[PATCH net 2/4] net-sysfs: check device is present when showing duplex

[Jamie Bainbridge <jamie.bainbridge@gmail.com>]

A sysfs reader can race with a device reset or removal.

This was fixed for speed_show with commit 4224cfd7fb65 ("net-sysfs: add
check for netdevice being present to speed_show") so add the same check
to duplex_show.

Fixes: 8ae6daca85c8 ("ethtool: Call ethtool's get/set_settings callbacks with cleaned data")

Signed-off-by: Jamie Bainbridge <jamie.bainbridge@gmail.com>
---
 net/core/net-sysfs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index 7fabe5afa3012ecad6551e12f478b755952933b8..3a539a2bd4d11c5f5d7b6f15a23d61439f178c3b 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -261,7 +261,7 @@ static ssize_t duplex_show(struct device *dev,
 	if (!rtnl_trylock())
 		return restart_syscall();
 
-	if (netif_running(netdev)) {
+	if (netif_running(netdev) && netif_device_present(netdev)) {
 		struct ethtool_link_ksettings cmd;
 
 		if (!__ethtool_get_link_ksettings(netdev, &cmd)) {
-- 
2.39.2