bpo-33871: Fix os.sendfile(), os.writev(), os.readv(), etc. (GH-7931)
* Fix integer overflow in os.readv(), os.writev(), os.preadv()
and os.pwritev() and in os.sendfile() with headers or trailers
arguments (on BSD-based OSes and MacOS).
* Fix sending the part of the file in os.sendfile() on MacOS.
Using the trailers argument could cause sending more bytes from
the input file than was specified.
Thanks Ned Deily for testing on 32-bit MacOS.
(cherry picked from commit 9d5727326af53ddd91016d98e16ae7cf829caa95)
Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
diff --git a/Lib/test/test_os.py b/Lib/test/test_os.py
index e509188..a140ae0 100644
--- a/Lib/test/test_os.py
+++ b/Lib/test/test_os.py
@@ -2532,12 +2532,14 @@
def __init__(self, conn):
asynchat.async_chat.__init__(self, conn)
self.in_buffer = []
+ self.accumulate = True
self.closed = False
self.push(b"220 ready\r\n")
def handle_read(self):
data = self.recv(4096)
- self.in_buffer.append(data)
+ if self.accumulate:
+ self.in_buffer.append(data)
def get_data(self):
return b''.join(self.in_buffer)
@@ -2618,6 +2620,8 @@
not sys.platform.startswith("sunos")
requires_headers_trailers = unittest.skipUnless(SUPPORT_HEADERS_TRAILERS,
'requires headers and trailers support')
+ requires_32b = unittest.skipUnless(sys.maxsize < 2**32,
+ 'test is only meaningful on 32-bit builds')
@classmethod
def setUpClass(cls):
@@ -2648,17 +2652,13 @@
self.server.stop()
self.server = None
- def sendfile_wrapper(self, sock, file, offset, nbytes, headers=[], trailers=[]):
+ def sendfile_wrapper(self, *args, **kwargs):
"""A higher level wrapper representing how an application is
supposed to use sendfile().
"""
- while 1:
+ while True:
try:
- if self.SUPPORT_HEADERS_TRAILERS:
- return os.sendfile(sock, file, offset, nbytes, headers,
- trailers)
- else:
- return os.sendfile(sock, file, offset, nbytes)
+ return os.sendfile(*args, **kwargs)
except OSError as err:
if err.errno == errno.ECONNRESET:
# disconnected
@@ -2749,20 +2749,22 @@
@requires_headers_trailers
def test_headers(self):
total_sent = 0
+ expected_data = b"x" * 512 + b"y" * 256 + self.DATA[:-1]
sent = os.sendfile(self.sockno, self.fileno, 0, 4096,
- headers=[b"x" * 512])
+ headers=[b"x" * 512, b"y" * 256])
+ self.assertLessEqual(sent, 512 + 256 + 4096)
total_sent += sent
offset = 4096
- nbytes = 4096
- while 1:
+ while total_sent < len(expected_data):
+ nbytes = min(len(expected_data) - total_sent, 4096)
sent = self.sendfile_wrapper(self.sockno, self.fileno,
offset, nbytes)
if sent == 0:
break
+ self.assertLessEqual(sent, nbytes)
total_sent += sent
offset += sent
- expected_data = b"x" * 512 + self.DATA
self.assertEqual(total_sent, len(expected_data))
self.client.close()
self.server.wait()
@@ -2778,12 +2780,30 @@
create_file(TESTFN2, file_data)
with open(TESTFN2, 'rb') as f:
- os.sendfile(self.sockno, f.fileno(), 0, len(file_data),
- trailers=[b"1234"])
+ os.sendfile(self.sockno, f.fileno(), 0, 5,
+ trailers=[b"123456", b"789"])
self.client.close()
self.server.wait()
data = self.server.handler_instance.get_data()
- self.assertEqual(data, b"abcdef1234")
+ self.assertEqual(data, b"abcde123456789")
+
+ @requires_headers_trailers
+ @requires_32b
+ def test_headers_overflow_32bits(self):
+ self.server.handler_instance.accumulate = False
+ with self.assertRaises(OSError) as cm:
+ os.sendfile(self.sockno, self.fileno, 0, 0,
+ headers=[b"x" * 2**16] * 2**15)
+ self.assertEqual(cm.exception.errno, errno.EINVAL)
+
+ @requires_headers_trailers
+ @requires_32b
+ def test_trailers_overflow_32bits(self):
+ self.server.handler_instance.accumulate = False
+ with self.assertRaises(OSError) as cm:
+ os.sendfile(self.sockno, self.fileno, 0, 0,
+ trailers=[b"x" * 2**16] * 2**15)
+ self.assertEqual(cm.exception.errno, errno.EINVAL)
@requires_headers_trailers
@unittest.skipUnless(hasattr(os, 'SF_NODISKIO'),
diff --git a/Lib/test/test_posix.py b/Lib/test/test_posix.py
index 7dea1be..d2cb1c9 100644
--- a/Lib/test/test_posix.py
+++ b/Lib/test/test_posix.py
@@ -20,6 +20,9 @@
_DUMMY_SYMLINK = os.path.join(tempfile.gettempdir(),
support.TESTFN + '-dummy-symlink')
+requires_32b = unittest.skipUnless(sys.maxsize < 2**32,
+ 'test is only meaningful on 32-bit builds')
+
class PosixTester(unittest.TestCase):
def setUp(self):
@@ -284,6 +287,7 @@
finally:
os.close(fd)
+ @unittest.skipUnless(hasattr(posix, 'preadv'), "test needs posix.preadv()")
@unittest.skipUnless(hasattr(posix, 'RWF_HIPRI'), "test needs posix.RWF_HIPRI")
def test_preadv_flags(self):
fd = os.open(support.TESTFN, os.O_RDWR | os.O_CREAT)
@@ -295,6 +299,19 @@
finally:
os.close(fd)
+ @unittest.skipUnless(hasattr(posix, 'preadv'), "test needs posix.preadv()")
+ @requires_32b
+ def test_preadv_overflow_32bits(self):
+ fd = os.open(support.TESTFN, os.O_RDWR | os.O_CREAT)
+ try:
+ buf = [bytearray(2**16)] * 2**15
+ with self.assertRaises(OSError) as cm:
+ os.preadv(fd, buf, 0)
+ self.assertEqual(cm.exception.errno, errno.EINVAL)
+ self.assertEqual(bytes(buf[0]), b'\0'* 2**16)
+ finally:
+ os.close(fd)
+
@unittest.skipUnless(hasattr(posix, 'pwrite'), "test needs posix.pwrite()")
def test_pwrite(self):
fd = os.open(support.TESTFN, os.O_RDWR | os.O_CREAT)
@@ -320,6 +337,7 @@
finally:
os.close(fd)
+ @unittest.skipUnless(hasattr(posix, 'pwritev'), "test needs posix.pwritev()")
@unittest.skipUnless(hasattr(posix, 'os.RWF_SYNC'), "test needs os.RWF_SYNC")
def test_pwritev_flags(self):
fd = os.open(support.TESTFN, os.O_RDWR | os.O_CREAT)
@@ -334,6 +352,17 @@
finally:
os.close(fd)
+ @unittest.skipUnless(hasattr(posix, 'pwritev'), "test needs posix.pwritev()")
+ @requires_32b
+ def test_pwritev_overflow_32bits(self):
+ fd = os.open(support.TESTFN, os.O_RDWR | os.O_CREAT)
+ try:
+ with self.assertRaises(OSError) as cm:
+ os.pwritev(fd, [b"x" * 2**16] * 2**15, 0)
+ self.assertEqual(cm.exception.errno, errno.EINVAL)
+ finally:
+ os.close(fd)
+
@unittest.skipUnless(hasattr(posix, 'posix_fallocate'),
"test needs posix.posix_fallocate()")
def test_posix_fallocate(self):
@@ -435,6 +464,17 @@
finally:
os.close(fd)
+ @unittest.skipUnless(hasattr(posix, 'writev'), "test needs posix.writev()")
+ @requires_32b
+ def test_writev_overflow_32bits(self):
+ fd = os.open(support.TESTFN, os.O_RDWR | os.O_CREAT)
+ try:
+ with self.assertRaises(OSError) as cm:
+ os.writev(fd, [b"x" * 2**16] * 2**15)
+ self.assertEqual(cm.exception.errno, errno.EINVAL)
+ finally:
+ os.close(fd)
+
@unittest.skipUnless(hasattr(posix, 'readv'), "test needs posix.readv()")
def test_readv(self):
fd = os.open(support.TESTFN, os.O_RDWR | os.O_CREAT)
@@ -457,6 +497,19 @@
finally:
os.close(fd)
+ @unittest.skipUnless(hasattr(posix, 'readv'), "test needs posix.readv()")
+ @requires_32b
+ def test_readv_overflow_32bits(self):
+ fd = os.open(support.TESTFN, os.O_RDWR | os.O_CREAT)
+ try:
+ buf = [bytearray(2**16)] * 2**15
+ with self.assertRaises(OSError) as cm:
+ os.readv(fd, buf)
+ self.assertEqual(cm.exception.errno, errno.EINVAL)
+ self.assertEqual(bytes(buf[0]), b'\0'* 2**16)
+ finally:
+ os.close(fd)
+
@unittest.skipUnless(hasattr(posix, 'dup'),
'test needs posix.dup()')
def test_dup(self):
diff --git a/Misc/NEWS.d/next/Library/2018-06-26-19-03-56.bpo-33871.XhlrGU.rst b/Misc/NEWS.d/next/Library/2018-06-26-19-03-56.bpo-33871.XhlrGU.rst
new file mode 100644
index 0000000..9fd1535
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2018-06-26-19-03-56.bpo-33871.XhlrGU.rst
@@ -0,0 +1,3 @@
+Fixed integer overflow in :func:`os.readv`, :func:`os.writev`,
+:func:`os.preadv` and :func:`os.pwritev` and in :func:`os.sendfile` with
+*headers* or *trailers* arguments (on BSD-based OSes and macOS).
diff --git a/Misc/NEWS.d/next/Security/2018-06-26-19-35-33.bpo-33871.S4HR9n.rst b/Misc/NEWS.d/next/Security/2018-06-26-19-35-33.bpo-33871.S4HR9n.rst
new file mode 100644
index 0000000..547342c
--- /dev/null
+++ b/Misc/NEWS.d/next/Security/2018-06-26-19-35-33.bpo-33871.S4HR9n.rst
@@ -0,0 +1,3 @@
+Fixed sending the part of the file in :func:`os.sendfile` on macOS. Using
+the *trailers* argument could cause sending more bytes from the input file
+than was specified.
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index c3682b4..d487e53 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -8026,12 +8026,13 @@
}
#if (defined(HAVE_SENDFILE) && (defined(__FreeBSD__) || defined(__DragonFly__) \
- || defined(__APPLE__))) || defined(HAVE_READV) || defined(HAVE_WRITEV)
-static Py_ssize_t
+ || defined(__APPLE__))) \
+ || defined(HAVE_READV) || defined(HAVE_PREADV) || defined (HAVE_PREADV2) \
+ || defined(HAVE_WRITEV) || defined(HAVE_PWRITEV) || defined (HAVE_PWRITEV2)
+static int
iov_setup(struct iovec **iov, Py_buffer **buf, PyObject *seq, Py_ssize_t cnt, int type)
{
Py_ssize_t i, j;
- Py_ssize_t blen, total = 0;
*iov = PyMem_New(struct iovec, cnt);
if (*iov == NULL) {
@@ -8056,11 +8057,9 @@
}
Py_DECREF(item);
(*iov)[i].iov_base = (*buf)[i].buf;
- blen = (*buf)[i].len;
- (*iov)[i].iov_len = blen;
- total += blen;
+ (*iov)[i].iov_len = (*buf)[i].len;
}
- return total;
+ return 0;
fail:
PyMem_Del(*iov);
@@ -8357,12 +8356,20 @@
}
if (i > 0) {
sf.hdr_cnt = (int)i;
- i = iov_setup(&(sf.headers), &hbuf,
- headers, sf.hdr_cnt, PyBUF_SIMPLE);
- if (i < 0)
+ if (iov_setup(&(sf.headers), &hbuf,
+ headers, sf.hdr_cnt, PyBUF_SIMPLE) < 0)
return NULL;
#ifdef __APPLE__
- sbytes += i;
+ for (i = 0; i < sf.hdr_cnt; i++) {
+ Py_ssize_t blen = sf.headers[i].iov_len;
+# define OFF_T_MAX 0x7fffffffffffffff
+ if (sbytes >= OFF_T_MAX - blen) {
+ PyErr_SetString(PyExc_OverflowError,
+ "sendfile() header is too large");
+ return NULL;
+ }
+ sbytes += blen;
+ }
#endif
}
}
@@ -8383,13 +8390,9 @@
}
if (i > 0) {
sf.trl_cnt = (int)i;
- i = iov_setup(&(sf.trailers), &tbuf,
- trailers, sf.trl_cnt, PyBUF_SIMPLE);
- if (i < 0)
+ if (iov_setup(&(sf.trailers), &tbuf,
+ trailers, sf.trl_cnt, PyBUF_SIMPLE) < 0)
return NULL;
-#ifdef __APPLE__
- sbytes += i;
-#endif
}
}
}