From e5c8d7acd31b27057ea42cd405d0b3ece097bc89 Mon Sep 17 00:00:00 2001 From: Zihan Xi Date: Wed, 9 Sep 2026 12:37:18 +0000 Subject: [PATCH] wifi: virt_wifi: don't transfer operstate before register virt_wifi_newlink() calls netif_stacked_transfer_operstate() before register_netdevice(). If the lower device is dormant, that queues the new netdev on lweventlist while it is still uninitialized. If registration fails after that, for example because of an invalid name such as "bad/name", free_netdev() immediately frees the object. A later linkwatch_fire_event() then use-after-frees the list entry. Move the transfer to after netdev_upper_dev_link(), as macvlan and ipvlan already do. Fixes: c7cdba31ed8b ("mac80211-next: rtnetlink wifi simulation device") Reported-by: Vega Assisted-by: LLM Co-developed-by: Luxing Yin Signed-off-by: Luxing Yin Signed-off-by: Zihan Xi Link: https://patch.msgid.link/f5a832fb0ab228ce6e2b5a91fba4ca8b79198a2f.1788948455.git.zihanx@nebusec.ai Signed-off-by: Johannes Berg --- drivers/net/wireless/virtual/virt_wifi.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/virtual/virt_wifi.c b/drivers/net/wireless/virtual/virt_wifi.c index b69a4650fba8..48afc2432f93 100644 --- a/drivers/net/wireless/virtual/virt_wifi.c +++ b/drivers/net/wireless/virtual/virt_wifi.c @@ -558,7 +558,6 @@ static int virt_wifi_newlink(struct net_device *dev, } eth_hw_addr_inherit(dev, priv->lowerdev); - netif_stacked_transfer_operstate(priv->lowerdev, dev); dev->ieee80211_ptr = kzalloc_obj(*dev->ieee80211_ptr); @@ -584,6 +583,8 @@ static int virt_wifi_newlink(struct net_device *dev, goto unregister_netdev; } + netif_stacked_transfer_operstate(priv->lowerdev, dev); + dev->priv_destructor = virt_wifi_net_device_destructor; priv->being_deleted = false; priv->is_connected = false;