tipc: Enhance filtering of out-dated link reset messages

Ensure TIPC ignores an out-dated link reset message whose session
number predates the current session number. (Previously, TIPC only
ignored an out-date reset message whose session number was equal
to the current link session number.)

Out-dated link reset messages should not occur under normal circumstances;
however, they can be generated if a link endpoint is unable to send a
link reset message right away and queues it for later delivery, but the
queued message is not sent until after the link is established.

Thanks to Laser [gotolaser@gmail.com] for diagnosing the problem and
contributing a prototype patch.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/net/tipc/link.c b/net/tipc/link.c
index e0bf6d5f1668419ee72772dd4ce4a68839058cef..b43beea54108205f1ef2ad7a7bbe7b247c37c03e 100644 (file)
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -2045,8 +2045,8 @@ static void link_recv_proto_msg(struct link *l_ptr, struct sk_buff *buf)
        case RESET_MSG:
                if (!link_working_unknown(l_ptr) &&
                    (l_ptr->peer_session != INVALID_SESSION)) {
-                       if (msg_session(msg) == l_ptr->peer_session)
-                               break; /* duplicate: ignore */
+                       if (less_eq(msg_session(msg), l_ptr->peer_session))
+                               break; /* duplicate or old reset: ignore */
                }
                /* fall thru' */
        case ACTIVATE_MSG: