Fix heap-use-after-free for _HAS_EXCEPTIONS=0

stl/inc/chrono

@@ -1725,9 +1725,15 @@ namespace chrono {
 
     _EXPORT_STD class _NODISCARD nonexistent_local_time : public runtime_error {
     public:
+#if _HAS_EXCEPTIONS
         template <class _Duration>
         nonexistent_local_time(const local_time<_Duration>& _Tp, const local_info& _Info)
             : runtime_error(_Make_string(_Tp, _Info)) {}
+#else // ^^^ _HAS_EXCEPTIONS / !_HAS_EXCEPTIONS vvv
+        template <class _Duration>
+        nonexistent_local_time(const local_time<_Duration>&, const local_info&)
+            : runtime_error("nonexistent local time") {}
+#endif // ^^^ !_HAS_EXCEPTIONS ^^^
 
     private:
         template <class _Duration>
@@ -1741,9 +1747,14 @@ namespace chrono {
 
     _EXPORT_STD class _NODISCARD ambiguous_local_time : public runtime_error {
     public:
+#if _HAS_EXCEPTIONS
         template <class _Duration>
         ambiguous_local_time(const local_time<_Duration>& _Tp, const local_info& _Info)
             : runtime_error(_Make_string(_Tp, _Info)) {}
+#else // ^^^ _HAS_EXCEPTIONS / !_HAS_EXCEPTIONS vvv
+        template <class _Duration>
+        ambiguous_local_time(const local_time<_Duration>&, const local_info&) : runtime_error("ambiguous local time") {}
+#endif // ^^^ !_HAS_EXCEPTIONS ^^^
 
     private:
         template <class _Duration>

stl/inc/system_error

@@ -470,10 +470,16 @@ private:
     }
 
 protected:
+#if _HAS_EXCEPTIONS
     _System_error(error_code _Errcode) : runtime_error(_Errcode.message()), _Mycode(_Errcode) {}
 
     _System_error(error_code _Errcode, const string& _Message)
         : runtime_error(_Makestr(_Errcode, _Message)), _Mycode(_Errcode) {}
+#else // ^^^ _HAS_EXCEPTIONS / !_HAS_EXCEPTIONS vvv
+    _System_error(error_code _Errcode) : runtime_error("system error"), _Mycode(_Errcode) {}
+
+    _System_error(error_code _Errcode, const string&) : runtime_error("system error"), _Mycode(_Errcode) {}
+#endif // ^^^ !_HAS_EXCEPTIONS ^^^
 
     error_code _Mycode; // the stored error code
 };

tests/std/test.lst

@@ -257,6 +257,7 @@ tests\GH_004930_char_traits_user_specialization
 tests\GH_005090_stl_hardening
 tests\GH_005204_regex_collating_ranges
 tests\GH_005244_regex_escape_sequences
+tests\GH_005276_system_error_heap_use_after_free
 tests\GH_005315_destructor_tombstones
 tests\LWG2381_num_get_floating_point
 tests\LWG2597_complex_branch_cut

tests/std/tests/GH_005276_system_error_heap_use_after_free/env.lst

@@ -0,0 +1,6 @@
+# Copyright (c) Microsoft Corporation.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+RUNALL_INCLUDE ..\usual_20_matrix.lst
+RUNALL_CROSSLIST
+*	PM_CL="/D_HAS_EXCEPTIONS=0"

tests/std/tests/GH_005276_system_error_heap_use_after_free/test.cpp

@@ -0,0 +1,49 @@
+// Copyright (c) Microsoft Corporation.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+#include <cassert>
+#include <chrono>
+#include <string>
+#include <string_view>
+#include <system_error>
+using namespace std;
+using namespace chrono;
+
+// GH-5276 <system_error>: heap-use-after-free for _HAS_EXCEPTIONS=0
+int main() {
+    const string str{"abc"};
+    const error_code ec{2, system_category()};
+    {
+        system_error syserr1{ec};
+        assert(syserr1.what() == "system error"sv);
+    }
+    {
+        system_error syserr2{ec, str};
+        assert(syserr2.what() == "system error"sv);
+    }
+    {
+        system_error syserr3{ec, "meow"};
+        assert(syserr3.what() == "system error"sv);
+    }
+    {
+        system_error syserr4{2, system_category()};
+        assert(syserr4.what() == "system error"sv);
+    }
+    {
+        system_error syserr5{2, system_category(), str};
+        assert(syserr5.what() == "system error"sv);
+    }
+    {
+        system_error syserr6{2, system_category(), "meow"};
+        assert(syserr6.what() == "system error"sv);
+    }
+
+    {
+        ambiguous_local_time alt{local_seconds{}, local_info{}};
+        assert(alt.what() == "ambiguous local time"sv);
+    }
+    {
+        nonexistent_local_time nlt{local_seconds{}, local_info{}};
+        assert(nlt.what() == "nonexistent local time"sv);
+    }
+}