From e9da0b56fe27206b49f39805f7dcda8a89379062 Mon Sep 17 00:00:00 2001
From: Oliver Neukum <oneukum@suse.com>
Date: Thu, 17 Feb 2022 14:10:44 +0100
Subject: [PATCH] sr9700: sanity check for packet length
Git-commit: e9da0b56fe27206b49f39805f7dcda8a89379062
References: bsc#1196836 CVE-2022-26966
Patch-mainline: v5.17-rc6
A malicious device can leak heap data to user space
providing bogus frame lengths. Introduce a sanity check.
Signed-off-by: Oliver Neukum <oneukum@suse.com>
Reviewed-by: Grant Grundler <grundler@chromium.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
drivers/net/usb/sr9700.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/usb/sr9700.c b/drivers/net/usb/sr9700.c
index b658510cc9a4..5a53e63d33a6 100644
--- a/drivers/net/usb/sr9700.c
+++ b/drivers/net/usb/sr9700.c
@@ -413,7 +413,7 @@ static int sr9700_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
/* ignore the CRC length */
len = (skb->data[1] | (skb->data[2] << 8)) - 4;
- if (len > ETH_FRAME_LEN)
+ if (len > ETH_FRAME_LEN || len > skb->len)
return 0;
/* the last packet of current skb */
--
2.34.1