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@xxxxxxxxxx> Tested-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Signed-off-by: Xin Long <lucien.xin@xxxxxxxxx> --- 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 -- To unsubscribe from this list: send the line "unsubscribe linux-sctp" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html