From 70eb25c6a6cde149affe8a587371a3a8ad295ba0 Mon Sep 17 00:00:00 2001 From: Szymon Heidrich Date: Thu, 16 Mar 2023 11:19:54 +0100 Subject: [PATCH] net: usb: smsc95xx: Limit packet length to skb->len [ Upstream commit ff821092cf02a70c2bccd2d19269f01e29aa52cf ] Packet length retrieved from descriptor may be larger than the actual socket buffer length. In such case the cloned skb passed up the network stack will leak kernel memory contents. Fixes: 2f7ca802bdae ("net: Add SMSC LAN9500 USB2.0 10/100 ethernet adapter driver") Signed-off-by: Szymon Heidrich Reviewed-by: Jakub Kicinski Link: https://lore.kernel.org/r/20230316101954.75836-1-szymon.heidrich@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/usb/smsc95xx.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/net/usb/smsc95xx.c b/drivers/net/usb/smsc95xx.c index 32d2c60d334d..563ecd27b93e 100644 --- a/drivers/net/usb/smsc95xx.c +++ b/drivers/net/usb/smsc95xx.c @@ -1833,6 +1833,12 @@ static int smsc95xx_rx_fixup(struct usbnet *dev, struct sk_buff *skb) size = (u16)((header & RX_STS_FL_) >> 16); align_count = (4 - ((size + NET_IP_ALIGN) % 4)) % 4; + if (unlikely(size > skb->len)) { + netif_dbg(dev, rx_err, dev->net, + "size err header=0x%08x\n", header); + return 0; + } + if (unlikely(header & RX_STS_ES_)) { netif_dbg(dev, rx_err, dev->net, "Error header=0x%08x\n", header);