From 34b2789f1d9bf8dcca9b5cb553d076ca2cd898ee Mon Sep 17 00:00:00 2001 From: Xin Long Date: Thu, 6 Apr 2017 13:10:52 +0800 Subject: [PATCH] sctp: listen on the sock only when it's state is listening or closed 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 Tested-by: Andrey Konovalov Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller --- net/sctp/socket.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/sctp/socket.c b/net/sctp/socket.c index c1401f43d40f..d9d4c92e06b3 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)) -- 2.20.1