Security patches from Apple: prevent int overflow when allocating memory

Lib/test/seq_tests.py

@@ -307,6 +307,8 @@ class CommonTest(unittest.TestCase):
             self.assertEqual(id(s), id(s*1))
 
     def test_bigrepeat(self):
+        import sys
+        if sys.maxint <= 2147483647:
             x = self.type2test([0])
             x *= 2**16
             self.assertRaises(MemoryError, x.__mul__, 2**16)

Lib/test/test_bigmem.py

 from test import test_support
-from test.test_support import bigmemtest, _1G, _2G
+from test.test_support import bigmemtest, _1G, _2G, _4G, precisionbigmemtest
 
 import unittest
 import operator
@@ -54,6 +54,22 @@ class StrTest(unittest.TestCase):
         self.assertEquals(s[lpadsize:-rpadsize], SUBSTR)
         self.assertEquals(s.strip(), SUBSTR.strip())
 
+    @precisionbigmemtest(size=_2G - 1, memuse=1)
+    def test_center_unicode(self, size):
+        SUBSTR = u' abc def ghi'
+        try:
+            s = SUBSTR.center(size)
+        except OverflowError:
+            pass # acceptable on 32-bit
+        else:
+            self.assertEquals(len(s), size)
+            lpadsize = rpadsize = (len(s) - len(SUBSTR)) // 2
+            if len(s) % 2:
+                lpadsize += 1
+            self.assertEquals(s[lpadsize:-rpadsize], SUBSTR)
+            self.assertEquals(s.strip(), SUBSTR.strip())
+            del s
+
     @bigmemtest(minsize=_2G, memuse=2)
     def test_count(self, size):
         SUBSTR = ' abc def ghi'
@@ -70,10 +86,44 @@ class StrTest(unittest.TestCase):
         s = '.' * size
         self.assertEquals(len(s.decode('utf-8')), size)
 
+    def basic_encode_test(self, size, enc, c=u'.', expectedsize=None):
+        if expectedsize is None:
+            expectedsize = size
+
+        s = c * size
+        self.assertEquals(len(s.encode(enc)), expectedsize)
+
     @bigmemtest(minsize=_2G + 2, memuse=3)
     def test_encode(self, size):
-        s = u'.' * size
-        self.assertEquals(len(s.encode('utf-8')), size)
+        return self.basic_encode_test(size, 'utf-8')
+
+    @precisionbigmemtest(size=_4G / 6 + 2, memuse=2)
+    def test_encode_raw_unicode_escape(self, size):
+        try:
+            return self.basic_encode_test(size, 'raw_unicode_escape')
+        except MemoryError:
+            pass # acceptable on 32-bit
+
+    @precisionbigmemtest(size=_4G / 5 + 70, memuse=3)
+    def test_encode_utf7(self, size):
+        try:
+            return self.basic_encode_test(size, 'utf7')
+        except MemoryError:
+            pass # acceptable on 32-bit
+
+    @precisionbigmemtest(size=_2G-1, memuse=2)
+    def test_decodeascii(self, size):
+        return self.basic_encode_test(size, 'ascii', c='A')
+
+    @precisionbigmemtest(size=_4G / 5, memuse=6+2)
+    def test_unicode_repr_oflw(self, size):
+        try:
+            s = u"\uAAAA"*size
+            r = repr(s)
+        except MemoryError:
+            pass # acceptable on 32-bit
+        else:
+            self.failUnless(s == eval(r))
 
     @bigmemtest(minsize=_2G, memuse=2)
     def test_endswith(self, size):
@@ -459,6 +509,11 @@ class StrTest(unittest.TestCase):
         self.assertEquals(s.count('\\'), size)
         self.assertEquals(s.count('0'), size * 2)
 
+    @bigmemtest(minsize=2**32 / 5, memuse=6+2)
+    def test_unicode_repr(self, size):
+        s = u"\uAAAA" * size
+        self.failUnless(len(repr(s)) > size)
+
     # This test is meaningful even with size < 2G, as long as the
     # doubled string is > 2G (but it tests more if both are > 2G :)
     @bigmemtest(minsize=_1G + 2, memuse=3)
@@ -642,6 +697,35 @@ class TupleTest(unittest.TestCase):
     def test_repeat_large(self, size):
         return self.basic_test_repeat(size)
 
+    @bigmemtest(minsize=_1G - 1, memuse=12)
+    def test_repeat_large_2(self, size):
+        return self.basic_test_repeat(size)
+
+    @precisionbigmemtest(size=_1G - 1, memuse=9)
+    def test_from_2G_generator(self, size):
+        try:
+            t = tuple(xrange(size))
+        except MemoryError:
+            pass # acceptable on 32-bit
+        else:
+            count = 0
+            for item in t:
+                self.assertEquals(item, count)
+                count += 1
+            self.assertEquals(count, size)
+
+    @precisionbigmemtest(size=_1G - 25, memuse=9)
+    def test_from_almost_2G_generator(self, size):
+        try:
+            t = tuple(xrange(size))
+            count = 0
+            for item in t:
+                self.assertEquals(item, count)
+                count += 1
+            self.assertEquals(count, size)
+        except MemoryError:
+            pass # acceptable, expected on 32-bit
+
     # Like test_concat, split in two.
     def basic_test_repr(self, size):
         t = (0,) * size
@@ -957,8 +1041,23 @@ class ListTest(unittest.TestCase):
         self.assertEquals(l[:10], [1] * 10)
         self.assertEquals(l[-10:], [5] * 10)
 
+class BufferTest(unittest.TestCase):
+
+    @precisionbigmemtest(size=_1G, memuse=4)
+    def test_repeat(self, size):
+        try:
+            b = buffer("AAAA")*size
+        except MemoryError:
+            pass # acceptable on 32-bit
+        else:
+            count = 0
+            for c in b:
+                self.assertEquals(c, 'A')
+                count += 1
+            self.assertEquals(count, size*4)
+
 def test_main():
-    test_support.run_unittest(StrTest, TupleTest, ListTest)
+    test_support.run_unittest(StrTest, TupleTest, ListTest, BufferTest)
 
 if __name__ == '__main__':
     if len(sys.argv) > 1:

Lib/test/test_strop.py

@@ -115,6 +115,25 @@ class StropFunctionTestCase(unittest.TestCase):
         strop.uppercase
         strop.whitespace
 
+    @test_support.precisionbigmemtest(size=test_support._2G - 1, memuse=5)
+    def test_stropjoin_huge_list(self, size):
+        a = "A" * size
+        try:
+            r = strop.join([a, a], a)
+        except OverflowError:
+            pass
+        else:
+            self.assertEquals(len(r), len(a) * 3)
+
+    @test_support.precisionbigmemtest(size=test_support._2G - 1, memuse=1)
+    def test_stropjoin_huge_tup(self, size):
+        a = "A" * size
+        try:
+            r = strop.join((a, a), a)
+        except OverflowError:
+            pass # acceptable on 32-bit
+        else:
+            self.assertEquals(len(r), len(a) * 3)
 
 transtable = '\000\001\002\003\004\005\006\007\010\011\012\013\014\015\016\017\020\021\022\023\024\025\026\027\030\031\032\033\034\035\036\037 !"#$%&\'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`xyzdefghijklmnopqrstuvwxyz{|}~\177\200\201\202\203\204\205\206\207\210\211\212\213\214\215\216\217\220\221\222\223\224\225\226\227\230\231\232\233\234\235\236\237\240\241\242\243\244\245\246\247\250\251\252\253\254\255\256\257\260\261\262\263\264\265\266\267\270\271\272\273\274\275\276\277\300\301\302\303\304\305\306\307\310\311\312\313\314\315\316\317\320\321\322\323\324\325\326\327\330\331\332\333\334\335\336\337\340\341\342\343\344\345\346\347\350\351\352\353\354\355\356\357\360\361\362\363\364\365\366\367\370\371\372\373\374\375\376\377'
 

Lib/test/test_support.py

@@ -33,6 +33,7 @@ verbose = 1              # Flag set to 0 by regrtest.py
 use_resources = None     # Flag set to [] by regrtest.py
 max_memuse = 0           # Disable bigmem tests (they will still be run with
                          # small sizes, to make sure they work.)
+real_max_memuse = 0
 
 # _original_stdout is meant to hold stdout at the time regrtest began.
 # This may be "the real" stdout, or IDLE's emulation of stdout, or whatever.
@@ -323,6 +324,7 @@ def run_with_locale(catstr, *locales):
 _1M = 1024*1024
 _1G = 1024 * _1M
 _2G = 2 * _1G
+_4G = 4 * _1G
 
 # Hack to get at the maximum value an internal index can take.
 class _Dummy:
@@ -333,6 +335,7 @@ MAX_Py_ssize_t = _Dummy()[:]
 def set_memlimit(limit):
     import re
     global max_memuse
+    global real_max_memuse
     sizes = {
         'k': 1024,
         'm': _1M,
@@ -344,6 +347,7 @@ def set_memlimit(limit):
     if m is None:
         raise ValueError('Invalid memory limit %r' % (limit,))
     memlimit = int(float(m.group(1)) * sizes[m.group(3).lower()])
+    real_max_memuse = memlimit
     if memlimit > MAX_Py_ssize_t:
         memlimit = MAX_Py_ssize_t
     if memlimit < _2G - 1:
@@ -389,6 +393,27 @@ def bigmemtest(minsize, memuse, overhead=5*_1M):
         return wrapper
     return decorator
 
+def precisionbigmemtest(size, memuse, overhead=5*_1M):
+    def decorator(f):
+        def wrapper(self):
+            if not real_max_memuse:
+                maxsize = 5147
+            else:
+                maxsize = size
+
+                if real_max_memuse and real_max_memuse < maxsize * memuse:
+                    if verbose:
+                        sys.stderr.write("Skipping %s because of memory "
+                                         "constraint\n" % (f.__name__,))
+                    return
+
+            return f(self, maxsize)
+        wrapper.size = size
+        wrapper.memuse = memuse
+        wrapper.overhead = overhead
+        return wrapper
+    return decorator
+
 def bigaddrspacetest(f):
     """Decorator for tests that fill the address space."""
     def wrapper(self):

Misc/NEWS

@@ -12,6 +12,8 @@ What's New in Python 2.5.3?
 Core and builtins
 -----------------
 
+- Apply security patches from Apple.
+
 - Issue #2620: Overflow checking when allocating or reallocating memory
   was not always being done properly in some python types and extension
   modules.  PyMem_MALLOC, PyMem_REALLOC, PyMem_NEW and PyMem_RESIZE have

Modules/gcmodule.c

@@ -1318,7 +1318,10 @@ PyObject *
 _PyObject_GC_Malloc(size_t basicsize)
 {
 	PyObject *op;
-	PyGC_Head *g = (PyGC_Head *)PyObject_MALLOC(
+	PyGC_Head *g;
+	if (basicsize > PY_SSIZE_T_MAX - sizeof(PyGC_Head))
+		return PyErr_NoMemory();
+	g = (PyGC_Head *)PyObject_MALLOC(
                 sizeof(PyGC_Head) + basicsize);
 	if (g == NULL)
 		return PyErr_NoMemory();
@@ -1361,6 +1364,8 @@ _PyObject_GC_Resize(PyVarObject *op, Py_ssize_t nitems)
 {
 	const size_t basicsize = _PyObject_VAR_SIZE(op->ob_type, nitems);
 	PyGC_Head *g = AS_GC(op);
+	if (basicsize > PY_SSIZE_T_MAX - sizeof(PyGC_Head))
+		return (PyVarObject *)PyErr_NoMemory();
 	g = (PyGC_Head *)PyObject_REALLOC(g,  sizeof(PyGC_Head) + basicsize);
 	if (g == NULL)
 		return (PyVarObject *)PyErr_NoMemory();

Modules/mmapmodule.c

@@ -223,7 +223,7 @@ mmap_read_method(mmap_object *self,
 		return(NULL);
 
 	/* silently 'adjust' out-of-range requests */
-	if ((self->pos + num_bytes) > self->size) {
+	if (num_bytes > self->size - self->pos) {
 		num_bytes -= (self->pos+num_bytes) - self->size;
 	}
 	result = Py_BuildValue("s#", self->data+self->pos, num_bytes);

Modules/stropmodule.c

@@ -216,6 +216,13 @@ strop_joinfields(PyObject *self, PyObject *args)
 				return NULL;
 			}
 			slen = PyString_GET_SIZE(item);
+			if (slen > PY_SSIZE_T_MAX - reslen ||
+			    seplen > PY_SSIZE_T_MAX - reslen - seplen) {
+				PyErr_SetString(PyExc_OverflowError,
+						"input too long");
+				Py_DECREF(res);
+				return NULL;
+			}
 			while (reslen + slen + seplen >= sz) {
 				if (_PyString_Resize(&res, sz * 2) < 0)
 					return NULL;
@@ -253,6 +260,14 @@ strop_joinfields(PyObject *self, PyObject *args)
 			return NULL;
 		}
 		slen = PyString_GET_SIZE(item);
+		if (slen > PY_SSIZE_T_MAX - reslen ||
+		    seplen > PY_SSIZE_T_MAX - reslen - seplen) {
+			PyErr_SetString(PyExc_OverflowError,
+					"input too long");
+			Py_DECREF(res);
+			Py_XDECREF(item);
+			return NULL;
+		}
 		while (reslen + slen + seplen >= sz) {
 			if (_PyString_Resize(&res, sz * 2) < 0) {
 				Py_DECREF(item);

Objects/bufferobject.c

@@ -427,6 +427,10 @@ buffer_repeat(PyBufferObject *self, Py_ssize_t count)
 		count = 0;
 	if (!get_buf(self, &ptr, &size, ANY_BUFFER))
 		return NULL;
+	if (count > PY_SSIZE_T_MAX / size) {
+		PyErr_SetString(PyExc_MemoryError, "result too large");
+		return NULL;
+	}
 	ob = PyString_FromStringAndSize(NULL, size * count);
 	if ( ob == NULL )
 		return NULL;

Objects/longobject.c

@@ -70,6 +70,8 @@ _PyLong_New(Py_ssize_t size)
 		PyErr_NoMemory();
 		return NULL;
 	}
+	/* XXX(nnorwitz): This can overflow --
+	   PyObject_NEW_VAR /  _PyObject_VAR_SIZE need to detect overflow */
 	return PyObject_NEW_VAR(PyLongObject, &PyLong_Type, size);
 }
 

Objects/stringobject.c

@@ -75,6 +75,11 @@ PyString_FromStringAndSize(const char *str, Py_ssize_t size)
 		return (PyObject *)op;
 	}
 
+	if (size > PY_SSIZE_T_MAX - sizeof(PyStringObject)) {
+		PyErr_SetString(PyExc_OverflowError, "string is too large");
+		return NULL;
+	}
+
 	/* Inline PyObject_NewVar */
 	op = (PyStringObject *)PyObject_MALLOC(sizeof(PyStringObject) + size);
 	if (op == NULL)
@@ -110,7 +115,7 @@ PyString_FromString(const char *str)
 
 	assert(str != NULL);
 	size = strlen(str);
-	if (size > PY_SSIZE_T_MAX) {
+	if (size > PY_SSIZE_T_MAX - sizeof(PyStringObject)) {
 		PyErr_SetString(PyExc_OverflowError,
 			"string is too long for a Python string");
 		return NULL;
@@ -971,14 +976,24 @@ string_concat(register PyStringObject *a, register PyObject *bb)
 		Py_INCREF(a);
 		return (PyObject *)a;
 	}
+	/* Check that string sizes are not negative, to prevent an
+	   overflow in cases where we are passed incorrectly-created
+	   strings with negative lengths (due to a bug in other code).
+	*/
 	size = a->ob_size + b->ob_size;
-	if (size < 0) {
+	if (a->ob_size < 0 || b->ob_size < 0 ||
+	    a->ob_size > PY_SSIZE_T_MAX - b->ob_size) {
 		PyErr_SetString(PyExc_OverflowError,
 				"strings are too large to concat");
 		return NULL;
 	}
 	  
 	/* Inline PyObject_NewVar */
+	if (size > PY_SSIZE_T_MAX - sizeof(PyStringObject)) {
+		PyErr_SetString(PyExc_OverflowError,
+				"strings are too large to concat");
+		return NULL;
+	}
 	op = (PyStringObject *)PyObject_MALLOC(sizeof(PyStringObject) + size);
 	if (op == NULL)
 		return PyErr_NoMemory();

Objects/tupleobject.c

@@ -60,11 +60,12 @@ PyTuple_New(register Py_ssize_t size)
 		Py_ssize_t nbytes = size * sizeof(PyObject *);
 		/* Check for overflow */
 		if (nbytes / sizeof(PyObject *) != (size_t)size ||
-		    (nbytes += sizeof(PyTupleObject) - sizeof(PyObject *))
-		    <= 0)
+		    (nbytes > PY_SSIZE_T_MAX - sizeof(PyTupleObject) - sizeof(PyObject *)))
 		{
 			return PyErr_NoMemory();
 		}
+		nbytes += sizeof(PyTupleObject) - sizeof(PyObject *);
+
 		op = PyObject_GC_NewVar(PyTupleObject, &PyTuple_Type, size);
 		if (op == NULL)
 			return NULL;

Objects/unicodeobject.c

@@ -240,6 +240,11 @@ PyUnicodeObject *_PyUnicode_New(Py_ssize_t length)
         return unicode_empty;
     }
 
+    /* Ensure we won't overflow the size. */
+    if (length > ((PY_SSIZE_T_MAX / sizeof(Py_UNICODE)) - 1)) {
+        return (PyUnicodeObject *)PyErr_NoMemory();
+    }
+
     /* Unicode freelist & memory allocation */
     if (unicode_freelist) {
         unicode = unicode_freelist;
@@ -1095,6 +1100,9 @@ PyObject *PyUnicode_EncodeUTF7(const Py_UNICODE *s,
     char * out;
     char * start;
 
+    if (cbAllocated / 5 != size)
+        return PyErr_NoMemory();
+
     if (size == 0)
 		return PyString_FromStringAndSize(NULL, 0);
 
@@ -1693,8 +1701,9 @@ PyUnicode_EncodeUTF16(const Py_UNICODE *s,
 {
     PyObject *v;
     unsigned char *p;
+    Py_ssize_t nsize, bytesize;
 #ifdef Py_UNICODE_WIDE
-    int i, pairs;
+    Py_ssize_t i, pairs;
 #else
     const int pairs = 0;
 #endif
@@ -1717,8 +1726,15 @@ PyUnicode_EncodeUTF16(const Py_UNICODE *s,
 	if (s[i] >= 0x10000)
 	    pairs++;
 #endif
-    v = PyString_FromStringAndSize(NULL,
-		  2 * (size + pairs + (byteorder == 0)));
+    /* 2 * (size + pairs + (byteorder == 0)) */
+    if (size > PY_SSIZE_T_MAX ||
+	size > PY_SSIZE_T_MAX - pairs - (byteorder == 0))
+	return PyErr_NoMemory();
+    nsize = (size + pairs + (byteorder == 0));
+    bytesize = nsize * 2;
+    if (bytesize / 2 != nsize)
+	return PyErr_NoMemory();
+    v = PyString_FromStringAndSize(NULL, bytesize);
     if (v == NULL)
         return NULL;
 
@@ -2046,6 +2062,11 @@ PyObject *unicodeescape_string(const Py_UNICODE *s,
     char *p;
 
     static const char *hexdigit = "0123456789abcdef";
+#ifdef Py_UNICODE_WIDE
+    const Py_ssize_t expandsize = 10;
+#else
+    const Py_ssize_t expandsize = 6;
+#endif
 
     /* Initial allocation is based on the longest-possible unichr
        escape.
@@ -2061,13 +2082,12 @@ PyObject *unicodeescape_string(const Py_UNICODE *s,
        escape.
     */
 
+    if (size > (PY_SSIZE_T_MAX - 2 - 1) / expandsize)
+	return PyErr_NoMemory();
+
     repr = PyString_FromStringAndSize(NULL,
         2
-#ifdef Py_UNICODE_WIDE
-        + 10*size
-#else
-        + 6*size
-#endif
+        + expandsize*size
         + 1);
     if (repr == NULL)
         return NULL;
@@ -2320,12 +2340,16 @@ PyObject *PyUnicode_EncodeRawUnicodeEscape(const Py_UNICODE *s,
     char *q;
 
     static const char *hexdigit = "0123456789abcdef";
-
 #ifdef Py_UNICODE_WIDE
-    repr = PyString_FromStringAndSize(NULL, 10 * size);
+    const Py_ssize_t expandsize = 10;
 #else
-    repr = PyString_FromStringAndSize(NULL, 6 * size);
+    const Py_ssize_t expandsize = 6;
 #endif
+    
+    if (size > PY_SSIZE_T_MAX / expandsize)
+	return PyErr_NoMemory();
+    
+    repr = PyString_FromStringAndSize(NULL, expandsize * size);
     if (repr == NULL)
         return NULL;
     if (size == 0)
@@ -4761,6 +4785,11 @@ PyUnicodeObject *pad(PyUnicodeObject *self,
         return self;
     }
 
+    if (left > PY_SSIZE_T_MAX - self->length ||
+	right > PY_SSIZE_T_MAX - (left + self->length)) {
+        PyErr_SetString(PyExc_OverflowError, "padded string is too long");
+        return NULL;
+    }
     u = _PyUnicode_New(left + self->length + right);
     if (u) {
         if (left)