[PATCH 4.9 84/97] r8152: add missing endpoint sanity check

[Greg Kroah-Hartman]

From: Johan Hovold <johan@xxxxxxxxxx>

[ Upstream commit 86f3f4cd53707ceeec079b83205c8d3c756eca93 ]

Add missing endpoint sanity check to probe in order to prevent a
NULL-pointer dereference (or slab out-of-bounds access) when retrieving
the interrupt-endpoint bInterval on ndo_open() in case a device lacks
the expected endpoints.

Fixes: 40a82917b1d3 ("net/usb/r8152: enable interrupt transfer")
Cc: hayeswang <hayeswang@xxxxxxxxxxx>
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/usb/r8152.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/net/usb/r8152.c
+++ b/drivers/net/usb/r8152.c
@@ -4365,6 +4365,9 @@ static int rtl8152_probe(struct usb_inte
 		return -ENODEV;
 	}
 
+	if (intf->cur_altsetting->desc.bNumEndpoints < 3)
+		return -ENODEV;
+
 	usb_reset_device(udev);
 	netdev = alloc_etherdev(sizeof(struct r8152));
 	if (!netdev) {