[PATCH 4.17 204/324] tipc: make function tipc_net_finalize() thread safe

[Greg Kroah-Hartman]

4.17-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jon Maloy <jon.maloy@xxxxxxxxxxxx>

[ Upstream commit 9faa89d4ed9d7d326f4763d262842270450f9b1f ]

The setting of the node address is not thread safe, meaning that
two discoverers may decide to set it simultanously, with a duplicate
entry in the name table as result. We fix that with this commit.

Fixes: 25b0b9c4e835 ("tipc: handle collisions of 32-bit node address hash values")
Signed-off-by: Jon Maloy <jon.maloy@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 net/tipc/net.c |   17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

--- a/net/tipc/net.c
+++ b/net/tipc/net.c
@@ -121,12 +121,17 @@ int tipc_net_init(struct net *net, u8 *n
 
 void tipc_net_finalize(struct net *net, u32 addr)
 {
-	tipc_set_node_addr(net, addr);
-	smp_mb();
-	tipc_named_reinit(net);
-	tipc_sk_reinit(net);
-	tipc_nametbl_publish(net, TIPC_CFG_SRV, addr, addr,
-			     TIPC_CLUSTER_SCOPE, 0, addr);
+	struct tipc_net *tn = tipc_net(net);
+
+	spin_lock_bh(&tn->node_list_lock);
+	if (!tipc_own_addr(net)) {
+		tipc_set_node_addr(net, addr);
+		tipc_named_reinit(net);
+		tipc_sk_reinit(net);
+		tipc_nametbl_publish(net, TIPC_CFG_SRV, addr, addr,
+				     TIPC_CLUSTER_SCOPE, 0, addr);
+	}
+	spin_unlock_bh(&tn->node_list_lock);
 }
 
 void tipc_net_stop(struct net *net)