[Bug libstdc++/81891] [5/6/7/8 Regression] heap-use-after-free if inserting element in std::unordered_map(InputIt, InputIt) throws

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81891

--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> ---
I think this might be all we need to do to fix it:

--- a/libstdc++-v3/include/bits/hashtable.h
+++ b/libstdc++-v3/include/bits/hashtable.h
@@ -973,17 +973,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
            _M_bucket_count = __bkt_count;
          }

-       __try
-         {
-           for (; __f != __l; ++__f)
-             this->insert(*__f);
-         }
-       __catch(...)
-         {
-           clear();
-           _M_deallocate_buckets();
-           __throw_exception_again;
-         }
+       for (; __f != __l; ++__f)
+         this->insert(*__f);
       }

   template<typename _Key, typename _Value,