diff options
| -rw-r--r-- | Include/bytearrayobject.h | 6 | ||||
| -rw-r--r-- | Lib/test/test_bytes.py | 7 | ||||
| -rw-r--r-- | Misc/NEWS | 5 | ||||
| -rw-r--r-- | Objects/bytearrayobject.c | 23 |
4 files changed, 23 insertions, 18 deletions
diff --git a/Include/bytearrayobject.h b/Include/bytearrayobject.h index 265b4bb..8702e5a 100644 --- a/Include/bytearrayobject.h +++ b/Include/bytearrayobject.h @@ -44,9 +44,13 @@ PyAPI_FUNC(char *) PyByteArray_AsString(PyObject *); PyAPI_FUNC(int) PyByteArray_Resize(PyObject *, Py_ssize_t); /* Macros, trading safety for speed */ -#define PyByteArray_AS_STRING(self) (assert(PyByteArray_Check(self)),((PyByteArrayObject *)(self))->ob_bytes) +#define PyByteArray_AS_STRING(self) \ + (assert(PyByteArray_Check(self)), \ + Py_SIZE(self) ? ((PyByteArrayObject *)(self))->ob_bytes : _PyByteArray_empty_string) #define PyByteArray_GET_SIZE(self) (assert(PyByteArray_Check(self)),Py_SIZE(self)) +extern char _PyByteArray_empty_string[]; + #ifdef __cplusplus } #endif diff --git a/Lib/test/test_bytes.py b/Lib/test/test_bytes.py index f2c9aa3..666894f 100644 --- a/Lib/test/test_bytes.py +++ b/Lib/test/test_bytes.py @@ -783,6 +783,13 @@ class ByteArrayTest(BaseBytesTest): self.assertRaises(BufferError, delslice) self.assertEquals(b, orig) + def test_empty_bytearray(self): + # Issue #7561: operations on empty bytearrays could crash in many + # situations, due to a fragile implementation of the + # PyByteArray_AS_STRING() C macro. + self.assertRaises(ValueError, int, bytearray(b'')) + + class AssortedBytesTest(unittest.TestCase): # # Test various combinations of bytes and bytearray @@ -12,6 +12,11 @@ What's New in Python 2.7 alpha 3? Core and Builtins ----------------- +- Issue #7561: Operations on empty bytearrays (such as `int(bytearray())`) + could crash in many places because of the PyByteArray_AS_STRING() macro + returning NULL. The macro now returns a statically allocated empty + string instead. + - Issue #7622: Improve the split(), rsplit(), splitlines() and replace() methods of bytes, bytearray and unicode objects by using a common implementation based on stringlib's fast search. Patch by Florent Xicluna. diff --git a/Objects/bytearrayobject.c b/Objects/bytearrayobject.c index 308bd07..fdeec4c 100644 --- a/Objects/bytearrayobject.c +++ b/Objects/bytearrayobject.c @@ -5,23 +5,16 @@ #include "structmember.h" #include "bytes_methods.h" -static PyByteArrayObject *nullbytes = NULL; +char _PyByteArray_empty_string[] = ""; void PyByteArray_Fini(void) { - Py_CLEAR(nullbytes); } int PyByteArray_Init(void) { - nullbytes = PyObject_New(PyByteArrayObject, &PyByteArray_Type); - if (nullbytes == NULL) - return 0; - nullbytes->ob_bytes = NULL; - Py_SIZE(nullbytes) = nullbytes->ob_alloc = 0; - nullbytes->ob_exports = 0; return 1; } @@ -74,7 +67,7 @@ bytearray_buffer_getreadbuf(PyByteArrayObject *self, Py_ssize_t index, const voi "accessing non-existent bytes segment"); return -1; } - *ptr = (void *)self->ob_bytes; + *ptr = (void *)PyByteArray_AS_STRING(self); return Py_SIZE(self); } @@ -86,7 +79,7 @@ bytearray_buffer_getwritebuf(PyByteArrayObject *self, Py_ssize_t index, const vo "accessing non-existent bytes segment"); return -1; } - *ptr = (void *)self->ob_bytes; + *ptr = (void *)PyByteArray_AS_STRING(self); return Py_SIZE(self); } @@ -106,7 +99,7 @@ bytearray_buffer_getcharbuf(PyByteArrayObject *self, Py_ssize_t index, const cha "accessing non-existent bytes segment"); return -1; } - *ptr = self->ob_bytes; + *ptr = PyByteArray_AS_STRING(self); return Py_SIZE(self); } @@ -119,10 +112,7 @@ bytearray_getbuffer(PyByteArrayObject *obj, Py_buffer *view, int flags) obj->ob_exports++; return 0; } - if (obj->ob_bytes == NULL) - ptr = ""; - else - ptr = obj->ob_bytes; + ptr = (void *) PyByteArray_AS_STRING(obj); ret = PyBuffer_FillInfo(view, (PyObject*)obj, ptr, Py_SIZE(obj), 0, flags); if (ret >= 0) { obj->ob_exports++; @@ -201,7 +191,7 @@ PyByteArray_FromStringAndSize(const char *bytes, Py_ssize_t size) Py_DECREF(new); return PyErr_NoMemory(); } - if (bytes != NULL) + if (bytes != NULL && size > 0) memcpy(new->ob_bytes, bytes, size); new->ob_bytes[size] = '\0'; /* Trailing null byte */ } @@ -1114,7 +1104,6 @@ bytearray_dealloc(PyByteArrayObject *self) #define STRINGLIB_LEN PyByteArray_GET_SIZE #define STRINGLIB_STR PyByteArray_AS_STRING #define STRINGLIB_NEW PyByteArray_FromStringAndSize -#define STRINGLIB_EMPTY nullbytes #define STRINGLIB_ISSPACE Py_ISSPACE #define STRINGLIB_ISLINEBREAK(x) ((x == '\n') || (x == '\r')) #define STRINGLIB_CHECK_EXACT PyByteArray_CheckExact |