From d8b228318935044dafe3a5bc07ee71a1f1424b8d Mon Sep 17 00:00:00 2001
From: Szymon Heidrich <szymon.heidrich@gmail.com>
Date: Mon, 13 Mar 2023 23:00:45 +0100
Subject: [PATCH] net: usb: smsc75xx: Limit packet length to skb->len
Git-commit: d8b228318935044dafe3a5bc07ee71a1f1424b8d
References: git-fixes
Patch-mainline: v6.3-rc3
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: d0cad871703b ("smsc75xx: SMSC LAN75xx USB gigabit ethernet adapter driver")
Signed-off-by: Szymon Heidrich <szymon.heidrich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
drivers/net/usb/smsc75xx.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/net/usb/smsc75xx.c b/drivers/net/usb/smsc75xx.c
index 95de452ff4da..db34f8d1d605 100644
--- a/drivers/net/usb/smsc75xx.c
+++ b/drivers/net/usb/smsc75xx.c
@@ -2212,7 +2212,8 @@ static int smsc75xx_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
dev->net->stats.rx_frame_errors++;
} else {
/* MAX_SINGLE_PACKET_SIZE + 4(CRC) + 2(COE) + 4(Vlan) */
- if (unlikely(size > (MAX_SINGLE_PACKET_SIZE + ETH_HLEN + 12))) {
+ if (unlikely(size > (MAX_SINGLE_PACKET_SIZE + ETH_HLEN + 12) ||
+ size > skb->len)) {
netif_dbg(dev, rx_err, dev->net,
"size err rx_cmd_a=0x%08x\n",
rx_cmd_a);
--
2.40.0