Index: compiler-rt/trunk/lib/asan/asan_errors.h
===================================================================
--- compiler-rt/trunk/lib/asan/asan_errors.h
+++ compiler-rt/trunk/lib/asan/asan_errors.h
@@ -122,12 +122,30 @@
   void Print();
 };
 
+struct ErrorFreeNotMalloced : ErrorBase {
+  // ErrorFreeNotMalloced doesn't own the stack trace.
+  const BufferedStackTrace *free_stack;
+  AddressDescription addr_description;
+  // VS2013 doesn't implement unrestricted unions, so we need a trivial default
+  // constructor
+  ErrorFreeNotMalloced() = default;
+  ErrorFreeNotMalloced(u32 tid, BufferedStackTrace *stack, uptr addr)
+      : ErrorBase(tid),
+        free_stack(stack),
+        addr_description(addr, /*shouldLockThreadRegistry=*/false) {
+    scariness.Clear();
+    scariness.Scare(40, "bad-free");
+  }
+  void Print();
+};
+
 // clang-format off
 #define ASAN_FOR_EACH_ERROR_KIND(macro) \
   macro(StackOverflow)                  \
   macro(DeadlySignal)                   \
   macro(DoubleFree)                     \
-  macro(NewDeleteSizeMismatch)
+  macro(NewDeleteSizeMismatch)          \
+  macro(FreeNotMalloced)
 // clang-format on
 
 #define ASAN_DEFINE_ERROR_KIND(name) kErrorKind##name,
Index: compiler-rt/trunk/lib/asan/asan_errors.cc
===================================================================
--- compiler-rt/trunk/lib/asan/asan_errors.cc
+++ compiler-rt/trunk/lib/asan/asan_errors.cc
@@ -123,4 +123,22 @@
       "ASAN_OPTIONS=new_delete_type_mismatch=0\n");
 }
 
+void ErrorFreeNotMalloced::Print() {
+  Decorator d;
+  Printf("%s", d.Warning());
+  char tname[128];
+  Report(
+      "ERROR: AddressSanitizer: attempting free on address "
+      "which was not malloc()-ed: %p in thread T%d%s\n",
+      addr_description.Address(), tid,
+      ThreadNameWithParenthesis(tid, tname, sizeof(tname)));
+  Printf("%s", d.EndWarning());
+  CHECK_GT(free_stack->size, 0);
+  scariness.Print();
+  GET_STACK_TRACE_FATAL(free_stack->trace[0], free_stack->top_frame_bp);
+  stack.Print();
+  addr_description.Print();
+  ReportErrorSummary("bad-free", &stack);
+}
+
 }  // namespace __asan
Index: compiler-rt/trunk/lib/asan/asan_report.cc
===================================================================
--- compiler-rt/trunk/lib/asan/asan_report.cc
+++ compiler-rt/trunk/lib/asan/asan_report.cc
@@ -350,20 +350,8 @@
 
 void ReportFreeNotMalloced(uptr addr, BufferedStackTrace *free_stack) {
   ScopedInErrorReport in_report;
-  Decorator d;
-  Printf("%s", d.Warning());
-  char tname[128];
-  u32 curr_tid = GetCurrentTidOrInvalid();
-  Report("ERROR: AddressSanitizer: attempting free on address "
-             "which was not malloc()-ed: %p in thread T%d%s\n", addr,
-         curr_tid, ThreadNameWithParenthesis(curr_tid, tname, sizeof(tname)));
-  Printf("%s", d.EndWarning());
-  CHECK_GT(free_stack->size, 0);
-  ScarinessScore::PrintSimple(40, "bad-free");
-  GET_STACK_TRACE_FATAL(free_stack->trace[0], free_stack->top_frame_bp);
-  stack.Print();
-  DescribeAddressIfHeap(addr);
-  ReportErrorSummary("bad-free", &stack);
+  ErrorFreeNotMalloced error(GetCurrentTidOrInvalid(), free_stack, addr);
+  in_report.ReportError(error);
 }
 
 void ReportAllocTypeMismatch(uptr addr, BufferedStackTrace *free_stack,