stop high memory use when fuzzing

pauldreik · Apr 21, 2019 · 99b2e08 · 99b2e08
1 parent 5efb24d
commit 99b2e08
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diff --git a/include/fmt/format-inl.h b/include/fmt/format-inl.h
@@ -744,6 +744,12 @@ void sprintf_format(Double value, internal::buffer<char>& buf,
   *format_ptr++ = type;
   *format_ptr = '\0';
 
+#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
+if(spec.precision>100000) {
+ throw std::runtime_error("fuzz mode - avoiding large precision");
+}
+#endif
+
   // Format using snprintf.
   char* start = FMT_NULL;
   for (;;) {

diff --git a/include/fmt/format.h b/include/fmt/format.h
@@ -535,6 +535,11 @@ class basic_memory_buffer : private Allocator, public internal::buffer<T> {
 
 template <typename T, std::size_t SIZE, typename Allocator>
 void basic_memory_buffer<T, SIZE, Allocator>::grow(std::size_t size) {
+#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
+if(size>10000000) {
+ throw std::runtime_error("fuzz mode - won't grow that much");
+}
+#endif
   std::size_t old_capacity = this->capacity();
   std::size_t new_capacity = old_capacity + old_capacity / 2;
   if (size > new_capacity) new_capacity = size;