From: Johan Hovold <johan@kernel.org>
Date: Mon, 13 Mar 2017 12:49:45 +0000 (+0100)
Subject: watchdog: pcwd_usb: fix NULL-deref at probe
X-Git-Tag: release-20171130_firefly~4^2~100^2~1^2~7^2~98
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=ea99c2248495b60a1f1075b670f426875cc8e189;p=firefly-linux-kernel-4.4.55.git

watchdog: pcwd_usb: fix NULL-deref at probe

commit 46c319b848268dab3f0e7c4a5b6e9146d3bca8a4 upstream.

Make sure to check the number of endpoints to avoid dereferencing a
NULL-pointer should a malicious device lack endpoints.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/watchdog/pcwd_usb.c b/drivers/watchdog/pcwd_usb.c
index 1a11aedc4fe8..9eb5b314ba06 100644
--- a/drivers/watchdog/pcwd_usb.c
+++ b/drivers/watchdog/pcwd_usb.c
@@ -630,6 +630,9 @@ static int usb_pcwd_probe(struct usb_interface *interface,
 		return -ENODEV;
 	}
 
+	if (iface_desc->desc.bNumEndpoints < 1)
+		return -ENODEV;
+
 	/* check out the endpoint: it has to be Interrupt & IN */
 	endpoint = &iface_desc->endpoint[0].desc;