Commits

Martin von Löwis committed 8cbe0bd

Added checks for integer overflows, contributed by Google. Some are
only available if asserts are left in the code, in cases where they
can't be triggered from Python code.

Comments (0)

Files changed (25)

  */
 
 #define PyMem_New(type, n) \
-	( (type *) PyMem_Malloc((n) * sizeof(type)) )
+  ( assert((n) <= PY_SIZE_MAX / sizeof(type)) , \
+	( (type *) PyMem_Malloc((n) * sizeof(type)) ) )
 #define PyMem_NEW(type, n) \
-	( (type *) PyMem_MALLOC((n) * sizeof(type)) )
+  ( assert((n) <= PY_SIZE_MAX / sizeof(type)) , \
+	( (type *) PyMem_MALLOC((n) * sizeof(type)) ) )
 
 #define PyMem_Resize(p, type, n) \
-	( (p) = (type *) PyMem_Realloc((p), (n) * sizeof(type)) )
+  ( assert((n) <= PY_SIZE_MAX / sizeof(type)) , \
+	( (p) = (type *) PyMem_Realloc((p), (n) * sizeof(type)) ) )
 #define PyMem_RESIZE(p, type, n) \
-	( (p) = (type *) PyMem_REALLOC((p), (n) * sizeof(type)) )
+  ( assert((n) <= PY_SIZE_MAX / sizeof(type)) , \
+	( (p) = (type *) PyMem_REALLOC((p), (n) * sizeof(type)) ) )
 
 /* PyMem{Del,DEL} are left over from ancient days, and shouldn't be used
  * anymore.  They're just confusing aliases for PyMem_{Free,FREE} now.
 #   error "Python needs a typedef for Py_ssize_t in pyport.h."
 #endif
 
+/* Largest possible value of size_t.
+   SIZE_MAX is part of C99, so it might be defined on some
+   platforms. If it is not defined, (size_t)-1 is a portable
+   definition for C89, due to the way signed->unsigned 
+   conversion is defined. */
+#ifdef SIZE_MAX
+#define PY_SIZE_MAX SIZE_MAX
+#else
+#define PY_SIZE_MAX ((size_t)-1)
+#endif
+
 /* Largest positive value of type Py_ssize_t. */
 #define PY_SSIZE_T_MAX ((Py_ssize_t)(((size_t)-1)>>1))
 /* Smallest negative value of type Py_ssize_t. */

Lib/test/test_array.py

 class DoubleTest(FPTest):
     typecode = 'd'
     minitemsize = 8
+
+    def test_alloc_overflow(self):
+        a = array.array('d', [-1]*65536)
+        try:
+            a *= 65536
+        except MemoryError:
+            pass
+        else:
+            self.fail("a *= 2**16 didn't raise MemoryError")
+        b = array.array('d', [ 2.71828183, 3.14159265, -1])
+        try:
+            b * 1431655766
+        except MemoryError:
+            pass
+        else:
+            self.fail("a * 1431655766 didn't raise MemoryError")
+
 tests.append(DoubleTest)
 
 def test_main(verbose=None):

Lib/test/test_struct.py

     value, = struct.unpack('>I', data)
     vereq(value, 0x12345678)
 
+def test_crasher():
+    assertRaises(MemoryError, struct.pack, "357913941c", "a")
+
 # Test methods to pack and unpack from buffers rather than strings.
 test_unpack_from()
 test_pack_into()
 test_pack_into_fn()
 test_unpack_with_buffer()
+test_crasher()
 Core and builtins
 -----------------
 
+- Added checks for integer overflows, contributed by Google. Some are
+  only available if asserts are left in the code, in cases where they
+  can't be triggered from Python code.
+
 - Issue #2045: Fix an infinite recursion triggered when printing a subclass of
   collections.defaultdict, if its default_factory is set to a bound method.
 
 		self->field = PyMem_Malloc(self->field_size);
 	}
 	else {
+		if (self->field_size > INT_MAX / 2) {
+			PyErr_NoMemory();
+			return 0;
+		} 
 		self->field_size *= 2;
 		self->field = PyMem_Realloc(self->field, self->field_size);
 	}
 static int
 join_check_rec_size(WriterObj *self, int rec_len)
 {
+
+	if (rec_len < 0 || rec_len > INT_MAX - MEM_INCR) {
+		PyErr_NoMemory();
+		return 0;
+	}
+
 	if (rec_len > self->rec_size) {
 		if (self->rec_size == 0) {
 			self->rec_size = (rec_len / MEM_INCR + 1) * MEM_INCR;

Modules/_struct.c

 		}
 	}
 
+	/* check for overflow */
+	if ((len + 1) > (PY_SSIZE_T_MAX / sizeof(formatcode))) {
+		PyErr_NoMemory();
+		return -1;
+	}
+
 	self->s_size = size;
 	self->s_len = len;
 	codes = PyMem_MALLOC((len + 1) * sizeof(formatcode));

Modules/arraymodule.c

 		PyErr_BadArgument();
 		return NULL;
 	}
+	if (a->ob_size > PY_SSIZE_T_MAX - b->ob_size) {
+		return PyErr_NoMemory();
+	}
 	size = a->ob_size + b->ob_size;
 	np = (arrayobject *) newarrayobject(&Arraytype, size, a->ob_descr);
 	if (np == NULL) {
 	Py_ssize_t nbytes;
 	if (n < 0)
 		n = 0;
+	if ((a->ob_size != 0) && (n > PY_SSIZE_T_MAX / a->ob_size)) {
+		return PyErr_NoMemory();
+	}
 	size = a->ob_size * n;
 	np = (arrayobject *) newarrayobject(&Arraytype, size, a->ob_descr);
 	if (np == NULL)
 			     "can only extend with array of same kind");
 		return -1;
 	}
+	if ((self->ob_size > PY_SSIZE_T_MAX - b->ob_size) ||
+		((self->ob_size + b->ob_size) > PY_SSIZE_T_MAX / self->ob_descr->itemsize)) {
+			PyErr_NoMemory();
+			return -1;
+	}
 	size = self->ob_size + b->ob_size;
         PyMem_RESIZE(self->ob_item, char, size*self->ob_descr->itemsize);
         if (self->ob_item == NULL) {
 		if (n < 0)
 			n = 0;
 		items = self->ob_item;
+		if ((self->ob_descr->itemsize != 0) && 
+			(self->ob_size > PY_SSIZE_T_MAX / self->ob_descr->itemsize)) {
+			return PyErr_NoMemory();
+		}
 		size = self->ob_size * self->ob_descr->itemsize;
 		if (n == 0) {
 			PyMem_FREE(items);
 			self->allocated = 0;
 		}
 		else {
+			if (size > PY_SSIZE_T_MAX / n) {
+				return PyErr_NoMemory();
+			}
 			PyMem_Resize(items, char, n * size);
 			if (items == NULL)
 				return PyErr_NoMemory();
 		Py_INCREF(dict);
 	}
 	if (array->ob_size > 0) {
+		if (array->ob_descr->itemsize 
+				> PY_SSIZE_T_MAX / array->ob_size) {
+			return PyErr_NoMemory();
+		}
 		result = Py_BuildValue("O(cs#)O", 
 			array->ob_type, 
 			array->ob_descr->typecode,
 			if ((*self->ob_descr->setitem)(self,
 					self->ob_size - n + i, v) != 0) {
 				self->ob_size -= n;
+				if (itemsize && (self->ob_size > PY_SSIZE_T_MAX / itemsize)) {
+					return PyErr_NoMemory();
+				}
 				PyMem_RESIZE(item, char,
 					          self->ob_size * itemsize);
 				self->ob_item = item;
 	n = n / itemsize;
 	if (n > 0) {
 		char *item = self->ob_item;
+		if ((n > PY_SSIZE_T_MAX - self->ob_size) ||
+			((self->ob_size + n) > PY_SSIZE_T_MAX / itemsize)) {
+				return PyErr_NoMemory();
+		}
 		PyMem_RESIZE(item, char, (self->ob_size + n) * itemsize);
 		if (item == NULL) {
 			PyErr_NoMemory();
 static PyObject *
 array_tostring(arrayobject *self, PyObject *unused)
 {
-	return PyString_FromStringAndSize(self->ob_item,
+	if (self->ob_size <= PY_SSIZE_T_MAX / self->ob_descr->itemsize) {
+		return PyString_FromStringAndSize(self->ob_item,
 				    self->ob_size * self->ob_descr->itemsize);
+	} else {
+		return PyErr_NoMemory();
+	}
 }
 
 PyDoc_STRVAR(tostring_doc,
 	}
 	if (n > 0) {
 		Py_UNICODE *item = (Py_UNICODE *) self->ob_item;
+		if (self->ob_size > PY_SSIZE_T_MAX - n) {
+			return PyErr_NoMemory();
+		}
 		PyMem_RESIZE(item, Py_UNICODE, self->ob_size + n);
 		if (item == NULL) {
 			PyErr_NoMemory();

Modules/audioop.c

 audioop_tostereo(PyObject *self, PyObject *args)
 {
         signed char *cp, *ncp;
-        int len, size, val1, val2, val = 0;
+        int len, new_len, size, val1, val2, val = 0;
         double fac1, fac2, fval, maxval;
         PyObject *rv;
         int i;
                 return 0;
         }
     
-        rv = PyString_FromStringAndSize(NULL, len*2);
+        new_len = len*2;
+        if (new_len < 0) {
+                PyErr_SetString(PyExc_MemoryError,
+                                "not enough memory for output buffer");
+                return 0;
+        }
+
+        rv = PyString_FromStringAndSize(NULL, new_len);
         if ( rv == 0 )
                 return 0;
         ncp = (signed char *)PyString_AsString(rv);
 {
         signed char *cp;
         unsigned char *ncp;
-        int len, size, size2, val = 0;
+        int len, new_len, size, size2, val = 0;
         PyObject *rv;
         int i, j;
 
                 return 0;
         }
     
-        rv = PyString_FromStringAndSize(NULL, (len/size)*size2);
+        new_len = (len/size)*size2;
+        if (new_len < 0) {
+                PyErr_SetString(PyExc_MemoryError,
+                                "not enough memory for output buffer");
+                return 0;
+        }
+        rv = PyString_FromStringAndSize(NULL, new_len);
         if ( rv == 0 )
                 return 0;
         ncp = (unsigned char *)PyString_AsString(rv);
         int chan, d, *prev_i, *cur_i, cur_o;
         PyObject *state, *samps, *str, *rv = NULL;
         int bytes_per_frame;
+        size_t alloc_size;
 
         weightA = 1;
         weightB = 0;
         inrate /= d;
         outrate /= d;
 
-        prev_i = (int *) malloc(nchannels * sizeof(int));
-        cur_i = (int *) malloc(nchannels * sizeof(int));
+        alloc_size = sizeof(int) * (unsigned)nchannels;
+        if (alloc_size < nchannels) {
+                PyErr_SetString(PyExc_MemoryError,
+                                "not enough memory for output buffer");
+                return 0;
+        }
+        prev_i = (int *) malloc(alloc_size);
+        cur_i = (int *) malloc(alloc_size);
         if (prev_i == NULL || cur_i == NULL) {
                 (void) PyErr_NoMemory();
                 goto exit;
         unsigned char *cp;
         unsigned char cval;
         signed char *ncp;
-        int len, size, val;
+        int len, new_len, size, val;
         PyObject *rv;
         int i;
 
                 return 0;
         }
     
-        rv = PyString_FromStringAndSize(NULL, len*size);
+        new_len = len*size;
+        if (new_len < 0) {
+                PyErr_SetString(PyExc_MemoryError,
+                                "not enough memory for output buffer");
+                return 0;
+        }
+        rv = PyString_FromStringAndSize(NULL, new_len);
         if ( rv == 0 )
                 return 0;
         ncp = (signed char *)PyString_AsString(rv);
     
-        for ( i=0; i < len*size; i += size ) {
+        for ( i=0; i < new_len; i += size ) {
                 cval = *cp++;
                 val = st_ulaw2linear16(cval);
         
         unsigned char *cp;
         unsigned char cval;
         signed char *ncp;
-        int len, size, val;
+        int len, new_len, size, val;
         PyObject *rv;
         int i;
 
                 return 0;
         }
     
-        rv = PyString_FromStringAndSize(NULL, len*size);
+        new_len = len*size;
+        if (new_len < 0) {
+                PyErr_SetString(PyExc_MemoryError,
+                                "not enough memory for output buffer");
+                return 0;
+        }
+        rv = PyString_FromStringAndSize(NULL, new_len);
         if ( rv == 0 )
                 return 0;
         ncp = (signed char *)PyString_AsString(rv);
     
-        for ( i=0; i < len*size; i += size ) {
+        for ( i=0; i < new_len; i += size ) {
                 cval = *cp++;
                 val = st_alaw2linear16(cval);
         
 {
         signed char *cp;
         signed char *ncp;
-        int len, size, valpred, step, delta, index, sign, vpdiff;
+        int len, new_len, size, valpred, step, delta, index, sign, vpdiff;
         PyObject *rv, *str, *state;
         int i, inputbuffer = 0, bufferstep;
 
         } else if ( !PyArg_ParseTuple(state, "ii", &valpred, &index) )
                 return 0;
     
-        str = PyString_FromStringAndSize(NULL, len*size*2);
+        new_len = len*size*2;
+        if (new_len < 0) {
+                PyErr_SetString(PyExc_MemoryError,
+                                "not enough memory for output buffer");
+                return 0;
+        }
+        str = PyString_FromStringAndSize(NULL, new_len);
         if ( str == 0 )
                 return 0;
         ncp = (signed char *)PyString_AsString(str);
         step = stepsizeTable[index];
         bufferstep = 0;
     
-        for ( i=0; i < len*size*2; i += size ) {
+        for ( i=0; i < new_len; i += size ) {
                 /* Step 1 - get the delta value and compute next index */
                 if ( bufferstep ) {
                         delta = inputbuffer & 0xf;

Modules/binascii.c

 #define BASE64_PAD '='
 
 /* Max binary chunk size; limited only by available memory */
-#define BASE64_MAXBIN (INT_MAX/2 - sizeof(PyStringObject) - 3)
+#define BASE64_MAXBIN (PY_SSIZE_T_MAX/2 - sizeof(PyStringObject) - 3)
 
 static unsigned char table_b2a_base64[] =
 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
 	if ( !PyArg_ParseTuple(args, "t#:a2b_uu", &ascii_data, &ascii_len) )
 		return NULL;
 
+	assert(ascii_len >= 0);
+
 	/* First byte: binary data length (in bytes) */
 	bin_len = (*ascii_data++ - ' ') & 077;
 	ascii_len--;
 	if ( !PyArg_ParseTuple(args, "t#:a2b_base64", &ascii_data, &ascii_len) )
 		return NULL;
 
+	assert(ascii_len >= 0);
+
+	if (ascii_len > PY_SSIZE_T_MAX - 3)
+		return PyErr_NoMemory();
+
 	bin_len = ((ascii_len+3)/4)*3; /* Upper bound, corrected later */
 
 	/* Allocate the buffer */
 
 	if ( !PyArg_ParseTuple(args, "s#:b2a_base64", &bin_data, &bin_len) )
 		return NULL;
+
+	assert(bin_len >= 0);
+
 	if ( bin_len > BASE64_MAXBIN ) {
 		PyErr_SetString(Error, "Too much data for base64 line");
 		return NULL;
 	if ( !PyArg_ParseTuple(args, "t#:a2b_hqx", &ascii_data, &len) )
 		return NULL;
 
+	assert(len >= 0);
+
+	if (len > PY_SSIZE_T_MAX - 2)
+		return PyErr_NoMemory();
+
 	/* Allocate a string that is too big (fixed later) 
 	   Add two to the initial length to prevent interning which
 	   would preclude subsequent resizing.  */
 	if ( !PyArg_ParseTuple(args, "s#:rlecode_hqx", &in_data, &len) )
 		return NULL;
 
+	assert(len >= 0);
+
+	if (len > PY_SSIZE_T_MAX / 2 - 2)
+		return PyErr_NoMemory();
+
 	/* Worst case: output is twice as big as input (fixed later) */
 	if ( (rv=PyString_FromStringAndSize(NULL, len*2+2)) == NULL )
 		return NULL;
 	if ( !PyArg_ParseTuple(args, "s#:b2a_hqx", &bin_data, &len) )
 		return NULL;
 
+	assert(len >= 0);
+
+	if (len > PY_SSIZE_T_MAX / 2 - 2)
+		return PyErr_NoMemory();
+
 	/* Allocate a buffer that is at least large enough */
 	if ( (rv=PyString_FromStringAndSize(NULL, len*2+2)) == NULL )
 		return NULL;
 	if ( !PyArg_ParseTuple(args, "s#:rledecode_hqx", &in_data, &in_len) )
 		return NULL;
 
+	assert(in_len >= 0);
+
 	/* Empty string is a special case */
 	if ( in_len == 0 )
 		return PyString_FromString("");
+    else if (in_len > PY_SSIZE_T_MAX / 2)
+        return PyErr_NoMemory();
 
 	/* Allocate a buffer of reasonable size. Resized when needed */
 	out_len = in_len*2;
 #define OUTBYTE(b) \
 	do { \
 		 if ( --out_len_left < 0 ) { \
+			  if ( out_len > PY_SSIZE_T_MAX / 2) return PyErr_NoMemory(); \
 			  _PyString_Resize(&rv, 2*out_len); \
 			  if ( rv == NULL ) return NULL; \
 			  out_data = (unsigned char *)PyString_AsString(rv) \
 	if ( !PyArg_ParseTuple(args, "s#i:crc_hqx", &bin_data, &len, &crc) )
 		return NULL;
 
-	while(len--) {
+	while(len-- > 0) {
 		crc=((crc<<8)&0xff00)^crctab_hqx[((crc>>8)&0xff)^*bin_data++];
 	}
 
 	/* only want the trailing 32 bits */
 	crc &= 0xFFFFFFFFUL;
 #endif
-	while (len--)
+	while (len-- > 0)
 		crc = crc_32_tab[(crc ^ *bin_data++) & 0xffUL] ^ (crc >> 8);
 		/* Note:  (crc >> 8) MUST zero fill on left */
 
 	if (!PyArg_ParseTuple(args, "s#:b2a_hex", &argbuf, &arglen))
 		return NULL;
 
+	assert(arglen >= 0);
+	if (arglen > PY_SSIZE_T_MAX / 2)
+		return PyErr_NoMemory();
+
 	retval = PyString_FromStringAndSize(NULL, arglen*2);
 	if (!retval)
 		return NULL;
 	if (!PyArg_ParseTuple(args, "s#:a2b_hex", &argbuf, &arglen))
 		return NULL;
 
+	assert(arglen >= 0);
+
 	/* XXX What should we do about strings with an odd length?  Should
 	 * we add an implicit leading zero, or a trailing zero?  For now,
 	 * raise an exception.

Modules/cPickle.c

 	if (self->read_func(self, &s, 4) < 0) return -1;
 
 	l = calc_binint(s, 4);
+	if (l < 0) {
+		/* Corrupt or hostile pickle -- we never write one like
+		 * this.
+		 */
+		PyErr_SetString(UnpicklingError,
+				"BINSTRING pickle has negative byte count");
+		return -1;
+	}
 
 	if (self->read_func(self, &s, l) < 0)
 		return -1;
 	if (self->read_func(self, &s, 4) < 0) return -1;
 
 	l = calc_binint(s, 4);
+	if (l < 0) {
+		/* Corrupt or hostile pickle -- we never write one like
+		 * this.
+		 */
+		PyErr_SetString(UnpicklingError,
+				"BINUNICODE pickle has negative byte count");
+		return -1;
+	}
 
 	if (self->read_func(self, &s, l) < 0)
 		return -1;

Modules/cStringIO.c

 static PyObject *
 IO_cgetval(PyObject *self) {
         if (!IO__opencheck(IOOOBJECT(self))) return NULL;
+        assert(IOOOBJECT(self)->pos >= 0);
         return PyString_FromStringAndSize(((IOobject*)self)->buf,
                                           ((IOobject*)self)->pos);
 }
         }
         else
                   s=self->string_size;
+        assert(self->pos >= 0);
         return PyString_FromStringAndSize(self->buf, s);
 }
 
         Py_ssize_t l;
 
         if (!IO__opencheck(IOOOBJECT(self))) return -1;
+        assert(IOOOBJECT(self)->pos >= 0);
+        assert(IOOOBJECT(self)->string_size >= 0);
         l = ((IOobject*)self)->string_size - ((IOobject*)self)->pos;  
         if (n < 0 || n > l) {
                 n = l;
         for (n = ((IOobject*)self)->buf + ((IOobject*)self)->pos,
                s = ((IOobject*)self)->buf + ((IOobject*)self)->string_size; 
              n < s && *n != '\n'; n++);
+
         if (n < s) n++;
 
         *output=((IOobject*)self)->buf + ((IOobject*)self)->pos;
         l = n - ((IOobject*)self)->buf - ((IOobject*)self)->pos;
-	assert(((IOobject*)self)->pos + l < INT_MAX);
-        ((IOobject*)self)->pos += (int)l;
+
+        assert(IOOOBJECT(self)->pos <= PY_SSIZE_T_MAX - l);
+        assert(IOOOBJECT(self)->pos >= 0);
+        assert(IOOOBJECT(self)->string_size >= 0);
+
+        ((IOobject*)self)->pos += l;
         return (int)l;
 }
 
                 n -= m;
                 self->pos -= m;
         }
+        assert(IOOOBJECT(self)->pos >= 0);
         return PyString_FromStringAndSize(output, n);
 }
 
 
         if (!IO__opencheck(self)) return NULL;
 
+        assert(self->pos >= 0);
         return PyInt_FromSsize_t(self->pos);
 }
 

Modules/cjkcodecs/multibytecodec.c

 static int
 expand_encodebuffer(MultibyteEncodeBuffer *buf, Py_ssize_t esize)
 {
-	Py_ssize_t orgpos, orgsize;
+	Py_ssize_t orgpos, orgsize, incsize;
 
 	orgpos = (Py_ssize_t)((char *)buf->outbuf -
 				PyString_AS_STRING(buf->outobj));
 	orgsize = PyString_GET_SIZE(buf->outobj);
-	if (_PyString_Resize(&buf->outobj, orgsize + (
-	    esize < (orgsize >> 1) ? (orgsize >> 1) | 1 : esize)) == -1)
+	incsize = (esize < (orgsize >> 1) ? (orgsize >> 1) | 1 : esize);
+
+	if (orgsize > PY_SSIZE_T_MAX - incsize)
+		return -1;
+
+	if (_PyString_Resize(&buf->outobj, orgsize + incsize) == -1)
 		return -1;
 
 	buf->outbuf = (unsigned char *)PyString_AS_STRING(buf->outobj) +orgpos;
 	buf.excobj = NULL;
 	buf.inbuf = buf.inbuf_top = *data;
 	buf.inbuf_end = buf.inbuf_top + datalen;
+
+	if (datalen > (PY_SSIZE_T_MAX - 16) / 2) {
+		PyErr_NoMemory();
+		goto errorexit;
+	}
+
 	buf.outobj = PyString_FromStringAndSize(NULL, datalen * 2 + 16);
 	if (buf.outobj == NULL)
 		goto errorexit;
 	origpending = ctx->pendingsize;
 
 	if (origpending > 0) {
+		if (datalen > PY_SSIZE_T_MAX - ctx->pendingsize) {
+			PyErr_NoMemory();
+			/* inbuf_tmp == NULL */
+			goto errorexit;
+		}
 		inbuf_tmp = PyMem_New(Py_UNICODE, datalen + ctx->pendingsize);
 		if (inbuf_tmp == NULL)
 			goto errorexit;
 	Py_ssize_t npendings;
 
 	npendings = (Py_ssize_t)(buf->inbuf_end - buf->inbuf);
-	if (npendings + ctx->pendingsize > MAXDECPENDING) {
-		PyErr_SetString(PyExc_UnicodeError, "pending buffer overflow");
-		return -1;
+	if (npendings + ctx->pendingsize > MAXDECPENDING ||
+		npendings > PY_SSIZE_T_MAX - ctx->pendingsize) {
+			PyErr_SetString(PyExc_UnicodeError, "pending buffer overflow");
+			return -1;
 	}
 	memcpy(ctx->pending + ctx->pendingsize, buf->inbuf, npendings);
 	ctx->pendingsize += npendings;
 		  PyObject *args, PyObject *kwargs)
 {
 	MultibyteDecodeBuffer buf;
-	char *data, *wdata;
+	char *data, *wdata = NULL;
 	Py_ssize_t wsize, finalsize = 0, size, origpending;
 	int final = 0;
 
 		wdata = data;
 	}
 	else {
+		if (size > PY_SSIZE_T_MAX - self->pendingsize) {
+			PyErr_NoMemory();
+			goto errorexit;
+		}
 		wsize = size + self->pendingsize;
 		wdata = PyMem_Malloc(wsize);
 		if (wdata == NULL)
 			PyObject *ctr;
 			char *ctrdata;
 
+			if (PyString_GET_SIZE(cres) > PY_SSIZE_T_MAX - self->pendingsize) {
+				PyErr_NoMemory();
+				goto errorexit;
+            }
 			rsize = PyString_GET_SIZE(cres) + self->pendingsize;
 			ctr = PyString_FromStringAndSize(NULL, rsize);
 			if (ctr == NULL)

Modules/datetimemodule.c

 	char sign;
 	int none;
 
+	assert(buflen >= 1);
+
 	offset = call_utcoffset(tzinfo, tzinfoarg, &none);
 	if (offset == -1 && PyErr_Occurred())
 		return -1;
 	 * a new format.  Since computing the replacements for those codes
 	 * is expensive, don't unless they're actually used.
 	 */
+	if (PyString_Size(format) > INT_MAX - 1) {
+		PyErr_NoMemory();
+		goto Done;
+	}
+
 	totalnew = PyString_Size(format) + 1;	/* realistic if no %z/%Z */
 	newfmt = PyString_FromStringAndSize(NULL, totalnew);
 	if (newfmt == NULL) goto Done;
 
 #include "md5.h"
 #include <string.h>
+#include <limits.h>
 
 #undef BYTE_ORDER	/* 1 = big-endian, -1 = little-endian, 0 = unknown */
 #ifdef ARCH_IS_BIG_ENDIAN
     if (nbytes <= 0)
 	return;
 
+    /* this special case is handled recursively */
+    if (nbytes > INT_MAX - offset) {
+        int overlap;
+
+        /* handle the append in two steps to prevent overflow */
+        overlap = 64 - offset;
+
+        md5_append(pms, data, overlap);
+        md5_append(pms, data + overlap, nbytes - overlap); 
+        return;
+    }
+
     /* Update the message length. */
     pms->count[1] += nbytes >> 29;
     pms->count[0] += nbits;

Modules/rgbimgmodule.c

 	Py_Int32 *starttab = NULL, *lengthtab = NULL;
 	FILE *inf = NULL;
 	IMAGE image;
-	int y, z, tablen;
+	int y, z, tablen, new_size;
 	int xsize, ysize, zsize;
 	int bpp, rle, cur, badorder;
 	int rlebuflen;
 	zsize = image.zsize;
 	if (rle) {
 		tablen = ysize * zsize * sizeof(Py_Int32);
+		rlebuflen = (int) (1.05 * xsize +10);
+		if ((tablen / sizeof(Py_Int32)) != (ysize * zsize) ||
+		    rlebuflen < 0) {
+			PyErr_NoMemory();
+			goto finally;
+		}
+
 		starttab = (Py_Int32 *)malloc(tablen);
 		lengthtab = (Py_Int32 *)malloc(tablen);
-		rlebuflen = (int) (1.05 * xsize +10);
 		rledat = (unsigned char *)malloc(rlebuflen);
 		if (!starttab || !lengthtab || !rledat) {
 			PyErr_NoMemory();
 
 		fseek(inf, 512 + 2 * tablen, SEEK_SET);
 		cur = 512 + 2 * tablen;
+		new_size = xsize * ysize + TAGLEN;
+		if (new_size < 0 || (new_size * sizeof(Py_Int32)) < 0) {
+			PyErr_NoMemory();
+			goto finally;
+		}
+
 		rv = PyString_FromStringAndSize((char *)NULL,
-				      (xsize * ysize + TAGLEN) * sizeof(Py_Int32));
+				      new_size * sizeof(Py_Int32));
 		if (rv == NULL)
 			goto finally;
 
 			copybw((Py_Int32 *) base, xsize * ysize);
 	}
 	else {
+		new_size = xsize * ysize + TAGLEN;
+		if (new_size < 0 || (new_size * sizeof(Py_Int32)) < 0) {
+			PyErr_NoMemory();
+			goto finally;
+		}
+
 		rv = PyString_FromStringAndSize((char *) 0,
-					   (xsize*ysize+TAGLEN)*sizeof(Py_Int32));
+						new_size*sizeof(Py_Int32));
 		if (rv == NULL)
 			goto finally;
 
 		return NULL;
 	}
 	tablen = ysize * zsize * sizeof(Py_Int32);
+	rlebuflen = (int) (1.05 * xsize + 10);
+
+	if ((tablen / sizeof(Py_Int32)) != (ysize * zsize) ||
+	    rlebuflen < 0 || (xsize * sizeof(Py_Int32)) < 0) {
+		PyErr_NoMemory();
+		goto finally;
+	}
 
 	starttab = (Py_Int32 *)malloc(tablen);
 	lengthtab = (Py_Int32 *)malloc(tablen);
-	rlebuflen = (int) (1.05 * xsize + 10);
 	rlebuf = (unsigned char *)malloc(rlebuflen);
 	lumbuf = (unsigned char *)malloc(xsize * sizeof(Py_Int32));
 	if (!starttab || !lengthtab || !rlebuf || !lumbuf) {

Modules/stropmodule.c

 	char* e;
 	char* p;
 	char* q;
-	Py_ssize_t i, j;
+	Py_ssize_t i, j, old_j;
 	PyObject* out;
 	char* string;
 	Py_ssize_t stringlen;
 	}
 
 	/* First pass: determine size of output string */
-	i = j = 0; /* j: current column; i: total of previous lines */
+	i = j = old_j = 0; /* j: current column; i: total of previous lines */
 	e = string + stringlen;
 	for (p = string; p < e; p++) {
-		if (*p == '\t')
+		if (*p == '\t') {
 			j += tabsize - (j%tabsize);
-		else {
+			if (old_j > j) {
+				PyErr_SetString(PyExc_OverflowError,
+						"new string is too long");
+				return NULL;
+			}
+			old_j = j;
+		} else {
 			j++;
 			if (*p == '\n') {
 				i += j;
 		}
 	}
 
+	if ((i + j) < 0) {
+		PyErr_SetString(PyExc_OverflowError, "new string is too long");
+		return NULL;
+	}
+
 	/* Second pass: create output string and fill it */
 	out = PyString_FromStringAndSize(NULL, i+j);
 	if (out == NULL)

Objects/bufferobject.c

 				"size must be zero or positive");
 		return NULL;
 	}
-	/* XXX: check for overflow in multiply */
+	if (sizeof(*b) > PY_SSIZE_T_MAX - size) {
+		/* unlikely */
+		return PyErr_NoMemory();
+	}
 	/* Inline PyObject_New */
 	o = (PyObject *)PyObject_MALLOC(sizeof(*b) + size);
 	if ( o == NULL )
 	if ( (count = (*pb->bf_getreadbuffer)(other, 0, &ptr2)) < 0 )
 		return NULL;
 
+	assert(count <= PY_SIZE_MAX - size);
+
  	ob = PyString_FromStringAndSize(NULL, size + count);
 	if ( ob == NULL )
 		return NULL;

Objects/listobject.c

 	 * system realloc().
 	 * The growth pattern is:  0, 4, 8, 16, 25, 35, 46, 58, 72, 88, ...
 	 */
-	new_allocated = (newsize >> 3) + (newsize < 9 ? 3 : 6) + newsize;
+	new_allocated = (newsize >> 3) + (newsize < 9 ? 3 : 6);
+
+	/* check for integer overflow */
+	if (new_allocated > PY_SIZE_MAX - newsize) {
+		PyErr_NoMemory();
+		return -1;
+	} else {
+		new_allocated += newsize;
+	}
+
 	if (newsize == 0)
 		new_allocated = 0;
 	items = self->ob_item;
 		return NULL;
 	}
 	nbytes = size * sizeof(PyObject *);
-	/* Check for overflow */
-	if (nbytes / sizeof(PyObject *) != (size_t)size)
+	/* Check for overflow without an actual overflow,
+	 *  which can cause compiler to optimise out */
+	if (size > PY_SIZE_MAX / sizeof(PyObject *))
 		return PyErr_NoMemory();
 	if (num_free_lists) {
 		num_free_lists--;
 	 * we don't care what's in the block.
 	 */
 	merge_freemem(ms);
+	if (need > PY_SSIZE_T_MAX / sizeof(PyObject*)) {
+		PyErr_NoMemory();
+		return -1;
+	}
 	ms->a = (PyObject **)PyMem_Malloc(need * sizeof(PyObject*));
 	if (ms->a) {
 		ms->alloced = need;
 				step = -step;
 			}
 
+			assert(slicelength <= PY_SIZE_MAX / sizeof(PyObject*));
+
 			garbage = (PyObject**)
 				PyMem_MALLOC(slicelength*sizeof(PyObject*));
 			if (!garbage) {

Objects/obmalloc.c

 		numarenas = maxarenas ? maxarenas << 1 : INITIAL_ARENA_OBJECTS;
 		if (numarenas <= maxarenas)
 			return NULL;	/* overflow */
+		if (numarenas > PY_SIZE_MAX / sizeof(*arenas))
+			return NULL;	/* overflow */
 		nbytes = numarenas * sizeof(*arenas);
-		if (nbytes / sizeof(*arenas) != numarenas)
-			return NULL;	/* overflow */
 		arenaobj = (struct arena_object *)realloc(arenas, nbytes);
 		if (arenaobj == NULL)
 			return NULL;
 	if (current_capacity < 0 || required_capacity < 0)
 		return E_OVERFLOW;
 	if (current_capacity < required_capacity) {
+		if (required_capacity > PY_SIZE_MAX / sizeof(node)) {
+			return E_NOMEM;
+		}
 		n = n1->n_child;
 		n = (node *) PyObject_REALLOC(n,
 					      required_capacity * sizeof(node));
 asdl_seq_new(int size, PyArena *arena)
 {
 	asdl_seq *seq = NULL;
-	size_t n = sizeof(asdl_seq) +
-			(size ? (sizeof(void *) * (size - 1)) : 0);
+	size_t n = (size ? (sizeof(void *) * (size - 1)) : 0);
+
+	/* check size is sane */
+	if (size < 0 || size == INT_MIN || 
+		(size && ((size - 1) > (PY_SIZE_MAX / sizeof(void *))))) {
+		PyErr_NoMemory();
+		return NULL;
+	}
+
+	/* check if size can be added safely */
+	if (n > PY_SIZE_MAX - sizeof(asdl_seq)) {
+		PyErr_NoMemory();
+		return NULL;
+	}
+
+	n += sizeof(asdl_seq);
 
 	seq = (asdl_seq *)PyArena_Malloc(arena, n);
 	if (!seq) {
 asdl_int_seq_new(int size, PyArena *arena)
 {
 	asdl_int_seq *seq = NULL;
-	size_t n = sizeof(asdl_seq) +
-			(size ? (sizeof(int) * (size - 1)) : 0);
+	size_t n = (size ? (sizeof(void *) * (size - 1)) : 0);
+
+	/* check size is sane */
+	if (size < 0 || size == INT_MIN || 
+		(size && ((size - 1) > (PY_SIZE_MAX / sizeof(void *))))) {
+			PyErr_NoMemory();
+			return NULL;
+	}
+
+	/* check if size can be added safely */
+	if (n > PY_SIZE_MAX - sizeof(asdl_seq)) {
+		PyErr_NoMemory();
+		return NULL;
+	}
+
+	n += sizeof(asdl_seq);
 
 	seq = (asdl_int_seq *)PyArena_Malloc(arena, n);
 	if (!seq) {
 	     	buf = (char *)s;
 		u = NULL;
 	} else {
+		/* check for integer overflow */
+		if (len > PY_SIZE_MAX / 4)
+			return NULL;
 		/* "\XX" may become "\u005c\uHHLL" (12 bytes) */
 		u = PyString_FromStringAndSize((char *)NULL, len * 4);
 		if (u == NULL)

Python/bltinmodule.c

 					PyString_AS_STRING(item)[0];
 			} else {
 				/* do we need more space? */
-				Py_ssize_t need = j + reslen + len-i-1;
+				Py_ssize_t need = j;
+
+				/* calculate space requirements while checking for overflow */
+				if (need > PY_SSIZE_T_MAX - reslen) {
+					Py_DECREF(item);
+					goto Fail_1;
+				}
+
+				need += reslen;
+
+				if (need > PY_SSIZE_T_MAX - len) {
+					Py_DECREF(item);
+					goto Fail_1;
+				}
+
+				need += len;
+
+				if (need <= i) {
+					Py_DECREF(item);
+					goto Fail_1;
+				}
+
+				need = need - i - 1;
+
+				assert(need >= 0);
+				assert(outlen >= 0);
+
 				if (need > outlen) {
 					/* overallocate, to avoid reallocations */
-					if (need<2*outlen)
+					if (outlen > PY_SSIZE_T_MAX / 2) {
+						Py_DECREF(item);
+						return NULL;
+					}
+
+					if (need<2*outlen) {
 						need = 2*outlen;
+          }
 					if (_PyString_Resize(&result, need)) {
 						Py_DECREF(item);
 						return NULL;
 			else {
 				/* do we need more space? */
 				Py_ssize_t need = j + reslen + len - i - 1;
+        
+				/* check that didnt overflow */
+				if ((j > PY_SSIZE_T_MAX - reslen) ||
+					((j + reslen) > PY_SSIZE_T_MAX - len) ||
+						((j + reslen + len) < i) ||
+							((j + reslen + len - i) <= 0)) {
+					Py_DECREF(item);
+					return NULL;
+				}
+
+				assert(need >= 0);
+				assert(outlen >= 0);
+				
 				if (need > outlen) {
 					/* overallocate,
 					   to avoid reallocations */
-					if (need < 2 * outlen)
-						need = 2 * outlen;
+					if (need < 2 * outlen) {
+            if (outlen > PY_SSIZE_T_MAX / 2) {
+              Py_DECREF(item);
+              return NULL;
+						} else {
+							need = 2 * outlen;
+				    }
+          }
+
 					if (PyUnicode_Resize(
 						&result, need) < 0) {
 						Py_DECREF(item);
 		return ident; /* Don't mangle if class is just underscores */
 	}
 	plen = strlen(p);
+
+	assert(1 <= PY_SSIZE_T_MAX - nlen);
+	assert(1 + nlen <= PY_SSIZE_T_MAX - plen);
+
 	ident = PyString_FromStringAndSize(NULL, 1 + nlen + plen);
 	if (!ident)
 		return 0;
 	unsigned int *blocks = (unsigned int *)PyMem_Malloc(len*sizeof(int));
 	int i,j, opcode, blockcnt = 0;
 
+	assert(len <= PY_SIZE_MAX / sizeof(int));
+
 	if (blocks == NULL) {
 		PyErr_NoMemory();
 		return NULL;
 		size_t oldsize, newsize;
 		oldsize = b->b_ialloc * sizeof(struct instr);
 		newsize = oldsize << 1;
+
+		if (oldsize > (PY_SIZE_MAX >> 1)) {
+			PyErr_NoMemory();
+			return -1;
+		}
+
 		if (newsize == 0) {
 			PyErr_NoMemory();
 			return -1;
 	a->a_lnotab = PyString_FromStringAndSize(NULL, DEFAULT_LNOTAB_SIZE);
 	if (!a->a_lnotab)
 		return 0;
+	if (nblocks > PY_SIZE_MAX / sizeof(basicblock *)) {
+		PyErr_NoMemory();
+		return 0;
+	}
 	a->a_postorder = (basicblock **)PyObject_Malloc(
 					    sizeof(basicblock *) * nblocks);
 	if (!a->a_postorder) {
 		nbytes = a->a_lnotab_off + 2 * ncodes;
 		len = PyString_GET_SIZE(a->a_lnotab);
 		if (nbytes >= len) {
-			if (len * 2 < nbytes)
+			if ((len <= INT_MAX / 2) && (len * 2 < nbytes))
 				len = nbytes;
-			else
+			else if (len <= INT_MAX / 2)
 				len *= 2;
+			else {
+				PyErr_NoMemory();
+				return 0;
+			}
 			if (_PyString_Resize(&a->a_lnotab, len) < 0)
 				return 0;
 		}
 		nbytes = a->a_lnotab_off + 2 * ncodes;
 		len = PyString_GET_SIZE(a->a_lnotab);
 		if (nbytes >= len) {
-			if (len * 2 < nbytes)
+			if ((len <= INT_MAX / 2) && len * 2 < nbytes)
 				len = nbytes;
-			else
+			else if (len <= INT_MAX / 2)
 				len *= 2;
+			else {
+				PyErr_NoMemory();
+				return 0;
+			}
 			if (_PyString_Resize(&a->a_lnotab, len) < 0)
 				return 0;
 		}
 	if (i->i_lineno && !assemble_lnotab(a, i))
 		return 0;
 	if (a->a_offset + size >= len) {
+		if (len > PY_SSIZE_T_MAX / 2)
+			return 0;
 		if (_PyString_Resize(&a->a_bytecode, len * 2) < 0)
 		    return 0;
 	}