From: Johannes Berg Date: Tue, 24 Jun 2025 11:07:49 +0000 (+0200) Subject: wifi: mac80211: finish link init before RCU publish X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=d87c3ca0f8f1ca4c25f2ed819e954952f4d8d709;p=linux-block.git wifi: mac80211: finish link init before RCU publish Since the link/conf pointers can be accessed without any protection other than RCU, make sure the data is actually set up before publishing the structures. Fixes: b2e8434f1829 ("wifi: mac80211: set up/tear down client vif links properly") Link: https://patch.msgid.link/20250624130749.9a308b713c74.I4a80f5eead112a38730939ea591d2e275c721256@changeid Signed-off-by: Johannes Berg --- diff --git a/net/mac80211/link.c b/net/mac80211/link.c index d40c2bd3b50b..4f7b7d0f64f2 100644 --- a/net/mac80211/link.c +++ b/net/mac80211/link.c @@ -93,9 +93,6 @@ void ieee80211_link_init(struct ieee80211_sub_if_data *sdata, if (link_id < 0) link_id = 0; - rcu_assign_pointer(sdata->vif.link_conf[link_id], link_conf); - rcu_assign_pointer(sdata->link[link_id], link); - if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) { struct ieee80211_sub_if_data *ap_bss; struct ieee80211_bss_conf *ap_bss_conf; @@ -145,6 +142,9 @@ void ieee80211_link_init(struct ieee80211_sub_if_data *sdata, ieee80211_link_debugfs_add(link); } + + rcu_assign_pointer(sdata->vif.link_conf[link_id], link_conf); + rcu_assign_pointer(sdata->link[link_id], link); } void ieee80211_link_stop(struct ieee80211_link_data *link)