Message-ID: <57eeadc0-487a-5503-1312-ff90899b0eb5@quicinc.com>
Date:   Thu, 9 Mar 2023 09:32:27 +0530
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Subject: Re: [PATCH 1/2] wifi: ath11k: fix null ptr dereference when tx
 offload is enabled
Content-Language: en-US
To:     Pradeep Kumar Chitrapu <quic_pradeepc@quicinc.com>,
        <ath11k@lists.infradead.org>
CC:     <linux-wireless@vger.kernel.org>
References: <20230308174703.12270-1-quic_pradeepc@quicinc.com>
 <20230308174703.12270-2-quic_pradeepc@quicinc.com>
From:   Vasanthakumar Thiagarajan <quic_vthiagar@quicinc.com>
In-Reply-To: <20230308174703.12270-2-quic_pradeepc@quicinc.com>
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On 3/8/2023 11:17 PM, Pradeep Kumar Chitrapu wrote:
> When tx offload is enabled, info->band from skb cb is 0. This
> causes null pointer access at mac80211 when sband is accessed.
> 

More specifically tx encap offload instead of tx offload will be clearer.


> In offload case, ndo_hard_start will bypass mac80211 tx and no
> function will set info->band in skb cb to correct value.
> 
> Tested-on: QCN9074 hw1.0 PCI WLAN.HK.2.4.0.1-01725-QCAHKSWPL_SILICONZ-1
> 
> Signed-off-by: Pradeep Kumar Chitrapu <quic_pradeepc@quicinc.com>
> ---
>   drivers/net/wireless/ath/ath11k/dp_tx.c | 26 ++++++++++++++++++++++---
>   1 file changed, 23 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/wireless/ath/ath11k/dp_tx.c b/drivers/net/wireless/ath/ath11k/dp_tx.c
> index 8afbba236935..0f3a32434970 100644
> --- a/drivers/net/wireless/ath/ath11k/dp_tx.c
> +++ b/drivers/net/wireless/ath/ath11k/dp_tx.c
> @@ -320,6 +320,8 @@ ath11k_dp_tx_htt_tx_complete_buf(struct ath11k_base *ab,
>   	struct ieee80211_tx_info *info;
>   	struct ath11k_skb_cb *skb_cb;
>   	struct ath11k *ar;
> +	struct ieee80211_vif *vif;
> +	u8 flags = 0;

Is this initialization needed with the way flags is assigned below?

>   
>   	spin_lock(&tx_ring->tx_idr_lock);
>   	msdu = idr_remove(&tx_ring->txbuf_idr, ts->msdu_id);
> @@ -341,6 +343,14 @@ ath11k_dp_tx_htt_tx_complete_buf(struct ath11k_base *ab,
>   
>   	dma_unmap_single(ab->dev, skb_cb->paddr, msdu->len, DMA_TO_DEVICE);
>   
> +	if (!skb_cb->vif) {
> +		dev_kfree_skb_any(msdu);
> +		return;
> +	}
> +
> +	flags = skb_cb->flags;
> +	vif = skb_cb->vif;
> +
>   	memset(&info->status, 0, sizeof(info->status));
>   
>   	if (ts->acked) {
> @@ -354,8 +364,10 @@ ath11k_dp_tx_htt_tx_complete_buf(struct ath11k_base *ab,
>   			info->flags |= IEEE80211_TX_STAT_NOACK_TRANSMITTED;
>   		}
>   	}
> -
> -	ieee80211_tx_status(ar->hw, msdu);
> +	if (flags & ATH11K_SKB_HW_80211_ENCAP)
> +		ieee80211_tx_status_8023(ar->hw, vif, msdu);
> +	else
> +		ieee80211_tx_status(ar->hw, msdu);
>   }
>   
>   static void
> @@ -524,6 +536,8 @@ static void ath11k_dp_tx_complete_msdu(struct ath11k *ar,
>   	struct ath11k_peer *peer;
>   	struct ath11k_sta *arsta;
>   	struct rate_info rate;
> +	struct ieee80211_vif *vif;
> +	u8 flags = 0;
>   

Same here on the initialization part.

>   	if (WARN_ON_ONCE(ts->buf_rel_source != HAL_WBM_REL_SRC_MODULE_TQM)) {
>   		/* Must not happen */
> @@ -544,6 +558,9 @@ static void ath11k_dp_tx_complete_msdu(struct ath11k *ar,
>   		return;
>   	}
>   
> +	flags = skb_cb->flags;
> +	vif = skb_cb->vif;
> +
>   	info = IEEE80211_SKB_CB(msdu);
>   	memset(&info->status, 0, sizeof(info->status));
>   
> @@ -610,7 +627,10 @@ static void ath11k_dp_tx_complete_msdu(struct ath11k *ar,
>   
>   	spin_unlock_bh(&ab->base_lock);
>   
> -	ieee80211_tx_status_ext(ar->hw, &status);
> +	if (flags & ATH11K_SKB_HW_80211_ENCAP)
> +		ieee80211_tx_status_8023(ar->hw, vif, msdu);
> +	else
> +		ieee80211_tx_status_ext(ar->hw, &status);
>   }
>   
>   static inline void ath11k_dp_tx_status_parse(struct ath11k_base *ab,


Vasanth