wifi: ath11k: fix invalid data access in ath11k_dp_rx_h_undecap_nwifi

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/
Signed-off-by: Miaoqing Pan <miaoqing.pan@oss.qualcomm.com>
Reviewed-by: Rameshkumar Sundaram <rameshkumar.sundaram@oss.qualcomm.com>
Reviewed-by: Baochen Qiang <baochen.qiang@oss.qualcomm.com>
Link: https://patch.msgid.link/20260512022351.2033155-2-miaoqing.pan@oss.qualcomm.com
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>

diff --git a/drivers/net/wireless/ath/ath11k/dp_rx.c b/drivers/net/wireless/ath/ath11k/dp_rx.c
index 2a413e3a07a78cc47b0c6a57dd1f0dbd2ee2f42a..9234212812547baef08a9acbcbb0ca353cded794 100644 (file)
--- a/drivers/net/wireless/ath/ath11k/dp_rx.c
+++ b/drivers/net/wireless/ath/ath11k/dp_rx.c
@@ -2503,6 +2503,29 @@ 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))
+               return true;
+
+       ab->soc_stats.invalid_rbm++;
+       WARN_ON_ONCE(1);
+       return false;
+}
+
 static int ath11k_dp_rx_process_msdu(struct ath11k *ar,
                                     struct sk_buff *msdu,
                                     struct sk_buff_head *msdu_list,
@@ -2573,6 +2596,11 @@ static int ath11k_dp_rx_process_msdu(struct ath11k *ar,
                }
        }
 
+       if (unlikely(!ath11k_dp_rx_check_nwifi_hdr_len_valid(ab, rx_desc, msdu))) {
+               ret = -EINVAL;
+               goto free_out;
+       }
+
        ath11k_dp_rx_h_ppdu(ar, rx_desc, rx_status);
        ath11k_dp_rx_h_mpdu(ar, msdu, rx_desc, rx_status);
 
@@ -3262,6 +3290,12 @@ mic_fail:
                    RX_FLAG_IV_STRIPPED | RX_FLAG_DECRYPTED;
        skb_pull(msdu, hal_rx_desc_sz);
 
+       if (unlikely(!ath11k_dp_rx_check_nwifi_hdr_len_valid(ar->ab, rx_desc,
+                                                            msdu))) {
+               dev_kfree_skb_any(msdu);
+               return -EINVAL;
+       }
+
        ath11k_dp_rx_h_ppdu(ar, rx_desc, rxs);
        ath11k_dp_rx_h_undecap(ar, msdu, rx_desc,
                               HAL_ENCRYPT_TYPE_TKIP_MIC, rxs, true);
@@ -3954,6 +3988,10 @@ static int ath11k_dp_rx_h_null_q_desc(struct ath11k *ar, struct sk_buff *msdu,
                skb_put(msdu, hal_rx_desc_sz + l3pad_bytes + msdu_len);
                skb_pull(msdu, hal_rx_desc_sz + l3pad_bytes);
        }
+
+       if (unlikely(!ath11k_dp_rx_check_nwifi_hdr_len_valid(ar->ab, desc, msdu)))
+               return -EINVAL;
+
        ath11k_dp_rx_h_ppdu(ar, desc, status);
 
        ath11k_dp_rx_h_mpdu(ar, msdu, desc, status);
@@ -3998,7 +4036,7 @@ static bool ath11k_dp_rx_h_reo_err(struct ath11k *ar, struct sk_buff *msdu,
        return drop;
 }
 
-static void ath11k_dp_rx_h_tkip_mic_err(struct ath11k *ar, struct sk_buff *msdu,
+static bool ath11k_dp_rx_h_tkip_mic_err(struct ath11k *ar, struct sk_buff *msdu,
                                        struct ieee80211_rx_status *status)
 {
        u16 msdu_len;
@@ -4006,6 +4044,7 @@ static void ath11k_dp_rx_h_tkip_mic_err(struct ath11k *ar, struct sk_buff *msdu,
        u8 l3pad_bytes;
        struct ath11k_skb_rxcb *rxcb = ATH11K_SKB_RXCB(msdu);
        u32 hal_rx_desc_sz = ar->ab->hw_params.hal_desc_sz;
+       struct ath11k_base *ab = ar->ab;
 
        rxcb->is_first_msdu = ath11k_dp_rx_h_msdu_end_first_msdu(ar->ab, desc);
        rxcb->is_last_msdu = ath11k_dp_rx_h_msdu_end_last_msdu(ar->ab, desc);
@@ -4015,6 +4054,9 @@ static void ath11k_dp_rx_h_tkip_mic_err(struct ath11k *ar, struct sk_buff *msdu,
        skb_put(msdu, hal_rx_desc_sz + l3pad_bytes + msdu_len);
        skb_pull(msdu, hal_rx_desc_sz + l3pad_bytes);
 
+       if (unlikely(!ath11k_dp_rx_check_nwifi_hdr_len_valid(ab, desc, msdu)))
+               return true;
+
        ath11k_dp_rx_h_ppdu(ar, desc, status);
 
        status->flag |= (RX_FLAG_MMIC_STRIPPED | RX_FLAG_MMIC_ERROR |
@@ -4022,19 +4064,21 @@ static void ath11k_dp_rx_h_tkip_mic_err(struct ath11k *ar, struct sk_buff *msdu,
 
        ath11k_dp_rx_h_undecap(ar, msdu, desc,
                               HAL_ENCRYPT_TYPE_TKIP_MIC, status, false);
+
+       return false;
 }
 
 static bool ath11k_dp_rx_h_rxdma_err(struct ath11k *ar,  struct sk_buff *msdu,
                                     struct ieee80211_rx_status *status)
 {
        struct ath11k_skb_rxcb *rxcb = ATH11K_SKB_RXCB(msdu);
-       bool drop = false;
+       bool drop;
 
        ar->ab->soc_stats.rxdma_error[rxcb->err_code]++;
 
        switch (rxcb->err_code) {
        case HAL_REO_ENTR_RING_RXDMA_ECODE_TKIP_MIC_ERR:
-               ath11k_dp_rx_h_tkip_mic_err(ar, msdu, status);
+               drop = ath11k_dp_rx_h_tkip_mic_err(ar, msdu, status);
                break;
        default:
                /* TODO: Review other rxdma error code to check if anything is