gh-114492: Initialize struct termios before calling tcgetattr() (GH-114495)

serhiy-storchaka · web-flow · commit d22c066b8025 · 2024-01-23T23:27:04.000+02:00
On Alpine Linux it could leave some field non-initialized.
diff --git a/Misc/NEWS.d/next/Library/2024-01-23-21-20-40.gh-issue-114492.vKxl5o.rst b/Misc/NEWS.d/next/Library/2024-01-23-21-20-40.gh-issue-114492.vKxl5o.rst
@@ -0,0 +1,2 @@
+Make the result of :func:`termios.tcgetattr` reproducible on Alpine Linux.
+Previously it could leave a random garbage in some fields.
diff --git a/Modules/termios.c b/Modules/termios.c
@@ -98,6 +98,8 @@ termios_tcgetattr_impl(PyObject *module, int fd)
     struct termios mode;
     int r;
 
+    /* Alpine Linux can leave some fields uninitialized. */
+    memset(&mode, 0, sizeof(mode));
     Py_BEGIN_ALLOW_THREADS
     r = tcgetattr(fd, &mode);
     Py_END_ALLOW_THREADS

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,2 @@`
	`1`	+Make the result of :func:`termios.tcgetattr` reproducible on Alpine Linux.
	`2`	`+Previously it could leave a random garbage in some fields.`