Issue #15726: Fix incorrect bounds checking in PyState_FindModule.

Patch by Robin Schreiber.

1 files changed, 45 insertions, 4 deletions

diff --git a/Python/pystate.c b/Python/pystate.c
index 13923313c0..8dc570ab75 100644
--- a/Python/pystate.c
+++ b/Python/pystate.c
@@ -69,7 +69,6 @@ PyInterpreterState_New(void)
             Py_FatalError("Can't initialize threads for interpreter");
 #endif
         interp->modules = NULL;
-        interp->modules_reloading = NULL;
         interp->modules_by_index = NULL;
         interp->sysdict = NULL;
         interp->builtins = NULL;
@@ -79,6 +78,7 @@ PyInterpreterState_New(void)
         interp->codec_error_registry = NULL;
         interp->codecs_initialized = 0;
         interp->fscodec_initialized = 0;
+        interp->importlib = NULL;
 #ifdef HAVE_DLOPEN
 #ifdef RTLD_NOW
         interp->dlopenflags = RTLD_NOW;
@@ -113,9 +113,9 @@ PyInterpreterState_Clear(PyInterpreterState *interp)
     Py_CLEAR(interp->codec_error_registry);
     Py_CLEAR(interp->modules);
     Py_CLEAR(interp->modules_by_index);
-    Py_CLEAR(interp->modules_reloading);
     Py_CLEAR(interp->sysdict);
     Py_CLEAR(interp->builtins);
+    Py_CLEAR(interp->importlib);
 }
 
 
@@ -239,9 +239,9 @@ _PyThreadState_Init(PyThreadState *tstate)
 }
 
 PyObject*
-PyState_FindModule(struct PyModuleDef* m)
+PyState_FindModule(struct PyModuleDef* module)
 {
-    Py_ssize_t index = m->m_base.m_index;
+    Py_ssize_t index = module->m_base.m_index;
     PyInterpreterState *state = PyThreadState_GET()->interp;
     PyObject *res;
     if (index == 0)
@@ -273,6 +273,47 @@ _PyState_AddModule(PyObject* module, struct PyModuleDef* def)
                           def->m_base.m_index, module);
 }
 
+int
+PyState_AddModule(PyObject* module, struct PyModuleDef* def)
+{
+    Py_ssize_t index;
+    PyInterpreterState *state = PyThreadState_GET()->interp;
+    if (!def) {
+        Py_FatalError("PyState_AddModule: Module Definition is NULL");
+        return -1;
+    }
+    index = def->m_base.m_index;
+    if (state->modules_by_index) {
+        if(PyList_GET_SIZE(state->modules_by_index) >= index) {
+            if(module == PyList_GET_ITEM(state->modules_by_index, index)) {
+                Py_FatalError("PyState_AddModule: Module already added!");
+                return -1;
+            }
+        }
+    }
+    return _PyState_AddModule(module, def);
+}
+
+int
+PyState_RemoveModule(struct PyModuleDef* def)
+{
+    Py_ssize_t index = def->m_base.m_index;
+    PyInterpreterState *state = PyThreadState_GET()->interp;
+    if (index == 0) {
+        Py_FatalError("PyState_RemoveModule: Module index invalid.");
+        return -1;
+    }
+    if (state->modules_by_index == NULL) {
+        Py_FatalError("PyState_RemoveModule: Interpreters module-list not acessible.");
+        return -1;
+    }
+    if (index > PyList_GET_SIZE(state->modules_by_index)) {
+        Py_FatalError("PyState_RemoveModule: Module index out of bounds.");
+        return -1;
+    }
+    return PyList_SetItem(state->modules_by_index, index, Py_None);
+}
+
 void
 PyThreadState_Clear(PyThreadState *tstate)
 {