[PATCH v3] wifi: mwifiex: validate event lengths before copying bodies

[Pengpeng Hou]

mwifiex event packets contain a four-byte event cause followed by the
event body. The USB and SDIO paths copy from data after that header using
the full packet length, so the source range extends four bytes beyond the
skb. The SDIO path also reads the event cause before validating the
packet and publishes oversized events without a copied body.

Reject SDIO events that are shorter than the header or larger than the
event buffer limit. Discard them through the same free-and-break contract
used for unknown upload types. Retain USB's existing error path and copy
only the bytes after the event header in both paths.

Signed-off-by: Pengpeng Hou <pengpeng@xxxxxxxxxxx>
---
Changes since v2: https://lore.kernel.org/all/20260720115119.80059-1-pengpeng@xxxxxxxxxxx/
- replace the new SDIO return -1 with free plus break as requested
- preserve USB's established error return contract
- rebase onto the current wireless tree

 drivers/net/wireless/marvell/mwifiex/sdio.c | 15 +++++++++++----
 drivers/net/wireless/marvell/mwifiex/usb.c  |  3 ++-
 2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/drivers/net/wireless/marvell/mwifiex/sdio.c b/drivers/net/wireless/marvell/mwifiex/sdio.c
index f039d6f19183..3588c36f64cf 100644
--- a/drivers/net/wireless/marvell/mwifiex/sdio.c
+++ b/drivers/net/wireless/marvell/mwifiex/sdio.c
@@ -1712,12 +1712,19 @@ static int mwifiex_decode_rx_packet(struct mwifiex_adapter *adapter,
 	case MWIFIEX_TYPE_EVENT:
 		mwifiex_dbg(adapter, EVENT,
 			    "info: --- Rx: Event ---\n");
+		if (skb->len < MWIFIEX_EVENT_HEADER_LEN ||
+		    skb->len > MAX_EVENT_SIZE) {
+			mwifiex_dbg(adapter, ERROR,
+				    "EVENT: invalid skb->len %u\n", skb->len);
+			dev_kfree_skb_any(skb);
+			break;
+		}
+
 		adapter->event_cause = get_unaligned_le32(skb->data);
 
-		if ((skb->len > 0) && (skb->len  < MAX_EVENT_SIZE))
-			memcpy(adapter->event_body,
-			       skb->data + MWIFIEX_EVENT_HEADER_LEN,
-			       skb->len);
+		memcpy(adapter->event_body,
+		       skb->data + MWIFIEX_EVENT_HEADER_LEN,
+		       skb->len - MWIFIEX_EVENT_HEADER_LEN);
 
 		/* event cause has been saved to adapter->event_cause */
 		adapter->event_received = true;
diff --git a/drivers/net/wireless/marvell/mwifiex/usb.c b/drivers/net/wireless/marvell/mwifiex/usb.c
index f4b94a1054f6..a6ed82e7228b 100644
--- a/drivers/net/wireless/marvell/mwifiex/usb.c
+++ b/drivers/net/wireless/marvell/mwifiex/usb.c
@@ -110,7 +110,8 @@ static int mwifiex_usb_recv(struct mwifiex_adapter *adapter,
 			}
 
 			memcpy(adapter->event_body, skb->data +
-			       MWIFIEX_EVENT_HEADER_LEN, skb->len);
+			       MWIFIEX_EVENT_HEADER_LEN,
+			       skb->len - MWIFIEX_EVENT_HEADER_LEN);
 
 			adapter->event_received = true;
 			adapter->event_skb = skb;
-- 
2.50.1 (Apple Git-155)