[Python-checkins] gh-95876: Fix format string in pegen error location code (GH-95877)

[miss-islington]

https://github.com/python/cpython/commit/1221e8c400933f24be69bd156f03cd1411746e6c
commit: 1221e8c400933f24be69bd156f03cd1411746e6c
branch: 3.11
author: Miss Islington (bot) <31488909+miss-islington at users.noreply.github.com>
committer: miss-islington <31488909+miss-islington at users.noreply.github.com>
date: 2022-08-11T02:19:20-07:00
summary:

gh-95876: Fix format string in pegen error location code (GH-95877)

(cherry picked from commit b4c857d0fd74abb1ede6fe083c4fa3ca728b2b83)

Co-authored-by: Christian Heimes <christian at python.org>

files:
A Misc/NEWS.d/next/Core and Builtins/2022-08-11-09-19-55.gh-issue-95876.YpQfoV.rst
M Parser/pegen_errors.c

diff --git a/Misc/NEWS.d/next/Core and Builtins/2022-08-11-09-19-55.gh-issue-95876.YpQfoV.rst b/Misc/NEWS.d/next/Core and Builtins/2022-08-11-09-19-55.gh-issue-95876.YpQfoV.rst
new file mode 100644
index 000000000000..96b69015a586
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2022-08-11-09-19-55.gh-issue-95876.YpQfoV.rst	
@@ -0,0 +1,4 @@
+Fix format string in ``_PyPegen_raise_error_known_location`` that can lead
+to memory corruption on some 64bit systems. The function was building a
+tuple with ``i`` (int) instead of ``n`` (Py_ssize_t) for Py_ssize_t
+arguments.
diff --git a/Parser/pegen_errors.c b/Parser/pegen_errors.c
index 5703088443ed..a0f4b9809e21 100644
--- a/Parser/pegen_errors.c
+++ b/Parser/pegen_errors.c
@@ -371,7 +371,7 @@ _PyPegen_raise_error_known_location(Parser *p, PyObject *errtype,
             }
         }
     }
-    tmp = Py_BuildValue("(OiiNii)", p->tok->filename, lineno, col_number, error_line, end_lineno, end_col_number);
+    tmp = Py_BuildValue("(OnnNnn)", p->tok->filename, lineno, col_number, error_line, end_lineno, end_col_number);
     if (!tmp) {
         goto error;
     }