tipc: fix a link reset issue due to retransmission failures

When a node joins a cluster while we are transmitting a fragment
stream over the broadcast link, it's missing the preceding fragments
needed to build a meaningful message. As a result, the node has to
drop it. However, as the fragment message is not acknowledged to
its sender before it's dropped, it accidentally causes link reset
of retransmission failure on the node.

Reported-by: Erik Hugne <erik.hugne@ericsson.com>
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Tested-by: Erik Hugne <erik.hugne@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 5 insertions, 3 deletions

diff --git a/net/tipc/bcast.c b/net/tipc/bcast.c
index 5aff0844d4d3..52307397e0b1 100644
--- a/net/tipc/bcast.c
+++ b/net/tipc/bcast.c
@@ -523,11 +523,13 @@ receive:
                         tipc_bclink_unlock(net);
                         tipc_node_unlock(node);
                 } else if (msg_user(msg) == MSG_FRAGMENTER) {
-                        tipc_buf_append(&node->bclink.reasm_buf, &buf);
-                        if (unlikely(!buf && !node->bclink.reasm_buf))
-                                goto unlock;
                         tipc_bclink_lock(net);
                         bclink_accept_pkt(node, seqno);
+                        tipc_buf_append(&node->bclink.reasm_buf, &buf);
+                        if (unlikely(!buf && !node->bclink.reasm_buf)) {
+                                tipc_bclink_unlock(net);
+                                goto unlock;
+                        }
                         bcl->stats.recv_fragments++;
                         if (buf) {
                                 bcl->stats.recv_fragmented++;