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Fix bug in marshal where bad data would cause a segfault due to 

lack of an infinite recursion check.

Contributed by Damien Miller at Google.
This commit is contained in:
Neal Norwitz 2007-05-16 20:09:36 +00:00
parent 4043a6bbd6
commit dc78cc6f7c
4 changed files with 164 additions and 69 deletions
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4
Lib/test/test_marshal.py
View File

@ -220,6 +220,10 @@ class BugsTestCase(unittest.TestCase):
except Exception:
pass
def test_recursion(self):
s = 'c' + ('X' * 4*4) + '{' * 2**20
self.assertRaises(ValueError, marshal.loads, s)
def test_main():
test_support.run_unittest(IntTestCase,
FloatTestCase,

1
Misc/ACKS
View File

@ -413,6 +413,7 @@ Dieter Maurer
Greg McFarlane
Michael McLay
Gordon McMillan
Damien Miller
Jay T. Miller
Chris McDonough
Andrew McNamara

3
Misc/NEWS
View File

@ -12,6 +12,9 @@ What's New in Python 2.5.2c1?
Library
-------
- Fix bug in marshal where bad data would cause a segfault due to
lack of an infinite recursion check.
- HTML-escape the plain traceback in cgitb's HTML output, to prevent
the traceback inadvertently or maliciously closing the comment and
injecting HTML into the error page.

225
Python/marshal.c
View File

@ -246,9 +246,16 @@ w_object(PyObject *v, WFILE *p)
goto exit;
}
else {
int ok;
o = PyInt_FromSsize_t(PyDict_Size(p->strings));
PyDict_SetItem(p->strings, v, o);
Py_DECREF(o);
ok = o &&
PyDict_SetItem(p->strings, v, o) >= 0;
Py_XDECREF(o);
if (!ok) {
p->depth--;
p->error = 1;
return;
}
w_byte(TYPE_INTERNED, p);
}
}
@ -413,7 +420,7 @@ PyMarshal_WriteObjectToFile(PyObject *x, FILE *fp, int version)
typedef WFILE RFILE; /* Same struct with different invariants */
#define rs_byte(p) (((p)->ptr != (p)->end) ? (unsigned char)*(p)->ptr++ : EOF)
#define rs_byte(p) (((p)->ptr < (p)->end) ? (unsigned char)*(p)->ptr++ : EOF)
#define r_byte(p) ((p)->fp ? getc((p)->fp) : rs_byte(p))
@ -504,42 +511,60 @@ r_object(RFILE *p)
PyObject *v, *v2, *v3;
long i, n;
int type = r_byte(p);
PyObject *retval;
p->depth++;
if (p->depth > MAX_MARSHAL_STACK_DEPTH) {
p->depth--;
PyErr_SetString(PyExc_ValueError, "recursion limit exceeded");
return NULL;
}
switch (type) {
case EOF:
PyErr_SetString(PyExc_EOFError,
"EOF read where object expected");
return NULL;
retval = NULL;
break;
case TYPE_NULL:
return NULL;
retval = NULL;
break;
case TYPE_NONE:
Py_INCREF(Py_None);
return Py_None;
retval = Py_None;
break;
case TYPE_STOPITER:
Py_INCREF(PyExc_StopIteration);
return PyExc_StopIteration;
retval = PyExc_StopIteration;
break;
case TYPE_ELLIPSIS:
Py_INCREF(Py_Ellipsis);
return Py_Ellipsis;
retval = Py_Ellipsis;
break;
case TYPE_FALSE:
Py_INCREF(Py_False);
return Py_False;
retval = Py_False;
break;
case TYPE_TRUE:
Py_INCREF(Py_True);
return Py_True;
retval = Py_True;
break;
case TYPE_INT:
return PyInt_FromLong(r_long(p));
retval = PyInt_FromLong(r_long(p));
break;
case TYPE_INT64:
return r_long64(p);
retval = r_long64(p);
break;
case TYPE_LONG:
{
@ -549,12 +574,15 @@ r_object(RFILE *p)
if (n < -INT_MAX || n > INT_MAX) {
PyErr_SetString(PyExc_ValueError,
"bad marshal data");
return NULL;
retval = NULL;
break;
}
size = n<0 ? -n : n;
ob = _PyLong_New(size);
if (ob == NULL)
return NULL;
if (ob == NULL) {
retval = NULL;
break;
}
ob->ob_size = n;
for (i = 0; i < size; i++) {
int digit = r_short(p);
@ -562,11 +590,14 @@ r_object(RFILE *p)
Py_DECREF(ob);
PyErr_SetString(PyExc_ValueError,
"bad marshal data");
return NULL;
ob = NULL;
break;
}
ob->ob_digit[i] = digit;
if (ob != NULL)
ob->ob_digit[i] = digit;
}
return (PyObject *)ob;
retval = (PyObject *)ob;
break;
}
case TYPE_FLOAT:
@ -577,13 +608,16 @@ r_object(RFILE *p)
if (n == EOF || r_string(buf, (int)n, p) != n) {
PyErr_SetString(PyExc_EOFError,
"EOF read where object expected");
return NULL;
retval = NULL;
break;
}
buf[n] = '\0';
PyFPE_START_PROTECT("atof", return 0)
retval = NULL;
PyFPE_START_PROTECT("atof", break)
dx = PyOS_ascii_atof(buf);
PyFPE_END_PROTECT(dx)
return PyFloat_FromDouble(dx);
retval = PyFloat_FromDouble(dx);
break;
}
case TYPE_BINARY_FLOAT:
@ -593,13 +627,16 @@ r_object(RFILE *p)
if (r_string((char*)buf, 8, p) != 8) {
PyErr_SetString(PyExc_EOFError,
"EOF read where object expected");
return NULL;
retval = NULL;
break;
}
x = _PyFloat_Unpack8(buf, 1);
if (x == -1.0 && PyErr_Occurred()) {
return NULL;
retval = NULL;
break;
}
return PyFloat_FromDouble(x);
retval = PyFloat_FromDouble(x);
break;
}
#ifndef WITHOUT_COMPLEX
@ -611,23 +648,27 @@ r_object(RFILE *p)
if (n == EOF || r_string(buf, (int)n, p) != n) {
PyErr_SetString(PyExc_EOFError,
"EOF read where object expected");
return NULL;
retval = NULL;
break;
}
buf[n] = '\0';
PyFPE_START_PROTECT("atof", return 0)
retval = NULL;
PyFPE_START_PROTECT("atof", break;)
c.real = PyOS_ascii_atof(buf);
PyFPE_END_PROTECT(c)
n = r_byte(p);
if (n == EOF || r_string(buf, (int)n, p) != n) {
PyErr_SetString(PyExc_EOFError,
"EOF read where object expected");
return NULL;
retval = NULL;
break;
}
buf[n] = '\0';
PyFPE_START_PROTECT("atof", return 0)
PyFPE_START_PROTECT("atof", break)
c.imag = PyOS_ascii_atof(buf);
PyFPE_END_PROTECT(c)
return PyComplex_FromCComplex(c);
retval = PyComplex_FromCComplex(c);
break;
}
case TYPE_BINARY_COMPLEX:
@ -637,22 +678,27 @@ r_object(RFILE *p)
if (r_string((char*)buf, 8, p) != 8) {
PyErr_SetString(PyExc_EOFError,
"EOF read where object expected");
return NULL;
retval = NULL;
break;
}
c.real = _PyFloat_Unpack8(buf, 1);
if (c.real == -1.0 && PyErr_Occurred()) {
return NULL;
retval = NULL;
break;
}
if (r_string((char*)buf, 8, p) != 8) {
PyErr_SetString(PyExc_EOFError,
"EOF read where object expected");
return NULL;
retval = NULL;
break;
}
c.imag = _PyFloat_Unpack8(buf, 1);
if (c.imag == -1.0 && PyErr_Occurred()) {
return NULL;
retval = NULL;
break;
}
return PyComplex_FromCComplex(c);
retval = PyComplex_FromCComplex(c);
break;
}
#endif
@ -661,32 +707,42 @@ r_object(RFILE *p)
n = r_long(p);
if (n < 0 || n > INT_MAX) {
PyErr_SetString(PyExc_ValueError, "bad marshal data");
return NULL;
retval = NULL;
break;
}
v = PyString_FromStringAndSize((char *)NULL, n);
if (v == NULL)
return v;
if (v == NULL) {
retval = NULL;
break;
}
if (r_string(PyString_AS_STRING(v), (int)n, p) != n) {
Py_DECREF(v);
PyErr_SetString(PyExc_EOFError,
"EOF read where object expected");
return NULL;
retval = NULL;
break;
}
if (type == TYPE_INTERNED) {
PyString_InternInPlace(&v);
PyList_Append(p->strings, v);
if (PyList_Append(p->strings, v) < 0) {
retval = NULL;
break;
}
}
return v;
retval = v;
break;
case TYPE_STRINGREF:
n = r_long(p);
if (n < 0 || n >= PyList_GET_SIZE(p->strings)) {
PyErr_SetString(PyExc_ValueError, "bad marshal data");
return NULL;
retval = NULL;
break;
}
v = PyList_GET_ITEM(p->strings, n);
Py_INCREF(v);
return v;
retval = v;
break;
#ifdef Py_USING_UNICODE
case TYPE_UNICODE:
@ -696,20 +752,25 @@ r_object(RFILE *p)
n = r_long(p);
if (n < 0 || n > INT_MAX) {
PyErr_SetString(PyExc_ValueError, "bad marshal data");
return NULL;
retval = NULL;
break;
}
buffer = PyMem_NEW(char, n);
if (buffer == NULL)
return PyErr_NoMemory();
if (buffer == NULL) {
retval = PyErr_NoMemory();
break;
}
if (r_string(buffer, (int)n, p) != n) {
PyMem_DEL(buffer);
PyErr_SetString(PyExc_EOFError,
"EOF read where object expected");
return NULL;
retval = NULL;
break;
}
v = PyUnicode_DecodeUTF8(buffer, n, NULL);
PyMem_DEL(buffer);
return v;
retval = v;
break;
}
#endif
@ -717,11 +778,14 @@ r_object(RFILE *p)
n = r_long(p);
if (n < 0 || n > INT_MAX) {
PyErr_SetString(PyExc_ValueError, "bad marshal data");
return NULL;
retval = NULL;
break;
}
v = PyTuple_New((int)n);
if (v == NULL)
return v;
if (v == NULL) {
retval = NULL;
break;
}
for (i = 0; i < n; i++) {
v2 = r_object(p);
if ( v2 == NULL ) {
@ -734,17 +798,21 @@ r_object(RFILE *p)
}
PyTuple_SET_ITEM(v, (int)i, v2);
}
return v;
retval = v;
break;
case TYPE_LIST:
n = r_long(p);
if (n < 0 || n > INT_MAX) {
PyErr_SetString(PyExc_ValueError, "bad marshal data");
return NULL;
retval = NULL;
break;
}
v = PyList_New((int)n);
if (v == NULL)
return v;
if (v == NULL) {
retval = NULL;
break;
}
for (i = 0; i < n; i++) {
v2 = r_object(p);
if ( v2 == NULL ) {
@ -755,14 +823,17 @@ r_object(RFILE *p)
v = NULL;
break;
}
PyList_SetItem(v, (int)i, v2);
PyList_SET_ITEM(v, (int)i, v2);
}
return v;
retval = v;
break;
case TYPE_DICT:
v = PyDict_New();
if (v == NULL)
return NULL;
if (v == NULL) {
retval = NULL;
break;
}
for (;;) {
PyObject *key, *val;
key = r_object(p);
@ -778,18 +849,22 @@ r_object(RFILE *p)
Py_DECREF(v);
v = NULL;
}
return v;
retval = v;
break;
case TYPE_SET:
case TYPE_FROZENSET:
n = r_long(p);
if (n < 0) {
if (n < 0 || n > INT_MAX) {
PyErr_SetString(PyExc_ValueError, "bad marshal data");
return NULL;
retval = NULL;
break;
}
v = PyTuple_New((int)n);
if (v == NULL)
return v;
if (v == NULL) {
retval = NULL;
break;
}
for (i = 0; i < n; i++) {
v2 = r_object(p);
if ( v2 == NULL ) {
@ -802,21 +877,25 @@ r_object(RFILE *p)
}
PyTuple_SET_ITEM(v, (int)i, v2);
}
if (v == NULL)
return v;
if (v == NULL) {
retval = NULL;
break;
}
if (type == TYPE_SET)
v3 = PySet_New(v);
else
v3 = PyFrozenSet_New(v);
Py_DECREF(v);
return v3;
retval = v3;
break;
case TYPE_CODE:
if (PyEval_GetRestricted()) {
PyErr_SetString(PyExc_RuntimeError,
"cannot unmarshal code objects in "
"restricted execution mode");
return NULL;
retval = NULL;
break;
}
else {
int argcount;
@ -888,15 +967,19 @@ r_object(RFILE *p)
Py_XDECREF(lnotab);
}
return v;
retval = v;
break;
default:
/* Bogus data got written, which isn't ideal.
This will let you keep working and recover. */
PyErr_SetString(PyExc_ValueError, "bad marshal data");
return NULL;
retval = NULL;
break;
}
p->depth--;
return retval;
}
static PyObject *
@ -1002,6 +1085,7 @@ PyMarshal_ReadObjectFromFile(FILE *fp)
PyObject *result;
rf.fp = fp;
rf.strings = PyList_New(0);
rf.depth = 0;
result = r_object(&rf);
Py_DECREF(rf.strings);
return result;
@ -1016,6 +1100,7 @@ PyMarshal_ReadObjectFromString(char *str, Py_ssize_t len)
rf.ptr = str;
rf.end = str + len;
rf.strings = PyList_New(0);
rf.depth = 0;
result = r_object(&rf);
Py_DECREF(rf.strings);
return result;
@ -1104,6 +1189,7 @@ marshal_load(PyObject *self, PyObject *f)
}
rf.fp = PyFile_AsFile(f);
rf.strings = PyList_New(0);
rf.depth = 0;
result = read_object(&rf);
Py_DECREF(rf.strings);
return result;
@ -1132,6 +1218,7 @@ marshal_loads(PyObject *self, PyObject *args)
rf.ptr = s;
rf.end = s + n;
rf.strings = PyList_New(0);
rf.depth = 0;
result = read_object(&rf);
Py_DECREF(rf.strings);
return result;