From 7a7c0a6438b8e7636d5a22e572892cc234f68297 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Sat, 27 May 2017 00:27:25 +0200 Subject: mac80211: fix TX aggregation start/stop callback race When starting or stopping an aggregation session, one of the steps is that the driver calls back to mac80211 that the start/stop can proceed. This is handled by queueing up a fake SKB and processing it from the normal iface/sdata work. Since this isn't flushed when disassociating, the following race is possible: * associate * start aggregation session * driver callback * disassociate * associate again to the same AP * callback processing runs, leading to a WARN_ON() that the TID hadn't requested aggregation If the second association isn't to the same AP, there would only be a message printed ("Could not find station: "), but the same race could happen. Fix this by not going the whole detour with a fake SKB etc. but simply looking up the aggregation session in the driver callback, marking it with a START_CB/STOP_CB bit and then scheduling the regular aggregation work that will now process these bits as well. This also simplifies the code and gets rid of the whole problem with allocation failures of said skb, which could have left the session in limbo. Reported-by: Jouni Malinen Signed-off-by: Johannes Berg --- net/mac80211/agg-tx.c | 128 ++++++++++++++++++--------------------------- net/mac80211/ht.c | 16 ++++-- net/mac80211/ieee80211_i.h | 14 ++--- net/mac80211/iface.c | 11 +--- net/mac80211/sta_info.h | 2 + 5 files changed, 71 insertions(+), 100 deletions(-) (limited to 'net/mac80211') diff --git a/net/mac80211/agg-tx.c b/net/mac80211/agg-tx.c index 60e2a62f7bef..cf2392b2ac71 100644 --- a/net/mac80211/agg-tx.c +++ b/net/mac80211/agg-tx.c @@ -7,7 +7,7 @@ * Copyright 2006-2007 Jiri Benc * Copyright 2007, Michael Wu * Copyright 2007-2010, Intel Corporation - * Copyright(c) 2015 Intel Deutschland GmbH + * Copyright(c) 2015-2017 Intel Deutschland GmbH * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as @@ -741,46 +741,43 @@ static void ieee80211_agg_tx_operational(struct ieee80211_local *local, ieee80211_agg_start_txq(sta, tid, true); } -void ieee80211_start_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u16 tid) +void ieee80211_start_tx_ba_cb(struct sta_info *sta, int tid, + struct tid_ampdu_tx *tid_tx) { - struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); + struct ieee80211_sub_if_data *sdata = sta->sdata; struct ieee80211_local *local = sdata->local; - struct sta_info *sta; - struct tid_ampdu_tx *tid_tx; - trace_api_start_tx_ba_cb(sdata, ra, tid); + if (WARN_ON(test_and_set_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state))) + return; + + if (test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state)) + ieee80211_agg_tx_operational(local, sta, tid); +} + +static struct tid_ampdu_tx * +ieee80211_lookup_tid_tx(struct ieee80211_sub_if_data *sdata, + const u8 *ra, u16 tid, struct sta_info **sta) +{ + struct tid_ampdu_tx *tid_tx; if (tid >= IEEE80211_NUM_TIDS) { ht_dbg(sdata, "Bad TID value: tid = %d (>= %d)\n", tid, IEEE80211_NUM_TIDS); - return; + return NULL; } - mutex_lock(&local->sta_mtx); - sta = sta_info_get_bss(sdata, ra); - if (!sta) { - mutex_unlock(&local->sta_mtx); + *sta = sta_info_get_bss(sdata, ra); + if (!*sta) { ht_dbg(sdata, "Could not find station: %pM\n", ra); - return; + return NULL; } - mutex_lock(&sta->ampdu_mlme.mtx); - tid_tx = rcu_dereference_protected_tid_tx(sta, tid); + tid_tx = rcu_dereference((*sta)->ampdu_mlme.tid_tx[tid]); - if (WARN_ON(!tid_tx)) { + if (WARN_ON(!tid_tx)) ht_dbg(sdata, "addBA was not requested!\n"); - goto unlock; - } - if (WARN_ON(test_and_set_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state))) - goto unlock; - - if (test_bit(HT_AGG_STATE_RESPONSE_RECEIVED, &tid_tx->state)) - ieee80211_agg_tx_operational(local, sta, tid); - - unlock: - mutex_unlock(&sta->ampdu_mlme.mtx); - mutex_unlock(&local->sta_mtx); + return tid_tx; } void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_vif *vif, @@ -788,19 +785,20 @@ void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_vif *vif, { struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); struct ieee80211_local *local = sdata->local; - struct ieee80211_ra_tid *ra_tid; - struct sk_buff *skb = dev_alloc_skb(0); + struct sta_info *sta; + struct tid_ampdu_tx *tid_tx; - if (unlikely(!skb)) - return; + trace_api_start_tx_ba_cb(sdata, ra, tid); - ra_tid = (struct ieee80211_ra_tid *) &skb->cb; - memcpy(&ra_tid->ra, ra, ETH_ALEN); - ra_tid->tid = tid; + rcu_read_lock(); + tid_tx = ieee80211_lookup_tid_tx(sdata, ra, tid, &sta); + if (!tid_tx) + goto out; - skb->pkt_type = IEEE80211_SDATA_QUEUE_AGG_START; - skb_queue_tail(&sdata->skb_queue, skb); - ieee80211_queue_work(&local->hw, &sdata->work); + set_bit(HT_AGG_STATE_START_CB, &tid_tx->state); + ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work); + out: + rcu_read_unlock(); } EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe); @@ -860,37 +858,18 @@ int ieee80211_stop_tx_ba_session(struct ieee80211_sta *pubsta, u16 tid) } EXPORT_SYMBOL(ieee80211_stop_tx_ba_session); -void ieee80211_stop_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u8 tid) +void ieee80211_stop_tx_ba_cb(struct sta_info *sta, int tid, + struct tid_ampdu_tx *tid_tx) { - struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); - struct ieee80211_local *local = sdata->local; - struct sta_info *sta; - struct tid_ampdu_tx *tid_tx; + struct ieee80211_sub_if_data *sdata = sta->sdata; bool send_delba = false; - trace_api_stop_tx_ba_cb(sdata, ra, tid); - - if (tid >= IEEE80211_NUM_TIDS) { - ht_dbg(sdata, "Bad TID value: tid = %d (>= %d)\n", - tid, IEEE80211_NUM_TIDS); - return; - } - - ht_dbg(sdata, "Stopping Tx BA session for %pM tid %d\n", ra, tid); - - mutex_lock(&local->sta_mtx); - - sta = sta_info_get_bss(sdata, ra); - if (!sta) { - ht_dbg(sdata, "Could not find station: %pM\n", ra); - goto unlock; - } + ht_dbg(sdata, "Stopping Tx BA session for %pM tid %d\n", + sta->sta.addr, tid); - mutex_lock(&sta->ampdu_mlme.mtx); spin_lock_bh(&sta->lock); - tid_tx = rcu_dereference_protected_tid_tx(sta, tid); - if (!tid_tx || !test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { + if (!test_bit(HT_AGG_STATE_STOPPING, &tid_tx->state)) { ht_dbg(sdata, "unexpected callback to A-MPDU stop for %pM tid %d\n", sta->sta.addr, tid); @@ -906,12 +885,8 @@ void ieee80211_stop_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u8 tid) spin_unlock_bh(&sta->lock); if (send_delba) - ieee80211_send_delba(sdata, ra, tid, + ieee80211_send_delba(sdata, sta->sta.addr, tid, WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE); - - mutex_unlock(&sta->ampdu_mlme.mtx); - unlock: - mutex_unlock(&local->sta_mtx); } void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_vif *vif, @@ -919,19 +894,20 @@ void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_vif *vif, { struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif); struct ieee80211_local *local = sdata->local; - struct ieee80211_ra_tid *ra_tid; - struct sk_buff *skb = dev_alloc_skb(0); + struct sta_info *sta; + struct tid_ampdu_tx *tid_tx; - if (unlikely(!skb)) - return; + trace_api_stop_tx_ba_cb(sdata, ra, tid); - ra_tid = (struct ieee80211_ra_tid *) &skb->cb; - memcpy(&ra_tid->ra, ra, ETH_ALEN); - ra_tid->tid = tid; + rcu_read_lock(); + tid_tx = ieee80211_lookup_tid_tx(sdata, ra, tid, &sta); + if (!tid_tx) + goto out; - skb->pkt_type = IEEE80211_SDATA_QUEUE_AGG_STOP; - skb_queue_tail(&sdata->skb_queue, skb); - ieee80211_queue_work(&local->hw, &sdata->work); + set_bit(HT_AGG_STATE_STOP_CB, &tid_tx->state); + ieee80211_queue_work(&local->hw, &sta->ampdu_mlme.work); + out: + rcu_read_unlock(); } EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb_irqsafe); diff --git a/net/mac80211/ht.c b/net/mac80211/ht.c index f4a528773563..6ca5442b1e03 100644 --- a/net/mac80211/ht.c +++ b/net/mac80211/ht.c @@ -7,6 +7,7 @@ * Copyright 2006-2007 Jiri Benc * Copyright 2007, Michael Wu * Copyright 2007-2010, Intel Corporation + * Copyright 2017 Intel Deutschland GmbH * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as @@ -289,8 +290,6 @@ void ieee80211_sta_tear_down_BA_sessions(struct sta_info *sta, { int i; - cancel_work_sync(&sta->ampdu_mlme.work); - for (i = 0; i < IEEE80211_NUM_TIDS; i++) { __ieee80211_stop_tx_ba_session(sta, i, reason); __ieee80211_stop_rx_ba_session(sta, i, WLAN_BACK_RECIPIENT, @@ -298,6 +297,9 @@ void ieee80211_sta_tear_down_BA_sessions(struct sta_info *sta, reason != AGG_STOP_DESTROY_STA && reason != AGG_STOP_PEER_REQUEST); } + + /* stopping might queue the work again - so cancel only afterwards */ + cancel_work_sync(&sta->ampdu_mlme.work); } void ieee80211_ba_session_work(struct work_struct *work) @@ -352,10 +354,16 @@ void ieee80211_ba_session_work(struct work_struct *work) spin_unlock_bh(&sta->lock); tid_tx = rcu_dereference_protected_tid_tx(sta, tid); - if (tid_tx && test_and_clear_bit(HT_AGG_STATE_WANT_STOP, - &tid_tx->state)) + if (!tid_tx) + continue; + + if (test_and_clear_bit(HT_AGG_STATE_START_CB, &tid_tx->state)) + ieee80211_start_tx_ba_cb(sta, tid, tid_tx); + if (test_and_clear_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state)) ___ieee80211_stop_tx_ba_session(sta, tid, AGG_STOP_LOCAL_REQUEST); + if (test_and_clear_bit(HT_AGG_STATE_STOP_CB, &tid_tx->state)) + ieee80211_stop_tx_ba_cb(sta, tid, tid_tx); } mutex_unlock(&sta->ampdu_mlme.mtx); } diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index f8f6c148f554..665501ac358f 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -1036,8 +1036,6 @@ struct ieee80211_rx_agg { enum sdata_queue_type { IEEE80211_SDATA_QUEUE_TYPE_FRAME = 0, - IEEE80211_SDATA_QUEUE_AGG_START = 1, - IEEE80211_SDATA_QUEUE_AGG_STOP = 2, IEEE80211_SDATA_QUEUE_RX_AGG_START = 3, IEEE80211_SDATA_QUEUE_RX_AGG_STOP = 4, }; @@ -1427,12 +1425,6 @@ ieee80211_get_sband(struct ieee80211_sub_if_data *sdata) return local->hw.wiphy->bands[band]; } -/* this struct represents 802.11n's RA/TID combination */ -struct ieee80211_ra_tid { - u8 ra[ETH_ALEN]; - u16 tid; -}; - /* this struct holds the value parsing from channel switch IE */ struct ieee80211_csa_ie { struct cfg80211_chan_def chandef; @@ -1794,8 +1786,10 @@ int __ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid, enum ieee80211_agg_stop_reason reason); int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid, enum ieee80211_agg_stop_reason reason); -void ieee80211_start_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u16 tid); -void ieee80211_stop_tx_ba_cb(struct ieee80211_vif *vif, u8 *ra, u8 tid); +void ieee80211_start_tx_ba_cb(struct sta_info *sta, int tid, + struct tid_ampdu_tx *tid_tx); +void ieee80211_stop_tx_ba_cb(struct sta_info *sta, int tid, + struct tid_ampdu_tx *tid_tx); void ieee80211_ba_session_work(struct work_struct *work); void ieee80211_tx_ba_session_handle_start(struct sta_info *sta, int tid); void ieee80211_release_reorder_timeout(struct sta_info *sta, int tid); diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c index 3bd5b81f5d81..8fae1a72e6a7 100644 --- a/net/mac80211/iface.c +++ b/net/mac80211/iface.c @@ -1237,7 +1237,6 @@ static void ieee80211_iface_work(struct work_struct *work) struct ieee80211_local *local = sdata->local; struct sk_buff *skb; struct sta_info *sta; - struct ieee80211_ra_tid *ra_tid; struct ieee80211_rx_agg *rx_agg; if (!ieee80211_sdata_running(sdata)) @@ -1253,15 +1252,7 @@ static void ieee80211_iface_work(struct work_struct *work) while ((skb = skb_dequeue(&sdata->skb_queue))) { struct ieee80211_mgmt *mgmt = (void *)skb->data; - if (skb->pkt_type == IEEE80211_SDATA_QUEUE_AGG_START) { - ra_tid = (void *)&skb->cb; - ieee80211_start_tx_ba_cb(&sdata->vif, ra_tid->ra, - ra_tid->tid); - } else if (skb->pkt_type == IEEE80211_SDATA_QUEUE_AGG_STOP) { - ra_tid = (void *)&skb->cb; - ieee80211_stop_tx_ba_cb(&sdata->vif, ra_tid->ra, - ra_tid->tid); - } else if (skb->pkt_type == IEEE80211_SDATA_QUEUE_RX_AGG_START) { + if (skb->pkt_type == IEEE80211_SDATA_QUEUE_RX_AGG_START) { rx_agg = (void *)&skb->cb; mutex_lock(&local->sta_mtx); sta = sta_info_get_bss(sdata, rx_agg->addr); diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h index 5609cacb20d5..ea0747d6a6da 100644 --- a/net/mac80211/sta_info.h +++ b/net/mac80211/sta_info.h @@ -116,6 +116,8 @@ enum ieee80211_sta_info_flags { #define HT_AGG_STATE_STOPPING 3 #define HT_AGG_STATE_WANT_START 4 #define HT_AGG_STATE_WANT_STOP 5 +#define HT_AGG_STATE_START_CB 6 +#define HT_AGG_STATE_STOP_CB 7 enum ieee80211_agg_stop_reason { AGG_STOP_DECLINED, -- cgit v1.2.3