This is a note to let you know that I've just added the patch titled net/rose: Fix to not accept on connected socket to the 4.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-rose-fix-to-not-accept-on-connected-socket.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit e4b63226728cefd4cd0334d9e3d58c8093d7fa4f Author: Hyunwoo Kim <v4bel@xxxxxxxxx> Date: Wed Jan 25 02:59:44 2023 -0800 net/rose: Fix to not accept on connected socket [ Upstream commit 14caefcf9837a2be765a566005ad82cd0d2a429f ] If you call listen() and accept() on an already connect()ed rose socket, accept() can successfully connect. This is because when the peer socket sends data to sendmsg, the skb with its own sk stored in the connected socket's sk->sk_receive_queue is connected, and rose_accept() dequeues the skb waiting in the sk->sk_receive_queue. This creates a child socket with the sk of the parent rose socket, which can cause confusion. Fix rose_listen() to return -EINVAL if the socket has already been successfully connected, and add lock_sock to prevent this issue. Signed-off-by: Hyunwoo Kim <v4bel@xxxxxxxxx> Reviewed-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx> Link: https://lore.kernel.org/r/20230125105944.GA133314@ubuntu Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/net/rose/af_rose.c b/net/rose/af_rose.c index 03a1ee221112e..4edd127bb8928 100644 --- a/net/rose/af_rose.c +++ b/net/rose/af_rose.c @@ -490,6 +490,12 @@ static int rose_listen(struct socket *sock, int backlog) { struct sock *sk = sock->sk; + lock_sock(sk); + if (sock->state != SS_UNCONNECTED) { + release_sock(sk); + return -EINVAL; + } + if (sk->sk_state != TCP_LISTEN) { struct rose_sock *rose = rose_sk(sk); @@ -499,8 +505,10 @@ static int rose_listen(struct socket *sock, int backlog) memset(rose->dest_digis, 0, AX25_ADDR_LEN * ROSE_MAX_DIGIS); sk->sk_max_ack_backlog = backlog; sk->sk_state = TCP_LISTEN; + release_sock(sk); return 0; } + release_sock(sk); return -EOPNOTSUPP; }