (AVAIL_RING_ADDR + AVAIL_RING_SIZE + 3) & !3_u64;
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fuzz_target!(|bytes| {
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if bytes.len() < QUEUE_DATA_SIZE || bytes.len() > (QUEUE_DATA_SIZE + MEM_SIZE) {
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return;
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}
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let mut watchdog = virtio_devices::Watchdog::new(
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"fuzzer_watchdog".to_owned(),
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EventFd::new(EFD_NONBLOCK).unwrap(),
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SeccompAction::Allow,
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EventFd::new(EFD_NONBLOCK).unwrap(),
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)
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.unwrap();
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let queue_data = &bytes[..QUEUE_DATA_SIZE];
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let mem_bytes = &bytes[QUEUE_DATA_SIZE..];
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// Setup the virt queue with the input bytes
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let q = setup_virt_queue(queue_data.try_into().unwrap());
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// Setup the guest memory with the input bytes
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let mem = GuestMemoryMmap::from_ranges(&[(GuestAddress(0), MEM_SIZE)]).unwrap();
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if mem.write_slice(mem_bytes, GuestAddress(0 as u64)).is_err() {
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return;
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}
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let guest_memory = GuestMemoryAtomic::new(mem);
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let evt = EventFd::new(0).unwrap();
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let queue_evt = unsafe { EventFd::from_raw_fd(libc::dup(evt.as_raw_fd())) };
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// Kick the 'queue' event before activate the watchdog device
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queue_evt.write(1).unwrap();
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watchdog
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.activate(
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guest_memory,
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Arc::new(NoopVirtioInterrupt {}),
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vec![(0, q, evt)],
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)
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.ok();
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// Wait for the events to finish and watchdog device worker thread to return
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watchdog.wait_for_epoll_threads();
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});
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pub struct NoopVirtioInterrupt {}
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impl VirtioInterrupt for NoopVirtioInterrupt {
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fn trigger(&self, _int_type: VirtioInterruptType) -> std::result::Result<(), std::io::Error> {
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Ok(())
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}
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}
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fn setup_virt_queue(bytes: &[u8; QUEUE_DATA_SIZE]) -> Queue {
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let mut q = Queue::new(QUEUE_SIZE).unwrap();
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q.set_next_avail(bytes[0] as u16); // 'u8' is enough given the 'QUEUE_SIZE' is small
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q.set_next_used(bytes[1] as u16);
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q.set_event_idx(bytes[2] % 2 != 0);
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q.set_size(bytes[3] as u16 % QUEUE_SIZE);
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q.try_set_desc_table_address(GuestAddress(DESC_TABLE_ADDR))
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.unwrap();
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q.try_set_avail_ring_address(GuestAddress(AVAIL_RING_ADDR))
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.unwrap();
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q.try_set_used_ring_address(GuestAddress(USED_RING_ADDR))
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.unwrap();
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q.set_ready(true);
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q
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}
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