[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);
 }