1 files changed, 6 insertions, 92 deletions

diff --git a/fuzzing/libfdt_fuzzer.c b/fuzzing/libfdt_fuzzer.c
index b433bbc..227e711 100644
--- a/fuzzing/libfdt_fuzzer.c
+++ b/fuzzing/libfdt_fuzzer.c
@@ -1,77 +1,18 @@
-/*
- * Copyright (C) 2022 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-/* Ensure assert() catches logical errors during fuzzing */
-#ifdef NDEBUG
-#undef NDEBUG
-#endif
-
-#include <inttypes.h>
 #include <assert.h>
-#include <stdbool.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
-#include <ctype.h>
-
-#include <sanitizer/asan_interface.h>
-#include <sanitizer/msan_interface.h>
 
 #include "libfdt.h"
 #include "libfdt_env.h"
 
-/* check memory region is valid, for the purpose of tooling such as asan */
-static void check_mem(const void *mem, size_t len) {
-
-  assert(mem);
-
-#if __has_feature(memory_sanitizer)
-  /* dumps if check fails */
-  __msan_check_mem_is_initialized((void *)mem, len);
-#endif
-
-#if __has_feature(address_sanitizer) || defined(__SANITIZE_ADDRESS__)
-  assert(!__asan_region_is_poisoned((void *)mem, len));
-#else
-  const volatile uint8_t *mem8 = mem;
-
-  /* Read each byte of memory for instrumentation */
-  for(size_t i = 0; i < len; i++) {
-    (void)mem8[i];
-  }
-#endif
-}
-
-
-static void walk_node_properties(const void *device_tree, int node) {
-  int property, len = 0;
-
-  fdt_for_each_property_offset(property, device_tree, node) {
-    const struct fdt_property *prop = fdt_get_property_by_offset(device_tree,
-                                                                 property, &len);
-    check_mem(prop->data, fdt32_to_cpu(prop->len));
-  }
-}
-
-
-static void walk_device_tree(const void *device_tree, int parent_node) {
+void walk_device_tree(const void *device_tree, int parent_node) {
   int len = 0;
   const char *node_name = fdt_get_name(device_tree, parent_node, &len);
   if (node_name != NULL) {
-    check_mem(node_name, len);
+    // avoid clang complaining about unused variable node_name and force
+    // ASan to validate string pointer in strlen call.
+    assert(strlen(node_name) == len);
   }
 
   uint32_t phandle = fdt_get_phandle(device_tree, parent_node);
@@ -79,8 +20,6 @@ static void walk_device_tree(const void *device_tree, int parent_node) {
     assert(parent_node == fdt_node_offset_by_phandle(device_tree, phandle));
   }
 
-  walk_node_properties(device_tree, parent_node);
-
   // recursively walk the node's children
   for (int node = fdt_first_subnode(device_tree, parent_node); node >= 0;
        node = fdt_next_subnode(device_tree, node)) {
@@ -88,7 +27,6 @@ static void walk_device_tree(const void *device_tree, int parent_node) {
   }
 }
 
-
 // Information on device tree is available in external/dtc/Documentation/
 // folder.
 int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
@@ -97,32 +35,8 @@ int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
 
   if (fdt_check_full(data, size) != 0) return 0;
 
-  walk_device_tree(data, /* parent_node */ 0);
+  int root_node_offset = 0;
+  walk_device_tree(data, root_node_offset);
 
   return 0;
 }
-
-#ifdef AFL_STANDALONE
-/* Entry point suitable for direct afl-fuzz invocation */
-int main(int argc, char *argv[]) {
-  uint8_t data[1024 * 1024];
-
-  if (argc != 2) {
-    fprintf(stderr, "missing argument\n");
-    return EXIT_FAILURE;
-  }
-
-  FILE *f = fopen(argv[1], "r");
-  if (!f) {
-    perror("fopen() failed");
-    return EXIT_FAILURE;
-  }
-
-  size_t size = fread(data, 1, sizeof(data), f);
-
-  fclose(f);
-
-  return LLVMFuzzerTestOneInput(data, size);
-}
-#endif
-