sctp: allow receiving msg when TCP-style sk is in CLOSED state

Commit 141ddefce7c8 ("sctp: change sk state to CLOSED instead of
CLOSING in sctp_sock_migrate") changed sk state to CLOSED if the
assoc is closed when sctp_accept clones a new sk.

If there is still data in sk receive queue, users will not be able
to read it any more, as sctp_recvmsg returns directly if sk state
is CLOSED.

This patch is to add CLOSED state check in sctp_recvmsg to allow
reading data from TCP-style sk with CLOSED state as what TCP does.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 8812e1b..9fc417a 100644 (file)
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -2079,7 +2079,7 @@ static int sctp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
        lock_sock(sk);
 
        if (sctp_style(sk, TCP) && !sctp_sstate(sk, ESTABLISHED) &&
-           !sctp_sstate(sk, CLOSING)) {
+           !sctp_sstate(sk, CLOSING) && !sctp_sstate(sk, CLOSED)) {
                err = -ENOTCONN;
                goto out;
        }