* [PATCH AUTOSEL 4.14 3/3] net/x25: Fix to not accept on connected socket
[not found] <20230131150126.1250471-1-sashal@kernel.org>
@ 2023-01-31 15:01 ` Sasha Levin
0 siblings, 0 replies; only message in thread
From: Sasha Levin @ 2023-01-31 15:01 UTC (permalink / raw)
To: linux-kernel, stable
Cc: Hyunwoo Kim, David S . Miller, Sasha Levin, ms, edumazet, kuba,
pabeni, linux-x25, netdev
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 e103ec39759f..73e293c3f2fb 100644
--- a/net/x25/af_x25.c
+++ b/net/x25/af_x25.c
@@ -496,6 +496,12 @@ 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;
--
2.39.0
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