From e48944b69c5c720a9ae5631daa4dbf27e8369371 Mon Sep 17 00:00:00 2001 From: Benjamin Peterson Date: Wed, 7 Mar 2012 14:50:25 -0600 Subject: keep the buffer object around while we're using it (closes #14212) --- Lib/test/test_re.py | 14 +++++++++- Misc/NEWS | 3 ++ Modules/_sre.c | 80 +++++++++++++++++++++++++++++++---------------------- Modules/sre.h | 2 ++ 4 files changed, 65 insertions(+), 34 deletions(-) diff --git a/Lib/test/test_re.py b/Lib/test/test_re.py index 0f39ead..4e18531 100644 --- a/Lib/test/test_re.py +++ b/Lib/test/test_re.py @@ -1,4 +1,5 @@ -from test.support import verbose, run_unittest +from test.support import verbose, run_unittest, gc_collect +import io import re from re import Scanner import sys @@ -16,6 +17,17 @@ import unittest class ReTests(unittest.TestCase): + def test_keep_buffer(self): + # See bug 14212 + b = bytearray(b'x') + it = re.finditer(b'a', b) + with self.assertRaises(BufferError): + b.extend(b'x'*400) + list(it) + del it + gc_collect() + b.extend(b'x'*400) + def test_weakref(self): s = 'QabbbcR' x = re.compile('ab+c') diff --git a/Misc/NEWS b/Misc/NEWS index 250dd81..58c63e8 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -549,6 +549,9 @@ Tests Extension Modules ----------------- +- Issue #14212: The re module didn't retain a reference to buffers it was + scanning, resulting in segfaults. + - Issue #13840: The error message produced by ctypes.create_string_buffer when given a Unicode string has been fixed. diff --git a/Modules/_sre.c b/Modules/_sre.c index a363de2..472b5a3 100644 --- a/Modules/_sre.c +++ b/Modules/_sre.c @@ -1664,7 +1664,7 @@ state_reset(SRE_STATE* state) } static void* -getstring(PyObject* string, Py_ssize_t* p_length, int* p_charsize) +getstring(PyObject* string, Py_ssize_t* p_length, int* p_charsize, Py_buffer *view) { /* given a python object, return a data pointer, a length (in characters), and a character size. return NULL if the object @@ -1674,7 +1674,6 @@ getstring(PyObject* string, Py_ssize_t* p_length, int* p_charsize) Py_ssize_t size, bytes; int charsize; void* ptr; - Py_buffer view; /* Unicode objects do not support the buffer API. So, get the data directly instead. */ @@ -1686,26 +1685,21 @@ getstring(PyObject* string, Py_ssize_t* p_length, int* p_charsize) } /* get pointer to string buffer */ - view.len = -1; + view->len = -1; buffer = Py_TYPE(string)->tp_as_buffer; if (!buffer || !buffer->bf_getbuffer || - (*buffer->bf_getbuffer)(string, &view, PyBUF_SIMPLE) < 0) { + (*buffer->bf_getbuffer)(string, view, PyBUF_SIMPLE) < 0) { PyErr_SetString(PyExc_TypeError, "expected string or buffer"); return NULL; } /* determine buffer size */ - bytes = view.len; - ptr = view.buf; - - /* Release the buffer immediately --- possibly dangerous - but doing something else would require some re-factoring - */ - PyBuffer_Release(&view); + bytes = view->len; + ptr = view->buf; if (bytes < 0) { PyErr_SetString(PyExc_TypeError, "buffer has negative size"); - return NULL; + goto err; } /* determine character size */ @@ -1719,7 +1713,7 @@ getstring(PyObject* string, Py_ssize_t* p_length, int* p_charsize) #endif else { PyErr_SetString(PyExc_TypeError, "buffer size mismatch"); - return NULL; + goto err; } *p_length = size; @@ -1728,8 +1722,13 @@ getstring(PyObject* string, Py_ssize_t* p_length, int* p_charsize) if (ptr == NULL) { PyErr_SetString(PyExc_ValueError, "Buffer is NULL"); + goto err; } return ptr; + err: + PyBuffer_Release(view); + view->buf = NULL; + return NULL; } LOCAL(PyObject*) @@ -1747,20 +1746,21 @@ state_init(SRE_STATE* state, PatternObject* pattern, PyObject* string, state->lastmark = -1; state->lastindex = -1; - ptr = getstring(string, &length, &charsize); + state->buffer.buf = NULL; + ptr = getstring(string, &length, &charsize, &state->buffer); if (!ptr) - return NULL; + goto err; - if (charsize == 1 && pattern->charsize > 1) { - PyErr_SetString(PyExc_TypeError, + if (charsize == 1 && pattern->charsize > 1) { + PyErr_SetString(PyExc_TypeError, "can't use a string pattern on a bytes-like object"); - return NULL; - } - if (charsize > 1 && pattern->charsize == 1) { - PyErr_SetString(PyExc_TypeError, + goto err; + } + if (charsize > 1 && pattern->charsize == 1) { + PyErr_SetString(PyExc_TypeError, "can't use a bytes pattern on a string-like object"); - return NULL; - } + goto err; + } /* adjust boundaries */ if (start < 0) @@ -1797,11 +1797,17 @@ state_init(SRE_STATE* state, PatternObject* pattern, PyObject* string, state->lower = sre_lower; return string; + err: + if (state->buffer.buf) + PyBuffer_Release(&state->buffer); + return NULL; } LOCAL(void) state_fini(SRE_STATE* state) { + if (state->buffer.buf) + PyBuffer_Release(&state->buffer); Py_XDECREF(state->string); data_stack_dealloc(state); } @@ -1863,6 +1869,8 @@ pattern_dealloc(PatternObject* self) { if (self->weakreflist != NULL) PyObject_ClearWeakRefs((PyObject *) self); + if (self->view.buf) + PyBuffer_Release(&self->view); Py_XDECREF(self->pattern); Py_XDECREF(self->groupindex); Py_XDECREF(self->indexgroup); @@ -2297,6 +2305,7 @@ pattern_subx(PatternObject* self, PyObject* ptemplate, PyObject* string, Py_ssize_t i, b, e; int bint; int filter_is_callable; + Py_buffer view; if (PyCallable_Check(ptemplate)) { /* sub/subn takes either a function or a template */ @@ -2306,7 +2315,8 @@ pattern_subx(PatternObject* self, PyObject* ptemplate, PyObject* string, } else { /* if not callable, check if it's a literal string */ int literal; - ptr = getstring(ptemplate, &n, &bint); + view.buf = NULL; + ptr = getstring(ptemplate, &n, &bint, &view); b = bint; if (ptr) { if (b == 1) { @@ -2320,6 +2330,8 @@ pattern_subx(PatternObject* self, PyObject* ptemplate, PyObject* string, PyErr_Clear(); literal = 0; } + if (view.buf) + PyBuffer_Release(&view); if (literal) { filter = ptemplate; Py_INCREF(filter); @@ -2661,6 +2673,7 @@ _compile(PyObject* self_, PyObject* args) Py_ssize_t groups = 0; PyObject* groupindex = NULL; PyObject* indexgroup = NULL; + if (!PyArg_ParseTuple(args, "OiO!|nOO", &pattern, &flags, &PyList_Type, &code, &groups, &groupindex, &indexgroup)) @@ -2675,6 +2688,7 @@ _compile(PyObject* self_, PyObject* args) self->pattern = NULL; self->groupindex = NULL; self->indexgroup = NULL; + self->view.buf = NULL; self->codesize = n; @@ -2694,15 +2708,15 @@ _compile(PyObject* self_, PyObject* args) return NULL; } - if (pattern == Py_None) - self->charsize = -1; - else { - Py_ssize_t p_length; - if (!getstring(pattern, &p_length, &self->charsize)) { - Py_DECREF(self); - return NULL; - } - } + if (pattern == Py_None) + self->charsize = -1; + else { + Py_ssize_t p_length; + if (!getstring(pattern, &p_length, &self->charsize, &self->view)) { + Py_DECREF(self); + return NULL; + } + } Py_INCREF(pattern); self->pattern = pattern; diff --git a/Modules/sre.h b/Modules/sre.h index 518c11d..aec9b54 100644 --- a/Modules/sre.h +++ b/Modules/sre.h @@ -31,6 +31,7 @@ typedef struct { int flags; /* flags used when compiling pattern source */ PyObject *weakreflist; /* List of weak references */ int charsize; /* pattern charsize (or -1) */ + Py_buffer view; /* pattern code */ Py_ssize_t codesize; SRE_CODE code[1]; @@ -80,6 +81,7 @@ typedef struct { char* data_stack; size_t data_stack_size; size_t data_stack_base; + Py_buffer buffer; /* current repeat context */ SRE_REPEAT *repeat; /* hooks */ -- cgit v0.12