[PATCH net] net: fix the missing unlock for detached devices

[Jakub Kicinski <kuba@kernel.org>]

The combined condition was left as is when we converted
from __dev_get_by_index() to netdev_get_by_index_lock().
There was no need to undo anything with the former, for
the latter we need an unlock.

Fixes: 1d22d3060b9b ("net: drop rtnl_lock for queue_mgmt operations")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
CC: jdamato@fastly.com
CC: almasrymina@google.com
CC: sdf@fomichev.me
CC: ap420073@gmail.com
---
 net/core/netdev-genl.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c
index 5d7af50fe702..230743bdbb14 100644
--- a/net/core/netdev-genl.c
+++ b/net/core/netdev-genl.c
@@ -861,14 +861,17 @@ int netdev_nl_bind_rx_doit(struct sk_buff *skb, struct genl_info *info)
 
 	mutex_lock(&priv->lock);
 
+	err = 0;
 	netdev = netdev_get_by_index_lock(genl_info_net(info), ifindex);
-	if (!netdev || !netif_device_present(netdev)) {
+	if (!netdev) {
 		err = -ENODEV;
 		goto err_unlock_sock;
 	}
-
-	if (!netdev_need_ops_lock(netdev)) {
+	if (!netif_device_present(netdev))
+		err = -ENODEV;
+	else if (!netdev_need_ops_lock(netdev))
 		err = -EOPNOTSUPP;
+	if (err) {
 		NL_SET_BAD_ATTR(info->extack,
 				info->attrs[NETDEV_A_DEV_IFINDEX]);
 		goto err_unlock;
-- 
2.49.0