This is a note to let you know that I've just added the patch titled
net: usb: smsc95xx: Limit packet length to skb->len
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-usb-smsc95xx-limit-packet-length-to-skb-len.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit f857425147e7c00655c29b456827cb8ea68757a1
Author: Szymon Heidrich <szymon.heidrich@xxxxxxxxx>
Date: Thu Mar 16 11:19:54 2023 +0100
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 <szymon.heidrich@xxxxxxxxx>
Reviewed-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230316101954.75836-1-szymon.heidrich@xxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/usb/smsc95xx.c b/drivers/net/usb/smsc95xx.c
index 4f29010e1aeff..0850486864135 100644
--- a/drivers/net/usb/smsc95xx.c
+++ b/drivers/net/usb/smsc95xx.c
@@ -1950,6 +1950,12 @@ 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);
