gh-120378: Fix crash caused by integer overflow in `curses` (#124555)

This is actually an upstream problem in curses, and has been reported
to them already:
https://lists.gnu.org/archive/html/bug-ncurses/2024-09/msg00101.html

This is a nice workaround in the meantime to prevent the segfault.

Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>

Lib/test/test_curses.py

@@ -1081,6 +1081,14 @@ class TestCurses(unittest.TestCase):
         self.assertEqual(curses.LINES, lines)
         self.assertEqual(curses.COLS, cols)
 
+        with self.assertRaises(OverflowError):
+            curses.resize_term(35000, 1)
+        with self.assertRaises(OverflowError):
+            curses.resize_term(1, 35000)
+        # GH-120378: Overflow failure in resize_term() causes refresh to fail
+        tmp = curses.initscr()
+        tmp.erase()
+
     @requires_curses_func('resizeterm')
     def test_resizeterm(self):
         curses.update_lines_cols()
@@ -1095,6 +1103,14 @@ class TestCurses(unittest.TestCase):
         self.assertEqual(curses.LINES, lines)
         self.assertEqual(curses.COLS, cols)
 
+        with self.assertRaises(OverflowError):
+            curses.resizeterm(35000, 1)
+        with self.assertRaises(OverflowError):
+            curses.resizeterm(1, 35000)
+        # GH-120378: Overflow failure in resizeterm() causes refresh to fail
+        tmp = curses.initscr()
+        tmp.erase()
+
     def test_ungetch(self):
         curses.ungetch(b'A')
         self.assertEqual(self.stdscr.getkey(), 'A')

Misc/NEWS.d/next/Library/2024-09-25-18-07-51.gh-issue-120378.NlBSz_.rst

@@ -0,0 +1,2 @@
+Fix a crash related to an integer overflow in :func:`curses.resizeterm`
+and :func:`curses.resize_term`.

Modules/_cursesmodule.c

@@ -4204,9 +4204,9 @@ NoArgNoReturnFunctionBody(resetty)
 /*[clinic input]
 _curses.resizeterm
 
-    nlines: int
+    nlines: short
         Height.
-    ncols: int
+    ncols: short
         Width.
     /
 
@@ -4217,8 +4217,8 @@ window dimensions (in particular the SIGWINCH handler).
 [clinic start generated code]*/
 
 static PyObject *
-_curses_resizeterm_impl(PyObject *module, int nlines, int ncols)
+_curses_resizeterm_impl(PyObject *module, short nlines, short ncols)
-/*[clinic end generated code: output=56d6bcc5194ad055 input=0fca02ebad5ffa82]*/
+/*[clinic end generated code: output=4de3abab50c67f02 input=414e92a63e3e9899]*/
 {
     PyObject *result;
 
@@ -4240,9 +4240,9 @@ _curses_resizeterm_impl(PyObject *module, int nlines, int ncols)
 /*[clinic input]
 _curses.resize_term
 
-    nlines: int
+    nlines: short
         Height.
-    ncols: int
+    ncols: short
         Width.
     /
 
@@ -4256,8 +4256,8 @@ without additional interaction with the application.
 [clinic start generated code]*/
 
 static PyObject *
-_curses_resize_term_impl(PyObject *module, int nlines, int ncols)
+_curses_resize_term_impl(PyObject *module, short nlines, short ncols)
-/*[clinic end generated code: output=9e26d8b9ea311ed2 input=2197edd05b049ed4]*/
+/*[clinic end generated code: output=46c6d749fa291dbd input=276afa43d8ea7091]*/
 {
     PyObject *result;
 

Modules/clinic/_cursesmodule.c.h

@@ -3693,25 +3693,55 @@ PyDoc_STRVAR(_curses_resizeterm__doc__,
     {"resizeterm", _PyCFunction_CAST(_curses_resizeterm), METH_FASTCALL, _curses_resizeterm__doc__},
 
 static PyObject *
-_curses_resizeterm_impl(PyObject *module, int nlines, int ncols);
+_curses_resizeterm_impl(PyObject *module, short nlines, short ncols);
 
 static PyObject *
 _curses_resizeterm(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
 {
     PyObject *return_value = NULL;
-    int nlines;
+    short nlines;
-    int ncols;
+    short ncols;
 
     if (!_PyArg_CheckPositional("resizeterm", nargs, 2, 2)) {
         goto exit;
     }
-    nlines = PyLong_AsInt(args[0]);
+    {
-    if (nlines == -1 && PyErr_Occurred()) {
+        long ival = PyLong_AsLong(args[0]);
-        goto exit;
+        if (ival == -1 && PyErr_Occurred()) {
+            goto exit;
+        }
+        else if (ival < SHRT_MIN) {
+            PyErr_SetString(PyExc_OverflowError,
+                            "signed short integer is less than minimum");
+            goto exit;
+        }
+        else if (ival > SHRT_MAX) {
+            PyErr_SetString(PyExc_OverflowError,
+                            "signed short integer is greater than maximum");
+            goto exit;
+        }
+        else {
+            nlines = (short) ival;
+        }
     }
-    ncols = PyLong_AsInt(args[1]);
+    {
-    if (ncols == -1 && PyErr_Occurred()) {
+        long ival = PyLong_AsLong(args[1]);
-        goto exit;
+        if (ival == -1 && PyErr_Occurred()) {
+            goto exit;
+        }
+        else if (ival < SHRT_MIN) {
+            PyErr_SetString(PyExc_OverflowError,
+                            "signed short integer is less than minimum");
+            goto exit;
+        }
+        else if (ival > SHRT_MAX) {
+            PyErr_SetString(PyExc_OverflowError,
+                            "signed short integer is greater than maximum");
+            goto exit;
+        }
+        else {
+            ncols = (short) ival;
+        }
     }
     return_value = _curses_resizeterm_impl(module, nlines, ncols);
 
@@ -3744,25 +3774,55 @@ PyDoc_STRVAR(_curses_resize_term__doc__,
     {"resize_term", _PyCFunction_CAST(_curses_resize_term), METH_FASTCALL, _curses_resize_term__doc__},
 
 static PyObject *
-_curses_resize_term_impl(PyObject *module, int nlines, int ncols);
+_curses_resize_term_impl(PyObject *module, short nlines, short ncols);
 
 static PyObject *
 _curses_resize_term(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
 {
     PyObject *return_value = NULL;
-    int nlines;
+    short nlines;
-    int ncols;
+    short ncols;
 
     if (!_PyArg_CheckPositional("resize_term", nargs, 2, 2)) {
         goto exit;
     }
-    nlines = PyLong_AsInt(args[0]);
+    {
-    if (nlines == -1 && PyErr_Occurred()) {
+        long ival = PyLong_AsLong(args[0]);
-        goto exit;
+        if (ival == -1 && PyErr_Occurred()) {
+            goto exit;
+        }
+        else if (ival < SHRT_MIN) {
+            PyErr_SetString(PyExc_OverflowError,
+                            "signed short integer is less than minimum");
+            goto exit;
+        }
+        else if (ival > SHRT_MAX) {
+            PyErr_SetString(PyExc_OverflowError,
+                            "signed short integer is greater than maximum");
+            goto exit;
+        }
+        else {
+            nlines = (short) ival;
+        }
     }
-    ncols = PyLong_AsInt(args[1]);
+    {
-    if (ncols == -1 && PyErr_Occurred()) {
+        long ival = PyLong_AsLong(args[1]);
-        goto exit;
+        if (ival == -1 && PyErr_Occurred()) {
+            goto exit;
+        }
+        else if (ival < SHRT_MIN) {
+            PyErr_SetString(PyExc_OverflowError,
+                            "signed short integer is less than minimum");
+            goto exit;
+        }
+        else if (ival > SHRT_MAX) {
+            PyErr_SetString(PyExc_OverflowError,
+                            "signed short integer is greater than maximum");
+            goto exit;
+        }
+        else {
+            ncols = (short) ival;
+        }
     }
     return_value = _curses_resize_term_impl(module, nlines, ncols);
 
@@ -4318,4 +4378,4 @@ _curses_has_extended_color_support(PyObject *module, PyObject *Py_UNUSED(ignored
 #ifndef _CURSES_USE_DEFAULT_COLORS_METHODDEF
     #define _CURSES_USE_DEFAULT_COLORS_METHODDEF
 #endif /* !defined(_CURSES_USE_DEFAULT_COLORS_METHODDEF) */
-/*[clinic end generated code: output=96887782374f070a input=a9049054013a1b77]*/
+/*[clinic end generated code: output=8745c1562b537fb4 input=a9049054013a1b77]*/