sctp: honor PMTU_DISABLED when handling icmp

sctp_sendmsg() could trigger PMTU updates even when PMTU_DISABLED was
set, as pmtu_pending could be set unconditionally during icmp handling
if the socket was in use by the application.

This patch fixes it by checking for PMTU_DISABLED when handling such
deferred updates.

Signed-off-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 bb08d44..ad89658 100644 (file)
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -1893,6 +1893,7 @@ static int sctp_sendmsg_to_asoc(struct sctp_association *asoc,
                                struct sctp_sndrcvinfo *sinfo)
 {
        struct sock *sk = asoc->base.sk;
+       struct sctp_sock *sp = sctp_sk(sk);
        struct net *net = sock_net(sk);
        struct sctp_datamsg *datamsg;
        bool wait_connect = false;
@@ -1911,13 +1912,14 @@ static int sctp_sendmsg_to_asoc(struct sctp_association *asoc,
                        goto err;
        }
 
-       if (sctp_sk(sk)->disable_fragments && msg_len > asoc->frag_point) {
+       if (sp->disable_fragments && msg_len > asoc->frag_point) {
                err = -EMSGSIZE;
                goto err;
        }
 
        if (asoc->pmtu_pending) {
-               sctp_assoc_sync_pmtu(asoc);
+               if (sp->param_flags & SPP_PMTUD_ENABLE)
+                       sctp_assoc_sync_pmtu(asoc);
                asoc->pmtu_pending = 0;
        }
 
@@ -1936,7 +1938,7 @@ static int sctp_sendmsg_to_asoc(struct sctp_association *asoc,
                if (err)
                        goto err;
 
-               if (sctp_sk(sk)->strm_interleave) {
+               if (sp->strm_interleave) {
                        timeo = sock_sndtimeo(sk, 0);
                        err = sctp_wait_for_connect(asoc, &timeo);
                        if (err)