gh-148850: Fix msan false positive in os.getrandom

petervanvugt · petervanvugt · commit 4a0bdb610f26 · 2026-04-23T11:20:40.000-07:00
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
@@ -17195,6 +17195,10 @@ os_getrandom_impl(PyObject *module, Py_ssize_t size, int flags)
         goto error;
     }
 
+#ifdef _Py_MEMORY_SANITIZER
+    __msan_unpoison(data, size);
+#endif
+
     return PyBytesWriter_FinishWithSize(writer, n);
 
 error:

Original file line number	Diff line number	Diff line change
`@@ -17195,6 +17195,10 @@ os_getrandom_impl(PyObject *module, Py_ssize_t size, int flags)`
`17195`	`17195`	`goto error;`
`17196`	`17196`	`}`
`17197`	`17197`
	`17198`	`+#ifdef _Py_MEMORY_SANITIZER`
	`17199`	`+ __msan_unpoison(data, size);`
	`17200`	`+#endif`
	`17201`	`+`
`17198`	`17202`	`return PyBytesWriter_FinishWithSize(writer, n);`
`17199`	`17203`
`17200`	`17204`	`error:`