wifi: ath12k: Fix invalid data access in ath12k_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 ath12k_dp_rx_h_undecap_nwifi function for
DP_RX_DECAP_TYPE_NATIVE_WIFI decap type and
potentially resulting in invalid data access and memory corruption.

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.

Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.3.1-00173-QCAHKSWPL_SILICONZ-1

Signed-off-by: Manish Dharanenthiran <[email protected]>
Signed-off-by: Tamizh Chelvam Raja <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jeff Johnson <[email protected]>

Author: Manish Dharanenthiran

drivers/net/wireless/ath/ath12k/dp_rx.c

@@ -2548,6 +2548,29 @@ static void ath12k_dp_rx_deliver_msdu(struct ath12k *ar, struct napi_struct *nap
 	ieee80211_rx_napi(ath12k_ar_to_hw(ar), pubsta, msdu, napi);
 }
 
+static bool ath12k_dp_rx_check_nwifi_hdr_len_valid(struct ath12k_base *ab,
+						   struct hal_rx_desc *rx_desc,
+						   struct sk_buff *msdu)
+{
+	struct ieee80211_hdr *hdr;
+	u8 decap_type;
+	u32 hdr_len;
+
+	decap_type = ath12k_dp_rx_h_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 ath12k_dp_rx_process_msdu(struct ath12k *ar,
 				     struct sk_buff *msdu,
 				     struct sk_buff_head *msdu_list,
@@ -2606,6 +2629,11 @@ static int ath12k_dp_rx_process_msdu(struct ath12k *ar,
 		}
 	}
 
+	if (unlikely(!ath12k_dp_rx_check_nwifi_hdr_len_valid(ab, rx_desc, msdu))) {
+		ret = -EINVAL;
+		goto free_out;
+	}
+
 	ath12k_dp_rx_h_ppdu(ar, rx_desc, rx_status);
 	ath12k_dp_rx_h_mpdu(ar, msdu, rx_desc, rx_status);
 
@@ -2996,6 +3024,9 @@ static int ath12k_dp_rx_h_verify_tkip_mic(struct ath12k *ar, struct ath12k_peer
 		    RX_FLAG_IV_STRIPPED | RX_FLAG_DECRYPTED;
 	skb_pull(msdu, hal_rx_desc_sz);
 
+	if (unlikely(!ath12k_dp_rx_check_nwifi_hdr_len_valid(ab, rx_desc, msdu)))
+		return -EINVAL;
+
 	ath12k_dp_rx_h_ppdu(ar, rx_desc, rxs);
 	ath12k_dp_rx_h_undecap(ar, msdu, rx_desc,
 			       HAL_ENCRYPT_TYPE_TKIP_MIC, rxs, true);
@@ -3738,6 +3769,9 @@ static int ath12k_dp_rx_h_null_q_desc(struct ath12k *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(!ath12k_dp_rx_check_nwifi_hdr_len_valid(ab, desc, msdu)))
+		return -EINVAL;
+
 	ath12k_dp_rx_h_ppdu(ar, desc, status);
 
 	ath12k_dp_rx_h_mpdu(ar, msdu, desc, status);
@@ -3782,7 +3816,7 @@ static bool ath12k_dp_rx_h_reo_err(struct ath12k *ar, struct sk_buff *msdu,
 	return drop;
 }
 
-static void ath12k_dp_rx_h_tkip_mic_err(struct ath12k *ar, struct sk_buff *msdu,
+static bool ath12k_dp_rx_h_tkip_mic_err(struct ath12k *ar, struct sk_buff *msdu,
 					struct ieee80211_rx_status *status)
 {
 	struct ath12k_base *ab = ar->ab;
@@ -3800,13 +3834,17 @@ static void ath12k_dp_rx_h_tkip_mic_err(struct ath12k *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(!ath12k_dp_rx_check_nwifi_hdr_len_valid(ab, desc, msdu)))
+		return true;
+
 	ath12k_dp_rx_h_ppdu(ar, desc, status);
 
 	status->flag |= (RX_FLAG_MMIC_STRIPPED | RX_FLAG_MMIC_ERROR |
 			 RX_FLAG_DECRYPTED);
 
 	ath12k_dp_rx_h_undecap(ar, msdu, desc,
 			       HAL_ENCRYPT_TYPE_TKIP_MIC, status, false);
+	return false;
 }
 
 static bool ath12k_dp_rx_h_rxdma_err(struct ath12k *ar,  struct sk_buff *msdu,
@@ -3825,7 +3863,7 @@ static bool ath12k_dp_rx_h_rxdma_err(struct ath12k *ar,  struct sk_buff *msdu,
 	case HAL_REO_ENTR_RING_RXDMA_ECODE_TKIP_MIC_ERR:
 		err_bitmap = ath12k_dp_rx_h_mpdu_err(ab, rx_desc);
 		if (err_bitmap & HAL_RX_MPDU_ERR_TKIP_MIC) {
-			ath12k_dp_rx_h_tkip_mic_err(ar, msdu, status);
+			drop = ath12k_dp_rx_h_tkip_mic_err(ar, msdu, status);
 			break;
 		}
 		fallthrough;