avoid overflow with large buffer sizes and/or offsets (closes #21831)
diff --git a/Misc/NEWS b/Misc/NEWS
index 3238d06..a077b4d 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -10,6 +10,9 @@
 Core and Builtins
 -----------------
 
+- Issue #21831: Avoid integer overflow when large sizes and offsets are given to
+  the buffer type.
+
 - Issue #1856: Avoid crashes and lockups when daemon threads run while the
   interpreter is shutting down; instead, these threads are now killed when they
   try to take the GIL.