From: Alexander Wetzel Date: Thu, 15 Sep 2022 15:09:46 +0200 Subject: [PATCH] mac80211: Ensure vif queues are operational after start Make sure local->queue_stop_reasons and vif.txqs_stopped stay in sync. When a new vif is created the queues may end up in an inconsistent state and be inoperable: Communication not using iTXQ will work, allowing to e.g. complete the association. But the 4-way handshake will time out. The sta will not send out any skbs queued in iTXQs. All normal attempts to start the queues will fail when reaching this state. local->queue_stop_reasons will have marked all queues as operational but vif.txqs_stopped will still be set, creating an inconsistent internal state. In reality this seems to be race between the mac80211 function ieee80211_do_open() setting SDATA_STATE_RUNNING and the wake_txqs_tasklet: Depending on the driver and the timing the queues may end up to be operational or not. Cc: stable@vger.kernel.org Fixes: f856373e2f31 ("wifi: mac80211: do not wake queues on a vif that is being stopped") Signed-off-by: Alexander Wetzel --- --- a/net/mac80211/util.c +++ b/net/mac80211/util.c @@ -301,14 +301,14 @@ static void __ieee80211_wake_txqs(struct local_bh_disable(); spin_lock(&fq->lock); + sdata->vif.txqs_stopped[ac] = false; + if (!test_bit(SDATA_STATE_RUNNING, &sdata->state)) goto out; if (sdata->vif.type == NL80211_IFTYPE_AP) ps = &sdata->bss->ps; - sdata->vif.txqs_stopped[ac] = false; - list_for_each_entry_rcu(sta, &local->sta_list, list) { if (sdata != sta->sdata) continue;