Index: lib/asan/asan_errors.h
===================================================================
--- lib/asan/asan_errors.h
+++ lib/asan/asan_errors.h
@@ -229,6 +229,25 @@
   void Print();
 };
 
+struct ErrorStringFunctionSizeOverflow : ErrorBase {
+  u32 tid;
+  // ErrorStringFunctionSizeOverflow doesn't own the stack trace.
+  BufferedStackTrace *stack;
+  AddressDescriptionBase addr_description;
+  uptr size;
+  // VS2013 doesn't implement unrestricted unions, so we need a trivial default
+  // constructor
+  ErrorStringFunctionSizeOverflow() = default;
+  ErrorStringFunctionSizeOverflow(u32 tid_, BufferedStackTrace *stack_,
+                                  uptr addr, uptr size_)
+      : tid(tid_), stack(stack_), size(size_) {
+    scariness.Clear();
+    scariness.Scare(10,  "negative-size-param");
+    addr_description = AddressDescription(addr);
+  }
+  void Print();
+};
+
 #define FOR_EACH_ERROR_KIND_MEMBER_NAME_PAIR(macro)             \
   macro(StackOverflow, stack_overflow)                          \
   macro(DeadlySignal, deadly_signal)                            \
@@ -240,7 +259,8 @@
   macro(SanitizerGetAllocatedSizeNotOwned,                      \
         sanitizer_get_allocated_size_not_owned)                 \
   macro(StringFunctionMemoryRangesOverlap,                      \
-        string_function_memory_ranges_overlap)
+        string_function_memory_ranges_overlap)                  \
+  macro(StringFunctionSizeOverflow, string_function_size_overflow)
 
 enum ErrorKind {
   kErrorKindInvalid = 0,
Index: lib/asan/asan_errors.cc
===================================================================
--- lib/asan/asan_errors.cc
+++ lib/asan/asan_errors.cc
@@ -209,4 +209,16 @@
   ReportErrorSummary(bug_type, stack);
 }
 
+void ErrorStringFunctionSizeOverflow::Print() {
+  Decorator d;
+  Printf("%s", d.Warning());
+  const char *bug_type = "negative-size-param";
+  Report("ERROR: AddressSanitizer: %s: (size=%zd)\n", bug_type, size);
+  Printf("%s", d.EndWarning());
+  scariness.Print();
+  stack->Print();
+  addr_description.Print();
+  ReportErrorSummary(bug_type, stack);
+}
+
 }  // namespace __asan
Index: lib/asan/asan_report.cc
===================================================================
--- lib/asan/asan_report.cc
+++ lib/asan/asan_report.cc
@@ -391,15 +391,9 @@
 void ReportStringFunctionSizeOverflow(uptr offset, uptr size,
                                       BufferedStackTrace *stack) {
   ScopedInErrorReport in_report;
-  Decorator d;
-  const char *bug_type = "negative-size-param";
-  Printf("%s", d.Warning());
-  Report("ERROR: AddressSanitizer: %s: (size=%zd)\n", bug_type, size);
-  Printf("%s", d.EndWarning());
-  ScarinessScore::PrintSimple(10, bug_type);
-  stack->Print();
-  PrintAddressDescription(offset, size, bug_type);
-  ReportErrorSummary(bug_type, stack);
+  ErrorStringFunctionSizeOverflow error(GetCurrentTidOrInvalid(), stack, offset,
+                                        size);
+  in_report.ReportError(error);
 }
 
 void ReportBadParamsToAnnotateContiguousContainer(uptr beg, uptr end,