diff --git a/Doc/data/python3.14.abi b/Doc/data/python3.14.abi index c13b44e0945389..88792d211ae2c3 100644 --- a/Doc/data/python3.14.abi +++ b/Doc/data/python3.14.abi @@ -1130,7 +1130,6 @@ - @@ -1448,7 +1447,6 @@ - @@ -24180,21 +24178,6 @@ - - - - - - - - - - - - - - - diff --git a/Include/internal/pycore_bytesobject.h b/Include/internal/pycore_bytesobject.h index 300e7f4896a39e..8ea9b3ebb88454 100644 --- a/Include/internal/pycore_bytesobject.h +++ b/Include/internal/pycore_bytesobject.h @@ -20,8 +20,9 @@ extern PyObject* _PyBytes_FromHex( // Helper for PyBytes_DecodeEscape that detects invalid escape chars. // Export for test_peg_generator. -PyAPI_FUNC(PyObject*) _PyBytes_DecodeEscape(const char *, Py_ssize_t, - const char *, const char **); +PyAPI_FUNC(PyObject*) _PyBytes_DecodeEscape2(const char *, Py_ssize_t, + const char *, + int *, const char **); // Substring Search. diff --git a/Include/internal/pycore_unicodeobject.h b/Include/internal/pycore_unicodeobject.h index c85d53b89accdb..3791b913c17546 100644 --- a/Include/internal/pycore_unicodeobject.h +++ b/Include/internal/pycore_unicodeobject.h @@ -139,14 +139,18 @@ extern PyObject* _PyUnicode_DecodeUnicodeEscapeStateful( // Helper for PyUnicode_DecodeUnicodeEscape that detects invalid escape // chars. // Export for test_peg_generator. -PyAPI_FUNC(PyObject*) _PyUnicode_DecodeUnicodeEscapeInternal( +PyAPI_FUNC(PyObject*) _PyUnicode_DecodeUnicodeEscapeInternal2( const char *string, /* Unicode-Escape encoded string */ Py_ssize_t length, /* size of string */ const char *errors, /* error handling */ Py_ssize_t *consumed, /* bytes consumed */ - const char **first_invalid_escape); /* on return, points to first - invalid escaped char in - string. */ + int *first_invalid_escape_char, /* on return, if not -1, contain the first + invalid escaped char (<= 0xff) or invalid + octal escape (> 0xff) in string. */ + const char **first_invalid_escape_ptr); /* on return, if not NULL, may + point to the first invalid escaped + char in string. + May be NULL if errors is not NULL. */ /* --- Raw-Unicode-Escape Codecs ---------------------------------------------- */ diff --git a/Lib/test/test_codeccallbacks.py b/Lib/test/test_codeccallbacks.py index 86e5e5c1474674..a767f67a02cf56 100644 --- a/Lib/test/test_codeccallbacks.py +++ b/Lib/test/test_codeccallbacks.py @@ -2,6 +2,7 @@ import codecs import html.entities import itertools +import re import sys import unicodedata import unittest @@ -1125,7 +1126,7 @@ def test_bug828737(self): text = 'abcghi'*n text.translate(charmap) - def test_mutatingdecodehandler(self): + def test_mutating_decode_handler(self): baddata = [ ("ascii", b"\xff"), ("utf-7", b"++"), @@ -1160,6 +1161,42 @@ def mutating(exc): for (encoding, data) in baddata: self.assertEqual(data.decode(encoding, "test.mutating"), "\u4242") + def test_mutating_decode_handler_unicode_escape(self): + decode = codecs.unicode_escape_decode + def mutating(exc): + if isinstance(exc, UnicodeDecodeError): + r = data.get(exc.object[:exc.end]) + if r is not None: + exc.object = r[0] + exc.object[exc.end:] + return ('\u0404', r[1]) + raise AssertionError("don't know how to handle %r" % exc) + + codecs.register_error('test.mutating2', mutating) + data = { + br'\x0': (b'\\', 0), + br'\x3': (b'xxx\\', 3), + br'\x5': (b'x\\', 1), + } + def check(input, expected, msg): + with self.assertWarns(DeprecationWarning) as cm: + self.assertEqual(decode(input, 'test.mutating2'), (expected, len(input))) + self.assertIn(msg, str(cm.warning)) + + check(br'\x0n\z', '\u0404\n\\z', r'"\z" is an invalid escape sequence') + check(br'\x0n\501', '\u0404\n\u0141', r'"\501" is an invalid octal escape sequence') + check(br'\x0z', '\u0404\\z', r'"\z" is an invalid escape sequence') + + check(br'\x3n\zr', '\u0404\n\\zr', r'"\z" is an invalid escape sequence') + check(br'\x3zr', '\u0404\\zr', r'"\z" is an invalid escape sequence') + check(br'\x3z5', '\u0404\\z5', r'"\z" is an invalid escape sequence') + check(memoryview(br'\x3z5x')[:-1], '\u0404\\z5', r'"\z" is an invalid escape sequence') + check(memoryview(br'\x3z5xy')[:-2], '\u0404\\z5', r'"\z" is an invalid escape sequence') + + check(br'\x5n\z', '\u0404\n\\z', r'"\z" is an invalid escape sequence') + check(br'\x5n\501', '\u0404\n\u0141', r'"\501" is an invalid octal escape sequence') + check(br'\x5z', '\u0404\\z', r'"\z" is an invalid escape sequence') + check(memoryview(br'\x5zy')[:-1], '\u0404\\z', r'"\z" is an invalid escape sequence') + # issue32583 def test_crashing_decode_handler(self): # better generating one more character to fill the extra space slot diff --git a/Lib/test/test_codecs.py b/Lib/test/test_codecs.py index 94fcf98e75721f..d42270da15ee32 100644 --- a/Lib/test/test_codecs.py +++ b/Lib/test/test_codecs.py @@ -1196,23 +1196,39 @@ def test_escape(self): check(br"[\1010]", b"[A0]") check(br"[\x41]", b"[A]") check(br"[\x410]", b"[A0]") + + def test_warnings(self): + decode = codecs.escape_decode + check = coding_checker(self, decode) for i in range(97, 123): b = bytes([i]) if b not in b'abfnrtvx': - with self.assertWarns(DeprecationWarning): + with self.assertWarnsRegex(DeprecationWarning, + r'"\\%c" is an invalid escape sequence' % i): check(b"\\" + b, b"\\" + b) - with self.assertWarns(DeprecationWarning): + with self.assertWarnsRegex(DeprecationWarning, + r'"\\%c" is an invalid escape sequence' % (i-32)): check(b"\\" + b.upper(), b"\\" + b.upper()) - with self.assertWarns(DeprecationWarning): + with self.assertWarnsRegex(DeprecationWarning, + r'"\\8" is an invalid escape sequence'): check(br"\8", b"\\8") with self.assertWarns(DeprecationWarning): check(br"\9", b"\\9") - with self.assertWarns(DeprecationWarning): + with self.assertWarnsRegex(DeprecationWarning, + r'"\\\xfa" is an invalid escape sequence') as cm: check(b"\\\xfa", b"\\\xfa") for i in range(0o400, 0o1000): - with self.assertWarns(DeprecationWarning): + with self.assertWarnsRegex(DeprecationWarning, + r'"\\%o" is an invalid octal escape sequence' % i): check(rb'\%o' % i, bytes([i & 0o377])) + with self.assertWarnsRegex(DeprecationWarning, + r'"\\z" is an invalid escape sequence'): + self.assertEqual(decode(br'\x\z', 'ignore'), (b'\\z', 4)) + with self.assertWarnsRegex(DeprecationWarning, + r'"\\501" is an invalid octal escape sequence'): + self.assertEqual(decode(br'\x\501', 'ignore'), (b'A', 6)) + def test_errors(self): decode = codecs.escape_decode self.assertRaises(ValueError, decode, br"\x") @@ -2661,24 +2677,40 @@ def test_escape_decode(self): check(br"[\x410]", "[A0]") check(br"\u20ac", "\u20ac") check(br"\U0001d120", "\U0001d120") + + def test_decode_warnings(self): + decode = codecs.unicode_escape_decode + check = coding_checker(self, decode) for i in range(97, 123): b = bytes([i]) if b not in b'abfnrtuvx': - with self.assertWarns(DeprecationWarning): + with self.assertWarnsRegex(DeprecationWarning, + r'"\\%c" is an invalid escape sequence' % i): check(b"\\" + b, "\\" + chr(i)) if b.upper() not in b'UN': - with self.assertWarns(DeprecationWarning): + with self.assertWarnsRegex(DeprecationWarning, + r'"\\%c" is an invalid escape sequence' % (i-32)): check(b"\\" + b.upper(), "\\" + chr(i-32)) - with self.assertWarns(DeprecationWarning): + with self.assertWarnsRegex(DeprecationWarning, + r'"\\8" is an invalid escape sequence'): check(br"\8", "\\8") with self.assertWarns(DeprecationWarning): check(br"\9", "\\9") - with self.assertWarns(DeprecationWarning): + with self.assertWarnsRegex(DeprecationWarning, + r'"\\\xfa" is an invalid escape sequence') as cm: check(b"\\\xfa", "\\\xfa") for i in range(0o400, 0o1000): - with self.assertWarns(DeprecationWarning): + with self.assertWarnsRegex(DeprecationWarning, + r'"\\%o" is an invalid octal escape sequence' % i): check(rb'\%o' % i, chr(i)) + with self.assertWarnsRegex(DeprecationWarning, + r'"\\z" is an invalid escape sequence'): + self.assertEqual(decode(br'\x\z', 'ignore'), ('\\z', 4)) + with self.assertWarnsRegex(DeprecationWarning, + r'"\\501" is an invalid octal escape sequence'): + self.assertEqual(decode(br'\x\501', 'ignore'), ('\u0141', 6)) + def test_decode_errors(self): decode = codecs.unicode_escape_decode for c, d in (b'x', 2), (b'u', 4), (b'U', 4): diff --git a/Misc/NEWS.d/next/Security/2025-05-09-20-22-54.gh-issue-133767.kN2i3Q.rst b/Misc/NEWS.d/next/Security/2025-05-09-20-22-54.gh-issue-133767.kN2i3Q.rst new file mode 100644 index 00000000000000..39d2f1e1a892cf --- /dev/null +++ b/Misc/NEWS.d/next/Security/2025-05-09-20-22-54.gh-issue-133767.kN2i3Q.rst @@ -0,0 +1,2 @@ +Fix use-after-free in the "unicode-escape" decoder with a non-"strict" error +handler. diff --git a/Objects/bytesobject.c b/Objects/bytesobject.c index fc407ec6bf99d6..87ea1162e03513 100644 --- a/Objects/bytesobject.c +++ b/Objects/bytesobject.c @@ -1075,10 +1075,11 @@ _PyBytes_FormatEx(const char *format, Py_ssize_t format_len, } /* Unescape a backslash-escaped string. */ -PyObject *_PyBytes_DecodeEscape(const char *s, +PyObject *_PyBytes_DecodeEscape2(const char *s, Py_ssize_t len, const char *errors, - const char **first_invalid_escape) + int *first_invalid_escape_char, + const char **first_invalid_escape_ptr) { int c; char *p; @@ -1092,7 +1093,8 @@ PyObject *_PyBytes_DecodeEscape(const char *s, return NULL; writer.overallocate = 1; - *first_invalid_escape = NULL; + *first_invalid_escape_char = -1; + *first_invalid_escape_ptr = NULL; end = s + len; while (s < end) { @@ -1130,9 +1132,10 @@ PyObject *_PyBytes_DecodeEscape(const char *s, c = (c<<3) + *s++ - '0'; } if (c > 0377) { - if (*first_invalid_escape == NULL) { - *first_invalid_escape = s-3; /* Back up 3 chars, since we've - already incremented s. */ + if (*first_invalid_escape_char == -1) { + *first_invalid_escape_char = c; + /* Back up 3 chars, since we've already incremented s. */ + *first_invalid_escape_ptr = s - 3; } } *p++ = c; @@ -1173,9 +1176,10 @@ PyObject *_PyBytes_DecodeEscape(const char *s, break; default: - if (*first_invalid_escape == NULL) { - *first_invalid_escape = s-1; /* Back up one char, since we've - already incremented s. */ + if (*first_invalid_escape_char == -1) { + *first_invalid_escape_char = (unsigned char)s[-1]; + /* Back up one char, since we've already incremented s. */ + *first_invalid_escape_ptr = s - 1; } *p++ = '\\'; s--; @@ -1195,18 +1199,19 @@ PyObject *PyBytes_DecodeEscape(const char *s, Py_ssize_t Py_UNUSED(unicode), const char *Py_UNUSED(recode_encoding)) { - const char* first_invalid_escape; - PyObject *result = _PyBytes_DecodeEscape(s, len, errors, - &first_invalid_escape); + int first_invalid_escape_char; + const char *first_invalid_escape_ptr; + PyObject *result = _PyBytes_DecodeEscape2(s, len, errors, + &first_invalid_escape_char, + &first_invalid_escape_ptr); if (result == NULL) return NULL; - if (first_invalid_escape != NULL) { - unsigned char c = *first_invalid_escape; - if ('4' <= c && c <= '7') { + if (first_invalid_escape_char != -1) { + if (first_invalid_escape_char > 0xff) { if (PyErr_WarnFormat(PyExc_DeprecationWarning, 1, - "b\"\\%.3s\" is an invalid octal escape sequence. " + "b\"\\%o\" is an invalid octal escape sequence. " "Such sequences will not work in the future. ", - first_invalid_escape) < 0) + first_invalid_escape_char) < 0) { Py_DECREF(result); return NULL; @@ -1216,7 +1221,7 @@ PyObject *PyBytes_DecodeEscape(const char *s, if (PyErr_WarnFormat(PyExc_DeprecationWarning, 1, "b\"\\%c\" is an invalid escape sequence. " "Such sequences will not work in the future. ", - c) < 0) + first_invalid_escape_char) < 0) { Py_DECREF(result); return NULL; diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c index eb3e1c48fd4050..4e1aafb91fc8f1 100644 --- a/Objects/unicodeobject.c +++ b/Objects/unicodeobject.c @@ -6621,13 +6621,15 @@ _PyUnicode_GetNameCAPI(void) /* --- Unicode Escape Codec ----------------------------------------------- */ PyObject * -_PyUnicode_DecodeUnicodeEscapeInternal(const char *s, +_PyUnicode_DecodeUnicodeEscapeInternal2(const char *s, Py_ssize_t size, const char *errors, Py_ssize_t *consumed, - const char **first_invalid_escape) + int *first_invalid_escape_char, + const char **first_invalid_escape_ptr) { const char *starts = s; + const char *initial_starts = starts; _PyUnicodeWriter writer; const char *end; PyObject *errorHandler = NULL; @@ -6635,7 +6637,8 @@ _PyUnicode_DecodeUnicodeEscapeInternal(const char *s, _PyUnicode_Name_CAPI *ucnhash_capi; // so we can remember if we've seen an invalid escape char or not - *first_invalid_escape = NULL; + *first_invalid_escape_char = -1; + *first_invalid_escape_ptr = NULL; if (size == 0) { if (consumed) { @@ -6723,9 +6726,12 @@ _PyUnicode_DecodeUnicodeEscapeInternal(const char *s, } } if (ch > 0377) { - if (*first_invalid_escape == NULL) { - *first_invalid_escape = s-3; /* Back up 3 chars, since we've - already incremented s. */ + if (*first_invalid_escape_char == -1) { + *first_invalid_escape_char = ch; + if (starts == initial_starts) { + /* Back up 3 chars, since we've already incremented s. */ + *first_invalid_escape_ptr = s - 3; + } } } WRITE_CHAR(ch); @@ -6820,9 +6826,12 @@ _PyUnicode_DecodeUnicodeEscapeInternal(const char *s, goto error; default: - if (*first_invalid_escape == NULL) { - *first_invalid_escape = s-1; /* Back up one char, since we've - already incremented s. */ + if (*first_invalid_escape_char == -1) { + *first_invalid_escape_char = c; + if (starts == initial_starts) { + /* Back up one char, since we've already incremented s. */ + *first_invalid_escape_ptr = s - 1; + } } WRITE_ASCII_CHAR('\\'); WRITE_CHAR(c); @@ -6867,19 +6876,20 @@ _PyUnicode_DecodeUnicodeEscapeStateful(const char *s, const char *errors, Py_ssize_t *consumed) { - const char *first_invalid_escape; - PyObject *result = _PyUnicode_DecodeUnicodeEscapeInternal(s, size, errors, + int first_invalid_escape_char; + const char *first_invalid_escape_ptr; + PyObject *result = _PyUnicode_DecodeUnicodeEscapeInternal2(s, size, errors, consumed, - &first_invalid_escape); + &first_invalid_escape_char, + &first_invalid_escape_ptr); if (result == NULL) return NULL; - if (first_invalid_escape != NULL) { - unsigned char c = *first_invalid_escape; - if ('4' <= c && c <= '7') { + if (first_invalid_escape_char != -1) { + if (first_invalid_escape_char > 0xff) { if (PyErr_WarnFormat(PyExc_DeprecationWarning, 1, - "\"\\%.3s\" is an invalid octal escape sequence. " + "\"\\%o\" is an invalid octal escape sequence. " "Such sequences will not work in the future. ", - first_invalid_escape) < 0) + first_invalid_escape_char) < 0) { Py_DECREF(result); return NULL; @@ -6889,7 +6899,7 @@ _PyUnicode_DecodeUnicodeEscapeStateful(const char *s, if (PyErr_WarnFormat(PyExc_DeprecationWarning, 1, "\"\\%c\" is an invalid escape sequence. " "Such sequences will not work in the future. ", - c) < 0) + first_invalid_escape_char) < 0) { Py_DECREF(result); return NULL; diff --git a/Parser/string_parser.c b/Parser/string_parser.c index d3631b114c5a3c..ebe68989d1af58 100644 --- a/Parser/string_parser.c +++ b/Parser/string_parser.c @@ -196,15 +196,18 @@ decode_unicode_with_escapes(Parser *parser, const char *s, size_t len, Token *t) len = (size_t)(p - buf); s = buf; - const char *first_invalid_escape; - v = _PyUnicode_DecodeUnicodeEscapeInternal(s, (Py_ssize_t)len, NULL, NULL, &first_invalid_escape); + int first_invalid_escape_char; + const char *first_invalid_escape_ptr; + v = _PyUnicode_DecodeUnicodeEscapeInternal2(s, (Py_ssize_t)len, NULL, NULL, + &first_invalid_escape_char, + &first_invalid_escape_ptr); // HACK: later we can simply pass the line no, since we don't preserve the tokens // when we are decoding the string but we preserve the line numbers. - if (v != NULL && first_invalid_escape != NULL && t != NULL) { - if (warn_invalid_escape_sequence(parser, s, first_invalid_escape, t) < 0) { - /* We have not decref u before because first_invalid_escape points - inside u. */ + if (v != NULL && first_invalid_escape_ptr != NULL && t != NULL) { + if (warn_invalid_escape_sequence(parser, s, first_invalid_escape_ptr, t) < 0) { + /* We have not decref u before because first_invalid_escape_ptr + points inside u. */ Py_XDECREF(u); Py_DECREF(v); return NULL; @@ -217,14 +220,17 @@ decode_unicode_with_escapes(Parser *parser, const char *s, size_t len, Token *t) static PyObject * decode_bytes_with_escapes(Parser *p, const char *s, Py_ssize_t len, Token *t) { - const char *first_invalid_escape; - PyObject *result = _PyBytes_DecodeEscape(s, len, NULL, &first_invalid_escape); + int first_invalid_escape_char; + const char *first_invalid_escape_ptr; + PyObject *result = _PyBytes_DecodeEscape2(s, len, NULL, + &first_invalid_escape_char, + &first_invalid_escape_ptr); if (result == NULL) { return NULL; } - if (first_invalid_escape != NULL) { - if (warn_invalid_escape_sequence(p, s, first_invalid_escape, t) < 0) { + if (first_invalid_escape_ptr != NULL) { + if (warn_invalid_escape_sequence(p, s, first_invalid_escape_ptr, t) < 0) { Py_DECREF(result); return NULL; }