From: Hyunwoo Kim <v4bel@theori.io>
To: ms@dev.tdt.de, davem@davemloft.net, edumazet@google.com,
kuba@kernel.org, pabeni@redhat.com, kuniyu@amazon.com
Cc: v4bel@theori.io, imv4bel@gmail.com, linux-x25@vger.kernel.org,
netdev@vger.kernel.org
Subject: [PATCH v3] net/x25: Fix to not accept on connected socket
Date: Wed, 25 Jan 2023 03:05:14 -0800 [thread overview]
Message-ID: <20230125110514.GA134174@ubuntu> (raw)
If you call listen() and accept() on an already connect()ed
x25 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 x25_accept() dequeues
the skb waiting in the sk->sk_receive_queue.
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 connected, and add lock_sock
to prevent this issue.
Signed-off-by: Hyunwoo Kim <v4bel@theori.io>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
---
v1 -> v2 : Change the flag to check to SS_UNCONNECTED
v2 -> v3 : Fix wrong patch description
---
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 3b55502b2965..5c7ad301d742 100644
--- a/net/x25/af_x25.c
+++ b/net/x25/af_x25.c
@@ -482,6 +482,12 @@ 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;
--
2.25.1
next reply other threads:[~2023-01-25 11:05 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-25 11:05 Hyunwoo Kim [this message]
2023-01-28 7:20 ` [PATCH v3] net/x25: Fix to not accept on connected socket patchwork-bot+netdevbpf
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20230125110514.GA134174@ubuntu \
--to=v4bel@theori.io \
--cc=davem@davemloft.net \
--cc=edumazet@google.com \
--cc=imv4bel@gmail.com \
--cc=kuba@kernel.org \
--cc=kuniyu@amazon.com \
--cc=linux-x25@vger.kernel.org \
--cc=ms@dev.tdt.de \
--cc=netdev@vger.kernel.org \
--cc=pabeni@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).