failover: Add missing check to validate 'slave_dev' in net_failover_slave_unregister

[ Upstream commit 9e7e6cabf371cc008cb2244a04c012b516753693 ]

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/net/net_failover.c: In function 'net_failover_slave_unregister':
drivers/net/net_failover.c:598:35: warning:
 variable 'primary_dev' set but not used [-Wunused-but-set-variable]

There should check the validity of 'slave_dev'.

Fixes: cfc80d9a1163 ("net: Introduce net_failover driver")

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/net_failover.c b/drivers/net/net_failover.c
index 7ae1856..5a749dc 100644 (file)
--- a/drivers/net/net_failover.c
+++ b/drivers/net/net_failover.c
@@ -603,6 +603,9 @@ static int net_failover_slave_unregister(struct net_device *slave_dev,
        primary_dev = rtnl_dereference(nfo_info->primary_dev);
        standby_dev = rtnl_dereference(nfo_info->standby_dev);
 
+       if (WARN_ON_ONCE(slave_dev != primary_dev && slave_dev != standby_dev))
+               return -ENODEV;
+
        vlan_vids_del_by_dev(slave_dev, failover_dev);
        dev_uc_unsync(slave_dev, failover_dev);
        dev_mc_unsync(slave_dev, failover_dev);