From 049cd6b563892b64edd606cfdf36c5d0f30b7b16 Mon Sep 17 00:00:00 2001 From: Guido van Rossum Date: Fri, 11 Oct 2002 00:43:48 +0000 Subject: Fix a nasty endcase reported by Armin Rigo in SF bug 618623: '%2147483647d' % -123 segfaults. This was because an integer overflow in a comparison caused the string resize to be skipped. After fixing the overflow, this could call _PyString_Resize() with a negative size, so I (1) test for that and raise MemoryError instead; (2) also added a test for negative newsize to _PyString_Resize(), raising SystemError as for all bad arguments. An identical bug existed in unicodeobject.c, of course. Will backport to 2.2.2. --- Objects/stringobject.c | 8 ++++++-- Objects/unicodeobject.c | 8 ++++++-- 2 files changed, 12 insertions(+), 4 deletions(-) diff --git a/Objects/stringobject.c b/Objects/stringobject.c index 6a9450a..5c5b6ae 100644 --- a/Objects/stringobject.c +++ b/Objects/stringobject.c @@ -3319,7 +3319,7 @@ _PyString_Resize(PyObject **pv, int newsize) register PyObject *v; register PyStringObject *sv; v = *pv; - if (!PyString_Check(v) || v->ob_refcnt != 1) { + if (!PyString_Check(v) || v->ob_refcnt != 1 || newsize < 0) { *pv = 0; Py_DECREF(v); PyErr_BadInternalCall(); @@ -3959,10 +3959,14 @@ PyString_Format(PyObject *format, PyObject *args) } if (width < len) width = len; - if (rescnt < width + (sign != 0)) { + if (rescnt - (sign != 0) < width) { reslen -= rescnt; rescnt = width + fmtcnt + 100; reslen += rescnt; + if (reslen < 0) { + Py_DECREF(result); + return PyErr_NoMemory(); + } if (_PyString_Resize(&result, reslen) < 0) return NULL; res = PyString_AS_STRING(result) diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c index eb8ee61..5f9f4a7 100644 --- a/Objects/unicodeobject.c +++ b/Objects/unicodeobject.c @@ -261,7 +261,7 @@ int PyUnicode_Resize(PyObject **unicode, return -1; } v = (PyUnicodeObject *)*unicode; - if (v == NULL || !PyUnicode_Check(v) || v->ob_refcnt != 1) { + if (v == NULL || !PyUnicode_Check(v) || v->ob_refcnt != 1 || length < 0) { PyErr_BadInternalCall(); return -1; } @@ -6483,10 +6483,14 @@ PyObject *PyUnicode_Format(PyObject *format, } if (width < len) width = len; - if (rescnt < width + (sign != 0)) { + if (rescnt - (sign != 0) < width) { reslen -= rescnt; rescnt = width + fmtcnt + 100; reslen += rescnt; + if (reslen < 0) { + Py_DECREF(result); + return PyErr_NoMemory(); + } if (_PyUnicode_Resize(&result, reslen) < 0) return NULL; res = PyUnicode_AS_UNICODE(result) -- cgit v0.12