[PATCH 5.6 003/161] net_failover: fixed rollback in net_failover_open()

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

From: Vasily Averin <vvs@virtuozzo.com>

[ Upstream commit e8224bfe77293494626f6eec1884fee7b87d0ced ]

found by smatch:
drivers/net/net_failover.c:65 net_failover_open() error:
 we previously assumed 'primary_dev' could be null (see line 43)

Fixes: cfc80d9a1163 ("net: Introduce net_failover driver")
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/net/net_failover.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/net/net_failover.c
+++ b/drivers/net/net_failover.c
@@ -61,7 +61,8 @@ static int net_failover_open(struct net_
 	return 0;
 
 err_standby_open:
-	dev_close(primary_dev);
+	if (primary_dev)
+		dev_close(primary_dev);
 err_primary_open:
 	netif_tx_disable(dev);
 	return err;