static int unix_scm_to_skb(struct scm_cookie *scm, struct sk_buff *skb, bool send_fds)
{
int err = 0;
+
UNIXCB(skb).pid = get_pid(scm->pid);
- UNIXCB(skb).cred = get_cred(scm->cred);
+ if (scm->cred)
+ UNIXCB(skb).cred = get_cred(scm->cred);
UNIXCB(skb).fp = NULL;
if (scm->fp && send_fds)
err = unix_attach_fds(scm, skb);
return err;
}
+/*
+ * Some apps rely on write() giving SCM_CREDENTIALS
+ * We include credentials if source or destination socket
+ * asserted SOCK_PASSCRED.
+ */
+static void maybe_add_creds(struct sk_buff *skb, const struct socket *sock,
+ const struct sock *other)
+{
+ if (UNIXCB(skb).cred)
+ return;
+ if (test_bit(SOCK_PASSCRED, &sock->flags) ||
+ !other->sk_socket ||
+ test_bit(SOCK_PASSCRED, &other->sk_socket->flags)) {
+ UNIXCB(skb).pid = get_pid(task_tgid(current));
+ UNIXCB(skb).cred = get_current_cred();
+ }
+}
+
/*
* Send AF_UNIX data.
*/
if (sock_flag(other, SOCK_RCVTSTAMP))
__net_timestamp(skb);
+ maybe_add_creds(skb, sock, other);
skb_queue_tail(&other->sk_receive_queue, skb);
if (max_level > unix_sk(other)->recursion_level)
unix_sk(other)->recursion_level = max_level;
(other->sk_shutdown & RCV_SHUTDOWN))
goto pipe_err_free;
+ maybe_add_creds(skb, sock, other);
skb_queue_tail(&other->sk_receive_queue, skb);
if (max_level > unix_sk(other)->recursion_level)
unix_sk(other)->recursion_level = max_level;