CVE-2026-64523
Gravedad:
Pendiente de análisis
Tipo:
No Disponible / Otro tipo
Fecha de publicación:
25/07/2026
Última modificación:
25/07/2026
Descripción
*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br />
<br />
net/handshake: Take a long-lived file reference at submit<br />
<br />
handshake_nl_accept_doit() needs the file pointer backing<br />
req->hr_sk->sk_socket to survive the window between<br />
handshake_req_next() and the subsequent FD_PREPARE() and get_file().<br />
The submit-side sock_hold() does not provide that. sk_refcnt keeps<br />
struct sock alive, but struct socket is owned by sock->file: when<br />
the consumer fputs the last file reference, sock_release() tears<br />
the socket down regardless of any sock_hold.<br />
<br />
Add an hr_file pointer to struct handshake_req and acquire an<br />
explicit reference on sock->file during handshake_req_submit().<br />
handshake_complete() and handshake_req_cancel() release the<br />
reference on the completion-bit-winning path.<br />
<br />
The submit error path must also release the file reference, but<br />
after rhashtable insertion a concurrent handshake_req_cancel() can<br />
discover the request and race the error path. Gate the error-path<br />
cleanup -- sk_destruct restoration, fput, and request destruction<br />
-- with test_and_set_bit(HANDSHAKE_F_REQ_COMPLETED), the same<br />
serialization handshake_complete() and handshake_req_cancel()<br />
already use. When cancel has already claimed ownership, the submit<br />
error path returns without touching the request; socket teardown<br />
handles final destruction.<br />
<br />
The accept-side dereferences are not yet retargeted; that change<br />
comes in the next patch.



