[Python-checkins] cpython (3.2): Issue #23055: Fixed a buffer overflow in PyUnicode_FromFormatV. Analysis
serhiy.storchaka
python-checkins at python.org
Tue Jan 27 21:33:37 CET 2015
https://hg.python.org/cpython/rev/f849f937f78c
changeset: 94339:f849f937f78c
branch: 3.2
parent: 94018:1ce98e85929d
user: Serhiy Storchaka <storchaka at gmail.com>
date: Tue Jan 27 22:18:34 2015 +0200
summary:
Issue #23055: Fixed a buffer overflow in PyUnicode_FromFormatV. Analysis
and fix by Guido Vranken.
files:
Lib/test/test_unicode.py | 141 ++++++++++++++++++++++++--
Misc/NEWS | 12 ++
Objects/unicodeobject.c | 37 +++---
3 files changed, 159 insertions(+), 31 deletions(-)
diff --git a/Lib/test/test_unicode.py b/Lib/test/test_unicode.py
--- a/Lib/test/test_unicode.py
+++ b/Lib/test/test_unicode.py
@@ -1661,7 +1661,10 @@
# Test PyUnicode_FromFormat()
def test_from_format(self):
support.import_module('ctypes')
- from ctypes import pythonapi, py_object, c_int
+ from ctypes import (
+ pythonapi, py_object, sizeof,
+ c_int, c_long, c_longlong, c_ssize_t,
+ c_uint, c_ulong, c_ulonglong, c_size_t, c_void_p)
if sys.maxunicode == 65535:
name = "PyUnicodeUCS2_FromFormat"
else:
@@ -1675,9 +1678,13 @@
for arg in args)
return _PyUnicode_FromFormat(format, *cargs)
+ def check_format(expected, format, *args):
+ text = PyUnicode_FromFormat(format, *args)
+ self.assertEqual(expected, text)
+
# ascii format, non-ascii argument
- text = PyUnicode_FromFormat(b'ascii\x7f=%U', 'unicode\xe9')
- self.assertEqual(text, 'ascii\x7f=unicode\xe9')
+ check_format('ascii\x7f=unicode\xe9',
+ b'ascii\x7f=%U', 'unicode\xe9')
# non-ascii format, ascii argument: ensure that PyUnicode_FromFormatV()
# raises an error
@@ -1686,25 +1693,131 @@
'string, got a non-ASCII byte: 0xe9$',
PyUnicode_FromFormat, b'unicode\xe9=%s', 'ascii')
- self.assertEqual(PyUnicode_FromFormat(b'%c', c_int(0xabcd)), '\uabcd')
- self.assertEqual(PyUnicode_FromFormat(b'%c', c_int(0x10ffff)), '\U0010ffff')
+ # test "%c"
+ check_format('\uabcd',
+ b'%c', c_int(0xabcd))
+ check_format('\U0010ffff',
+ b'%c', c_int(0x10ffff))
+ with self.assertRaises(OverflowError):
+ PyUnicode_FromFormat(b'%c', c_int(0x110000))
+ # Issue #18183
+ check_format('\U00010000\U00100000',
+ b'%c%c', c_int(0x10000), c_int(0x100000))
- # other tests
- text = PyUnicode_FromFormat(b'%%A:%A', 'abc\xe9\uabcd\U0010ffff')
- self.assertEqual(text, r"%A:'abc\xe9\uabcd\U0010ffff'")
+ # test "%"
+ check_format('%',
+ b'%')
+ check_format('%',
+ b'%%')
+ check_format('%s',
+ b'%%s')
+ check_format('[%]',
+ b'[%%]')
+ check_format('%abc',
+ b'%%%s', b'abc')
- text = PyUnicode_FromFormat(b'repr=%V', 'abc', b'xyz')
- self.assertEqual(text, 'repr=abc')
+ # test %S
+ check_format("repr=\u20acABC",
+ b'repr=%S', '\u20acABC')
+
+ # test %R
+ check_format("repr='\u20acABC'",
+ b'repr=%R', '\u20acABC')
+
+ # test integer formats (%i, %d, %u)
+ check_format('010',
+ b'%03i', c_int(10))
+ check_format('0010',
+ b'%0.4i', c_int(10))
+ check_format('-123',
+ b'%i', c_int(-123))
+
+ check_format('-123',
+ b'%d', c_int(-123))
+ check_format('-123',
+ b'%ld', c_long(-123))
+ check_format('-123',
+ b'%lld', c_longlong(-123))
+ check_format('-123',
+ b'%zd', c_ssize_t(-123))
+
+ check_format('123',
+ b'%u', c_uint(123))
+ check_format('123',
+ b'%lu', c_ulong(123))
+ check_format('123',
+ b'%llu', c_ulonglong(123))
+ check_format('123',
+ b'%zu', c_size_t(123))
+
+ # test long output
+ min_longlong = -(2 ** (8 * sizeof(c_longlong) - 1))
+ max_longlong = -min_longlong - 1
+ check_format(str(min_longlong),
+ b'%lld', c_longlong(min_longlong))
+ check_format(str(max_longlong),
+ b'%lld', c_longlong(max_longlong))
+ max_ulonglong = 2 ** (8 * sizeof(c_ulonglong)) - 1
+ check_format(str(max_ulonglong),
+ b'%llu', c_ulonglong(max_ulonglong))
+ PyUnicode_FromFormat(b'%p', c_void_p(-1))
+
+ # test padding (width and/or precision)
+ check_format('123'.rjust(10, '0'),
+ b'%010i', c_int(123))
+ check_format('123'.rjust(100),
+ b'%100i', c_int(123))
+ check_format('123'.rjust(100, '0'),
+ b'%.100i', c_int(123))
+ check_format('123'.rjust(80, '0').rjust(100),
+ b'%100.80i', c_int(123))
+
+ check_format('123'.rjust(10, '0'),
+ b'%010u', c_uint(123))
+ check_format('123'.rjust(100),
+ b'%100u', c_uint(123))
+ check_format('123'.rjust(100, '0'),
+ b'%.100u', c_uint(123))
+ check_format('123'.rjust(80, '0').rjust(100),
+ b'%100.80u', c_uint(123))
+
+ check_format('123'.rjust(10, '0'),
+ b'%010x', c_int(0x123))
+ check_format('123'.rjust(100),
+ b'%100x', c_int(0x123))
+ check_format('123'.rjust(100, '0'),
+ b'%.100x', c_int(0x123))
+ check_format('123'.rjust(80, '0').rjust(100),
+ b'%100.80x', c_int(0x123))
+
+ # test %A
+ check_format(r"%A:'abc\xe9\uabcd\U0010ffff'",
+ b'%%A:%A', 'abc\xe9\uabcd\U0010ffff')
+
+ # test %V
+ check_format('repr=abc',
+ b'repr=%V', 'abc', b'xyz')
# Test string decode from parameter of %s using utf-8.
# b'\xe4\xba\xba\xe6\xb0\x91' is utf-8 encoded byte sequence of
# '\u4eba\u6c11'
- text = PyUnicode_FromFormat(b'repr=%V', None, b'\xe4\xba\xba\xe6\xb0\x91')
- self.assertEqual(text, 'repr=\u4eba\u6c11')
+ check_format('repr=\u4eba\u6c11',
+ b'repr=%V', None, b'\xe4\xba\xba\xe6\xb0\x91')
#Test replace error handler.
- text = PyUnicode_FromFormat(b'repr=%V', None, b'abc\xff')
- self.assertEqual(text, 'repr=abc\ufffd')
+ check_format('repr=abc\ufffd',
+ b'repr=%V', None, b'abc\xff')
+
+ # not supported: copy the raw format string. these tests are just here
+ # to check for crashs and should not be considered as specifications
+ check_format('%s',
+ b'%1%s', b'abc')
+ check_format('%1abc',
+ b'%1abc')
+ check_format('%+i',
+ b'%+i', c_int(10))
+ check_format('%s',
+ b'%.%s', b'abc')
# Test PyUnicode_AsWideChar()
def test_aswidechar(self):
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -2,6 +2,18 @@
Python News
+++++++++++
+What's New in Python 3.2.7?
+============================
+
+*Release date: XXXX-XX-XX*
+
+Core and Builtins
+-----------------
+
+- Issue #23055: Fixed a buffer overflow in PyUnicode_FromFormatV. Analysis
+ and fix by Guido Vranken.
+
+
What's New in Python 3.2.6?
===========================
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -759,15 +759,10 @@
* result in an array) */
for (f = format; *f; f++) {
if (*f == '%') {
- if (*(f+1)=='%')
- continue;
- if (*(f+1)=='S' || *(f+1)=='R' || *(f+1)=='A' || *(f+1) == 'V')
- ++callcount;
- while (Py_ISDIGIT((unsigned)*f))
- width = (width*10) + *f++ - '0';
- while (*++f && *f != '%' && !Py_ISALPHA((unsigned)*f))
- ;
- if (*f == 's')
+ f++;
+ while (*f && *f != '%' && !Py_ISALPHA((unsigned)*f))
+ f++;
+ if (*f == 's' || *f=='S' || *f=='R' || *f=='A' || *f=='V')
++callcount;
}
else if (128 <= (unsigned char)*f) {
@@ -794,12 +789,16 @@
#ifdef HAVE_LONG_LONG
int longlongflag = 0;
#endif
- const char* p = f;
+ const char* p = f++;
width = 0;
while (Py_ISDIGIT((unsigned)*f))
width = (width*10) + *f++ - '0';
- while (*++f && *f != '%' && !Py_ISALPHA((unsigned)*f))
- ;
+ precision = 0;
+ if (*f == '.') {
+ f++;
+ while (Py_ISDIGIT((unsigned)*f))
+ precision = (precision*10) + *f++ - '0';
+ }
/* skip the 'l' or 'z' in {%ld, %zd, %lu, %zu} since
* they don't affect the amount of space we reserve.
@@ -823,16 +822,18 @@
switch (*f) {
case 'c':
{
+ int ordinal = va_arg(count, int);
+ if (ordinal < 0 || ordinal > 0x10ffff) {
+ PyErr_SetString(PyExc_OverflowError,
+ "%c arg not in range(0x110000)");
+ goto fail;
+ }
#ifndef Py_UNICODE_WIDE
- int ordinal = va_arg(count, int);
if (ordinal > 0xffff)
n += 2;
else
- n++;
-#else
- (void)va_arg(count, int);
+#endif
n++;
-#endif
break;
}
case '%':
@@ -840,6 +841,8 @@
break;
case 'd': case 'u': case 'i': case 'x':
(void) va_arg(count, int);
+ if (width < precision)
+ width = precision;
#ifdef HAVE_LONG_LONG
if (longlongflag) {
if (width < MAX_LONG_LONG_CHARS)
--
Repository URL: https://hg.python.org/cpython
More information about the Python-checkins
mailing list