Fix #9324: Add parameter validation to signal.signal on Windows in order
to prevent crashes.
diff --git a/Modules/signalmodule.c b/Modules/signalmodule.c
index f4fd964..b5846fa 100644
--- a/Modules/signalmodule.c
+++ b/Modules/signalmodule.c
@@ -255,8 +255,23 @@
     int sig_num;
     PyObject *old_handler;
     void (*func)(int);
+#ifdef MS_WINDOWS
+    int cur_sig, num_valid_sigs = 6;
+    static int valid_sigs[] = {SIGABRT, SIGFPE, SIGILL, SIGINT,
+                               SIGSEGV, SIGTERM};
+    BOOL valid_sig = FALSE;
+#endif
     if (!PyArg_ParseTuple(args, "iO:signal", &sig_num, &obj))
         return NULL;
+#ifdef MS_WINDOWS
+    /* Validate that sig_num is one of the allowable signals */
+    for (cur_sig = 0; cur_sig < num_valid_sigs; cur_sig++)
+        valid_sig |= (sig_num == valid_sigs[cur_sig]);
+    if (!valid_sig) {
+        PyErr_SetString(PyExc_ValueError, "signal number out of range");
+        return NULL;
+    }
+#endif
 #ifdef WITH_THREAD
     if (PyThread_get_thread_ident() != main_thread) {
         PyErr_SetString(PyExc_ValueError,