netdev - [PATCH] net: usb: lan78xx: Limit packet length to skb->len

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Fri, 17 Mar 2023 16:32:17 +0100
From:   Szymon Heidrich <szymon.heidrich@...il.com>
To:     woojung.huh@...rochip.com, UNGLinuxDriver@...rochip.com,
        kuba@...nel.org, davem@...emloft.net, edumazet@...gle.com
Cc:     pabeni@...hat.com, szymon.heidrich@...il.com,
        linux-usb@...r.kernel.org, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH] net: usb: lan78xx: 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.

Additionally prevent integer underflow when size is less than
ETH_FCS_LEN.

Fixes: 55d7de9de6c3 ("Microchip's LAN7800 family USB 2/3 to 10/100/1000 Ethernet device driver")
Signed-off-by: Szymon Heidrich <szymon.heidrich@...il.com>
---
 drivers/net/usb/lan78xx.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c
index 068488890..e7d27be84 100644
--- a/drivers/net/usb/lan78xx.c
+++ b/drivers/net/usb/lan78xx.c
@@ -3579,10 +3579,24 @@ static int lan78xx_rx(struct lan78xx_net *dev, struct sk_buff *skb,
 		size = (rx_cmd_a & RX_CMD_A_LEN_MASK_);
 		align_count = (4 - ((size + RXW_PADDING) % 4)) % 4;
 
+		if (unlikely(size > skb->len)) {
+			netif_dbg(dev, rx_err, dev->net,
+				  "size err rx_cmd_a=0x%08x\n",
+				  rx_cmd_a);
+			return 0;
+		}
+
 		if (unlikely(rx_cmd_a & RX_CMD_A_RED_)) {
 			netif_dbg(dev, rx_err, dev->net,
 				  "Error rx_cmd_a=0x%08x", rx_cmd_a);
 		} else {
+			if (unlikely(size < ETH_FCS_LEN)) {
+				netif_dbg(dev, rx_err, dev->net,
+					  "size err rx_cmd_a=0x%08x\n",
+					  rx_cmd_a);
+				return 0;
+			}
+
 			u32 frame_len = size - ETH_FCS_LEN;
 			struct sk_buff *skb2;
 
-- 
2.40.0