[PATCH ath-next] wifi: ath12k: free skb during idr cleanup callback

[Muna Sinada]

From: Karthik M <quic_karm at quicinc.com>

ath12k just like ath11k [1] did not handle skb cleanup during idr
cleanup callback. Both ath12k_mac_vif_txmgmt_idr_remove() and
ath12k_mac_tx_mgmt_pending_free() performed idr cleanup and DMA
unmapping for skb but only ath12k_mac_tx_mgmt_pending_free() freed
skb. As a result, during vdev deletion a memory leak occurs.

Refactor all clean up steps into a new function. New function
ath12k_mac_tx_mgmt_free() creates a centralized area where idr
cleanup, DMA unmapping for skb and freeing skb is performed. Utilize
skb pointer given by idr_remove(), instead of passed as a function
argument because IDR will be protected by locking. This will prevent
concurrent modification of the same IDR.

Now ath12k_mac_tx_mgmt_pending_free() and
ath12k_mac_vif_txmgmt_idr_remove() call ath12k_mac_tx_mgmt_free().

Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.4.1-00199-QCAHKSWPL_SILICONZ-1

Link: https://lore.kernel.org/r/1637832614-13831-1-git-send-email-quic_srirrama@quicinc.com > # [1]
Fixes: d889913205cf ("wifi: ath12k: driver for Qualcomm Wi-Fi 7 devices")
Signed-off-by: Karthik M <quic_karm at quicinc.com>
Signed-off-by: Muna Sinada <muna.sinada at oss.qualcomm.com>
---
 drivers/net/wireless/ath/ath12k/mac.c | 34 ++++++++++++++-------------
 1 file changed, 18 insertions(+), 16 deletions(-)

diff --git a/drivers/net/wireless/ath/ath12k/mac.c b/drivers/net/wireless/ath/ath12k/mac.c
index 1d7b60aa5cb0..eacab798630a 100644
--- a/drivers/net/wireless/ath/ath12k/mac.c
+++ b/drivers/net/wireless/ath/ath12k/mac.c
@@ -8290,23 +8290,32 @@ static void ath12k_mgmt_over_wmi_tx_drop(struct ath12k *ar, struct sk_buff *skb)
 		wake_up(&ar->txmgmt_empty_waitq);
 }
 
-int ath12k_mac_tx_mgmt_pending_free(int buf_id, void *skb, void *ctx)
+static void ath12k_mac_tx_mgmt_free(struct ath12k *ar, int buf_id)
 {
-	struct sk_buff *msdu = skb;
+	struct sk_buff *msdu;
 	struct ieee80211_tx_info *info;
-	struct ath12k *ar = ctx;
-	struct ath12k_base *ab = ar->ab;
 
 	spin_lock_bh(&ar->txmgmt_idr_lock);
-	idr_remove(&ar->txmgmt_idr, buf_id);
+	msdu = idr_remove(&ar->txmgmt_idr, buf_id);
 	spin_unlock_bh(&ar->txmgmt_idr_lock);
-	dma_unmap_single(ab->dev, ATH12K_SKB_CB(msdu)->paddr, msdu->len,
+
+	if (!msdu)
+		return;
+
+	dma_unmap_single(ar->ab->dev, ATH12K_SKB_CB(msdu)->paddr, msdu->len,
 			 DMA_TO_DEVICE);
 
 	info = IEEE80211_SKB_CB(msdu);
 	memset(&info->status, 0, sizeof(info->status));
 
-	ath12k_mgmt_over_wmi_tx_drop(ar, skb);
+	ath12k_mgmt_over_wmi_tx_drop(ar, msdu);
+}
+
+int ath12k_mac_tx_mgmt_pending_free(int buf_id, void *skb, void *ctx)
+{
+	struct ath12k *ar = ctx;
+
+	ath12k_mac_tx_mgmt_free(ar, buf_id);
 
 	return 0;
 }
@@ -8315,17 +8324,10 @@ static int ath12k_mac_vif_txmgmt_idr_remove(int buf_id, void *skb, void *ctx)
 {
 	struct ieee80211_vif *vif = ctx;
 	struct ath12k_skb_cb *skb_cb = ATH12K_SKB_CB(skb);
-	struct sk_buff *msdu = skb;
 	struct ath12k *ar = skb_cb->ar;
-	struct ath12k_base *ab = ar->ab;
 
-	if (skb_cb->vif == vif) {
-		spin_lock_bh(&ar->txmgmt_idr_lock);
-		idr_remove(&ar->txmgmt_idr, buf_id);
-		spin_unlock_bh(&ar->txmgmt_idr_lock);
-		dma_unmap_single(ab->dev, skb_cb->paddr, msdu->len,
-				 DMA_TO_DEVICE);
-	}
+	if (skb_cb->vif == vif)
+		ath12k_mac_tx_mgmt_free(ar, buf_id);
 
 	return 0;
 }

base-commit: 32be3ca4cf78b309dfe7ba52fe2d7cc3c23c5634
-- 
2.34.1