tighten memory allocation

pauldreik · Apr 27, 2019 · 793d97b · 793d97b
1 parent e2301f2
commit 793d97b
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Showing 2 changed files with 7 additions and 7 deletions.
diff --git a/fuzzing/one_arg.cpp b/fuzzing/one_arg.cpp
@@ -26,8 +26,9 @@ doit(const uint8_t* Data, std::size_t Size)
   Data += N;
   Size -= N;
   // allocates as tight as possible, making it easier to catch buffer overruns
-  std::vector<char> buf(Data, Data + Size);
-  buf.resize(Size + 1, '\0');
+  // also, make it null terminated.
+  std::vector<char> buf(Size + 1);
+  std::memcpy(buf.data(), Data, Size);
   std::string message = fmt::format(buf.data(), item);
 }
 

diff --git a/fuzzing/two_args.cpp b/fuzzing/two_args.cpp
@@ -54,9 +54,10 @@ doit_time(const uint8_t* Data, std::size_t Size)
   std::memcpy(&item, Data, N);
   Data += N;
   Size -= N;
-  // allocates as tight as possible, making it easier to catch buffer overruns
-  std::vector<char> buf(Data, Data + Size);
-  buf.resize(Size + 1, '\0');
+  // allocates as tight as possible, making it easier to catch buffer overruns.
+  // also, make it null terminated.
+  std::vector<char> buf(Size + 1);
+  std::memcpy(buf.data(), Data, Size);
   auto* b = std::localtime(&item);
   if (b) {
     std::string message = fmt::format(buf.data(), *b);
@@ -113,8 +114,6 @@ LLVMFuzzerTestOneInput(const uint8_t* Data, std::size_t Size)
 
   auto outer = [=](auto param1) {
     auto inner = [=](auto param2) {
-      // std::cout<<"invoked with param1="<<sizeof(param1)<<"
-      // param2="<<sizeof(param2)<<'\n';
       doit<decltype(param1), decltype(param2)>(Data, Size);
     };
     invoke(second, inner);