Re: [PATCH v2 5/5] wifi: ath12k: avoid IDR mutation during vif mgmt TX cleanup

[Baochen Qiang <baochen.qiang@oss.qualcomm.com>]

On 10/3/2026 5:21 PM, Jiale Yao wrote:
> ath12k_mac_vdev_delete() 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: d889913205cf ("wifi: ath12k: driver for Qualcomm Wi-Fi 7 devices")
> Signed-off-by: Jiale Yao <yaojiale02@163.com>
> ---
>  drivers/net/wireless/ath/ath12k/mac.c | 21 +++++++++++----------
>  1 file changed, 11 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/net/wireless/ath/ath12k/mac.c b/drivers/net/wireless/ath/ath12k/mac.c
> index c0acb92b7320..108ace48cc97 100644
> --- a/drivers/net/wireless/ath/ath12k/mac.c
> +++ b/drivers/net/wireless/ath/ath12k/mac.c
> @@ -9196,16 +9196,18 @@ void ath12k_mac_tx_mgmt_pending_free(struct ath12k *ar)
>  		ath12k_mac_tx_mgmt_free(ar, buf_id);
>  }
>  
> -static int ath12k_mac_vif_txmgmt_idr_remove(int buf_id, void *skb, void *ctx)
> +static void ath12k_mac_vif_txmgmt_cleanup(struct ath12k *ar,
> +					  struct ieee80211_vif *vif)
>  {
> -	struct ieee80211_vif *vif = ctx;
> -	struct ath12k_skb_cb *skb_cb = ATH12K_SKB_CB(skb);
> -	struct ath12k *ar = skb_cb->ar;
> -
> -	if (skb_cb->vif == vif)
> -		ath12k_mac_tx_mgmt_free(ar, buf_id);
> +	struct ath12k_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 = ATH12K_SKB_CB(skb);

this has the same UAF risk as Ramesh pointed in ath11k patch (patch 3/5).

> +		if (skb_cb->vif == vif)
> +			ath12k_mac_tx_mgmt_free(ar, buf_id);
> +	}
>  }
>  
>  static int ath12k_mac_mgmt_tx_wmi(struct ath12k *ar, struct ath12k_link_vif *arvif,
> @@ -10967,8 +10969,7 @@ static int ath12k_mac_vdev_delete(struct ath12k *ar, struct ath12k_link_vif *arv
>  	ath12k_peer_cleanup(ar, arvif->vdev_id);
>  	ath12k_ahvif_put_link_cache(ahvif, arvif->link_id);
>  
> -	idr_for_each(&ar->txmgmt_idr,
> -		     ath12k_mac_vif_txmgmt_idr_remove, vif);
> +	ath12k_mac_vif_txmgmt_cleanup(ar, vif);
>  
>  	ath12k_mac_vif_unref(ath12k_ab_to_dp(ab), vif);
>