From e294f0aa47e4844f3d3c8766c02accd5a76a7d4e Mon Sep 17 00:00:00 2001 From: Szymon Heidrich Date: Mon, 13 Mar 2023 23:00:45 +0100 Subject: [PATCH] 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: d0cad871703b ("smsc75xx: SMSC LAN75xx USB gigabit ethernet adapter driver") Signed-off-by: Szymon Heidrich Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- 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 378a12ae2d95..0b3d11e28faa 100644 --- a/drivers/net/usb/smsc75xx.c +++ b/drivers/net/usb/smsc75xx.c @@ -2211,7 +2211,8 @@ 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);