[PATCH 4.4 18/54] ax88172a: fix ax88172a_unbind() failures

Greg Kroah-Hartman
2020-07-30T08:11:25Z

From: George Kennedy <george.kennedy@oracle.com>

[ Upstream commit c28d9a285668c799eeae2f7f93e929a6028a4d6d ]

If ax88172a_unbind() fails, make sure that the return code is
less than zero so that cleanup is done properly and avoid UAF.

Fixes: a9a51bd727d1 ("ax88172a: fix information leak on short answers")
Signed-off-by: George Kennedy <george.kennedy@oracle.com>
Reported-by: syzbot+4cd84f527bf4a10fc9c1@syzkaller.appspotmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/usb/ax88172a.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/net/usb/ax88172a.c b/drivers/net/usb/ax88172a.c
index 6b1d03b73eeb8..6b734c7ffec39 100644
--- a/drivers/net/usb/ax88172a.c
+++ b/drivers/net/usb/ax88172a.c
@@ -245,6 +245,7 @@ static int ax88172a_bind(struct usbnet *dev, struct usb_interface *intf)
ret = asix_read_cmd(dev, AX_CMD_READ_NODE_ID, 0, 0, ETH_ALEN, buf);
if (ret < ETH_ALEN) {
netdev_err(dev->net, "Failed to read MAC address: %d\n", ret);
+ ret = -EIO;
goto free;
}
memcpy(dev->net->dev_addr, buf, ETH_ALEN);
--
2.25.1