[PATCH net] sctp: listen on the sock only when it's state is listening or closed

[PATCH net] sctp: listen on the sock only when it's state is listening or closed

[Xin Long]

Now sctp doesn't check sock's state before listening on it. It could
even cause changing a sock with any state to become a listening sock
when doing sctp_listen.

This patch is to fix it by checking sock's state in sctp_listen, so
that it will listen on the sock with right state.

Reported-by: Andrey Konovalov <andreyknvl@google.com>
Tested-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
---
 net/sctp/socket.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index c1401f4..d9d4c92 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -7034,6 +7034,9 @@ int sctp_inet_listen(struct socket *sock, int backlog)
 	if (sock->state != SS_UNCONNECTED)
 		goto out;
 
+	if (!sctp_sstate(sk, LISTENING) && !sctp_sstate(sk, CLOSED))
+		goto out;
+
 	/* If backlog is zero, disable listening. */
 	if (!backlog) {
 		if (sctp_sstate(sk, CLOSED))
-- 
2.1.0

Re: [PATCH net] sctp: listen on the sock only when it's state is listening or closed

[Marcelo Ricardo Leitner]

On Thu, Apr 06, 2017 at 01:10:52PM +0800, Xin Long wrote:
> Now sctp doesn't check sock's state before listening on it. It could
> even cause changing a sock with any state to become a listening sock
> when doing sctp_listen.
> 
> This patch is to fix it by checking sock's state in sctp_listen, so
> that it will listen on the sock with right state.
> 
> Reported-by: Andrey Konovalov <andreyknvl@google.com>
> Tested-by: Andrey Konovalov <andreyknvl@google.com>
> Signed-off-by: Xin Long <lucien.xin@gmail.com>

Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>

Dave, please consider this for -stable. Thanks

> ---
>  net/sctp/socket.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/net/sctp/socket.c b/net/sctp/socket.c
> index c1401f4..d9d4c92 100644
> --- a/net/sctp/socket.c
> +++ b/net/sctp/socket.c
> @@ -7034,6 +7034,9 @@ int sctp_inet_listen(struct socket *sock, int backlog)
>  	if (sock->state != SS_UNCONNECTED)
>  		goto out;
>  
> +	if (!sctp_sstate(sk, LISTENING) && !sctp_sstate(sk, CLOSED))
> +		goto out;
> +
>  	/* If backlog is zero, disable listening. */
>  	if (!backlog) {
>  		if (sctp_sstate(sk, CLOSED))
> -- 
> 2.1.0
> 
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Re: [PATCH net] sctp: listen on the sock only when it's state is listening or closed

[David Miller]

From: Xin Long <lucien.xin@gmail.com>
Date: Thu,  6 Apr 2017 13:10:52 +0800

> Now sctp doesn't check sock's state before listening on it. It could
> even cause changing a sock with any state to become a listening sock
> when doing sctp_listen.
> 
> This patch is to fix it by checking sock's state in sctp_listen, so
> that it will listen on the sock with right state.
> 
> Reported-by: Andrey Konovalov <andreyknvl@google.com>
> Tested-by: Andrey Konovalov <andreyknvl@google.com>
> Signed-off-by: Xin Long <lucien.xin@gmail.com>

Applied and queued up for -stable.