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python: add patch

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This commit is contained in:
Juergen Daubert 2018-03-05 14:28:41 +01:00
parent 44a2a4397f
commit 48168e96b4
1 changed files with 258 additions and 0 deletions
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258
python/CVE-2018-1000030.patch Normal file
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@ -0,0 +1,258 @@
--- a/Lib/test/test_file2k.py 2018-02-16 17:49:45.180147747 -0500
+++ b/Lib/test/test_file2k.py 2018-02-16 17:51:06.870149602 -0500
@@ -652,6 +652,33 @@ class FileThreadingTests(unittest.TestCa
self.f.writelines('')
self._test_close_open_io(io_func)
+ def test_iteration_torture(self):
+ # bpo-31530
+ with open(self.filename, "wb") as fp:
+ for i in xrange(2**20):
+ fp.write(b"0"*50 + b"\n")
+ with open(self.filename, "rb") as f:
+ def it():
+ for l in f:
+ pass
+ self._run_workers(it, 10)
+
+ def test_iteration_seek(self):
+ # bpo-31530: Crash when concurrently seek and iterate over a file.
+ with open(self.filename, "wb") as fp:
+ for i in xrange(10000):
+ fp.write(b"0"*50 + b"\n")
+ with open(self.filename, "rb") as f:
+ it = iter([1] + [0]*10) # one thread reads, others seek
+ def iterate():
+ if next(it):
+ for l in f:
+ pass
+ else:
+ for i in xrange(100):
+ f.seek(i*100, 0)
+ self._run_workers(iterate, 10)
+
@unittest.skipUnless(os.name == 'posix', 'test requires a posix system.')
class TestFileSignalEINTR(unittest.TestCase):
--- a/Objects/fileobject.c 2018-02-16 17:49:45.304147750 -0500
+++ b/Objects/fileobject.c 2018-02-16 17:51:06.872149603 -0500
@@ -430,7 +430,7 @@ close_the_file(PyFileObject *f)
if (f->ob_refcnt > 0) {
PyErr_SetString(PyExc_IOError,
"close() called during concurrent "
- "operation on the same file object.");
+ "operation on the same file object");
} else {
/* This should not happen unless someone is
* carelessly playing with the PyFileObject
@@ -438,7 +438,7 @@ close_the_file(PyFileObject *f)
* pointer. */
PyErr_SetString(PyExc_SystemError,
"PyFileObject locking error in "
- "destructor (refcnt <= 0 at close).");
+ "destructor (refcnt <= 0 at close)");
}
return NULL;
}
@@ -604,7 +604,12 @@ err_iterbuffered(void)
return NULL;
}
-static void drop_readahead(PyFileObject *);
+static void
+drop_file_readahead(PyFileObject *f)
+{
+ PyMem_FREE(f->f_buf);
+ f->f_buf = NULL;
+}
/* Methods */
@@ -627,7 +632,7 @@ file_dealloc(PyFileObject *f)
Py_XDECREF(f->f_mode);
Py_XDECREF(f->f_encoding);
Py_XDECREF(f->f_errors);
- drop_readahead(f);
+ drop_file_readahead(f);
Py_TYPE(f)->tp_free((PyObject *)f);
}
@@ -762,7 +767,7 @@ file_seek(PyFileObject *f, PyObject *arg
if (f->f_fp == NULL)
return err_closed();
- drop_readahead(f);
+ drop_file_readahead(f);
whence = 0;
if (!PyArg_ParseTuple(args, "O|i:seek", &offobj, &whence))
return NULL;
@@ -2221,12 +2226,16 @@ static PyGetSetDef file_getsetlist[] = {
{0},
};
+typedef struct {
+ char *buf, *bufptr, *bufend;
+} readaheadbuffer;
+
static void
-drop_readahead(PyFileObject *f)
+drop_readaheadbuffer(readaheadbuffer *rab)
{
- if (f->f_buf != NULL) {
- PyMem_Free(f->f_buf);
- f->f_buf = NULL;
+ if (rab->buf != NULL) {
+ PyMem_FREE(rab->buf);
+ rab->buf = NULL;
}
}
@@ -2234,35 +2243,34 @@ drop_readahead(PyFileObject *f)
(unless at EOF) and no more than bufsize. Returns negative value on
error, will set MemoryError if bufsize bytes cannot be allocated. */
static int
-readahead(PyFileObject *f, Py_ssize_t bufsize)
+readahead(PyFileObject *f, readaheadbuffer *rab, Py_ssize_t bufsize)
{
Py_ssize_t chunksize;
- if (f->f_buf != NULL) {
- if( (f->f_bufend - f->f_bufptr) >= 1)
+ if (rab->buf != NULL) {
+ if ((rab->bufend - rab->bufptr) >= 1)
return 0;
else
- drop_readahead(f);
+ drop_readaheadbuffer(rab);
}
- if ((f->f_buf = (char *)PyMem_Malloc(bufsize)) == NULL) {
+ if ((rab->buf = PyMem_MALLOC(bufsize)) == NULL) {
PyErr_NoMemory();
return -1;
}
FILE_BEGIN_ALLOW_THREADS(f)
errno = 0;
- chunksize = Py_UniversalNewlineFread(
- f->f_buf, bufsize, f->f_fp, (PyObject *)f);
+ chunksize = Py_UniversalNewlineFread(rab->buf, bufsize, f->f_fp, (PyObject *)f);
FILE_END_ALLOW_THREADS(f)
if (chunksize == 0) {
if (ferror(f->f_fp)) {
PyErr_SetFromErrno(PyExc_IOError);
clearerr(f->f_fp);
- drop_readahead(f);
+ drop_readaheadbuffer(rab);
return -1;
}
}
- f->f_bufptr = f->f_buf;
- f->f_bufend = f->f_buf + chunksize;
+ rab->bufptr = rab->buf;
+ rab->bufend = rab->buf + chunksize;
return 0;
}
@@ -2272,45 +2280,43 @@ readahead(PyFileObject *f, Py_ssize_t bu
logarithmic buffer growth to about 50 even when reading a 1gb line. */
static PyStringObject *
-readahead_get_line_skip(PyFileObject *f, Py_ssize_t skip, Py_ssize_t bufsize)
+readahead_get_line_skip(PyFileObject *f, readaheadbuffer *rab, Py_ssize_t skip, Py_ssize_t bufsize)
{
PyStringObject* s;
char *bufptr;
char *buf;
Py_ssize_t len;
- if (f->f_buf == NULL)
- if (readahead(f, bufsize) < 0)
+ if (rab->buf == NULL)
+ if (readahead(f, rab, bufsize) < 0)
return NULL;
- len = f->f_bufend - f->f_bufptr;
+ len = rab->bufend - rab->bufptr;
if (len == 0)
- return (PyStringObject *)
- PyString_FromStringAndSize(NULL, skip);
- bufptr = (char *)memchr(f->f_bufptr, '\n', len);
+ return (PyStringObject *)PyString_FromStringAndSize(NULL, skip);
+ bufptr = (char *)memchr(rab->bufptr, '\n', len);
if (bufptr != NULL) {
bufptr++; /* Count the '\n' */
- len = bufptr - f->f_bufptr;
- s = (PyStringObject *)
- PyString_FromStringAndSize(NULL, skip + len);
+ len = bufptr - rab->bufptr;
+ s = (PyStringObject *)PyString_FromStringAndSize(NULL, skip + len);
if (s == NULL)
return NULL;
- memcpy(PyString_AS_STRING(s) + skip, f->f_bufptr, len);
- f->f_bufptr = bufptr;
- if (bufptr == f->f_bufend)
- drop_readahead(f);
+ memcpy(PyString_AS_STRING(s) + skip, rab->bufptr, len);
+ rab->bufptr = bufptr;
+ if (bufptr == rab->bufend)
+ drop_readaheadbuffer(rab);
} else {
- bufptr = f->f_bufptr;
- buf = f->f_buf;
- f->f_buf = NULL; /* Force new readahead buffer */
+ bufptr = rab->bufptr;
+ buf = rab->buf;
+ rab->buf = NULL; /* Force new readahead buffer */
assert(len <= PY_SSIZE_T_MAX - skip);
- s = readahead_get_line_skip(f, skip + len, bufsize + (bufsize>>2));
+ s = readahead_get_line_skip(f, rab, skip + len, bufsize + (bufsize>>2));
if (s == NULL) {
- PyMem_Free(buf);
+ PyMem_FREE(buf);
return NULL;
}
memcpy(PyString_AS_STRING(s) + skip, bufptr, len);
- PyMem_Free(buf);
+ PyMem_FREE(buf);
}
return s;
}
@@ -2328,7 +2334,30 @@ file_iternext(PyFileObject *f)
if (!f->readable)
return err_mode("reading");
- l = readahead_get_line_skip(f, 0, READAHEAD_BUFSIZE);
+ {
+ /*
+ Multiple threads can enter this method while the GIL is released
+ during file read and wreak havoc on the file object's readahead
+ buffer. To avoid dealing with cross-thread coordination issues, we
+ cache the file buffer state locally and only set it back on the file
+ object when we're done.
+ */
+ readaheadbuffer rab = {f->f_buf, f->f_bufptr, f->f_bufend};
+ f->f_buf = NULL;
+ l = readahead_get_line_skip(f, &rab, 0, READAHEAD_BUFSIZE);
+ /*
+ Make sure the file's internal read buffer is cleared out. This will
+ only do anything if some other thread interleaved with us during
+ readahead. We want to drop any changeling buffer, so we don't leak
+ memory. We may lose data, but that's what you get for reading the same
+ file object in multiple threads.
+ */
+ drop_file_readahead(f);
+ f->f_buf = rab.buf;
+ f->f_bufptr = rab.bufptr;
+ f->f_bufend = rab.bufend;
+ }
+
if (l == NULL || PyString_GET_SIZE(l) == 0) {
Py_XDECREF(l);
return NULL;
@@ -2692,7 +2721,7 @@ int PyObject_AsFileDescriptor(PyObject *
}
else {
PyErr_SetString(PyExc_TypeError,
- "argument must be an int, or have a fileno() method.");
+ "argument must be an int, or have a fileno() method");
return -1;
}