Re: [PATCH ath-next v2 1/8] wifi: ath12k: fix out-of-bounds access on TX stats arrays

[Jeff Johnson <jeff.johnson@oss.qualcomm.com>]

On 8/6/2026 6:24 AM, Pardeep Kaur wrote:
> From: Pardeep Kaur <pardeep.kaur@oss.qualcomm.com>
> 
> The fw_tx_status[], tx_wbm_rel_source[], and tqm_rel_reason[] arrays
> are indexed directly by values read from hardware without bounds checks.
> Values at or beyond MAX_FW_TX_STATUS, HAL_WBM_REL_SRC_MODULE_MAX, or
> MAX_TQM_RELEASE_REASON respectively would write past the end of the
> arrays causing memory corruption.
> 
> Add bounds checks using likely() and WARN_ON_ONCE() before incrementing
> each counter, consistent with the existing pattern used elsewhere in
> the ath12k codebase.
> 
> Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.6.r1-00402-QCAHKSWPL_SILICONZ-1
> 
> Fixes: c5c62287e690 ("wifi: ath12k: Add device dp stats support")
> Signed-off-by: Pardeep Kaur <pardeep.kaur@oss.qualcomm.com>
> ---
>  drivers/net/wireless/ath/ath12k/wifi7/dp_tx.c | 15 ++++++++++++---
>  1 file changed, 12 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/wireless/ath/ath12k/wifi7/dp_tx.c b/drivers/net/wireless/ath/ath12k/wifi7/dp_tx.c
> index 587d58eeccfa..632230e77802 100644
> --- a/drivers/net/wireless/ath/ath12k/wifi7/dp_tx.c
> +++ b/drivers/net/wireless/ath/ath12k/wifi7/dp_tx.c
> @@ -582,7 +582,10 @@ ath12k_dp_tx_process_htt_tx_complete(struct ath12k_dp *dp, void *desc,
>  
>  	wbm_status = le32_get_bits(status_desc->info0,
>  				   HTT_TX_WBM_COMP_INFO0_STATUS);
> -	dp->device_stats.fw_tx_status[wbm_status]++;
> +	if (likely(wbm_status < MAX_FW_TX_STATUS))
> +		dp->device_stats.fw_tx_status[wbm_status]++;
> +	else
> +		WARN_ON_ONCE(1);

My review agent tells me this will now double warn since the default: case of
the switch (wbm_status) that follows will also ath12k_warn()

So for wbm_status warn in one place or the other, but not both

>  
>  	switch (wbm_status) {
>  	case HAL_WBM_REL_HTT_TX_COMP_STATUS_OK:
> @@ -984,11 +987,17 @@ void ath12k_wifi7_dp_tx_completion_handler(struct ath12k_dp *dp, int ring_id)
>  		/* Find the HAL_WBM_RELEASE_INFO0_REL_SRC_MODULE value */
>  		buf_rel_source = le32_get_bits(tx_status->info0,
>  					       HAL_WBM_RELEASE_INFO0_REL_SRC_MODULE);
> -		dp->device_stats.tx_wbm_rel_source[buf_rel_source]++;
> +		if (likely(buf_rel_source < HAL_WBM_REL_SRC_MODULE_MAX))
> +			dp->device_stats.tx_wbm_rel_source[buf_rel_source]++;
> +		else
> +			WARN_ON_ONCE(1);
>  
>  		rel_status = le32_get_bits(tx_status->info0,
>  					   HAL_WBM_COMPL_TX_INFO0_TQM_RELEASE_REASON);
> -		dp->device_stats.tqm_rel_reason[rel_status]++;
> +		if (likely(rel_status < MAX_TQM_RELEASE_REASON))
> +			dp->device_stats.tqm_rel_reason[rel_status]++;
> +		else
> +			WARN_ON_ONCE(1);
>  
>  		/* Release descriptor as soon as extracting necessary info
>  		 * to reduce contention
> base-commit: 691e5e43b2aa
> --
> 2.34.1