Merge: CVE-2023-53125: net: usb: smsc75xx: Limit packet length to skb->len

MR: https://gitlab.com/redhat/rhel/src/kernel/rhel-9/-/merge_requests/4431

JIRA: https://issues.redhat.com/browse/RHEL-112247
CVE: CVE-2023-53125

```
net: usb: smsc75xx: Limit packet length to skb->len

Packet length retrieved from skb data may be larger than
the actual socket buffer length (up to 9026 bytes). In such
case the cloned skb passed up the network stack will leak
kernel memory contents.

Fixes: d0cad87 ("smsc75xx: SMSC LAN75xx USB gigabit ethernet adapter driver")
Signed-off-by: Szymon Heidrich <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
(cherry picked from commit d8b2283)

```

Signed-off-by: CKI Backport Bot <[email protected]>

---

<small>Created 2025-09-01 19:27 UTC by backporter - [KWF FAQ](https://red.ht/kernel_workflow_doc) - [Slack #team-kernel-workflow](https://redhat-internal.slack.com/archives/C04LRUPMJQ5) - [Source](https://gitlab.com/cki-project/kernel-workflow/-/blob/main/webhook/utils/backporter.py) - [Documentation](https://gitlab.com/cki-project/kernel-workflow/-/blob/main/docs/README.backporter.md) - [Report an issue](https://issues.redhat.com/secure/CreateIssueDetails!init.jspa?pid=12334433&issuetype=1&priority=4&summary=backporter+webhook+issue&components=kernel-workflow+/+backporter)</small>

Approved-by: Jakub Ramaseuski <[email protected]>
Approved-by: Izabela Bakollari <[email protected]>
Approved-by: CKI KWF Bot <[email protected]>

Merged-by: Augusto Caringi <[email protected]>

Author: caringi

drivers/net/usb/smsc75xx.c

@@ -2201,6 +2201,13 @@ static int smsc75xx_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
 		size = (rx_cmd_a & RX_CMD_A_LEN) - RXW_PADDING;
 		align_count = (4 - ((size + RXW_PADDING) % 4)) % 4;
 
+		if (unlikely(size > skb->len)) {
+			netif_dbg(dev, rx_err, dev->net,
+				  "size err rx_cmd_a=0x%08x\n",
+				  rx_cmd_a);
+			return 0;
+		}
+
 		if (unlikely(rx_cmd_a & RX_CMD_A_RED)) {
 			netif_dbg(dev, rx_err, dev->net,
 				  "Error rx_cmd_a=0x%08x\n", rx_cmd_a);