[SCTP]: Re-order SCTP initializations to avoid race with sctp_rcv()

Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 28 insertions, 21 deletions

diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c
index ca527a27dd05..84cd53635fe8 100644
--- a/net/sctp/ipv6.c
+++ b/net/sctp/ipv6.c
@@ -992,45 +992,52 @@ static struct sctp_pf sctp_pf_inet6_specific = {
 	.af            = &sctp_ipv6_specific,
 };
 
-/* Initialize IPv6 support and register with inet6 stack.  */
+/* Initialize IPv6 support and register with socket layer.  */
 int sctp_v6_init(void)
 {
-	int rc = proto_register(&sctpv6_prot, 1);
+	int rc;
 
+	/* Register the SCTP specific PF_INET6 functions. */
+	sctp_register_pf(&sctp_pf_inet6_specific, PF_INET6);
+
+	/* Register the SCTP specific AF_INET6 functions. */
+	sctp_register_af(&sctp_ipv6_specific);
+
+	rc = proto_register(&sctpv6_prot, 1);
 	if (rc)
-		goto out;
-	/* Register inet6 protocol. */
-	rc = -EAGAIN;
-	if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
-		goto out_unregister_sctp_proto;
+		return rc;
 
 	/* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
 	inet6_register_protosw(&sctpv6_seqpacket_protosw);
 	inet6_register_protosw(&sctpv6_stream_protosw);
 
-	/* Register the SCTP specific PF_INET6 functions. */
-	sctp_register_pf(&sctp_pf_inet6_specific, PF_INET6);
-
-	/* Register the SCTP specific AF_INET6 functions. */
-	sctp_register_af(&sctp_ipv6_specific);
+	return 0;
+}
 
+/* Register with inet6 layer. */
+int sctp_v6_add_protocol(void)
+{
 	/* Register notifier for inet6 address additions/deletions. */
 	register_inet6addr_notifier(&sctp_inet6addr_notifier);
-	rc = 0;
-out:
-	return rc;
-out_unregister_sctp_proto:
-	proto_unregister(&sctpv6_prot);
-	goto out;
+
+	if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
+		return -EAGAIN;
+
+	return 0;
 }
 
 /* IPv6 specific exit support. */
 void sctp_v6_exit(void)
 {
-	list_del(&sctp_ipv6_specific.list);
-	inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
 	inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
 	inet6_unregister_protosw(&sctpv6_stream_protosw);
-	unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
 	proto_unregister(&sctpv6_prot);
+	list_del(&sctp_ipv6_specific.list);
+}
+
+/* Unregister with inet6 layer. */
+void sctp_v6_del_protocol(void)
+{
+	inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
+	unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
 }