Re: [PATCH ath-next 1/2] wifi: ath11k: fix invalid data access in ath11k_dp_rx_h_undecap_nwifi

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

On 5/31/2026 8:47 PM, Baochen Qiang wrote:
> 
> 
> On 5/12/2026 10:23 AM, Miaoqing Pan wrote:
>> In certain cases, hardware might provide packets with a
>> length greater than the maximum native Wi-Fi header length.
>> This can lead to accessing and modifying fields in the header
>> within the ath11k_dp_rx_h_undecap_nwifi() function for the
>> DP_RX_DECAP_TYPE_NATIVE_WIFI decap type and
>> potentially result in invalid data access and memory corruption.
>>
>> Kernel stack is corrupted in: ath11k_dp_rx_h_undecap+0x6b0/0x6b0 [ath11k]
>> Call trace:
>>  ath11k_dp_rx_h_mpdu+0x0/0x2e8 [ath11k]
>>  ath11k_dp_rx_h_mpdu+0x1e0/0x2e8 [ath11k]
>>  ath11k_dp_rx_wbm_err+0x1e0/0x450 [ath11k]
>>  ath11k_dp_rx_process_wbm_err+0x2fc/0x460 [ath11k]
>>  ath11k_dp_service_srng+0x2e0/0x348 [ath11k]
>>
>> Add a sanity check before processing the SKB to prevent invalid
>> data access in the undecap native Wi-Fi function for the
>> DP_RX_DECAP_TYPE_NATIVE_WIFI decap type.
>>
>> This adapted from the discussion/patch of the ath12k driver [1].
>>
>> Tested-on: WCN6855 hw2.1 PCI WLAN.HSP.1.1-04685-QCAHSPSWPL_V1_V2_SILICONZ_IOE-1
>>
>> Link: https://lore.kernel.org/linux-wireless/20250211090302.4105141-1-tamizh.raja@oss.qualcomm.com/ # [1]
>> Signed-off-by: Miaoqing Pan <miaoqing.pan@oss.qualcomm.com>
>> ---
>>  drivers/net/wireless/ath/ath11k/dp_rx.c | 50 +++++++++++++++++++++++--
>>  1 file changed, 47 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/net/wireless/ath/ath11k/dp_rx.c b/drivers/net/wireless/ath/ath11k/dp_rx.c
>> index fe79109adc70..fbe2061a544d 100644
>> --- a/drivers/net/wireless/ath/ath11k/dp_rx.c
>> +++ b/drivers/net/wireless/ath/ath11k/dp_rx.c
>> @@ -2502,6 +2502,29 @@ static void ath11k_dp_rx_deliver_msdu(struct ath11k *ar, struct napi_struct *nap
>>  	ieee80211_rx_napi(ar->hw, pubsta, msdu, napi);
>>  }
>>  
>> +static bool ath11k_dp_rx_check_nwifi_hdr_len_valid(struct ath11k_base *ab,
>> +						   struct hal_rx_desc *rx_desc,
>> +						   struct sk_buff *msdu)
>> +{
>> +	struct ieee80211_hdr *hdr;
>> +	u8 decap_type;
>> +	u32 hdr_len;
>> +
>> +	decap_type = ath11k_dp_rx_h_msdu_start_decap_type(ab, rx_desc);
>> +	if (decap_type != DP_RX_DECAP_TYPE_NATIVE_WIFI)
>> +		return true;
>> +
>> +	hdr = (struct ieee80211_hdr *)msdu->data;
>> +	hdr_len = ieee80211_hdrlen(hdr->frame_control);
>> +
>> +	if ((likely(hdr_len <= DP_MAX_NWIFI_HDR_LEN)))
> 
> nit: Double parentheses on likely()
I've fixed this in the 'pending' branch:
https://git.kernel.org/pub/scm/linux/kernel/git/ath/ath.git/commit/?h=pending&id=99f35f3f082fca14fc3324e48abd805871d39c69