[PATCH v3 1/2] wifi: ath12k: Don't drop tx_status when peer cannot be found

[Karthikeyan Kathirvel]

From: Sven Eckelmann <sven at narfation.org>

When a station idles for a long time, hostapd will try to send a QoS Null
frame to the station as "poll". NL80211_CMD_PROBE_CLIENT is used for this
purpose. And the skb will be added to ack_status_frame - waiting for a
completion via ieee80211_report_ack_skb().

But when the peer was already removed before the tx_complete arrives, the
peer will be missing. And when using dev_kfree_skb_any (instead of going
through mac80211), the entry will stay inside ack_status_frames. This IDR
will therefore run full after 8K request were generated for such clients.
At this point, the access point will then just stall and not allow any new
clients because idr_alloc() for ack_status_frame will fail.

ieee80211_free_txskb() on the other hand will (when required) call
ieee80211_report_ack_skb() and make sure that (when required) remove the
entry from the ack_status_frame.

Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.0.1-00029-QCAHKSWPL_SILICONZ-1

Fixes: d889913205cf ("wifi: ath12k: driver for Qualcomm Wi-Fi 7 devices")
Signed-off-by: Sven Eckelmann <sven at narfation.org>
Signed-off-by: Sarika Sharma <quic_sarishar at quicinc.com>
Signed-off-by: Karthikeyan Kathirvel <quic_kathirve at quicinc.com>
Link: https://lore.kernel.org/r/20230802-ath11k-ack_status_leak-v2-1-c0af729d6229@narfation.org
---
 drivers/net/wireless/ath/ath12k/dp_tx.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/ath/ath12k/dp_tx.c b/drivers/net/wireless/ath/ath12k/dp_tx.c
index 9b6d7d72f57c..6a387f1f9567 100644
--- a/drivers/net/wireless/ath/ath12k/dp_tx.c
+++ b/drivers/net/wireless/ath/ath12k/dp_tx.c
@@ -448,6 +448,7 @@ static void ath12k_dp_tx_complete_msdu(struct ath12k *ar,
 				       struct hal_tx_status *ts)
 {
 	struct ath12k_base *ab = ar->ab;
+	struct ath12k_hw *ah = ar->ah;
 	struct ieee80211_tx_info *info;
 	struct ath12k_skb_cb *skb_cb;
 
@@ -466,12 +467,12 @@ static void ath12k_dp_tx_complete_msdu(struct ath12k *ar,
 	rcu_read_lock();
 
 	if (!rcu_dereference(ab->pdevs_active[ar->pdev_idx])) {
-		dev_kfree_skb_any(msdu);
+		ieee80211_free_txskb(ah->hw, msdu);
 		goto exit;
 	}
 
 	if (!skb_cb->vif) {
-		dev_kfree_skb_any(msdu);
+		ieee80211_free_txskb(ah->hw, msdu);
 		goto exit;
 	}
 
-- 
2.34.1