[tipc-discussion] [PATCH net-next v2 10/10] tipc: use bearer lock to protect links list when link is created

[Ying X. <yin...@wi...>]

When the 'links' list of tipc_bearer structure is traversed in
tipc_block_bearer() to reset all links owned by the bearer and
and each link entry from the list is removed in bearer_disable()
to delete all links attached to the bearer, the list is always
protected by its bearer lock, however, when one new link entry is
inserted into the list when link is created, the bearer lock isn't
held. So it's unsafe for us at the moment.

Signed-off-by: Ying Xue <yin...@wi...>
---
 net/tipc/discover.c |    3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/tipc/discover.c b/net/tipc/discover.c
index 8f86fcf..f4c3682 100644
--- a/net/tipc/discover.c
+++ b/net/tipc/discover.c
@@ -157,6 +157,8 @@ void tipc_disc_recv_msg(struct sk_buff *buf, struct tipc_bearer *b_ptr)
 		if (!n_ptr)
 			return;
 	}
+
+	spin_lock_bh(&b_ptr->lock);
 	tipc_node_lock(n_ptr);
 
 	/* Prepare to validate requesting node's signature and media address */
@@ -245,6 +247,7 @@ void tipc_disc_recv_msg(struct sk_buff *buf, struct tipc_bearer *b_ptr)
 	}
 exit:
 	tipc_node_unlock(n_ptr);
+	spin_unlock_bh(&b_ptr->lock);
 }
 
 /**
-- 
1.7.9.5