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

[Jamie Bainbridge]

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 dormant_show.

Fixes: b00055aacdb1 ("[NET] core: add RFC2863 operstate")

Signed-off-by: Jamie Bainbridge <jamie.bainbridge@xxxxxxxxx>
---
 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 17927832a4fbb56d3e1dfbed29c567d70ab944be..ff2a1f6ef7e18be56c2de51902519066431e47a8 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -303,7 +303,7 @@ static ssize_t dormant_show(struct device *dev,
 {
 	struct net_device *netdev = to_net_dev(dev);
 
-	if (netif_running(netdev))
+	if (netif_running(netdev) && netif_device_present(netdev))
 		return sysfs_emit(buf, fmt_dec, !!netif_dormant(netdev));
 
 	return -EINVAL;
-- 
2.39.2