https://github.com/python/cpython/commit/6c695bfad45ddde73d0d674286800fbe295f0627 commit: 6c695bfad45ddde73d0d674286800fbe295f0627 branch: main author: scrieve <[email protected]> committer: vstinner <[email protected]> date: 2026-10-27T22:56:42Z summary:
gh-160561: Close the duplicated descriptor when socket.fromfd() fails (#160579) Co-authored-by: wlkr73 <[email protected]> Co-authored-by: lumenyr <[email protected]> Co-authored-by: Victor Stinner <[email protected]> files: A Misc/NEWS.d/next/Library/2026-10-24-07-58-00.gh-issue-160561.b3Kq1z.rst M Lib/socket.py M Lib/test/test_socket.py diff --git a/Lib/socket.py b/Lib/socket.py index 21a852155abb3b3..df99cc04ca85546 100644 --- a/Lib/socket.py +++ b/Lib/socket.py @@ -572,7 +572,11 @@ def fromfd(fd, family, type, proto=0): descriptor. The remaining arguments are the same as for socket(). """ nfd = dup(fd) - return socket(family, type, proto, nfd) + try: + return socket(family, type, proto, nfd) + except: + close(nfd) + raise if hasattr(_socket.socket, "sendmsg"): def send_fds(sock, buffers, fds, flags=0, address=None): diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py index e4b3d848923f8c9..51b666bbaba8271 100644 --- a/Lib/test/test_socket.py +++ b/Lib/test/test_socket.py @@ -3195,6 +3195,23 @@ def testFromFd(self): def _testFromFd(self): self.serv_conn.send(MSG) + def testFromFdError(self): + # Make sure that the fromfd() duplicated socket is closed on error. + fd = self.cli_conn.fileno() + fd_count_before = os_helper.fd_count() + + with self.assertRaises(TypeError): + socket.fromfd(fd, "not-a-valid-family", socket.SOCK_STREAM) + with self.assertRaises(TypeError): + socket.fromfd(fd, socket.AF_INET, "not-a-valid-type") + with self.assertRaises(OverflowError): + socket.fromfd(fd, socket.AF_INET, 1 << 100) + + self.assertEqual(os_helper.fd_count(), fd_count_before) + + def _testFromFdError(self): + pass + def testDup(self): # Testing dup() sock = self.cli_conn.dup() diff --git a/Misc/NEWS.d/next/Library/2026-10-24-07-58-00.gh-issue-160561.b3Kq1z.rst b/Misc/NEWS.d/next/Library/2026-10-24-07-58-00.gh-issue-160561.b3Kq1z.rst new file mode 100644 index 000000000000000..c49cd6a83e90bf4 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2026-10-24-07-58-00.gh-issue-160561.b3Kq1z.rst @@ -0,0 +1 @@ +Fix a descriptor leak in :func:`socket.fromfd` when the socket constructor rejects its arguments. The duplicated descriptor was never closed. _______________________________________________ Python-checkins mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3//lists/python-checkins.python.org Member address: [email protected]
