75 lines
2.1 KiB
C++
75 lines
2.1 KiB
C++
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/*
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* Copyright (C) 2022 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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#include <cstdint>
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#include <fuzzer/FuzzedDataProvider.h>
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extern "C" {
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#include "libufdt_sysdeps.h"
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#include "ufdt_overlay.h"
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}
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/* Count split value, plus 1 byte for dto and overlay each */
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constexpr uint32_t kMinData = sizeof(uint32_t) + 2;
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constexpr uint32_t kMaxData = 1024 * 512;
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/* libFuzzer driver.
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* We need two dtb's to test merging, so split the input data block, using
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* the first 4 bytes to give the dtb length, the rest being overlay.
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* The mkcorpus helper program can construct these files.
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*/
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extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
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/* Bound input size */
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if (size < kMinData || size > kMaxData) {
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return 0;
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}
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FuzzedDataProvider fdp(data, size);
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/* Read fixed length header */
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auto hdr = fdp.ConsumeBytes<uint8_t>(4);
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/* Extract the length, network byte order */
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const uint32_t dtb_len = hdr[0] << 24 | hdr[1] << 16 | hdr[2] << 8 | hdr[3];
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/* Ensure the dtb and overlay are non-zero length */
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if (dtb_len == 0 || dtb_len >= size - 1) {
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return 0;
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}
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auto dtb = fdp.ConsumeBytes<uint8_t>(dtb_len);
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auto overlay = fdp.ConsumeRemainingBytes<uint8_t>();
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/* Check headers */
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auto fdt_dtb = ufdt_install_blob(dtb.data(), dtb.size());
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auto fdt_overlay = ufdt_install_blob(overlay.data(), overlay.size());
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if (!fdt_dtb || !fdt_overlay) {
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return 0;
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}
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struct fdt_header *res =
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ufdt_apply_overlay(fdt_dtb, dtb.size(), fdt_overlay, overlay.size());
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if (res) {
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dto_free(res);
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}
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return 0;
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}
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