From: Johan Hovold <johan@kernel.org>
Date: Mon, 13 Mar 2017 12:47:51 +0000 (+0100)
Subject: USB: wusbcore: fix NULL-deref at probe
X-Git-Tag: v3.12.73~55
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=84eeabc2289c82b471e4c9932f0741570673fb41;p=thirdparty%2Fkernel%2Fstable.git

USB: wusbcore: fix NULL-deref at probe

commit 03ace948a4eb89d1cf51c06afdfc41ebca5fdb27 upstream.

Make sure to check the number of endpoints to avoid dereferencing a
NULL-pointer or accessing memory beyond the endpoint array should a
malicious device lack the expected endpoints.

This specifically fixes the NULL-pointer dereference when probing HWA HC
devices.

Fixes: df3654236e31 ("wusb: add the Wire Adapter (WA) core")
Cc: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
Cc: David Vrabel <david.vrabel@csr.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---

diff --git a/drivers/usb/wusbcore/wa-hc.c b/drivers/usb/wusbcore/wa-hc.c
index a09b65ebd9bb7..2bb0fd3f34236 100644
--- a/drivers/usb/wusbcore/wa-hc.c
+++ b/drivers/usb/wusbcore/wa-hc.c
@@ -38,6 +38,9 @@ int wa_create(struct wahc *wa, struct usb_interface *iface)
 	int result;
 	struct device *dev = &iface->dev;
 
+	if (iface->cur_altsetting->desc.bNumEndpoints < 3)
+		return -ENODEV;
+
 	result = wa_rpipes_create(wa);
 	if (result < 0)
 		goto error_rpipes_create;