ax88172a: fix information leak on short answers

[ Upstream commit a9a51bd727 ]

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 <oneukum@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Oliver Neukum 2019-11-14 11:16:01 +01:00 committed by Greg Kroah-Hartman
parent c4a0f567e6
commit 20beeb3008

View file

@ -208,7 +208,7 @@ 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, 0);
if (ret < 0) {
if (ret < ETH_ALEN) {
netdev_err(dev->net, "Failed to read MAC address: %d\n", ret);
goto free;
}