From: Szymon Heidrich <szymon.heidrich@gmail.com>
Date: Thu, 16 Mar 2023 11:19:54 +0100
Subject: [PATCH] net: usb: smsc95xx: Limit packet length to skb->len
References: bsc#1012628
Patch-mainline: 6.2.9
Git-commit: ff821092cf02a70c2bccd2d19269f01e29aa52cf
[ 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@gmail.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20230316101954.75836-1-szymon.heidrich@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
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 32d2c60d..563ecd27 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);
--
2.35.3