Merged revisions 77989 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk
........
r77989 | antoine.pitrou | 2010-02-05 18:05:54 +0100 (ven., 05 févr. 2010) | 6 lines
Issue #5677: Explicitly forbid write operations on read-only file objects,
and read operations on write-only file objects. On Windows, the system C
library would return a bogus result; on Solaris, it was possible to crash
the interpreter. Patch by Stefan Krah.
........
diff --git a/Include/fileobject.h b/Include/fileobject.h
index 56cf40a..96c1e57 100644
--- a/Include/fileobject.h
+++ b/Include/fileobject.h
@@ -28,6 +28,8 @@
PyObject *weakreflist; /* List of weak references */
int unlocked_count; /* Num. currently running sections of code
using f_fp with the GIL released. */
+ int readable;
+ int writable;
} PyFileObject;
PyAPI_DATA(PyTypeObject) PyFile_Type;
diff --git a/Lib/test/test_file.py b/Lib/test/test_file.py
index b4f494b..ed100c1 100644
--- a/Lib/test/test_file.py
+++ b/Lib/test/test_file.py
@@ -86,6 +86,8 @@
self.assert_(repr(self.f).startswith("<open file '" + TESTFN))
def testErrors(self):
+ self.f.close()
+ self.f = open(TESTFN, 'rb')
f = self.f
self.assertEquals(f.name, TESTFN)
self.assert_(not f.isatty())
@@ -123,6 +125,40 @@
def testReadWhenWriting(self):
self.assertRaises(IOError, self.f.read)
+ def testIssue5677(self):
+ # Remark: Do not perform more than one test per open file,
+ # since that does NOT catch the readline error on Windows.
+ data = 'xxx'
+ for mode in ['w', 'wb', 'a', 'ab']:
+ for attr in ['read', 'readline', 'readlines']:
+ self.f = open(TESTFN, mode)
+ self.f.write(data)
+ self.assertRaises(IOError, getattr(self.f, attr))
+ self.f.close()
+
+ self.f = open(TESTFN, mode)
+ self.f.write(data)
+ self.assertRaises(IOError, lambda: [line for line in self.f])
+ self.f.close()
+
+ self.f = open(TESTFN, mode)
+ self.f.write(data)
+ self.assertRaises(IOError, self.f.readinto, bytearray(len(data)))
+ self.f.close()
+
+ for mode in ['r', 'rb', 'U', 'Ub', 'Ur', 'rU', 'rbU', 'rUb']:
+ self.f = open(TESTFN, mode)
+ self.assertRaises(IOError, self.f.write, data)
+ self.f.close()
+
+ self.f = open(TESTFN, mode)
+ self.assertRaises(IOError, self.f.writelines, [data, data])
+ self.f.close()
+
+ self.f = open(TESTFN, mode)
+ self.assertRaises(IOError, self.f.truncate)
+ self.f.close()
+
class OtherFileTests(unittest.TestCase):
def testOpenDir(self):
diff --git a/Lib/test/test_sys.py b/Lib/test/test_sys.py
index a882984..149f473 100644
--- a/Lib/test/test_sys.py
+++ b/Lib/test/test_sys.py
@@ -538,7 +538,7 @@
# enumerate
check(enumerate([]), size(h + 'l3P'))
# file
- check(self.file, size(h + '4P2i4P3i3Pi'))
+ check(self.file, size(h + '4P2i4P3i3P3i'))
# float
check(float(0), size(h + 'd'))
# sys.floatinfo
diff --git a/Misc/ACKS b/Misc/ACKS
index 528281d..6562b7e 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -391,6 +391,7 @@
Greg Kochanski
Damon Kohler
Joseph Koshy
+Stefan Krah
Bob Kras
Holger Krekel
Michael Kremer
diff --git a/Misc/NEWS b/Misc/NEWS
index 3c19cce..d6c81b3 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,11 @@
Core and Builtins
-----------------
+- Issue #5677: Explicitly forbid write operations on read-only file objects,
+ and read operations on write-only file objects. On Windows, the system C
+ library would return a bogus result; on Solaris, it was possible to crash
+ the interpreter. Patch by Stefan Krah.
+
- Issue #7819: Check sys.call_tracing() arguments types.
- Issue #7788: Fix an interpreter crash produced by deleting a list
diff --git a/Objects/fileobject.c b/Objects/fileobject.c
index e01f38e..52d8120 100644
--- a/Objects/fileobject.c
+++ b/Objects/fileobject.c
@@ -173,6 +173,13 @@
f->f_encoding = Py_None;
Py_INCREF(Py_None);
f->f_errors = Py_None;
+ f->readable = f->writable = 0;
+ if (strchr(mode, 'r') != NULL || f->f_univ_newline)
+ f->readable = 1;
+ if (strchr(mode, 'w') != NULL || strchr(mode, 'a') != NULL)
+ f->writable = 1;
+ if (strchr(mode, '+') != NULL)
+ f->readable = f->writable = 1;
if (f->f_mode == NULL)
return NULL;
@@ -487,6 +494,13 @@
return NULL;
}
+static PyObject *
+err_mode(char *action)
+{
+ PyErr_Format(PyExc_IOError, "File not open for %s", action);
+ return NULL;
+}
+
/* Refuse regular file I/O if there's data in the iteration-buffer.
* Mixing them would cause data to arrive out of order, as the read*
* methods don't use the iteration buffer. */
@@ -701,6 +715,8 @@
if (f->f_fp == NULL)
return err_closed();
+ if (!f->writable)
+ return err_mode("writing");
if (!PyArg_UnpackTuple(args, "truncate", 0, 1, &newsizeobj))
return NULL;
@@ -949,6 +965,8 @@
if (f->f_fp == NULL)
return err_closed();
+ if (!f->readable)
+ return err_mode("reading");
/* refuse to mix with f.next() */
if (f->f_buf != NULL &&
(f->f_bufend - f->f_bufptr) > 0 &&
@@ -1018,6 +1036,8 @@
if (f->f_fp == NULL)
return err_closed();
+ if (!f->readable)
+ return err_mode("reading");
/* refuse to mix with f.next() */
if (f->f_buf != NULL &&
(f->f_bufend - f->f_bufptr) > 0 &&
@@ -1389,6 +1409,8 @@
PyFileObject *fo = (PyFileObject *)f;
if (fo->f_fp == NULL)
return err_closed();
+ if (!fo->readable)
+ return err_mode("reading");
/* refuse to mix with f.next() */
if (fo->f_buf != NULL &&
(fo->f_bufend - fo->f_bufptr) > 0 &&
@@ -1477,6 +1499,8 @@
if (f->f_fp == NULL)
return err_closed();
+ if (!f->readable)
+ return err_mode("reading");
/* refuse to mix with f.next() */
if (f->f_buf != NULL &&
(f->f_bufend - f->f_bufptr) > 0 &&
@@ -1510,6 +1534,8 @@
if (f->f_fp == NULL)
return err_closed();
+ if (!f->readable)
+ return err_mode("reading");
/* refuse to mix with f.next() */
if (f->f_buf != NULL &&
(f->f_bufend - f->f_bufptr) > 0 &&
@@ -1628,6 +1654,8 @@
Py_ssize_t n, n2;
if (f->f_fp == NULL)
return err_closed();
+ if (!f->writable)
+ return err_mode("writing");
if (f->f_binary) {
if (!PyArg_ParseTuple(args, "s*", &pbuf))
return NULL;
@@ -1665,6 +1693,8 @@
assert(seq != NULL);
if (f->f_fp == NULL)
return err_closed();
+ if (!f->writable)
+ return err_mode("writing");
result = NULL;
list = NULL;
@@ -2105,6 +2135,8 @@
if (f->f_fp == NULL)
return err_closed();
+ if (!f->readable)
+ return err_mode("reading");
l = readahead_get_line_skip(f, 0, READAHEAD_BUFSIZE);
if (l == NULL || PyString_GET_SIZE(l) == 0) {