Commit 8d8e95fd authored Jul 28, 2020 by Johan Hovold Committed by David S. Miller Jul 28, 2020

net: lan78xx: add missing endpoint sanity check



Add the missing endpoint sanity check to prevent a NULL-pointer
dereference should a malicious device lack the expected endpoints.

Note that the driver has a broken endpoint-lookup helper,
lan78xx_get_endpoints(), which can end up accepting interfaces in an
altsetting without endpoints as long as *some* altsetting has a bulk-in
and a bulk-out endpoint.

Fixes: 55d7de9d ("Microchip's LAN7800 family USB 2/3 to 10/100/1000 Ethernet device driver")
Cc: Woojung.Huh@microchip.com <Woojung.Huh@microchip.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent e911e99a

drivers/net/usb/lan78xx.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -3759,6 +3759,11 @@ static int lan78xx_probe(struct usb_interface *intf,
		netdev->max_mtu = MAX_SINGLE_PACKET_SIZE;
		netif_set_gso_max_size(netdev, MAX_SINGLE_PACKET_SIZE - MAX_HEADER);

		if (intf->cur_altsetting->desc.bNumEndpoints < 3) {
		ret = -ENODEV;
		goto out3;
		}

		dev->ep_blkin = (intf->cur_altsetting)->endpoint + 0;
		dev->ep_blkout = (intf->cur_altsetting)->endpoint + 1;
		dev->ep_intr = (intf->cur_altsetting)->endpoint + 2;

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