Commit ff821092 authored by Szymon Heidrich's avatar Szymon Heidrich Committed by Jakub Kicinski
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net: usb: smsc95xx: Limit packet length to skb->len 



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: 2f7ca802 ("net: Add SMSC LAN9500 USB2.0 10/100 ethernet adapter driver")
Signed-off-by: default avatarSzymon Heidrich <szymon.heidrich@gmail.com>
Reviewed-by: default avatarJakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20230316101954.75836-1-szymon.heidrich@gmail.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 30796d0d

drivers/net/usb/smsc95xx.c

+6 −0
Original line number Diff line number Diff line
@@ -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);