From 6b302b9e61388cd7601503b0ff9ceca80c522df2 Mon Sep 17 00:00:00 2001
From: Varun Khaneja <aawc@users.noreply.github.com>
Date: Fri, 17 Nov 2017 14:47:43 -0800
Subject: [PATCH] Use same filename for the input file created in disk (#994)

* Use the same file name always to avoid creating new files

* Minor: formatting changes

* Use PID for the filename
---
 projects/unrar/unrar_fuzzer.cc | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/projects/unrar/unrar_fuzzer.cc b/projects/unrar/unrar_fuzzer.cc
index f19b53a5a..084aa6a8f 100644
--- a/projects/unrar/unrar_fuzzer.cc
+++ b/projects/unrar/unrar_fuzzer.cc
@@ -1,20 +1,27 @@
+#include <fstream>
 #include <memory>
-#include <stddef.h>
-#include <string>
+#include <sstream>
 #include <unistd.h>
 
 #include "rar.hpp"
 
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
-  char filename[] = "mytemp.XXXXXX";
-  int fd = mkstemp(filename);
-  write(fd, data, size);
+  std::stringstream ss;
+  ss << "temp-" << getpid() << ".rar";
+  static const std::string filename = ss.str();
+  std::ofstream file(filename,
+                     std::ios::binary | std::ios::out | std::ios::trunc);
+  if (!file.is_open()) {
+    return 0;
+  }
+  file.write(reinterpret_cast<const char *>(data), size);
+  file.close();
 
   std::unique_ptr<CommandData> cmd_data(new CommandData);
   cmd_data->ParseArg(const_cast<wchar_t *>(L"-p"));
   cmd_data->ParseArg(const_cast<wchar_t *>(L"x"));
   cmd_data->ParseDone();
-  std::wstring wide_filename(filename, filename + strlen(filename));
+  std::wstring wide_filename(filename.begin(), filename.end());
   cmd_data->AddArcName(wide_filename.c_str());
 
   try {
@@ -23,8 +30,7 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
   } catch (...) {
   }
 
-  close(fd);
-  unlink(filename);
+  unlink(filename.c_str());
 
   return 0;
 }