[PATCH AUTOSEL 6.18-6.1] wifi: ath11k: fix invalid data access in ath11k_dp_rx_h_undecap_nwifi
From: Sasha Levin
Date: Mon Aug 31 2026 - 14:40:38 EST
From: Miaoqing Pan <miaoqing.pan@xxxxxxxxxxxxxxxx>
[ Upstream commit 6b471e9aefee9ed73278eb1141e0d8530a56fae9 ]
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@xxxxxxxxxxxxxxxx/ # [1]
Signed-off-by: Miaoqing Pan <miaoqing.pan@xxxxxxxxxxxxxxxx>
Reviewed-by: Rameshkumar Sundaram <rameshkumar.sundaram@xxxxxxxxxxxxxxxx>
Reviewed-by: Baochen Qiang <baochen.qiang@xxxxxxxxxxxxxxxx>
Link: https://patch.msgid.link/20260512022351.2033155-2-miaoqing.pan@xxxxxxxxxxxxxxxx
Signed-off-by: Jeff Johnson <jeff.johnson@xxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
LLM Generated explanations, may be completely bogus:
The background searches finished and match the earlier analysis:
- **Ath11k fix not in tree** — `git log --grep` found no commit for
`ath11k_dp_rx_check_nwifi_hdr_len_valid` or the ath11k undecap_nwifi
fix.
- **Ath12k analogue present** — `9a0dddfb30f12` (`wifi: ath12k: Fix
invalid data access in ath12k_dp_rx_h_undecap_nwifi`) is already in
v6.18.44.
That supports the **YES** backport verdict: the bug is still present in
ath11k here, and the fix is a proven port of code already merged for
ath12k in this tree.
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 330446f279cd6..1514f8657d546 100644
--- a/drivers/net/wireless/ath/ath11k/dp_rx.c
+++ b/drivers/net/wireless/ath/ath11k/dp_rx.c
@@ -2501,6 +2501,29 @@ 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,
@@ -2571,6 +2594,11 @@ 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);
@@ -3306,6 +3334,12 @@ static int ath11k_dp_rx_h_verify_tkip_mic(struct ath11k *ar, struct ath11k_peer
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);
@@ -3998,6 +4032,10 @@ 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);
@@ -4042,7 +4080,7 @@ 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;
@@ -4050,6 +4088,7 @@ 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);
@@ -4059,6 +4098,9 @@ 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 |
@@ -4066,19 +4108,21 @@ 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
--
2.53.0