Thanks to visit codestin.com
Credit goes to github.com

Skip to content

[3.8] bpo-35714: Reject null characters in struct format strings (GH-16928) #20419

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 2 commits into from
May 26, 2020
Merged

[3.8] bpo-35714: Reject null characters in struct format strings (GH-16928) #20419

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
06175ec
[3.8] bpo-35714: Reject null characters in struct format strings (GH-…
ZackerySpytz May 25, 2020
f0c4e0f
Fixes for 3.8
ZackerySpytz May 26, 2020
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
7 changes: 7 additions & 0 deletions Lib/test/test_struct.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -652,6 +652,13 @@ def test_format_attr(self):
s2 = struct.Struct(s.format.encode())
self.assertEqual(s2.format, s.format)

def test_issue35714(self):
# Embedded null characters should not be allowed in format strings.
for s in '\0', '2\0i', b'\0':
with self.assertRaisesRegex(struct.error,
'embedded null character'):
struct.calcsize(s)


class UnpackIteratorTest(unittest.TestCase):
"""
Expand Down
2 changes: 2 additions & 0 deletions Misc/NEWS.d/next/Library/2019-10-25-23-45-49.bpo-35714.fw3xb7.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,2 @@
:exc:`struct.error` is now raised if there is a null character in a
:mod:`struct` format string.
4 changes: 4 additions & 0 deletions Modules/_struct.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1285,6 +1285,10 @@ prepare_s(PyStructObject *self)
size_t ncodes;

fmt = PyBytes_AS_STRING(self->s_format);
if (strlen(fmt) != (size_t)PyBytes_GET_SIZE(self->s_format)) {
PyErr_SetString(StructError, "embedded null character");
return -1;
}

f = whichtable(&fmt);

Expand Down