[PATCH 3/5] wifi: ath11k: avoid IDR mutation during vif mgmt TX cleanup

[Jiale Yao]

ath11k_mac_op_remove_interface() walks txmgmt_idr with idr_for_each(),
and its callback removes each entry belonging to the interface. Removing
the current entry can invalidate the radix-tree iterator retained by
idr_for_each().

Move the walk into a helper that uses idr_for_each_entry(). It performs a
fresh lookup for every iteration, so each matching entry can be removed
through the locked removal helper without retaining iterator state across
the removal.

Fixes: d5c65159f289 ("ath11k: driver for Qualcomm IEEE 802.11ax devices")
Signed-off-by: Jiale Yao <yaojiale02@xxxxxxx>
---
 drivers/net/wireless/ath/ath11k/mac.c | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/drivers/net/wireless/ath/ath11k/mac.c b/drivers/net/wireless/ath/ath11k/mac.c
index 696f9dd65ad4..07de423086c9 100644
--- a/drivers/net/wireless/ath/ath11k/mac.c
+++ b/drivers/net/wireless/ath/ath11k/mac.c
@@ -6181,16 +6181,18 @@ int ath11k_mac_tx_mgmt_pending_free(int buf_id, void *skb, void *ctx)
 	return 0;
 }
 
-static int ath11k_mac_vif_txmgmt_idr_remove(int buf_id, void *skb, void *ctx)
+static void ath11k_mac_vif_txmgmt_cleanup(struct ath11k *ar,
+					  struct ieee80211_vif *vif)
 {
-	struct ieee80211_vif *vif = ctx;
-	struct ath11k_skb_cb *skb_cb = ATH11K_SKB_CB((struct sk_buff *)skb);
-	struct ath11k *ar = skb_cb->ar;
-
-	if (skb_cb->vif == vif)
-		ath11k_mac_tx_mgmt_free(ar, buf_id);
+	struct ath11k_skb_cb *skb_cb;
+	struct sk_buff *skb;
+	int buf_id;
 
-	return 0;
+	idr_for_each_entry(&ar->txmgmt_idr, skb, buf_id) {
+		skb_cb = ATH11K_SKB_CB(skb);
+		if (skb_cb->vif == vif)
+			ath11k_mac_tx_mgmt_free(ar, buf_id);
+	}
 }
 
 static int ath11k_mac_mgmt_tx_wmi(struct ath11k *ar, struct ath11k_vif *arvif,
@@ -7421,8 +7423,7 @@ static void ath11k_mac_op_remove_interface(struct ieee80211_hw *hw,
 
 	ath11k_peer_cleanup(ar, arvif->vdev_id);
 
-	idr_for_each(&ar->txmgmt_idr,
-		     ath11k_mac_vif_txmgmt_idr_remove, vif);
+	ath11k_mac_vif_txmgmt_cleanup(ar, vif);
 
 	for (i = 0; i < ab->hw_params.hal_params->num_tx_rings; i++) {
 		spin_lock_bh(&ab->dp.tx_ring[i].tx_idr_lock);
-- 
2.34.1