From 646285eedae8c42d2ce86d5fc91af4cf935009fa Mon Sep 17 00:00:00 2001
From: Julien Voisin <jvoisin@users.noreply.github.com>
Date: Fri, 14 Oct 2022 18:56:28 +0200
Subject: [PATCH] Simplify libarchive's fuzzer (#8781)

Co-authored-by: Julien Voisin <jvoisin@google.com>
---
 projects/libarchive/libarchive_fuzzer.cc | 26 +++++-------------------
 1 file changed, 5 insertions(+), 21 deletions(-)

diff --git a/projects/libarchive/libarchive_fuzzer.cc b/projects/libarchive/libarchive_fuzzer.cc
index 6e4c3b9d5..8b7cce428 100644
--- a/projects/libarchive/libarchive_fuzzer.cc
+++ b/projects/libarchive/libarchive_fuzzer.cc
@@ -20,23 +20,7 @@
 #include "archive.h"
 #include "archive_entry.h"
 
-struct Buffer {
-  const uint8_t *buf;
-  size_t len;
-};
-
-ssize_t reader_callback(struct archive *a, void *client_data,
-                        const void **block) {
-  Buffer *buffer = reinterpret_cast<Buffer *>(client_data);
-  *block = buffer->buf;
-  ssize_t len = buffer->len;
-  buffer->len = 0;
-  return len;
-}
-
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *buf, size_t len) {
-  int ret;
-  ssize_t r;
   struct archive *a = archive_read_new();
 
   archive_read_support_filter_all(a);
@@ -48,13 +32,12 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t *buf, size_t len) {
     return 0;
   }
 
-  Buffer buffer = {buf, len};
-  archive_read_open(a, &buffer, NULL, reader_callback, NULL);
+  archive_read_open_memory(a, buf, len);
 
-  std::vector<uint8_t> data_buffer(getpagesize(), 0);
-  struct archive_entry *entry;
   while(1) {
-    ret = archive_read_next_header(a, &entry);
+    std::vector<uint8_t> data_buffer(getpagesize(), 0);
+    struct archive_entry *entry;
+    int ret = archive_read_next_header(a, &entry);
     if (ret == ARCHIVE_EOF || ret == ARCHIVE_FATAL)
       break;
     if (ret == ARCHIVE_RETRY)
@@ -76,6 +59,7 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t *buf, size_t len) {
     (void)archive_entry_uid(entry);
     (void)archive_entry_mtime(entry);
 
+    ssize_t r;
     while ((r = archive_read_data(a, data_buffer.data(),
             data_buffer.size())) > 0)
       ;