From: Hyunwoo Kim v4bel@theori.io
[ Upstream commit f2b0b5210f67c56a3bcdf92ff665fb285d6e0067 ]
When listen() and accept() are called on an x25 socket that connect() succeeds, accept() succeeds immediately. This is because x25_connect() queues the skb to sk->sk_receive_queue, and x25_accept() dequeues it.
This creates a child socket with the sk of the parent x25 socket, which can cause confusion.
Fix x25_listen() to return -EINVAL if the socket has already been successfully connect()ed to avoid this issue.
Signed-off-by: Hyunwoo Kim v4bel@theori.io Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/x25/af_x25.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/net/x25/af_x25.c b/net/x25/af_x25.c index 77d8adb27ec7..9d0328bb30ca 100644 --- a/net/x25/af_x25.c +++ b/net/x25/af_x25.c @@ -497,6 +497,12 @@ static int x25_listen(struct socket *sock, int backlog) int rc = -EOPNOTSUPP;
lock_sock(sk); + if (sock->state != SS_UNCONNECTED) { + rc = -EINVAL; + release_sock(sk); + return rc; + } + if (sk->sk_state != TCP_LISTEN) { memset(&x25_sk(sk)->dest_addr, 0, X25_ADDR_LEN); sk->sk_max_ack_backlog = backlog;