[PATCH ath-next v2] wifi: ath12k: Add MSDU length validation for tkip mic error error

[Nithyanantham Paramasivam]

From: P Praneesh <quic_ppranees at quicinc.com>

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.

Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.3.1-00173-QCAHKSWPL_SILICONZ-1
Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0.c5-00481-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3

Fixes: d889913205cf ("wifi: ath12k: driver for Qualcomm Wi-Fi 7 devices")
Signed-off-by: P Praneesh <quic_ppranees at quicinc.com>
Signed-off-by: Nithyanantham Paramasivam <nithyanantham.paramasivam at oss.qualcomm.com>
---
v2:
- Signed off mail updated
---
 drivers/net/wireless/ath/ath12k/dp_rx.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/net/wireless/ath/ath12k/dp_rx.c b/drivers/net/wireless/ath/ath12k/dp_rx.c
index 96785d60d671..52ccafefd35e 100644
--- a/drivers/net/wireless/ath/ath12k/dp_rx.c
+++ b/drivers/net/wireless/ath/ath12k/dp_rx.c
@@ -3869,6 +3869,15 @@ static bool ath12k_dp_rx_h_tkip_mic_err(struct ath12k *ar, struct sk_buff *msdu,
 
 	l3pad_bytes = ath12k_dp_rx_h_l3pad(ab, desc);
 	msdu_len = ath12k_dp_rx_h_msdu_len(ab, desc);
+
+	if ((hal_rx_desc_sz + l3pad_bytes + msdu_len) > DP_RX_BUFFER_SIZE) {
+		ath12k_dbg(ab, ATH12K_DBG_DATA,
+			   "invalid msdu len in tkip mic err %u\n", msdu_len);
+		ath12k_dbg_dump(ab, ATH12K_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);
 

base-commit: d0bcc5eaaa611aacbffe6b2cc2fb64bfc3bdfcbc
-- 
2.17.1