tipc: Ignore broadcast acknowledgements that are out-of-range

Adds checks to TIPC's broadcast link so that it ignores any
acknowledgement message containing a sequence number that does not
correspond to an unacknowledged message currently in the broadcast
link's transmit queue.

This change prevents the broadcast link from becoming stalled if a
newly booted node receives stale broadcast link acknowledgement
information from another node that has not yet fully synchronized
its end of the broadcast link to reflect the current state of the
new node's end.

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

1 files changed, 2 insertions, 4 deletions

diff --git a/net/tipc/link.c b/net/tipc/link.c
index 332915e43043..4eff342326e2 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -1733,10 +1733,8 @@ void tipc_recv_msg(struct sk_buff *head, struct tipc_bearer *b_ptr)
 
                 /* Release acked messages */
 
-                if (less(n_ptr->bclink.acked, msg_bcast_ack(msg))) {
-                        if (tipc_node_is_up(n_ptr) && n_ptr->bclink.supported)
-                                tipc_bclink_acknowledge(n_ptr, msg_bcast_ack(msg));
-                }
+                if (tipc_node_is_up(n_ptr) && n_ptr->bclink.supported)
+                        tipc_bclink_acknowledge(n_ptr, msg_bcast_ack(msg));
 
                 crs = l_ptr->first_out;
                 while ((crs != l_ptr->next_out) &&