Issue #17119: Fixed integer overflows when processing large strings and tuples
in the tkinter module.
diff --git a/Modules/_tkinter.c b/Modules/_tkinter.c
index cdb28e5..6ca8625 100644
--- a/Modules/_tkinter.c
+++ b/Modules/_tkinter.c
@@ -47,6 +47,9 @@
#define PyBool_FromLong PyLong_FromLong
#endif
+#define CHECK_SIZE(size, elemsize) \
+ ((size_t)(size) <= Py_MAX((size_t)INT_MAX, UINT_MAX / (size_t)(elemsize)))
+
/* Starting with Tcl 8.4, many APIs offer const-correctness. Unfortunately,
making _tkinter correct for this API means to break earlier
versions. USE_COMPAT_CONST allows to make _tkinter work with both 8.4 and
@@ -364,7 +367,7 @@
char **argv = NULL;
int fvStore[ARGSZ];
int *fv = NULL;
- int argc = 0, fvc = 0, i;
+ Py_ssize_t argc = 0, fvc = 0, i;
char *res = NULL;
if (!(tmp = PyList_New(0)))
@@ -386,8 +389,12 @@
argc = PyTuple_Size(args);
if (argc > ARGSZ) {
- argv = (char **)ckalloc(argc * sizeof(char *));
- fv = (int *)ckalloc(argc * sizeof(int));
+ if (!CHECK_SIZE(argc, sizeof(char *))) {
+ PyErr_SetString(PyExc_OverflowError, "tuple is too long");
+ goto finally;
+ }
+ argv = (char **)ckalloc((size_t)argc * sizeof(char *));
+ fv = (int *)ckalloc((size_t)argc * sizeof(int));
if (argv == NULL || fv == NULL) {
PyErr_NoMemory();
goto finally;
@@ -966,12 +973,18 @@
else if (PyFloat_Check(value))
return Tcl_NewDoubleObj(PyFloat_AS_DOUBLE(value));
else if (PyTuple_Check(value)) {
- Tcl_Obj **argv = (Tcl_Obj**)
- ckalloc(PyTuple_Size(value)*sizeof(Tcl_Obj*));
- int i;
+ Tcl_Obj **argv;
+ Py_ssize_t size, i;
+
+ size = PyTuple_Size(value);
+ if (!CHECK_SIZE(size, sizeof(Tcl_Obj *))) {
+ PyErr_SetString(PyExc_OverflowError, "tuple is too long");
+ return NULL;
+ }
+ argv = (Tcl_Obj **) ckalloc(((size_t)size) * sizeof(Tcl_Obj *));
if(!argv)
return 0;
- for(i=0;i<PyTuple_Size(value);i++)
+ for (i = 0; i < size; i++)
argv[i] = AsObj(PyTuple_GetItem(value,i));
result = Tcl_NewListObj(PyTuple_Size(value), argv);
ckfree(FREECAST argv);
@@ -990,6 +1003,10 @@
inbuf = PyUnicode_DATA(value);
size = PyUnicode_GET_LENGTH(value);
+ if (!CHECK_SIZE(size, sizeof(Tcl_UniChar))) {
+ PyErr_SetString(PyExc_OverflowError, "string is too long");
+ return NULL;
+ }
kind = PyUnicode_KIND(value);
allocsize = ((size_t)size) * sizeof(Tcl_UniChar);
outbuf = (Tcl_UniChar*)ckalloc(allocsize);
@@ -1145,7 +1162,7 @@
Tkapp_CallArgs(PyObject *args, Tcl_Obj** objStore, int *pobjc)
{
Tcl_Obj **objv = objStore;
- int objc = 0, i;
+ Py_ssize_t objc = 0, i;
if (args == NULL)
/* do nothing */;
@@ -1160,7 +1177,11 @@
objc = PyTuple_Size(args);
if (objc > ARGSZ) {
- objv = (Tcl_Obj **)ckalloc(objc * sizeof(char *));
+ if (!CHECK_SIZE(objc, sizeof(Tcl_Obj *))) {
+ PyErr_SetString(PyExc_OverflowError, "tuple is too long");
+ return NULL;
+ }
+ objv = (Tcl_Obj **)ckalloc(((size_t)objc) * sizeof(Tcl_Obj *));
if (objv == NULL) {
PyErr_NoMemory();
objc = 0;