wifi: ath11k: add MSDU length validation for TKIP MIC error

In the WBM error path, while processing TKIP MIC errors, MSDU length
is fetched from the hal_rx_desc's msdu_end. This MSDU length is
directly passed to skb_put() without validation. In stress test
scenarios, the WBM error ring may receive invalid descriptors, which
could lead to an invalid MSDU length.

To fix this, add a check to drop the skb when the calculated MSDU
length is greater than the skb size.

This is 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/20250416021903.3178962-1-nithyanantham.paramasivam@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/20260512022351.2033155-3-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 9234212812547baef08a9acbcbb0ca353cded794..9e90d8e3f1557a1ae0e54c8dfd8c4d8b253cac15 100644 (file)
--- a/drivers/net/wireless/ath/ath11k/dp_rx.c
+++ b/drivers/net/wireless/ath/ath11k/dp_rx.c
@@ -4051,6 +4051,15 @@ static bool ath11k_dp_rx_h_tkip_mic_err(struct ath11k *ar, struct sk_buff *msdu,
 
        l3pad_bytes = ath11k_dp_rx_h_msdu_end_l3pad(ar->ab, desc);
        msdu_len = ath11k_dp_rx_h_msdu_start_msdu_len(ar->ab, desc);
+
+       if (unlikely(hal_rx_desc_sz + l3pad_bytes + msdu_len > DP_RX_BUFFER_SIZE)) {
+               ath11k_dbg(ab, ATH11K_DBG_DATA,
+                          "invalid msdu len in tkip mic err %u\n", msdu_len);
+               ath11k_dbg_dump(ab, ATH11K_DBG_DATA, NULL, "", desc,
+                               sizeof(*desc));
+               return true;
+       }
+
        skb_put(msdu, hal_rx_desc_sz + l3pad_bytes + msdu_len);
        skb_pull(msdu, hal_rx_desc_sz + l3pad_bytes);