[tipc-discussion] [PATCH net-next v4 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 or it's
iterated in bearer_disable() to delete all links attached to the
bearer, the list is always protected by bearer lock. But when one
new link entry is inserted into the "links" list when a link is
created, the list isn't protected by bearer lock. Obviously, it's
unsafe for us.

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