Commit 9fabdd79 authored Mar 13, 2023 by Szymon Heidrich Committed by Greg Kroah-Hartman Mar 22, 2023

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



[ Upstream commit d8b228318935044dafe3a5bc07ee71a1f1424b8d ]

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: d0cad871 ("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: Sasha Levin <sashal@kernel.org>

parent b0c202a8

drivers/net/usb/smsc75xx.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -2210,7 +2210,8 @@ 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);