ath9k: fix a buffer leak in A-MPDU completion

commit 73e194639d90594d06d0c10019c0ab4638869135 upstream.

When ath_tx_complete_aggr() is called, it's responsible for returning
all buffers in the linked list. This was not done when the STA lookup
failed, leading to a race condition that could leak a few buffers when
a STA just disconnected.
Fix this by immediately returning all buffers to the free list in this case.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
index 2b305ff204f1c7669274613c6f457464ea2c8bfe..191794ec7eb30d51d993c75bb86aa7ebdc070d3a 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -329,6 +329,7 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
        int isaggr, txfail, txpending, sendbar = 0, needreset = 0, nbad = 0;
        bool rc_update = true;
        struct ieee80211_tx_rate rates[4];
+       unsigned long flags;
 
        skb = bf->bf_mpdu;
        hdr = (struct ieee80211_hdr *)skb->data;
@@ -344,6 +345,10 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq,
        sta = ieee80211_find_sta_by_hw(hw, hdr->addr1);
        if (!sta) {
                rcu_read_unlock();
+
+               spin_lock_irqsave(&sc->tx.txbuflock, flags);
+               list_splice_tail_init(bf_q, &sc->tx.txbuf);
+               spin_unlock_irqrestore(&sc->tx.txbuflock, flags);
                return;
        }