diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c index f4f7e7691077bf6fb47ab1dcb4d9de04bcec8844..8f6b593a921f39855d29116c614a4c92903e6580 100644 --- a/net/mac80211/cfg.c +++ b/net/mac80211/cfg.c @@ -933,6 +933,7 @@ static int ieee80211_start_ap(struct wiphy *wiphy, struct net_device *dev, IEEE80211_CHANCTX_SHARED); if (err) return err; + ieee80211_vif_copy_chanctx_to_vlans(sdata, false); /* * Apply control port protocol, this allows us to @@ -1047,6 +1048,7 @@ static int ieee80211_stop_ap(struct wiphy *wiphy, struct net_device *dev) local->total_ps_buffered -= skb_queue_len(&sdata->u.ap.ps.bc_buf); skb_queue_purge(&sdata->u.ap.ps.bc_buf); + ieee80211_vif_copy_chanctx_to_vlans(sdata, true); ieee80211_vif_release_channel(sdata); return 0; diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c index 1bfe0a8b19d222c95c3878d157114e9e85a0443b..b5b50762f03e6ca1dbfacb924f77a3712a8cd229 100644 --- a/net/mac80211/chan.c +++ b/net/mac80211/chan.c @@ -198,15 +198,6 @@ static void __ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata) ctx = container_of(conf, struct ieee80211_chanctx, conf); - if (sdata->vif.type == NL80211_IFTYPE_AP) { - struct ieee80211_sub_if_data *vlan; - - /* for the VLAN list */ - ASSERT_RTNL(); - list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list) - rcu_assign_pointer(vlan->vif.chanctx_conf, NULL); - } - ieee80211_unassign_vif_chanctx(sdata, ctx); if (ctx->refcount == 0) ieee80211_free_chanctx(local, ctx); @@ -326,15 +317,6 @@ int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata, goto out; } - if (sdata->vif.type == NL80211_IFTYPE_AP) { - struct ieee80211_sub_if_data *vlan; - - /* for the VLAN list */ - ASSERT_RTNL(); - list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list) - rcu_assign_pointer(vlan->vif.chanctx_conf, &ctx->conf); - } - ieee80211_recalc_smps_chanctx(local, ctx); out: mutex_unlock(&local->chanctx_mtx); @@ -369,6 +351,40 @@ void ieee80211_vif_vlan_copy_chanctx(struct ieee80211_sub_if_data *sdata) mutex_unlock(&local->chanctx_mtx); } +void ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata, + bool clear) +{ + struct ieee80211_local *local = sdata->local; + struct ieee80211_sub_if_data *vlan; + struct ieee80211_chanctx_conf *conf; + + ASSERT_RTNL(); + + if (WARN_ON(sdata->vif.type != NL80211_IFTYPE_AP)) + return; + + mutex_lock(&local->chanctx_mtx); + + /* + * Check that conf exists, even when clearing this function + * must be called with the AP's channel context still there + * as it would otherwise cause VLANs to have an invalid + * channel context pointer for a while, possibly pointing + * to a channel context that has already been freed. + */ + conf = rcu_dereference_protected(sdata->vif.chanctx_conf, + lockdep_is_held(&local->chanctx_mtx)); + WARN_ON(!conf); + + if (clear) + conf = NULL; + + list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list) + rcu_assign_pointer(vlan->vif.chanctx_conf, conf); + + mutex_unlock(&local->chanctx_mtx); +} + void ieee80211_iter_chan_contexts_atomic( struct ieee80211_hw *hw, void (*iter)(struct ieee80211_hw *hw, diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index 080cf0942ce7768b0797c33d0de62fa0d26ab428..8e884fcbe79b05cf39925bb03c1b3a9326b1f7b9 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -1605,6 +1605,8 @@ ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata, enum ieee80211_chanctx_mode mode); void ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata); void ieee80211_vif_vlan_copy_chanctx(struct ieee80211_sub_if_data *sdata); +void ieee80211_vif_copy_chanctx_to_vlans(struct ieee80211_sub_if_data *sdata, + bool clear); void ieee80211_recalc_smps_chanctx(struct ieee80211_local *local, struct ieee80211_chanctx *chanctx);