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

Greg Kroah-Hartman
2018-08-23T08:58:52Z

From: Jon Maloy <jon.maloy@ericsson.com>

[ 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@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
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)