From 602ff39cf2b646d4ddc2085e4715b0ada72e2875 Mon Sep 17 00:00:00 2001 From: Oliver Neukum Date: Thu, 14 Nov 2019 11:16:01 +0100 Subject: [PATCH] ax88172a: fix information leak on short answers [ Upstream commit a9a51bd727d141a67b589f375fe69d0e54c4fe22 ] If a malicious device gives a short MAC it can elicit up to 5 bytes of leaked memory out of the driver. We need to check for ETH_ALEN instead. Reported-by: syzbot+a8d4acdad35e6bbca308@syzkaller.appspotmail.com Signed-off-by: Oliver Neukum Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/usb/ax88172a.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/usb/ax88172a.c b/drivers/net/usb/ax88172a.c index 5f18fcb8dcc7..6b1d03b73eeb 100644 --- a/drivers/net/usb/ax88172a.c +++ b/drivers/net/usb/ax88172a.c @@ -243,7 +243,7 @@ static int ax88172a_bind(struct usbnet *dev, struct usb_interface *intf) /* Get the MAC address */ ret = asix_read_cmd(dev, AX_CMD_READ_NODE_ID, 0, 0, ETH_ALEN, buf); - if (ret < 0) { + if (ret < ETH_ALEN) { netdev_err(dev->net, "Failed to read MAC address: %d\n", ret); goto free; }